diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..fd4df93
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,230 @@
+name: CI/PR
+
+on: [push, pull_request]
+
+env:
+  DEVELOPER: 1
+
+jobs:
+  windows-build:
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: download git-sdk-64-minimal
+      shell: bash
+      run: a=git-sdk-64-minimal && mkdir -p $a && curl -# https://wingit.blob.core.windows.net/ci-artifacts/$a.tar.xz | tar -C $a -xJf -
+    - name: build
+      shell: powershell
+      env:
+        HOME: ${{runner.workspace}}
+        MSYSTEM: MINGW64
+        NO_PERL: 1
+      run: |
+        & .\git-sdk-64-minimal\usr\bin\bash.exe -lc @"
+        printf '%s\n' /git-sdk-64-minimal/ >>.git/info/exclude
+
+          ci/make-test-artifacts.sh artifacts
+        "@
+    - name: upload build artifacts
+      uses: actions/upload-artifact@v1
+      with:
+        name: windows-artifacts
+        path: artifacts
+  windows-test:
+    runs-on: windows-latest
+    needs: [windows-build]
+    strategy:
+      matrix:
+        nr: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    steps:
+    - uses: actions/checkout@v1
+    - name: download git-sdk-64-minimal
+      shell: bash
+      run: a=git-sdk-64-minimal && mkdir -p $a && curl -# https://wingit.blob.core.windows.net/ci-artifacts/$a.tar.xz | tar -C $a -xJf -
+    - name: download build artifacts
+      uses: actions/download-artifact@v1
+      with:
+        name: windows-artifacts
+        path: ${{github.workspace}}
+    - name: extract build artifacts
+      shell: bash
+      run: tar xf artifacts.tar.gz
+    - name: test
+      shell: powershell
+      run: |
+        & .\git-sdk-64-minimal\usr\bin\bash.exe -lc @"
+          # Let Git ignore the SDK
+          printf '%s\n' /git-sdk-64-minimal/ >>.git/info/exclude
+
+          ci/run-test-slice.sh ${{matrix.nr}} 10
+        "@
+    - name: ci/print-test-failures.sh
+      if: failure()
+      shell: powershell
+      run: |
+        & .\git-sdk-64-minimal\usr\bin\bash.exe -lc ci/print-test-failures.sh
+    - name: Upload failed tests' directories
+      if: failure() && env.FAILED_TEST_ARTIFACTS != ''
+      uses: actions/upload-artifact@v1
+      with:
+        name: failed-tests-windows
+        path: ${{env.FAILED_TEST_ARTIFACTS}}
+  vs-build:
+    env:
+      MSYSTEM: MINGW64
+      NO_PERL: 1
+      GIT_CONFIG_PARAMETERS: "'user.name=CI' 'user.email=ci@git'"
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: download git-sdk-64-minimal
+      shell: bash
+      run: a=git-sdk-64-minimal && mkdir -p $a && curl -# https://wingit.blob.core.windows.net/ci-artifacts/$a.tar.xz | tar -C $a -xJf -
+    - name: generate Visual Studio solution
+      shell: powershell
+      run: |
+        & .\git-sdk-64-minimal\usr\bin\bash.exe -lc @"
+          make NDEBUG=1 DEVELOPER=1 vcxproj
+        "@
+        if (!$?) { exit(1) }
+    - name: download vcpkg artifacts
+      shell: powershell
+      run: |
+        $urlbase = "https://dev.azure.com/git/git/_apis/build/builds"
+        $id = ((Invoke-WebRequest -UseBasicParsing "${urlbase}?definitions=9&statusFilter=completed&resultFilter=succeeded&`$top=1").content | ConvertFrom-JSON).value[0].id
+        $downloadUrl = ((Invoke-WebRequest -UseBasicParsing "${urlbase}/$id/artifacts").content | ConvertFrom-JSON).value[0].resource.downloadUrl
+        (New-Object Net.WebClient).DownloadFile($downloadUrl, "compat.zip")
+        Expand-Archive compat.zip -DestinationPath . -Force
+        Remove-Item compat.zip
+    - name: add msbuild to PATH
+      uses: microsoft/setup-msbuild@v1.0.0
+    - name: MSBuild
+      run: msbuild git.sln -property:Configuration=Release -property:Platform=x64 -maxCpuCount:4 -property:PlatformToolset=v142
+    - name: bundle artifact tar
+      shell: powershell
+      env:
+        MSVC: 1
+        VCPKG_ROOT: ${{github.workspace}}\compat\vcbuild\vcpkg
+      run: |
+        & compat\vcbuild\vcpkg_copy_dlls.bat release
+        if (!$?) { exit(1) }
+        & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
+          mkdir -p artifacts &&
+          eval \"`$(make -n artifacts-tar INCLUDE_DLLS_IN_ARTIFACTS=YesPlease ARTIFACTS_DIRECTORY=artifacts 2>&1 | grep ^tar)\"
+        "@
+    - name: upload build artifacts
+      uses: actions/upload-artifact@v1
+      with:
+        name: vs-artifacts
+        path: artifacts
+  vs-test:
+    runs-on: windows-latest
+    needs: [vs-build]
+    strategy:
+      matrix:
+        nr: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    steps:
+    - uses: actions/checkout@v1
+    - name: download git-64-portable
+      shell: bash
+      run: a=git-64-portable && mkdir -p $a && curl -# https://wingit.blob.core.windows.net/ci-artifacts/$a.tar.xz | tar -C $a -xJf -
+    - name: download build artifacts
+      uses: actions/download-artifact@v1
+      with:
+        name: vs-artifacts
+        path: ${{github.workspace}}
+    - name: extract build artifacts
+      shell: bash
+      run: tar xf artifacts.tar.gz
+    - name: test (parallel)
+      shell: powershell
+      env:
+        MSYSTEM: MINGW64
+        NO_SVN_TESTS: 1
+        GIT_TEST_SKIP_REBASE_P: 1
+      run: |
+        & git-64-portable\git-cmd.exe --command=usr\bin\bash.exe -lc @"
+          # Let Git ignore the SDK and the test-cache
+          printf '%s\n' /git-64-portable/ /test-cache/ >>.git/info/exclude
+
+          cd t &&
+          PATH=\"`$PWD/helper:`$PATH\" &&
+          test-tool.exe run-command testsuite --jobs=10 -V -x --write-junit-xml \
+                  `$(test-tool.exe path-utils slice-tests \
+                          ${{matrix.nr}} 10 t[0-9]*.sh)
+        "@
+  regular:
+    strategy:
+      matrix:
+        vector:
+          - jobname: linux-clang
+            cc: clang
+            pool: ubuntu-latest
+          - jobname: linux-gcc
+            cc: gcc
+            pool: ubuntu-latest
+          - jobname: osx-clang
+            cc: clang
+            pool: macos-latest
+          - jobname: osx-gcc
+            cc: gcc
+            pool: macos-latest
+          - jobname: GETTEXT_POISON
+            cc: gcc
+            pool: ubuntu-latest
+    env:
+      CC: ${{matrix.vector.cc}}
+      jobname: ${{matrix.vector.jobname}}
+    runs-on: ${{matrix.vector.pool}}
+    steps:
+    - uses: actions/checkout@v1
+    - run: ci/install-dependencies.sh
+    - run: ci/run-build-and-tests.sh
+    - run: ci/print-test-failures.sh
+      if: failure()
+    - name: Upload failed tests' directories
+      if: failure() && env.FAILED_TEST_ARTIFACTS != ''
+      uses: actions/upload-artifact@v1
+      with:
+        name: failed-tests-${{matrix.vector.jobname}}
+        path: ${{env.FAILED_TEST_ARTIFACTS}}
+  dockerized:
+    strategy:
+      matrix:
+        vector:
+        - jobname: linux-musl
+          image: alpine
+        - jobname: Linux32
+          image: daald/ubuntu32:xenial
+    env:
+      jobname: ${{matrix.vector.jobname}}
+    runs-on: ubuntu-latest
+    container: ${{matrix.vector.image}}
+    steps:
+    - uses: actions/checkout@v1
+    - run: ci/install-docker-dependencies.sh
+    - run: ci/run-build-and-tests.sh
+    - run: ci/print-test-failures.sh
+      if: failure()
+    - name: Upload failed tests' directories
+      if: failure() && env.FAILED_TEST_ARTIFACTS != ''
+      uses: actions/upload-artifact@v1
+      with:
+        name: failed-tests-${{matrix.vector.jobname}}
+        path: ${{env.FAILED_TEST_ARTIFACTS}}
+  static-analysis:
+    env:
+      jobname: StaticAnalysis
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - run: ci/install-dependencies.sh
+    - run: ci/run-static-analysis.sh
+  documentation:
+    env:
+      jobname: Documentation
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - run: ci/install-dependencies.sh
+    - run: ci/test-documentation.sh
diff --git a/.gitignore b/.gitignore
index aebe7c0..188bd1c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,7 +83,6 @@
 /git-init-db
 /git-interpret-trailers
 /git-instaweb
-/git-legacy-stash
 /git-log
 /git-ls-files
 /git-ls-remote
diff --git a/.travis.yml b/.travis.yml
index fc5730b..05f3e3f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,7 +16,7 @@
 
 matrix:
   include:
-    - env: jobname=GIT_TEST_GETTEXT_POISON
+    - env: jobname=GETTEXT_POISON
       os: linux
       compiler:
       addons:
@@ -32,7 +32,15 @@
       services:
         - docker
       before_install:
-      script: ci/run-linux32-docker.sh
+      script: ci/run-docker.sh
+    - env: jobname=linux-musl
+      os: linux
+      compiler:
+      addons:
+      services:
+        - docker
+      before_install:
+      script: ci/run-docker.sh
     - env: jobname=StaticAnalysis
       os: linux
       compiler:
diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index ed4e443..390ceec 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -91,8 +91,6 @@
 
    - No shell arrays.
 
-   - No strlen ${#parameter}.
-
    - No pattern replacement ${parameter/pattern/string}.
 
  - We use Arithmetic Expansion $(( ... )).
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 8fe829c..15d9d04 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -30,6 +30,7 @@
 MAN7_TXT += gitcvs-migration.txt
 MAN7_TXT += gitdiffcore.txt
 MAN7_TXT += giteveryday.txt
+MAN7_TXT += gitfaq.txt
 MAN7_TXT += gitglossary.txt
 MAN7_TXT += gitnamespaces.txt
 MAN7_TXT += gitremote-helpers.txt
@@ -149,32 +150,9 @@
 -include ../config.mak.autogen
 -include ../config.mak
 
-#
-# For docbook-xsl ...
-#	-1.68.1,	no extra settings are needed?
-#	1.69.0,		set ASCIIDOC_ROFF?
-#	1.69.1-1.71.0,	set DOCBOOK_SUPPRESS_SP?
-#	1.71.1,		set ASCIIDOC_ROFF?
-#	1.72.0,		set DOCBOOK_XSL_172.
-#	1.73.0-,	no extra settings are needed
-#
-
-ifdef DOCBOOK_XSL_172
-ASCIIDOC_EXTRA += -a git-asciidoc-no-roff
-MANPAGE_XSL = manpage-1.72.xsl
-else
-	ifndef ASCIIDOC_ROFF
-	# docbook-xsl after 1.72 needs the regular XSL, but will not
-	# pass-thru raw roff codes from asciidoc.conf, so turn them off.
-	ASCIIDOC_EXTRA += -a git-asciidoc-no-roff
-	endif
-endif
 ifndef NO_MAN_BOLD_LITERAL
 XMLTO_EXTRA += -m manpage-bold-literal.xsl
 endif
-ifdef DOCBOOK_SUPPRESS_SP
-XMLTO_EXTRA += -m manpage-suppress-sp.xsl
-endif
 
 # Newer DocBook stylesheet emits warning cruft in the output when
 # this is not set, and if set it shows an absolute link.  Older
diff --git a/Documentation/MyFirstObjectWalk.txt b/Documentation/MyFirstObjectWalk.txt
index aa828df..c3f2d1a 100644
--- a/Documentation/MyFirstObjectWalk.txt
+++ b/Documentation/MyFirstObjectWalk.txt
@@ -357,9 +357,6 @@
 	...
 
 	while ((commit = get_revision(rev))) {
-		if (!commit)
-			continue;
-
 		strbuf_reset(&prettybuf);
 		pp_commit_easy(CMIT_FMT_ONELINE, commit, &prettybuf);
 		puts(prettybuf.buf);
diff --git a/Documentation/RelNotes/2.17.4.txt b/Documentation/RelNotes/2.17.4.txt
new file mode 100644
index 0000000..7d794ca
--- /dev/null
+++ b/Documentation/RelNotes/2.17.4.txt
@@ -0,0 +1,16 @@
+Git v2.17.4 Release Notes
+=========================
+
+This release is to address the security issue: CVE-2020-5260
+
+Fixes since v2.17.3
+-------------------
+
+ * With a crafted URL that contains a newline in it, the credential
+   helper machinery can be fooled to give credential information for
+   a wrong host.  The attack has been made impossible by forbidding
+   a newline character in any value passed via the credential
+   protocol.
+
+Credit for finding the vulnerability goes to Felix Wilhelm of Google
+Project Zero.
diff --git a/Documentation/RelNotes/2.17.5.txt b/Documentation/RelNotes/2.17.5.txt
new file mode 100644
index 0000000..2abb821
--- /dev/null
+++ b/Documentation/RelNotes/2.17.5.txt
@@ -0,0 +1,22 @@
+Git v2.17.5 Release Notes
+=========================
+
+This release is to address a security issue: CVE-2020-11008
+
+Fixes since v2.17.4
+-------------------
+
+ * With a crafted URL that contains a newline or empty host, or lacks
+   a scheme, the credential helper machinery can be fooled into
+   providing credential information that is not appropriate for the
+   protocol in use and host being contacted.
+
+   Unlike the vulnerability CVE-2020-5260 fixed in v2.17.4, the
+   credentials are not for a host of the attacker's choosing; instead,
+   they are for some unspecified host (based on how the configured
+   credential helper handles an absent "host" parameter).
+
+   The attack has been made impossible by refusing to work with
+   under-specified credential patterns.
+
+Credit for finding the vulnerability goes to Carlo Arenas.
diff --git a/Documentation/RelNotes/2.18.3.txt b/Documentation/RelNotes/2.18.3.txt
new file mode 100644
index 0000000..25143f0
--- /dev/null
+++ b/Documentation/RelNotes/2.18.3.txt
@@ -0,0 +1,5 @@
+Git v2.18.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.18.4.txt b/Documentation/RelNotes/2.18.4.txt
new file mode 100644
index 0000000..e8ef858
--- /dev/null
+++ b/Documentation/RelNotes/2.18.4.txt
@@ -0,0 +1,5 @@
+Git v2.18.4 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.19.4.txt b/Documentation/RelNotes/2.19.4.txt
new file mode 100644
index 0000000..35d0ae5
--- /dev/null
+++ b/Documentation/RelNotes/2.19.4.txt
@@ -0,0 +1,5 @@
+Git v2.19.4 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.19.5.txt b/Documentation/RelNotes/2.19.5.txt
new file mode 100644
index 0000000..18a4dcb
--- /dev/null
+++ b/Documentation/RelNotes/2.19.5.txt
@@ -0,0 +1,5 @@
+Git v2.19.5 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.20.3.txt b/Documentation/RelNotes/2.20.3.txt
new file mode 100644
index 0000000..f6eccd1
--- /dev/null
+++ b/Documentation/RelNotes/2.20.3.txt
@@ -0,0 +1,5 @@
+Git v2.20.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.20.4.txt b/Documentation/RelNotes/2.20.4.txt
new file mode 100644
index 0000000..5a9e24e
--- /dev/null
+++ b/Documentation/RelNotes/2.20.4.txt
@@ -0,0 +1,5 @@
+Git v2.20.4 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.21.2.txt b/Documentation/RelNotes/2.21.2.txt
new file mode 100644
index 0000000..a0fb83b
--- /dev/null
+++ b/Documentation/RelNotes/2.21.2.txt
@@ -0,0 +1,5 @@
+Git v2.21.2 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.21.3.txt b/Documentation/RelNotes/2.21.3.txt
new file mode 100644
index 0000000..2ca0aa5
--- /dev/null
+++ b/Documentation/RelNotes/2.21.3.txt
@@ -0,0 +1,5 @@
+Git v2.21.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.22.3.txt b/Documentation/RelNotes/2.22.3.txt
new file mode 100644
index 0000000..57296f6
--- /dev/null
+++ b/Documentation/RelNotes/2.22.3.txt
@@ -0,0 +1,5 @@
+Git v2.22.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.22.4.txt b/Documentation/RelNotes/2.22.4.txt
new file mode 100644
index 0000000..8b5f3e3
--- /dev/null
+++ b/Documentation/RelNotes/2.22.4.txt
@@ -0,0 +1,5 @@
+Git v2.22.4 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.23.2.txt b/Documentation/RelNotes/2.23.2.txt
new file mode 100644
index 0000000..b697cbe
--- /dev/null
+++ b/Documentation/RelNotes/2.23.2.txt
@@ -0,0 +1,5 @@
+Git v2.23.2 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.23.3.txt b/Documentation/RelNotes/2.23.3.txt
new file mode 100644
index 0000000..2e35490
--- /dev/null
+++ b/Documentation/RelNotes/2.23.3.txt
@@ -0,0 +1,5 @@
+Git v2.23.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.24.2.txt b/Documentation/RelNotes/2.24.2.txt
new file mode 100644
index 0000000..0049f65
--- /dev/null
+++ b/Documentation/RelNotes/2.24.2.txt
@@ -0,0 +1,5 @@
+Git v2.24.2 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.24.3.txt b/Documentation/RelNotes/2.24.3.txt
new file mode 100644
index 0000000..5302e0f
--- /dev/null
+++ b/Documentation/RelNotes/2.24.3.txt
@@ -0,0 +1,5 @@
+Git v2.24.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.25.3.txt b/Documentation/RelNotes/2.25.3.txt
new file mode 100644
index 0000000..15f7f21
--- /dev/null
+++ b/Documentation/RelNotes/2.25.3.txt
@@ -0,0 +1,5 @@
+Git v2.25.3 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.25.4.txt b/Documentation/RelNotes/2.25.4.txt
new file mode 100644
index 0000000..0dbb5da
--- /dev/null
+++ b/Documentation/RelNotes/2.25.4.txt
@@ -0,0 +1,5 @@
+Git v2.25.4 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.26.1.txt b/Documentation/RelNotes/2.26.1.txt
new file mode 100644
index 0000000..1b4ecb3
--- /dev/null
+++ b/Documentation/RelNotes/2.26.1.txt
@@ -0,0 +1,5 @@
+Git v2.26.1 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.4; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.26.2.txt b/Documentation/RelNotes/2.26.2.txt
new file mode 100644
index 0000000..d434d0c
--- /dev/null
+++ b/Documentation/RelNotes/2.26.2.txt
@@ -0,0 +1,5 @@
+Git v2.26.2 Release Notes
+=========================
+
+This release merges the security fix that appears in v2.17.5; see
+the release notes for that version for details.
diff --git a/Documentation/RelNotes/2.27.0.txt b/Documentation/RelNotes/2.27.0.txt
new file mode 100644
index 0000000..680dfe6
--- /dev/null
+++ b/Documentation/RelNotes/2.27.0.txt
@@ -0,0 +1,331 @@
+Git 2.27 Release Notes
+======================
+
+Updates since v2.26
+-------------------
+
+Backward compatibility notes
+
+ * When "git describe C" finds that commit C is pointed by a signed or
+   annotated tag, which records T as its tagname in the object, the
+   command gives T as its answer.  Even if the user renames or moves
+   such a tag from its natural location in the "refs/tags/" hierarchy,
+   "git describe C" would still give T as the answer, but in such a
+   case "git show T^0" would no longer work as expected.  There may be
+   nothing at "refs/tags/T" or even worse there may be a different tag
+   instead.
+
+   Starting from this version, "git describe" will always use the
+   "long" version, as if the "--long" option were given, when giving
+   its output based on such a misplaced tag to work around the problem.
+
+ * "git pull" issues a warning message until the pull.rebase
+   configuration variable is explicitly given, which some existing
+   users may find annoying---those who prefer not to rebase need to
+   set the variable to false to squelch the warning.
+
+
+UI, Workflows & Features
+
+ * A handful of options to configure SSL when talking to proxies have
+   been added.
+
+ * Smudge/clean conversion filters are now given more information
+   (e.g. the object of the tree-ish in which the blob being converted
+   appears, in addition to its path, which has already been given).
+
+ * When "git describe C" finds an annotated tag with tagname A to be
+   the best name to explain commit C, and the tag is stored in a
+   "wrong" place in the refs/tags hierarchy, e.g. refs/tags/B, the
+   command gave a warning message but used A (not B) to describe C.
+   If C is exactly at the tag, the describe output would be "A", but
+   "git rev-parse A^0" would not be equal as "git rev-parse C^0".  The
+   behavior of the command has been changed to use the "long" form
+   i.e. A-0-gOBJECTNAME, which is correctly interpreted by rev-parse.
+
+ * "git pull" learned to warn when no pull.rebase configuration
+   exists, and neither --[no-]rebase nor --ff-only is given (which
+   would result a merge).
+
+ * "git p4" learned four new hooks and also "--no-verify" option to
+   bypass them (and the existing "p4-pre-submit" hook).
+
+ * "git pull" shares many options with underlying "git fetch", but
+   some of them were not documented and some of those that would make
+   sense to pass down were not passed down.
+
+ * "git rebase" learned the "--no-gpg-sign" option to countermand
+   commit.gpgSign the user may have.
+
+ * The output from "git format-patch" uses RFC 2047 encoding for
+   non-ASCII letters on From: and Subject: headers, so that it can
+   directly be fed to e-mail programs.  A new option has been added
+   to produce these headers in raw.
+
+ * "git log" learned "--show-pulls" that helps pathspec limited
+   history views; a merge commit that takes the whole change from a
+   side branch, which is normally omitted from the output, is shown
+   in addition to the commits that introduce real changes.
+
+ * The interactive input from various codepaths are consolidated and
+   any prompt possibly issued earlier are fflush()ed before we read.
+
+ * Allow "git rebase" to reapply all local commits, even if the may be
+   already in the upstream, without checking first.
+
+ * The 'pack.useSparse' configuration variable now defaults to 'true',
+   enabling an optimization that has been experimental since Git 2.21.
+
+ * "git rebase" happens to call some hooks meant for "checkout" and
+   "commit" by this was not a designed behaviour than historical
+   accident.  This has been documented.
+
+ * "git merge" learns the "--autostash" option.
+
+ * "sparse-checkout" UI improvements.
+
+ * "git update-ref --stdin" learned a handful of new verbs to let the
+   user control ref update transactions more explicitly, which helps
+   as an ingredient to implement two-phase commit-style atomic
+   ref-updates across multiple repositories.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The advise API has been revamped to allow more systematic enumeration of
+   advice knobs in the future.
+
+ * SHA-256 transition continues.
+
+ * The code to interface with GnuPG has been refactored.
+
+ * "git stash" has kept an escape hatch to use the scripted version
+   for a few releases, which got stale.  It has been removed.
+
+ * Enable tests that require GnuPG on Windows.
+
+ * Minor test usability improvement.
+
+ * Trace2 enhancement to allow logging of the environment variables.
+
+ * Test clean-up continues.
+
+ * Perf-test update.
+
+ * A Windows-specific test element has been made more robust against
+   misuse from both user's environment and programmer's errors.
+
+ * Various tests have been updated to work around issues found with
+   shell utilities that come with busybox etc.
+
+ * The config API made mixed uses of int and size_t types to represent
+   length of various pieces of text it parsed, which has been updated
+   to use the correct type (i.e. size_t) throughout.
+
+ * The "--decorate-refs" and "--decorate-refs-exclude" options "git
+   log" takes have learned a companion configuration variable
+   log.excludeDecoration that sits at the lowest priority in the
+   family.
+
+ * A new CI job to build and run test suite on linux with musl libc
+   has been added.
+
+ * Update the CI configuration to use GitHub Actions, retiring the one
+   based on Azure Pipelines.
+
+ * The directory traversal code had redundant recursive calls which
+   made its performance characteristics exponential with respect to
+   the depth of the tree, which was corrected.
+
+
+Fixes since v2.26
+-----------------
+
+ * The real_path() convenience function can easily be misused; with a
+   bit of code refactoring in the callers' side, its use has been
+   eliminated.
+   (merge 49d3c4b481 am/real-path-fix later to maint).
+
+ * Update "git p4" to work with Python 3.
+   (merge 6bb40ed20a yz/p4-py3 later to maint).
+
+ * The mechanism to prevent "git commit" from making an empty commit
+   or amending during an interrupted cherry-pick was broken during the
+   rewrite of "git rebase" in C, which has been corrected.
+   (merge 430b75f720 pw/advise-rebase-skip later to maint).
+
+ * Fix "git checkout --recurse-submodules" of a nested submodule
+   hierarchy.
+   (merge 846f34d351 pb/recurse-submodules-fix later to maint).
+
+ * The "--fork-point" mode of "git rebase" regressed when the command
+   was rewritten in C back in 2.20 era, which has been corrected.
+   (merge f08132f889 at/rebase-fork-point-regression-fix later to maint).
+
+ * The import-tars importer (in contrib/fast-import/) used to create
+   phony files at the top-level of the repository when the archive
+   contains global PAX headers, which made its own logic to detect and
+   omit the common leading directory ineffective, which has been
+   corrected.
+   (merge c839fcff65 js/import-tars-do-not-make-phony-files-from-pax-headers later to maint).
+
+ * Simplify the commit ancestry connectedness check in a partial clone
+   repository in which "promised" objects are assumed to be obtainable
+   lazily on-demand from promisor remote repositories.
+   (merge 2b98478c6f jt/connectivity-check-optim-in-partial-clone later to maint).
+
+ * The server-end of the v2 protocol to serve "git clone" and "git
+   fetch" was not prepared to see a delim packets at unexpected
+   places, which led to a crash.
+   (merge cacae4329f jk/harden-protocol-v2-delim-handling later to maint).
+
+ * When fed a midx that records no objects, some codepaths tried to
+   loop from 0 through (num_objects-1), which, due to integer
+   arithmetic wrapping around, made it nonsense operation with out of
+   bounds array accesses.  The code has been corrected to reject such
+   an midx file.
+   (merge 796d61cdc0 dr/midx-avoid-int-underflow later to maint).
+
+ * Utitiles run via the run_command() API were not spawned correctly
+   on Cygwin, when the paths to them are given as a full path with
+   backslashes.
+   (merge 05ac8582bc ak/run-command-on-cygwin-fix later to maint).
+
+ * "git pull --rebase" tried to run a rebase even after noticing that
+   the pull results in a fast-forward and no rebase is needed nor
+   sensible, for the past few years due to a mistake nobody noticed.
+   (merge fbae70ddc6 en/pull-do-not-rebase-after-fast-forwarding later to maint).
+
+ * "git rebase" with the merge backend did not work well when the
+   rebase.abbreviateCommands configuration was set.
+   (merge de9f1d3ef4 ag/rebase-merge-allow-ff-under-abbrev-command later to maint).
+
+ * The logic to auto-follow tags by "git clone --single-branch" was
+   not careful to avoid lazy-fetching unnecessary tags, which has been
+   corrected.
+   (merge 167a575e2d jk/use-quick-lookup-in-clone-for-tag-following later to maint).
+
+ * "git rebase -i" did not leave the reflog entries correctly.
+   (merge 1f6965f994 en/sequencer-reflog-action later to maint).
+
+ * The more aggressive updates to remote-tracking branches we had for
+   the past 7 years or so were not reflected in the documentation,
+   which has been corrected.
+   (merge a44088435c pb/pull-fetch-doc later to maint).
+
+ * We've left the command line parsing of "git log :/a/b/" broken for
+   about a full year without anybody noticing, which has been
+   corrected.
+   (merge 0220461071 jc/missing-ref-store-fix later to maint).
+
+ * Misc fixes for Windows.
+   (merge 3efc128cd5 js/mingw-fixes later to maint).
+
+ * "git rebase" (again) learns to honor "--no-keep-empty", which lets
+   the user to discard commits that are empty from the beginning (as
+   opposed to the ones that become empty because of rebasing).  The
+   interactive rebase also marks commits that are empty in the todo.
+   (merge 50ed76148a en/rebase-no-keep-empty later to maint).
+
+ * Parsing the host part out of URL for the credential helper has been corrected.
+   (merge 4c5971e18a jk/credential-parsing-end-of-host-in-URL later to maint).
+
+ * Document the recommended way to abort a failing test early (e.g. by
+   exiting a loop), which is to say "return 1".
+   (merge 7cc112dc95 jc/doc-test-leaving-early later to maint).
+
+ * The code that refreshes the last access and modified time of
+   on-disk packfiles and loose object files have been updated.
+   (merge 312cd76130 lr/freshen-file-fix later to maint).
+
+ * Validation of push certificate has been made more robust against
+   timing attacks.
+   (merge 719483e547 bc/constant-memequal later to maint).
+
+ * The custom hash function used by "git fast-import" has been
+   replaced with the one from hashmap.c, which gave us a nice
+   performance boost.
+   (merge d8410a816b jk/fast-import-use-hashmap later to maint).
+
+ * The "git submodule" command did not initialize a few variables it
+   internally uses and was affected by variable settings leaked from
+   the environment.
+   (merge 65d100c4dd lx/submodule-clear-variables later to maint).
+
+ * Raise the minimum required version of docbook-xsl package to 1.74,
+   as 1.74.0 was from late 2008, which is more than 10 years old, and
+   drop compatibility cruft from our documentation suite.
+   (merge 3c255ad660 ma/doc-discard-docbook-xsl-1.73 later to maint).
+
+ * "git log" learns "--[no-]mailmap" as a synonym to "--[no-]use-mailmap"
+   (merge 88acccda38 jc/log-no-mailmap later to maint).
+
+ * "git commit-graph write --expire-time=<timestamp>" did not use the
+   given timestamp correctly, which has been corrected.
+   (merge b09b785c78 ds/commit-graph-expiry-fix later to maint).
+
+ * Tests update to use "test-chmtime" instead of "touch -t".
+   (merge e892a56845 ds/t5319-touch-fix later to maint).
+
+ * "git diff" in a partial clone learned to avoid lazy loading blob
+   objects in more casese when they are not needed.
+   (merge 95acf11a3d jt/avoid-prefetch-when-able-in-diff later to maint).
+
+ * "git push --atomic" used to show failures for refs that weren't
+   even pushed, which has been corrected.
+   (merge dfe1b7f19c jx/atomic-push later to maint).
+
+ * Code in builtin/*, i.e. those can only be called from within
+   built-in subcommands, that implements bulk of a couple of
+   subcommands have been moved to libgit.a so that they could be used
+   by others.
+   (merge 9460fd48b5 dl/libify-a-few later to maint).
+
+ * Allowing the user to split a patch hunk while "git stash -p" does
+   not work well; a band-aid has been added to make this (partially)
+   work better.
+
+ * "git diff-tree --pretty --notes" used to hit an assertion failure,
+   as it forgot to initialize the notes subsystem.
+   (merge 5778b22b3d tb/diff-tree-with-notes later to maint).
+
+ * "git range-diff" fixes.
+   (merge 8d1675eb7f vd/range-diff-with-custom-pretty-format-fix later to maint).
+
+ * "git grep" did not quote a path with unusual character like other
+   commands (like "git diff", "git status") do, but did quote when run
+   from a subdirectory, both of which has been corrected.
+   (merge 45115d8490 mt/grep-cquote-path later to maint).
+
+ * GNU/Hurd is also among the ones that need the fopen() wrapper.
+   (merge 274a1328fb jc/gnu-hurd-lets-fread-read-dirs later to maint).
+
+ * Those fetching over protocol v2 from linux-next and other kernel
+   repositories are reporting that v2 often fetches way too much than
+   needed.
+   (merge 11c7f2a30b jn/demote-proto2-from-default later to maint).
+
+ * Other code cleanup, docfix, build fix, etc.
+   (merge 564956f358 jc/maintain-doc later to maint).
+   (merge 7422b2a0a1 sg/commit-slab-clarify-peek later to maint).
+   (merge 9c688735f6 rs/doc-passthru-fetch-options later to maint).
+   (merge 757c2ba3e2 en/oidset-uninclude-hashmap later to maint).
+   (merge 8312aa7d74 jc/config-tar later to maint).
+   (merge d00a5bdd50 ss/submodule-foreach-cb later to maint).
+   (merge 64d1022e14 ar/test-style-fixes later to maint).
+   (merge 4a465443a6 ds/doc-clone-filter later to maint).
+   (merge bb2dbe301b jk/t3419-drop-expensive-tests later to maint).
+   (merge d3507cc712 js/test-junit-finalization-fix later to maint).
+   (merge 2149b6748f bc/faq later to maint).
+   (merge 12dc0879f1 jk/test-cleanup later to maint).
+   (merge 344420bf0f pb/rebase-doc-typofix later to maint).
+   (merge 7cd54d37dc dl/wrapper-fix-indentation later to maint).
+   (merge 78725ebda9 jc/allow-strlen-substitution-in-shell-scripts later to maint).
+   (merge 2ecfcdecc6 jm/gitweb-fastcgi-utf8 later to maint).
+   (merge 0740d0a5d3 jk/oid-array-cleanups later to maint).
+   (merge a1aba0c95c js/t0007-typofix later to maint).
+   (merge 76ba7fa225 ma/config-doc-fix later to maint).
+   (merge 826f0c0df2 js/subtree-doc-update-to-asciidoctor-2 later to maint).
+   (merge 88eaf361e0 eb/mboxrd-doc later to maint).
+   (merge 051cc54941 tm/zsh-complete-switch-restore later to maint).
+   (merge 39102cf4fe ms/doc-revision-illustration-fix later to maint).
diff --git a/Documentation/asciidoc.conf b/Documentation/asciidoc.conf
index 8fc4b67..3e4c139 100644
--- a/Documentation/asciidoc.conf
+++ b/Documentation/asciidoc.conf
@@ -31,24 +31,6 @@
 endif::backend-docbook[]
 
 ifdef::backend-docbook[]
-ifndef::git-asciidoc-no-roff[]
-# "unbreak" docbook-xsl v1.68 for manpages. v1.69 works with or without this.
-# v1.72 breaks with this because it replaces dots not in roff requests.
-[listingblock]
-<example><title>{title}</title>
-<literallayout class="monospaced">
-ifdef::doctype-manpage[]
-&#10;.ft C&#10;
-endif::doctype-manpage[]
-|
-ifdef::doctype-manpage[]
-&#10;.ft&#10;
-endif::doctype-manpage[]
-</literallayout>
-{title#}</example>
-endif::git-asciidoc-no-roff[]
-
-ifdef::git-asciidoc-no-roff[]
 ifdef::doctype-manpage[]
 # The following two small workarounds insert a simple paragraph after screen
 [listingblock]
@@ -67,7 +49,6 @@
 {title#}</para></formalpara>
 {title%}<simpara></simpara>
 endif::doctype-manpage[]
-endif::git-asciidoc-no-roff[]
 endif::backend-docbook[]
 
 ifdef::doctype-manpage[]
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 08b13ba..74009d5 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -220,12 +220,12 @@
 ; affected by the condition
 [includeIf "gitdir:/path/to/group/"]
 	path = foo.inc
-----
 
-	; include only if we are in a worktree where foo-branch is
-	; currently checked out
-	[includeIf "onbranch:foo-branch"]
-		path = foo.inc
+; include only if we are in a worktree where foo-branch is
+; currently checked out
+[includeIf "onbranch:foo-branch"]
+	path = foo.inc
+----
 
 Values
 ~~~~~~
@@ -447,6 +447,8 @@
 
 include::config/tag.txt[]
 
+include::config/tar.txt[]
+
 include::config/trace2.txt[]
 
 include::config/transfer.txt[]
diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt
index 875f8c8..4e3a5c0 100644
--- a/Documentation/config/feature.txt
+++ b/Documentation/config/feature.txt
@@ -12,9 +12,6 @@
 	setting if you are interested in providing feedback on experimental
 	features. The new default values are:
 +
-* `pack.useSparse=true` uses a new algorithm when constructing a pack-file
-which can improve `git push` performance in repos with many files.
-+
 * `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by
 skipping more commits at a time, reducing the number of round trips.
 +
diff --git a/Documentation/config/fetch.txt b/Documentation/config/fetch.txt
index f119402..b1a9b14 100644
--- a/Documentation/config/fetch.txt
+++ b/Documentation/config/fetch.txt
@@ -1,11 +1,14 @@
 fetch.recurseSubmodules::
-	This option can be either set to a boolean value or to 'on-demand'.
+	This option controls whether `git fetch` (and the underlying fetch
+	in `git pull`) will recursively fetch into populated submodules.
+	This option can be set either to a boolean value or to 'on-demand'.
 	Setting it to a boolean changes the behavior of fetch and pull to
-	unconditionally recurse into submodules when set to true or to not
-	recurse at all when set to false. When set to 'on-demand' (the default
-	value), fetch and pull will only recurse into a populated submodule
-	when its superproject retrieves a commit that updates the submodule's
+	recurse unconditionally into submodules when set to true or to not
+	recurse at all when set to false. When set to 'on-demand', fetch and
+	pull will only recurse into a populated submodule when its
+	superproject retrieves a commit that updates the submodule's
 	reference.
+	Defaults to 'on-demand', or to the value of 'submodule.recurse' if set.
 
 fetch.fsckObjects::
 	If it is set to true, git-fetch-pack will check all fetched
diff --git a/Documentation/config/format.txt b/Documentation/config/format.txt
index 45c7bd5..564e809 100644
--- a/Documentation/config/format.txt
+++ b/Documentation/config/format.txt
@@ -57,6 +57,11 @@
 	`.patch`. Use this variable to change that suffix (make sure to
 	include the dot if you want it).
 
+format.encodeEmailHeaders::
+	Encode email headers that have non-ASCII characters with
+	"Q-encoding" (described in RFC 2047) for email transmission.
+	Defaults to true.
+
 format.pretty::
 	The default pretty format for log/show/whatchanged command,
 	See linkgit:git-log[1], linkgit:git-show[1],
diff --git a/Documentation/config/http.txt b/Documentation/config/http.txt
index e806033..3968fbb 100644
--- a/Documentation/config/http.txt
+++ b/Documentation/config/http.txt
@@ -29,6 +29,27 @@
 * `ntlm` - NTLM authentication (compare the --ntlm option of `curl(1)`)
 --
 
+http.proxySSLCert::
+	The pathname of a file that stores a client certificate to use to authenticate
+	with an HTTPS proxy. Can be overridden by the `GIT_PROXY_SSL_CERT` environment
+	variable.
+
+http.proxySSLKey::
+	The pathname of a file that stores a private key to use to authenticate with
+	an HTTPS proxy. Can be overridden by the `GIT_PROXY_SSL_KEY` environment
+	variable.
+
+http.proxySSLCertPasswordProtected::
+	Enable Git's password prompt for the proxy SSL certificate.  Otherwise OpenSSL
+	will prompt the user, possibly many times, if the certificate or private key
+	is encrypted. Can be overriden by the `GIT_PROXY_SSL_CERT_PASSWORD_PROTECTED`
+	environment variable.
+
+http.proxySSLCAInfo::
+	Pathname to the file containing the certificate bundle that should be used to
+	verify the proxy with when using an HTTPS proxy. Can be overriden by the
+	`GIT_PROXY_SSL_CAINFO` environment variable.
+
 http.emptyAuth::
 	Attempt authentication without seeking a username or password.  This
 	can be used to attempt GSS-Negotiate authentication without specifying
diff --git a/Documentation/config/log.txt b/Documentation/config/log.txt
index e9e1e39..208d5fd 100644
--- a/Documentation/config/log.txt
+++ b/Documentation/config/log.txt
@@ -18,6 +18,12 @@
 	names are shown. This is the same as the `--decorate` option
 	of the `git log`.
 
+log.excludeDecoration::
+	Exclude the specified patterns from the log decorations. This is
+	similar to the `--decorate-refs-exclude` command-line option, but
+	the config option can be overridden by the `--decorate-refs`
+	option.
+
 log.follow::
 	If `true`, `git log` will act as if the `--follow` option was used when
 	a single <path> is given.  This has the same limitations as `--follow`,
diff --git a/Documentation/config/merge.txt b/Documentation/config/merge.txt
index 6a31393..cb2ed58 100644
--- a/Documentation/config/merge.txt
+++ b/Documentation/config/merge.txt
@@ -70,6 +70,16 @@
 	Whether to print the diffstat between ORIG_HEAD and the merge result
 	at the end of the merge.  True by default.
 
+merge.autoStash::
+	When set to true, automatically create a temporary stash entry
+	before the operation begins, and apply it after the operation
+	ends.  This means that you can run merge on a dirty worktree.
+	However, use with care: the final stash application after a
+	successful merge might result in non-trivial conflicts.
+	This option can be overridden by the `--no-autostash` and
+	`--autostash` options of linkgit:git-merge[1].
+	Defaults to false.
+
 merge.tool::
 	Controls which merge tool is used by linkgit:git-mergetool[1].
 	The list below shows the valid built-in values.
diff --git a/Documentation/config/pack.txt b/Documentation/config/pack.txt
index 0dac580..837f1b1 100644
--- a/Documentation/config/pack.txt
+++ b/Documentation/config/pack.txt
@@ -119,8 +119,8 @@
 	objects. This can have significant performance benefits when
 	computing a pack to send a small change. However, it is possible
 	that extra objects are added to the pack-file if the included
-	commits contain certain types of direct renames. Default is `false`
-	unless `feature.experimental` is enabled.
+	commits contain certain types of direct renames. Default is
+	`true`.
 
 pack.writeBitmaps (deprecated)::
 	This is a deprecated synonym for `repack.writeBitmaps`.
diff --git a/Documentation/config/protocol.txt b/Documentation/config/protocol.txt
index 756591d..0b40141 100644
--- a/Documentation/config/protocol.txt
+++ b/Documentation/config/protocol.txt
@@ -48,7 +48,7 @@
 	If set, clients will attempt to communicate with a server
 	using the specified protocol version.  If the server does
 	not support it, communication falls back to version 0.
-	If unset, the default is `2`.
+	If unset, the default is `0`.
 	Supported versions:
 +
 --
diff --git a/Documentation/config/push.txt b/Documentation/config/push.txt
index 0a7aa32..f5e5b38 100644
--- a/Documentation/config/push.txt
+++ b/Documentation/config/push.txt
@@ -112,3 +112,5 @@
 	is 'no' then default behavior of ignoring submodules when pushing
 	is retained. You may override this configuration at time of push by
 	specifying '--recurse-submodules=check|on-demand|no'.
+	If not set, 'no' is used by default, unless 'submodule.recurse' is
+	set (in which case a 'true' value means 'on-demand').
diff --git a/Documentation/config/stash.txt b/Documentation/config/stash.txt
index abc7ef4..00eb354 100644
--- a/Documentation/config/stash.txt
+++ b/Documentation/config/stash.txt
@@ -1,17 +1,9 @@
 stash.useBuiltin::
-       Set to `false` to use the legacy shell script implementation of
-       linkgit:git-stash[1]. Is `true` by default, which means use
-       the built-in rewrite of it in C.
-+
-The C rewrite is first included with Git version 2.22 (and Git for Windows
-version 2.19). This option serves as an escape hatch to re-enable the
-legacy version in case any bugs are found in the rewrite. This option and
-the shell script version of linkgit:git-stash[1] will be removed in some
-future release.
-+
-If you find some reason to set this option to `false`, other than
-one-off testing, you should report the behavior difference as a bug in
-Git (see https://git-scm.com/community for details).
+	Unused configuration variable.  Used in Git versions 2.22 to
+	2.26 as an escape hatch to enable the legacy shellscript
+	implementation of stash.  Now the built-in rewrite of it in C
+	is always used. Setting this will emit a warning, to alert any
+	remaining users that setting this now does nothing.
 
 stash.showPatch::
 	If this is set to true, the `git stash show` command without an
diff --git a/Documentation/config/submodule.txt b/Documentation/config/submodule.txt
index b331771..d7a63c8 100644
--- a/Documentation/config/submodule.txt
+++ b/Documentation/config/submodule.txt
@@ -59,9 +59,17 @@
 
 submodule.recurse::
 	Specifies if commands recurse into submodules by default. This
-	applies to all commands that have a `--recurse-submodules` option,
-	except `clone`.
+	applies to all commands that have a `--recurse-submodules` option
+	(`checkout`, `fetch`, `grep`, `pull`, `push`, `read-tree`, `reset`,
+	`restore` and `switch`) except `clone` and `ls-files`.
 	Defaults to false.
+	When set to true, it can be deactivated via the
+	`--no-recurse-submodules` option. Note that some Git commands
+	lacking this option may call some of the above commands affected by
+	`submodule.recurse`; for instance `git remote update` will call
+	`git fetch` but does not have a `--no-recurse-submodules` option.
+	For these commands a workaround is to temporarily change the
+	configuration value by using `git -c submodule.recurse=0`.
 
 submodule.fetchJobs::
 	Specifies how many submodules are fetched/cloned at the same time.
diff --git a/Documentation/config/tag.txt b/Documentation/config/tag.txt
index 6d9110d..5062a05 100644
--- a/Documentation/config/tag.txt
+++ b/Documentation/config/tag.txt
@@ -15,10 +15,3 @@
 	convenient to use an agent to avoid typing your gpg passphrase
 	several times. Note that this option doesn't affect tag signing
 	behavior enabled by "-u <keyid>" or "--local-user=<keyid>" options.
-
-tar.umask::
-	This variable can be used to restrict the permission bits of
-	tar archive entries.  The default is 0002, which turns off the
-	world write bit.  The special value "user" indicates that the
-	archiving user's umask will be used instead.  See umask(2) and
-	linkgit:git-archive[1].
diff --git a/Documentation/config/tar.txt b/Documentation/config/tar.txt
new file mode 100644
index 0000000..de8ff48
--- /dev/null
+++ b/Documentation/config/tar.txt
@@ -0,0 +1,6 @@
+tar.umask::
+	This variable can be used to restrict the permission bits of
+	tar archive entries.  The default is 0002, which turns off the
+	world write bit.  The special value "user" indicates that the
+	archiving user's umask will be used instead.  See umask(2) and
+	linkgit:git-archive[1].
diff --git a/Documentation/config/trace2.txt b/Documentation/config/trace2.txt
index 4ce0b9a..01d3afd 100644
--- a/Documentation/config/trace2.txt
+++ b/Documentation/config/trace2.txt
@@ -48,6 +48,15 @@
 	May be overridden by the `GIT_TRACE2_CONFIG_PARAMS` environment
 	variable.  Unset by default.
 
+trace2.envVars::
+	A comma-separated list of "important" environment variables that should
+	be recorded in the trace2 output.  For example,
+	`GIT_HTTP_USER_AGENT,GIT_CONFIG` would cause the trace2 output to
+	contain events listing the overrides for HTTP user agent and the
+	location of the Git configuration file (assuming any are set).  May be
+	overriden by the `GIT_TRACE2_ENV_VARS` environment variable.  Unset by
+	default.
+
 trace2.destinationDebug::
 	Boolean.  When true Git will print error messages when a
 	trace target destination cannot be opened for writing.
diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt
index a115a1a..6e2a160 100644
--- a/Documentation/fetch-options.txt
+++ b/Documentation/fetch-options.txt
@@ -61,10 +61,8 @@
 See also the `fetch.negotiationAlgorithm` configuration variable
 documented in linkgit:git-config[1].
 
-ifndef::git-pull[]
 --dry-run::
 	Show what would be done, without making any changes.
-endif::git-pull[]
 
 -f::
 --force::
@@ -95,6 +93,7 @@
 --[no-]write-commit-graph::
 	Write a commit-graph after fetching. This overrides the config
 	setting `fetch.writeCommitGraph`.
+endif::git-pull[]
 
 -p::
 --prune::
@@ -107,6 +106,7 @@
 	was cloned with the --mirror option), then they are also
 	subject to pruning. Supplying `--prune-tags` is a shorthand for
 	providing the tag refspec.
+ifndef::git-pull[]
 +
 See the PRUNING section below for more details.
 
@@ -133,7 +133,6 @@
 	behavior for a remote may be specified with the remote.<name>.tagOpt
 	setting. See linkgit:git-config[1].
 
-ifndef::git-pull[]
 --refmap=<refspec>::
 	When fetching refs listed on the command line, use the
 	specified refspec (can be given more than once) to map the
@@ -154,6 +153,7 @@
 	is used (though tags may be pruned anyway if they are also the
 	destination of an explicit refspec; see `--prune`).
 
+ifndef::git-pull[]
 --recurse-submodules[=yes|on-demand|no]::
 	This option controls if and under what conditions new commits of
 	populated submodules should be fetched too. It can be used as a
@@ -163,7 +163,9 @@
 	value. Use 'on-demand' to only recurse into a populated submodule
 	when the superproject retrieves a commit that updates the submodule's
 	reference to a commit that isn't already in the local submodule
-	clone.
+	clone. By default, 'on-demand' is used, unless
+	`fetch.recurseSubmodules` is set (see linkgit:git-config[1]).
+endif::git-pull[]
 
 -j::
 --jobs=<n>::
@@ -177,9 +179,11 @@
 Typically, parallel recursive and multi-remote fetches will be faster. By
 default fetches are performed sequentially, not in parallel.
 
+ifndef::git-pull[]
 --no-recurse-submodules::
 	Disable recursive fetching of submodules (this has the same effect as
 	using the `--recurse-submodules=no` option).
+endif::git-pull[]
 
 --set-upstream::
 	If the remote is fetched successfully, pull and add upstream
@@ -188,6 +192,7 @@
 	see `branch.<name>.merge` and `branch.<name>.remote` in
 	linkgit:git-config[1].
 
+ifndef::git-pull[]
 --submodule-prefix=<path>::
 	Prepend <path> to paths printed in informative messages
 	such as "Fetching submodule foo".  This option is used
@@ -200,7 +205,6 @@
 	recursion (such as settings in linkgit:gitmodules[5] and
 	linkgit:git-config[1]) override this option, as does
 	specifying --[no-]recurse-submodules directly.
-endif::git-pull[]
 
 -u::
 --update-head-ok::
@@ -210,6 +214,7 @@
 	to communicate with 'git fetch', and unless you are
 	implementing your own Porcelain you are not supposed to
 	use it.
+endif::git-pull[]
 
 --upload-pack <upload-pack>::
 	When given, and the repository to fetch from is handled
diff --git a/Documentation/git-am.txt b/Documentation/git-am.txt
index ab5754e..38c0852 100644
--- a/Documentation/git-am.txt
+++ b/Documentation/git-am.txt
@@ -148,9 +148,12 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign commits. The `keyid` argument is optional and
 	defaults to the committer identity; if specified, it must be
-	stuck to the option without a space.
+	stuck to the option without a space. `--no-gpg-sign` is useful to
+	countermand both `commit.gpgSign` configuration variable, and
+	earlier `--gpg-sign`.
 
 --continue::
 -r::
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index c8fb995..5b697ee 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -292,11 +292,11 @@
 
 --recurse-submodules::
 --no-recurse-submodules::
-	Using `--recurse-submodules` will update the content of all initialized
+	Using `--recurse-submodules` will update the content of all active
 	submodules according to the commit recorded in the superproject. If
 	local modifications in a submodule would be overwritten the checkout
 	will fail unless `-f` is used. If nothing (or `--no-recurse-submodules`)
-	is used, the work trees of submodules will not be updated.
+	is used, submodules working trees will not be updated.
 	Just like linkgit:git-submodule[1], this will detach `HEAD` of the
 	submodule.
 
diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index 83ce51a..75feeef 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -109,9 +109,12 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign commits. The `keyid` argument is optional and
 	defaults to the committer identity; if specified, it must be
-	stuck to the option without a space.
+	stuck to the option without a space. `--no-gpg-sign` is useful to
+	countermand both `commit.gpgSign` configuration variable, and
+	earlier `--gpg-sign`.
 
 --ff::
 	If the current HEAD is the same as the parent of the
diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index bf24f18..08d6045 100644
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -15,7 +15,8 @@
 	  [--dissociate] [--separate-git-dir <git dir>]
 	  [--depth <depth>] [--[no-]single-branch] [--no-tags]
 	  [--recurse-submodules[=<pathspec>]] [--[no-]shallow-submodules]
-	  [--[no-]remote-submodules] [--jobs <n>] [--sparse] [--] <repository>
+	  [--[no-]remote-submodules] [--jobs <n>] [--sparse]
+	  [--filter=<filter>] [--] <repository>
 	  [<directory>]
 
 DESCRIPTION
@@ -162,6 +163,16 @@
 	of the repository. The sparse-checkout file can be
 	modified to grow the working directory as needed.
 
+--filter=<filter-spec>::
+	Use the partial clone feature and request that the server sends
+	a subset of reachable objects according to a given object filter.
+	When using `--filter`, the supplied `<filter-spec>` is used for
+	the partial clone filter. For example, `--filter=blob:none` will
+	filter out all blobs (file contents) until needed by Git. Also,
+	`--filter=blob:limit=<size>` will filter out all blobs of size
+	at least `<size>`. For more details on filter specifications, see
+	the `--filter` option in linkgit:git-rev-list[1].
+
 --mirror::
 	Set up a mirror of the source repository.  This implies `--bare`.
 	Compared to `--bare`, `--mirror` not only maps local branches of the
diff --git a/Documentation/git-commit-tree.txt b/Documentation/git-commit-tree.txt
index ec15ee8..2e2c581 100644
--- a/Documentation/git-commit-tree.txt
+++ b/Documentation/git-commit-tree.txt
@@ -61,13 +61,11 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign commits. The `keyid` argument is optional and
 	defaults to the committer identity; if specified, it must be
-	stuck to the option without a space.
-
---no-gpg-sign::
-	Do not GPG-sign commit, to countermand a `--gpg-sign` option
-	given earlier on the command line.
+	stuck to the option without a space. `--no-gpg-sign` is useful to
+	countermand a `--gpg-sign` option given earlier on the command line.
 
 Commit Information
 ------------------
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 13f6539..a3baea3 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -348,13 +348,12 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign commits. The `keyid` argument is optional and
 	defaults to the committer identity; if specified, it must be
-	stuck to the option without a space.
-
---no-gpg-sign::
-	Countermand `commit.gpgSign` configuration variable that is
-	set to force each and every commit to be signed.
+	stuck to the option without a space. `--no-gpg-sign` is useful to
+	countermand both `commit.gpgSign` configuration variable, and
+	earlier `--gpg-sign`.
 
 \--::
 	Do not interpret any more arguments as options.
diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index 7889f95..77c6b3d 100644
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -122,6 +122,26 @@
 Relative and non-relative marks may be combined by interweaving
 --(no-)-relative-marks with the --(import|export)-marks= options.
 
+Submodule Rewriting
+~~~~~~~~~~~~~~~~~~~
+
+--rewrite-submodules-from=<name>:<file>::
+--rewrite-submodules-to=<name>:<file>::
+  Rewrite the object IDs for the submodule specified by <name> from the values
+	used in the from <file> to those used in the to <file>. The from marks should
+	have been created by `git fast-export`, and the to marks should have been
+	created by `git fast-import` when importing that same submodule.
++
+<name> may be any arbitrary string not containing a colon character, but the
+same value must be used with both options when specifying corresponding marks.
+Multiple submodules may be specified with different values for <name>. It is an
+error not to use these options in corresponding pairs.
++
+These options are primarily useful when converting a repository from one hash
+algorithm to another; without them, fast-import will fail if it encounters a
+submodule because it has no way of writing the object ID into the new hash
+algorithm.
+
 Performance and Compression Tuning
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 0d4f895..0f81d04 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -24,6 +24,7 @@
 		   [(--reroll-count|-v) <n>]
 		   [--to=<email>] [--cc=<email>]
 		   [--[no-]cover-letter] [--quiet]
+		   [--[no-]encode-email-headers]
 		   [--no-notes | --notes[=<ref>]]
 		   [--interdiff=<previous>]
 		   [--range-diff=<previous> [--creation-factor=<percent>]]
@@ -253,6 +254,13 @@
 	containing the branch description, shortlog and the overall diffstat.  You can
 	fill in a description in the file before sending it out.
 
+--encode-email-headers::
+--no-encode-email-headers::
+	Encode email headers that have non-ASCII characters with
+	"Q-encoding" (described in RFC 2047), instead of outputting the
+	headers verbatim. Defaults to the value of the
+	`format.encodeEmailHeaders` configuration variable.
+
 --interdiff=<previous>::
 	As a reviewer aid, insert an interdiff into the cover letter,
 	or as commentary of the lone patch of a 1-patch series, showing
diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
index ddb6acc..a7f9bc9 100644
--- a/Documentation/git-grep.txt
+++ b/Documentation/git-grep.txt
@@ -93,7 +93,7 @@
 	with `--no-index`.
 
 --recurse-submodules::
-	Recursively search in each submodule that has been initialized and
+	Recursively search in each submodule that is active and
 	checked out in the repository.  When used in combination with the
 	<tree> option the prefix of all submodule output will be the name of
 	the parent project's <tree> object. This option has no effect
@@ -206,8 +206,10 @@
 
 -z::
 --null::
-	Output \0 instead of the character that normally follows a
-	file name.
+	Use \0 as the delimiter for pathnames in the output, and print
+	them verbatim. Without this option, pathnames with "unusual"
+	characters are quoted as explained for the configuration
+	variable core.quotePath (see git-config(1)).
 
 -o::
 --only-matching::
diff --git a/Documentation/git-init.txt b/Documentation/git-init.txt
index 32880aa..adc6adf 100644
--- a/Documentation/git-init.txt
+++ b/Documentation/git-init.txt
@@ -10,7 +10,7 @@
 --------
 [verse]
 'git init' [-q | --quiet] [--bare] [--template=<template_directory>]
-	  [--separate-git-dir <git dir>]
+	  [--separate-git-dir <git dir>] [--object-format=<format]
 	  [--shared[=<permissions>]] [directory]
 
 
@@ -48,6 +48,11 @@
 Create a bare repository. If `GIT_DIR` environment is not set, it is set to the
 current working directory.
 
+--object-format=<format>::
+
+Specify the given object format (hash algorithm) for the repository.  The valid
+values are 'sha1' and (if enabled) 'sha256'.  'sha1' is the default.
+
 --template=<template_directory>::
 
 Specify the directory from which templates will be used.  (See the "TEMPLATE
diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index bed09bb..20e6d21 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -43,12 +43,16 @@
 	If no `--decorate-refs` is given, pretend as if all refs were
 	included.  For each candidate, do not use it for decoration if it
 	matches any patterns given to `--decorate-refs-exclude` or if it
-	doesn't match any of the patterns given to `--decorate-refs`.
+	doesn't match any of the patterns given to `--decorate-refs`. The
+	`log.excludeDecoration` config option allows excluding refs from
+	the decorations, but an explicit `--decorate-refs` pattern will
+	override a match in `log.excludeDecoration`.
 
 --source::
 	Print out the ref name given on the command line by which each
 	commit was reached.
 
+--[no-]mailmap::
 --[no-]use-mailmap::
 	Use mailmap file to map author and committer names and email
 	addresses to canonical real names and email addresses. See
diff --git a/Documentation/git-ls-files.txt b/Documentation/git-ls-files.txt
index 8461c0e..3cb2ebb 100644
--- a/Documentation/git-ls-files.txt
+++ b/Documentation/git-ls-files.txt
@@ -148,7 +148,7 @@
 	top directory.
 
 --recurse-submodules::
-	Recursively calls ls-files on each submodule in the repository.
+	Recursively calls ls-files on each active submodule in the repository.
 	Currently there is only support for the --cached mode.
 
 --abbrev[=<n>]::
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 092529c..ec06b2f 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -94,7 +94,8 @@
 
 --abort::
 	Abort the current conflict resolution process, and
-	try to reconstruct the pre-merge state.
+	try to reconstruct the pre-merge state. If an autostash entry is
+	present, apply it to the worktree.
 +
 If there were uncommitted worktree changes present when the merge
 started, 'git merge --abort' will in some cases be unable to
@@ -102,11 +103,15 @@
 commit or stash your changes before running 'git merge'.
 +
 'git merge --abort' is equivalent to 'git reset --merge' when
-`MERGE_HEAD` is present.
+`MERGE_HEAD` is present unless `MERGE_AUTOSTASH` is also present in
+which case 'git merge --abort' applies the stash entry to the worktree
+whereas 'git reset --merge' will save the stashed changes in the stash
+reflog.
 
 --quit::
 	Forget about the current merge in progress. Leave the index
-	and the working tree as-is.
+	and the working tree as-is. If `MERGE_AUTOSTASH` is present, the
+	stash entry will be saved to the stash reflog.
 
 --continue::
 	After a 'git merge' stops due to conflicts you can conclude the
diff --git a/Documentation/git-p4.txt b/Documentation/git-p4.txt
index 3494a1d..dab9609 100644
--- a/Documentation/git-p4.txt
+++ b/Documentation/git-p4.txt
@@ -374,14 +374,55 @@
     been submitted. Implies --disable-rebase. Can also be set with
     git-p4.disableP4Sync. Sync with origin/master still goes ahead if possible.
 
-Hook for submit
-~~~~~~~~~~~~~~~
+Hooks for submit
+----------------
+
+p4-pre-submit
+~~~~~~~~~~~~~
+
 The `p4-pre-submit` hook is executed if it exists and is executable.
 The hook takes no parameters and nothing from standard input. Exiting with
 non-zero status from this script prevents `git-p4 submit` from launching.
+It can be bypassed with the `--no-verify` command line option.
 
 One usage scenario is to run unit tests in the hook.
 
+p4-prepare-changelist
+~~~~~~~~~~~~~~~~~~~~~
+
+The `p4-prepare-changelist` hook is executed right after preparing
+the default changelist message and before the editor is started.
+It takes one parameter, the name of the file that contains the
+changelist text. Exiting with a non-zero status from the script
+will abort the process.
+
+The purpose of the hook is to edit the message file in place,
+and it is not supressed by the `--no-verify` option. This hook
+is called even if `--prepare-p4-only` is set.
+
+p4-changelist
+~~~~~~~~~~~~~
+
+The `p4-changelist` hook is executed after the changelist
+message has been edited by the user. It can be bypassed with the
+`--no-verify` option. It takes a single parameter, the name
+of the file that holds the proposed changelist text. Exiting
+with a non-zero status causes the command to abort.
+
+The hook is allowed to edit the changelist file and can be used
+to normalize the text into some project standard format. It can
+also be used to refuse the Submit after inspect the message file.
+
+p4-post-changelist
+~~~~~~~~~~~~~~~~~~
+
+The `p4-post-changelist` hook is invoked after the submit has
+successfully occured in P4. It takes no parameters and is meant
+primarily for notification and cannot affect the outcome of the
+git p4 submit action.
+
+
+
 Rebase options
 ~~~~~~~~~~~~~~
 These options can be used to modify 'git p4 rebase' behavior.
diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
index fecdf26..eaa2f2a 100644
--- a/Documentation/git-pack-objects.txt
+++ b/Documentation/git-pack-objects.txt
@@ -14,7 +14,7 @@
 	[--local] [--incremental] [--window=<n>] [--depth=<n>]
 	[--revs [--unpacked | --all]] [--keep-pack=<pack-name>]
 	[--stdout [--filter=<filter-spec>] | base-name]
-	[--shallow] [--keep-true-parents] [--sparse] < object-list
+	[--shallow] [--keep-true-parents] [--[no-]sparse] < object-list
 
 
 DESCRIPTION
@@ -196,14 +196,16 @@
 	Add --no-reuse-object if you want to force a uniform compression
 	level on all data no matter the source.
 
---sparse::
-	Use the "sparse" algorithm to determine which objects to include in
+--[no-]sparse::
+	Toggle the "sparse" algorithm to determine which objects to include in
 	the pack, when combined with the "--revs" option. This algorithm
 	only walks trees that appear in paths that introduce new objects.
 	This can have significant performance benefits when computing
 	a pack to send a small change. However, it is possible that extra
 	objects are added to the pack-file if the included commits contain
-	certain types of direct renames.
+	certain types of direct renames. If this option is not included,
+	it defaults to the value of `pack.useSparse`, which is true unless
+	otherwise specified.
 
 --thin::
 	Create a "thin" pack by omitting the common objects between a
diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt
index dfb901f..5c3fb67 100644
--- a/Documentation/git-pull.txt
+++ b/Documentation/git-pull.txt
@@ -85,8 +85,9 @@
 	Pass --verbose to git-fetch and git-merge.
 
 --[no-]recurse-submodules[=yes|on-demand|no]::
-	This option controls if new commits of all populated submodules should
-	be fetched and updated, too (see linkgit:git-config[1] and
+	This option controls if new commits of populated submodules should
+	be fetched, and if the working trees of active submodules should be
+	updated, too (see linkgit:git-fetch[1], linkgit:git-config[1] and
 	linkgit:gitmodules[5]).
 +
 If the checkout is done via rebase, local submodule commits are rebased as well.
@@ -133,15 +134,6 @@
 --no-rebase::
 	Override earlier --rebase.
 
---autostash::
---no-autostash::
-	Before starting rebase, stash local modifications away (see
-	linkgit:git-stash[1]) if needed, and apply the stash entry when
-	done. `--no-autostash` is useful to override the `rebase.autoStash`
-	configuration variable (see linkgit:git-config[1]).
-+
-This option is only valid when "--rebase" is used.
-
 Options related to fetching
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -229,9 +221,9 @@
 $ git pull origin next
 ------------------------------------------------
 +
-This leaves a copy of `next` temporarily in FETCH_HEAD, but
-does not update any remote-tracking branches. Using remote-tracking
-branches, the same can be done by invoking fetch and merge:
+This leaves a copy of `next` temporarily in FETCH_HEAD, and
+updates the remote-tracking branch `origin/next`.
+The same can be done by invoking fetch and merge:
 +
 ------------------------------------------------
 $ git fetch origin
diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index da33f84..5fa8bab 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt
@@ -116,9 +116,9 @@
 	located in.
 
 --[no-]recurse-submodules::
-	Using --recurse-submodules will update the content of all initialized
+	Using --recurse-submodules will update the content of all active
 	submodules according to the commit recorded in the superproject by
-	calling read-tree recursively, also setting the submodules HEAD to be
+	calling read-tree recursively, also setting the submodules' HEAD to be
 	detached at that commit.
 
 --no-sparse-checkout::
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index f7a6033..c70c1ec 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -256,7 +256,8 @@
 --quit::
 	Abort the rebase operation but HEAD is not reset back to the
 	original branch. The index and working tree are also left
-	unchanged as a result.
+	unchanged as a result. If a temporary stash entry was created
+	using --autostash, it will be saved to the stash reflog.
 
 --apply:
 	Use applying strategies to rebase (calling `git-am`
@@ -277,20 +278,51 @@
 	Other options, like --exec, will use the default of drop unless
 	-i/--interactive is explicitly specified.
 +
-Note that commits which start empty are kept, and commits which are
-clean cherry-picks (as determined by `git log --cherry-mark ...`) are
-always dropped.
+Note that commits which start empty are kept (unless --no-keep-empty
+is specified), and commits which are clean cherry-picks (as determined
+by `git log --cherry-mark ...`) are detected and dropped as a
+preliminary step (unless --reapply-cherry-picks is passed).
 +
 See also INCOMPATIBLE OPTIONS below.
 
+--no-keep-empty::
 --keep-empty::
-	No-op.  Rebasing commits that started empty (had no change
-	relative to their parent) used to fail and this option would
-	override that behavior, allowing commits with empty changes to
-	be rebased.  Now commits with no changes do not cause rebasing
-	to halt.
+	Do not keep commits that start empty before the rebase
+	(i.e. that do not change anything from its parent) in the
+	result.  The default is to keep commits which start empty,
+	since creating such commits requires passing the --allow-empty
+	override flag to `git commit`, signifying that a user is very
+	intentionally creating such a commit and thus wants to keep
+	it.
 +
-See also BEHAVIORAL DIFFERENCES and INCOMPATIBLE OPTIONS below.
+Usage of this flag will probably be rare, since you can get rid of
+commits that start empty by just firing up an interactive rebase and
+removing the lines corresponding to the commits you don't want.  This
+flag exists as a convenient shortcut, such as for cases where external
+tools generate many empty commits and you want them all removed.
++
+For commits which do not start empty but become empty after rebasing,
+see the --empty flag.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--reapply-cherry-picks::
+--no-reapply-cherry-picks::
+	Reapply all clean cherry-picks of any upstream commit instead
+	of preemptively dropping them. (If these commits then become
+	empty after rebasing, because they contain a subset of already
+	upstream changes, the behavior towards them is controlled by
+	the `--empty` flag.)
++
+By default (or if `--no-reapply-cherry-picks` is given), these commits
+will be automatically dropped.  Because this necessitates reading all
+upstream commits, this can be expensive in repos with a large number
+of upstream commits that need to be read.
++
+`--reapply-cherry-picks` allows rebase to forgo reading all upstream
+commits, potentially improving performance.
++
+See also INCOMPATIBLE OPTIONS below.
 
 --allow-empty-message::
 	No-op.  Rebasing commits with an empty message used to fail
@@ -354,9 +386,12 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign commits. The `keyid` argument is optional and
 	defaults to the committer identity; if specified, it must be
-	stuck to the option without a space.
+	stuck to the option without a space. `--no-gpg-sign` is useful to
+	countermand both `commit.gpgSign` configuration variable, and
+	earlier `--gpg-sign`.
 
 -q::
 --quiet::
@@ -587,8 +622,9 @@
  * --preserve-merges
  * --interactive
  * --exec
- * --keep-empty
+ * --no-keep-empty
  * --empty=
+ * --reapply-cherry-picks
  * --edit-todo
  * --root when used in combination with --onto
 
@@ -605,7 +641,7 @@
 -----------------------
 
 git rebase has two primary backends: apply and merge.  (The apply
-backend used to known as the 'am' backend, but the name led to
+backend used to be known as the 'am' backend, but the name led to
 confusion as it looks like a verb instead of a noun.  Also, the merge
 backend used to be known as the interactive backend, but it is now
 used for non-interactive cases as well.  Both were renamed based on
@@ -620,12 +656,15 @@
 also drops commits that become empty and has no option for controlling
 this behavior.
 
-The merge backend keeps intentionally empty commits.  Similar to the
-apply backend, by default the merge backend drops commits that become
-empty unless -i/--interactive is specified (in which case it stops and
-asks the user what to do).  The merge backend also has an
---empty={drop,keep,ask} option for changing the behavior of handling
-commits that become empty.
+The merge backend keeps intentionally empty commits by default (though
+with -i they are marked as empty in the todo list editor, or they can
+be dropped automatically with --no-keep-empty).
+
+Similar to the apply backend, by default the merge backend drops
+commits that become empty unless -i/--interactive is specified (in
+which case it stops and asks the user what to do).  The merge backend
+also has an --empty={drop,keep,ask} option for changing the behavior
+of handling commits that become empty.
 
 Directory rename detection
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -684,9 +723,17 @@
 ~~~~~
 
 The apply backend has not traditionally called the post-commit hook,
-while the merge backend has.  However, this was by accident of
-implementation rather than by design.  Both backends should have the
-same behavior, though it is not clear which one is correct.
+while the merge backend has.  Both have called the post-checkout hook,
+though the merge backend has squelched its output.  Further, both
+backends only call the post-checkout hook with the starting point
+commit of the rebase, not the intermediate commits nor the final
+commit.  In each case, the calling of these hooks was by accident of
+implementation rather than by design (both backends were originally
+implemented as shell scripts and happened to invoke other commands
+like 'git checkout' or 'git commit' that would call the hooks).  Both
+backends should have the same behavior, though it is not entirely
+clear which, if any, is correct.  We will likely make rebase stop
+calling either of these hooks in the future.
 
 Interruptability
 ~~~~~~~~~~~~~~~~
@@ -1002,7 +1049,8 @@
 'subsystem' did.
 
 In that case, the fix is easy because 'git rebase' knows to skip
-changes that are already present in the new upstream.  So if you say
+changes that are already present in the new upstream (unless
+`--reapply-cherry-picks` is given). So if you say
 (assuming you're on 'topic')
 ------------
     $ git rebase subsystem
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index 932080c..252e2d4 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -87,6 +87,12 @@
 	different between `<commit>` and `HEAD`.
 	If a file that is different between `<commit>` and `HEAD` has local
 	changes, reset is aborted.
+
+--[no-]recurse-submodules::
+	When the working tree is updated, using --recurse-submodules will
+	also recursively reset the working tree of all active submodules
+	according to the commit recorded in the superproject, also setting
+	the submodules' HEAD to be detached at that commit.
 --
 
 See "Reset, restore and revert" in linkgit:git[1] for the differences
diff --git a/Documentation/git-restore.txt b/Documentation/git-restore.txt
index 5bf60d4..8e3b339 100644
--- a/Documentation/git-restore.txt
+++ b/Documentation/git-restore.txt
@@ -107,6 +107,17 @@
 	patterns and unconditionally restores any files in
 	`<pathspec>`.
 
+--recurse-submodules::
+--no-recurse-submodules::
+	If `<pathspec>` names an active submodule and the restore location
+	includes the working tree, the submodule will only be updated if
+	this option is given, in which case its working tree will be
+	restored to the commit recorded in the superproject, and any local
+	modifications overwritten. If nothing (or
+	`--no-recurse-submodules`) is used, submodules working trees will
+	not be updated. Just like linkgit:git-checkout[1], this will detach
+	`HEAD` of the submodule.
+
 --overlay::
 --no-overlay::
 	In overlay mode, the command never removes files when
diff --git a/Documentation/git-revert.txt b/Documentation/git-revert.txt
index 9d22270..044276e 100644
--- a/Documentation/git-revert.txt
+++ b/Documentation/git-revert.txt
@@ -90,9 +90,12 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign commits. The `keyid` argument is optional and
 	defaults to the committer identity; if specified, it must be
-	stuck to the option without a space.
+	stuck to the option without a space. `--no-gpg-sign` is useful to
+	countermand both `commit.gpgSign` configuration variable, and
+	earlier `--gpg-sign`.
 
 -s::
 --signoff::
diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt
index c0342e5..1a3ace6 100644
--- a/Documentation/git-sparse-checkout.txt
+++ b/Documentation/git-sparse-checkout.txt
@@ -70,6 +70,16 @@
 	`core.sparseCheckoutCone` is enabled, the given patterns are interpreted
 	as directory names as in the 'set' subcommand.
 
+'reapply::
+	Reapply the sparsity pattern rules to paths in the working tree.
+	Commands like merge or rebase can materialize paths to do their
+	work (e.g. in order to show you a conflict), and other
+	sparse-checkout commands might fail to sparsify an individual file
+	(e.g. because it has unstaged changes or conflicts).  In such
+	cases, it can make sense to run `git sparse-checkout reapply` later
+	after cleaning up affected paths (e.g. resolving conflicts, undoing
+	or committing changes, etc.).
+
 'disable'::
 	Disable the `core.sparseCheckout` config setting, and restore the
 	working directory to include all files. Leaves the sparse-checkout
diff --git a/Documentation/git-switch.txt b/Documentation/git-switch.txt
index 1979003..3759c3a 100644
--- a/Documentation/git-switch.txt
+++ b/Documentation/git-switch.txt
@@ -181,9 +181,9 @@
 --recurse-submodules::
 --no-recurse-submodules::
 	Using `--recurse-submodules` will update the content of all
-	initialized submodules according to the commit recorded in the
+	active submodules according to the commit recorded in the
 	superproject. If nothing (or `--no-recurse-submodules`) is
-	used, the work trees of submodules will not be updated. Just
+	used, submodules working trees will not be updated. Just
 	like linkgit:git-submodule[1], this will detach `HEAD` of the
 	submodules.
 
diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt
index 9671423..3e737c2 100644
--- a/Documentation/git-update-ref.txt
+++ b/Documentation/git-update-ref.txt
@@ -66,6 +66,10 @@
 	delete SP <ref> [SP <oldvalue>] LF
 	verify SP <ref> [SP <oldvalue>] LF
 	option SP <opt> LF
+	start LF
+	prepare LF
+	commit LF
+	abort LF
 
 With `--create-reflog`, update-ref will create a reflog for each ref
 even if one would not ordinarily be created.
@@ -83,6 +87,10 @@
 	delete SP <ref> NUL [<oldvalue>] NUL
 	verify SP <ref> NUL [<oldvalue>] NUL
 	option SP <opt> NUL
+	start NUL
+	prepare NUL
+	commit NUL
+	abort NUL
 
 In this format, use 40 "0" to specify a zero value, and use the empty
 string to specify a missing value.
@@ -107,13 +115,31 @@
 
 verify::
 	Verify <ref> against <oldvalue> but do not change it.  If
-	<oldvalue> zero or missing, the ref must not exist.
+	<oldvalue> is zero or missing, the ref must not exist.
 
 option::
 	Modify behavior of the next command naming a <ref>.
 	The only valid option is `no-deref` to avoid dereferencing
 	a symbolic ref.
 
+start::
+	Start a transaction. In contrast to a non-transactional session, a
+	transaction will automatically abort if the session ends without an
+	explicit commit.
+
+prepare::
+	Prepare to commit the transaction. This will create lock files for all
+	queued reference updates. If one reference could not be locked, the
+	transaction will be aborted.
+
+commit::
+	Commit all reference updates queued for the transaction, ending the
+	transaction.
+
+abort::
+	Abort the transaction, releasing all locks if the transaction is in
+	prepared state.
+
 If all <ref>s can be locked with matching <oldvalue>s
 simultaneously, all modifications are performed.  Otherwise, no
 modifications are performed.  Note that while each individual
diff --git a/Documentation/git.txt b/Documentation/git.txt
index b0672bd..9d6769e 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -493,6 +493,12 @@
 	details. This variable has lower precedence than other path
 	variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY...
 
+`GIT_DEFAULT_HASH_ALGORITHM`::
+	If this variable is set, the default hash algorithm for new
+	repositories will be set to this value. This value is currently
+	ignored when cloning; the setting of the remote repository
+	is used instead. The default is "sha1".
+
 Git Commits
 ~~~~~~~~~~~
 `GIT_AUTHOR_NAME`::
diff --git a/Documentation/gitfaq.txt b/Documentation/gitfaq.txt
new file mode 100644
index 0000000..1cf83df
--- /dev/null
+++ b/Documentation/gitfaq.txt
@@ -0,0 +1,337 @@
+gitfaq(7)
+=========
+
+NAME
+----
+gitfaq - Frequently asked questions about using Git
+
+SYNOPSIS
+--------
+gitfaq
+
+DESCRIPTION
+-----------
+
+The examples in this FAQ assume a standard POSIX shell, like `bash` or `dash`,
+and a user, A U Thor, who has the account `author` on the hosting provider
+`git.example.org`.
+
+Configuration
+-------------
+
+[[user-name]]
+What should I put in `user.name`?::
+	You should put your personal name, generally a form using a given name
+	and family name.  For example, the current maintainer of Git uses "Junio
+	C Hamano".  This will be the name portion that is stored in every commit
+	you make.
++
+This configuration doesn't have any effect on authenticating to remote services;
+for that, see `credential.username` in linkgit:git-config[1].
+
+[[http-postbuffer]]
+What does `http.postBuffer` really do?::
+	This option changes the size of the buffer that Git uses when pushing
+	data to a remote over HTTP or HTTPS.  If the data is larger than this
+	size, libcurl, which handles the HTTP support for Git, will use chunked
+	transfer encoding since it isn't known ahead of time what the size of
+	the pushed data will be.
++
+Leaving this value at the default size is fine unless you know that either the
+remote server or a proxy in the middle doesn't support HTTP/1.1 (which
+introduced the chunked transfer encoding) or is known to be broken with chunked
+data.  This is often (erroneously) suggested as a solution for generic push
+problems, but since almost every server and proxy supports at least HTTP/1.1,
+raising this value usually doesn't solve most push problems.  A server or proxy
+that didn't correctly support HTTP/1.1 and chunked transfer encoding wouldn't be
+that useful on the Internet today, since it would break lots of traffic.
++
+Note that increasing this value will increase the memory used on every relevant
+push that Git does over HTTP or HTTPS, since the entire buffer is allocated
+regardless of whether or not it is all used.  Thus, it's best to leave it at the
+default unless you are sure you need a different value.
+
+[[configure-editor]]
+How do I configure a different editor?::
+	If you haven't specified an editor specifically for Git, it will by default
+	use the editor you've configured using the `VISUAL` or `EDITOR` environment
+	variables, or if neither is specified, the system default (which is usually
+	`vi`).  Since some people find `vi` difficult to use or prefer a different
+	editor, it may be desirable to change the editor used.
++
+If you want to configure a general editor for most programs which need one, you
+can edit your shell configuration (e.g., `~/.bashrc` or `~/.zshenv`) to contain
+a line setting the `EDITOR` or `VISUAL` environment variable to an appropriate
+value.  For example, if you prefer the editor `nano`, then you could write the
+following:
++
+----
+export VISUAL=nano
+----
++
+If you want to configure an editor specifically for Git, you can either set the
+`core.editor` configuration value or the `GIT_EDITOR` environment variable.  You
+can see linkgit:git-var[1] for details on the order in which these options are
+consulted.
++
+Note that in all cases, the editor value will be passed to the shell, so any
+arguments containing spaces should be appropriately quoted.  Additionally, if
+your editor normally detaches from the terminal when invoked, you should specify
+it with an argument that makes it not do that, or else Git will not see any
+changes.  An example of a configuration addressing both of these issues on
+Windows would be the configuration `"C:\Program Files\Vim\gvim.exe" --nofork`,
+which quotes the filename with spaces and specifies the `--nofork` option to
+avoid backgrounding the process.
+
+Credentials
+-----------
+
+[[http-credentials]]
+How do I specify my credentials when pushing over HTTP?::
+	The easiest way to do this is to use a credential helper via the
+	`credential.helper` configuration.  Most systems provide a standard
+	choice to integrate with the system credential manager.  For example,
+	Git for Windows provides the `wincred` credential manager, macOS has the
+	`osxkeychain` credential manager, and Unix systems with a standard
+	desktop environment can use the `libsecret` credential manager.  All of
+	these store credentials in an encrypted store to keep your passwords or
+	tokens secure.
++
+In addition, you can use the `store` credential manager which stores in a file
+in your home directory, or the `cache` credential manager, which does not
+permanently store your credentials, but does prevent you from being prompted for
+them for a certain period of time.
++
+You can also just enter your password when prompted.  While it is possible to
+place the password (which must be percent-encoded) in the URL, this is not
+particularly secure and can lead to accidental exposure of credentials, so it is
+not recommended.
+
+[[http-credentials-environment]]
+How do I read a password or token from an environment variable?::
+	The `credential.helper` configuration option can also take an arbitrary
+	shell command that produces the credential protocol on standard output.
+	This is useful when passing credentials into a container, for example.
++
+Such a shell command can be specified by starting the option value with an
+exclamation point.  If your password or token were stored in the `GIT_TOKEN`,
+you could run the following command to set your credential helper:
++
+----
+$ git config credential.helper \
+	'!f() { echo username=author; echo "password=$GIT_TOKEN"; };f'
+----
+
+[[http-reset-credentials]]
+How do I change the password or token I've saved in my credential manager?::
+	Usually, if the password or token is invalid, Git will erase it and
+	prompt for a new one.  However, there are times when this doesn't always
+	happen.  To change the password or token, you can erase the existing
+	credentials and then Git will prompt for new ones.  To erase
+	credentials, use a syntax like the following (substituting your username
+	and the hostname):
++
+----
+$ echo url=https://author@git.example.org | git credential reject
+----
+
+[[multiple-accounts-http]]
+How do I use multiple accounts with the same hosting provider using HTTP?::
+	Usually the easiest way to distinguish between these accounts is to use
+	the username in the URL.  For example, if you have the accounts `author`
+	and `committer` on `git.example.org`, you can use the URLs
+	https://author@git.example.org/org1/project1.git and
+	https://committer@git.example.org/org2/project2.git.  This way, when you
+	use a credential helper, it will automatically try to look up the
+	correct credentials for your account.  If you already have a remote set
+	up, you can change the URL with something like `git remote set-url
+	origin https://author@git.example.org/org1/project1.git` (see
+	linkgit:git-remote[1] for details).
+
+[[multiple-accounts-ssh]]
+How do I use multiple accounts with the same hosting provider using SSH?::
+	With most hosting providers that support SSH, a single key pair uniquely
+	identifies a user.  Therefore, to use multiple accounts, it's necessary
+	to create a key pair for each account.  If you're using a reasonably
+	modern OpenSSH version, you can create a new key pair with something
+	like `ssh-keygen -t ed25519 -f ~/.ssh/id_committer`.  You can then
+	register the public key (in this case, `~/.ssh/id_committer.pub`; note
+	the `.pub`) with the hosting provider.
++
+Most hosting providers use a single SSH account for pushing; that is, all users
+push to the `git` account (e.g., `git@git.example.org`).  If that's the case for
+your provider, you can set up multiple aliases in SSH to make it clear which key
+pair to use.  For example, you could write something like the following in
+`~/.ssh/config`, substituting the proper private key file:
++
+----
+# This is the account for author on git.example.org.
+Host example_author
+	HostName git.example.org
+	User git
+	# This is the key pair registered for author with git.example.org.
+	IdentityFile ~/.ssh/id_author
+	IdentitiesOnly yes
+# This is the account for committer on git.example.org.
+Host example_committer
+	HostName git.example.org
+	User git
+	# This is the key pair registered for committer with git.example.org.
+	IdentityFile ~/.ssh/id_committer
+	IdentitiesOnly yes
+----
++
+Then, you can adjust your push URL to use `git@example_author` or
+`git@example_committer` instead of `git@example.org` (e.g., `git remote set-url
+git@example_author:org1/project1.git`).
+
+Common Issues
+-------------
+
+[[last-commit-amend]]
+I've made a mistake in the last commit.  How do I change it?::
+	You can make the appropriate change to your working tree, run `git add
+	<file>` or `git rm <file>`, as appropriate, to stage it, and then `git
+	commit --amend`.  Your change will be included in the commit, and you'll
+	be prompted to edit the commit message again; if you wish to use the
+	original message verbatim, you can use the `--no-edit` option to `git
+	commit` in addition, or just save and quit when your editor opens.
+
+[[undo-previous-change]]
+I've made a change with a bug and it's been included in the main branch.  How should I undo it?::
+	The usual way to deal with this is to use `git revert`.  This preserves
+	the history that the original change was made and was a valuable
+	contribution, but also introduces a new commit that undoes those changes
+	because the original had a problem.  The commit message of the revert
+	indicates the commit which was reverted and is usually edited to include
+	an explanation as to why the revert was made.
+
+[[ignore-tracked-files]]
+How do I ignore changes to a tracked file?::
+	Git doesn't provide a way to do this.  The reason is that if Git needs
+	to overwrite this file, such as during a checkout, it doesn't know
+	whether the changes to the file are precious and should be kept, or
+	whether they are irrelevant and can safely be destroyed.  Therefore, it
+	has to take the safe route and always preserve them.
++
+It's tempting to try to use certain features of `git update-index`, namely the
+assume-unchanged and skip-worktree bits, but these don't work properly for this
+purpose and shouldn't be used this way.
++
+If your goal is to modify a configuration file, it can often be helpful to have
+a file checked into the repository which is a template or set of defaults which
+can then be copied alongside and modified as appropriate.  This second, modified
+file is usually ignored to prevent accidentally committing it.
+
+Hooks
+-----
+
+[[restrict-with-hooks]]
+How do I use hooks to prevent users from making certain changes?::
+	The only safe place to make these changes is on the remote repository
+	(i.e., the Git server), usually in the `pre-receive` hook or in a
+	continuous integration (CI) system.  These are the locations in which
+	policy can be enforced effectively.
++
+It's common to try to use `pre-commit` hooks (or, for commit messages,
+`commit-msg` hooks) to check these things, which is great if you're working as a
+solo developer and want the tooling to help you.  However, using hooks on a
+developer machine is not effective as a policy control because a user can bypass
+these hooks with `--no-verify` without being noticed (among various other ways).
+Git assumes that the user is in control of their local repositories and doesn't
+try to prevent this or tattle on the user.
++
+In addition, some advanced users find `pre-commit` hooks to be an impediment to
+workflows that use temporary commits to stage work in progress or that create
+fixup commits, so it's better to push these kinds of checks to the server
+anyway.
+
+Cross-Platform Issues
+---------------------
+
+[[windows-text-binary]]
+I'm on Windows and my text files are detected as binary.::
+	Git works best when you store text files as UTF-8.  Many programs on
+	Windows support UTF-8, but some do not and only use the little-endian
+	UTF-16 format, which Git detects as binary.  If you can't use UTF-8 with
+	your programs, you can specify a working tree encoding that indicates
+	which encoding your files should be checked out with, while still
+	storing these files as UTF-8 in the repository.  This allows tools like
+	linkgit:git-diff[1] to work as expected, while still allowing your tools
+	to work.
++
+To do so, you can specify a linkgit:gitattributes[5] pattern with the
+`working-tree-encoding` attribute.  For example, the following pattern sets all
+C files to use UTF-16LE-BOM, which is a common encoding on Windows:
++
+----
+*.c	working-tree-encoding=UTF-16LE-BOM
+----
++
+You will need to run `git add --renormalize` to have this take effect.  Note
+that if you are making these changes on a project that is used across platforms,
+you'll probably want to make it in a per-user configuration file or in the one
+in `$GIT_DIR/info/attributes`, since making it in a `.gitattributes` file in the
+repository will apply to all users of the repository.
++
+See the following entry for information about normalizing line endings as well,
+and see linkgit:gitattributes[5] for more information about attribute files.
+
+[[windows-diff-control-m]]
+I'm on Windows and git diff shows my files as having a `^M` at the end.::
+	By default, Git expects files to be stored with Unix line endings.  As such,
+	the carriage return (`^M`) that is part of a Windows line ending is shown
+	because it is considered to be trailing whitespace.  Git defaults to showing
+	trailing whitespace only on new lines, not existing ones.
++
+You can store the files in the repository with Unix line endings and convert
+them automatically to your platform's line endings.  To do that, set the
+configuration option `core.eol` to `native` and see the following entry for
+information about how to configure files as text or binary.
++
+You can also control this behavior with the `core.whitespace` setting if you
+don't wish to remove the carriage returns from your line endings.
+
+[[recommended-storage-settings]]
+What's the recommended way to store files in Git?::
+	While Git can store and handle any file of any type, there are some
+	settings that work better than others.  In general, we recommend that
+	text files be stored in UTF-8 without a byte-order mark (BOM) with LF
+	(Unix-style) endings.  We also recommend the use of UTF-8 (again,
+	without BOM) in commit messages.  These are the settings that work best
+	across platforms and with tools such as `git diff` and `git merge`.
++
+Additionally, if you have a choice between storage formats that are text based
+or non-text based, we recommend storing files in the text format and, if
+necessary, transforming them into the other format.  For example, a text-based
+SQL dump with one record per line will work much better for diffing and merging
+than an actual database file.  Similarly, text-based formats such as Markdown
+and AsciiDoc will work better than binary formats such as Microsoft Word and
+PDF.
++
+Similarly, storing binary dependencies (e.g., shared libraries or JAR files) or
+build products in the repository is generally not recommended.  Dependencies and
+build products are best stored on an artifact or package server with only
+references, URLs, and hashes stored in the repository.
++
+We also recommend setting a linkgit:gitattributes[5] file to explicitly mark
+which files are text and which are binary.  If you want Git to guess, you can
+set the attribute `text=auto`.  For example, the following might be appropriate
+in some projects:
++
+----
+# By default, guess.
+*	text=auto
+# Mark all C files as text.
+*.c	text
+# Mark all JPEG files as binary.
+*.jpg	binary
+----
++
+These settings help tools pick the right format for output such as patches and
+result in files being checked out in the appropriate line ending for the
+platform.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
index 3dccab5..81f2a87 100644
--- a/Documentation/githooks.txt
+++ b/Documentation/githooks.txt
@@ -522,12 +522,61 @@
 hook to limit its search.  On error, it will fall back to verifying
 all files and folders.
 
+p4-changelist
+~~~~~~~~~~~~~
+
+This hook is invoked by `git-p4 submit`.
+
+The `p4-changelist` hook is executed after the changelist
+message has been edited by the user. It can be bypassed with the
+`--no-verify` option. It takes a single parameter, the name
+of the file that holds the proposed changelist text. Exiting
+with a non-zero status causes the command to abort.
+
+The hook is allowed to edit the changelist file and can be used
+to normalize the text into some project standard format. It can
+also be used to refuse the Submit after inspect the message file.
+
+Run `git-p4 submit --help` for details.
+
+p4-prepare-changelist
+~~~~~~~~~~~~~~~~~~~~~
+
+This hook is invoked by `git-p4 submit`.
+
+The `p4-prepare-changelist` hook is executed right after preparing
+the default changelist message and before the editor is started.
+It takes one parameter, the name of the file that contains the
+changelist text. Exiting with a non-zero status from the script
+will abort the process.
+
+The purpose of the hook is to edit the message file in place,
+and it is not supressed by the `--no-verify` option. This hook
+is called even if `--prepare-p4-only` is set.
+
+Run `git-p4 submit --help` for details.
+
+p4-post-changelist
+~~~~~~~~~~~~~~~~~~
+
+This hook is invoked by `git-p4 submit`.
+
+The `p4-post-changelist` hook is invoked after the submit has
+successfully occured in P4. It takes no parameters and is meant
+primarily for notification and cannot affect the outcome of the
+git p4 submit action.
+
+Run `git-p4 submit --help` for details.
+
 p4-pre-submit
 ~~~~~~~~~~~~~
 
 This hook is invoked by `git-p4 submit`. It takes no parameters and nothing
 from standard input. Exiting with non-zero status from this script prevent
-`git-p4 submit` from launching. Run `git-p4 submit --help` for details.
+`git-p4 submit` from launching. It can be bypassed with the `--no-verify`
+command line option. Run `git-p4 submit --help` for details.
+
+
 
 post-index-change
 ~~~~~~~~~~~~~~~~~
diff --git a/Documentation/gitsubmodules.txt b/Documentation/gitsubmodules.txt
index c476f89..f9f4e65 100644
--- a/Documentation/gitsubmodules.txt
+++ b/Documentation/gitsubmodules.txt
@@ -271,7 +271,8 @@
 into submodules. The 'init' and 'update' subcommands of 'git submodule'
 will maintain submodules checked out and at an appropriate revision in
 your working tree. Alternatively you can set 'submodule.recurse' to have
-'checkout' recursing into submodules.
+'checkout' recursing into submodules (note that 'submodule.recurse' also
+affects other git commands, see linkgit:git-config[1] for a complete list).
 
 
 SEE ALSO
diff --git a/Documentation/howto/maintain-git.txt b/Documentation/howto/maintain-git.txt
index ca43787..73be8b4 100644
--- a/Documentation/howto/maintain-git.txt
+++ b/Documentation/howto/maintain-git.txt
@@ -154,15 +154,17 @@
    - Anything unobvious that is applicable to 'master' (in other
      words, does not depend on anything that is still in 'next'
      and not in 'master') is applied to a new topic branch that
-     is forked from the tip of 'master'.  This includes both
+     is forked from the tip of 'master' (or the last feature release,
+     which is a bit older than 'master').  This includes both
      enhancements and unobvious fixes to 'master'.  A topic
      branch is named as ai/topic where "ai" is two-letter string
      named after author's initial and "topic" is a descriptive name
      of the topic (in other words, "what's the series is about").
 
    - An unobvious fix meant for 'maint' is applied to a new
-     topic branch that is forked from the tip of 'maint'.  The
-     topic is named as ai/maint-topic.
+     topic branch that is forked from the tip of 'maint' (or the
+     oldest and still relevant maintenance branch).  The
+     topic may be named as ai/maint-topic.
 
    - Changes that pertain to an existing topic are applied to
      the branch, but:
@@ -174,24 +176,40 @@
    - Replacement patches to an existing topic are accepted only
      for commits not in 'next'.
 
-   The above except the "replacement" are all done with:
+   The initial round is done with:
 
      $ git checkout ai/topic ;# or "git checkout -b ai/topic master"
      $ git am -sc3 mailbox
 
-   while patch replacement is often done by:
+   and replacing an existing topic with subsequent round is done with:
 
-     $ git format-patch ai/topic~$n..ai/topic ;# export existing
+     $ git checkout master...ai/topic ;# try to reapply to the same base
+     $ git am -sc3 mailbox
 
-   then replace some parts with the new patch, and reapplying:
+   to prepare the new round on a detached HEAD, and then
 
-     $ git checkout ai/topic
-     $ git reset --hard ai/topic~$n
-     $ git am -sc3 -s 000*.txt
+     $ git range-diff @{-1}...
+     $ git diff @{-1}
 
-   The full test suite is always run for 'maint' and 'master'
-   after patch application; for topic branches the tests are run
-   as time permits.
+   to double check what changed since the last round, and finally
+
+     $ git checkout -B @{-1}
+
+   to conclude (the last step is why a topic already in 'next' is
+   not replaced but updated incrementally).
+
+   Whether it is the initial round or a subsequent round, the topic
+   may not build even in isolation, or may break the build when
+   merged to integration branches due to bugs.  There may already
+   be obvious and trivial improvements suggested on the list.  The
+   maintainer often adds an extra commit, with "SQUASH???" in its
+   title, to fix things up, before publishing the integration
+   branches to make it usable by other developers for testing.
+   These changes are what the maintainer is not 100% committed to
+   (trivial typofixes etc. are often squashed directly into the
+   patches that need fixing, without being applied as a separate
+   "SQUASH???" commit), so that they can be removed easily as needed.
+
 
  - Merge maint to master as needed:
 
@@ -371,6 +389,14 @@
    be included in the next feature release.  Being in the
    'master' branch typically is.
 
+ * Due to the nature of "SQUASH???" fix-ups, if the original author
+   agrees with the suggested changes, it is OK to squash them to
+   appropriate patches in the next round (when the suggested change
+   is small enough, the author should not even bother with
+   "Helped-by").  It is also OK to drop them from the next round
+   when the original author does not agree with the suggestion, but
+   the author is expected to say why somewhere in the discussion.
+
 
 Appendix
 --------
diff --git a/Documentation/manpage-1.72.xsl b/Documentation/manpage-1.72.xsl
deleted file mode 100644
index b4d315c..0000000
--- a/Documentation/manpage-1.72.xsl
+++ /dev/null
@@ -1,14 +0,0 @@
-<!-- manpage-1.72.xsl:
-     special settings for manpages rendered from asciidoc+docbook
-     handles peculiarities in docbook-xsl 1.72.0 -->
-<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-		version="1.0">
-
-<xsl:import href="manpage-base.xsl"/>
-
-<!-- these are the special values for the roff control characters
-     needed for docbook-xsl 1.72.0 -->
-<xsl:param name="git.docbook.backslash">&#x2593;</xsl:param>
-<xsl:param name="git.docbook.dot"      >&#x2302;</xsl:param>
-
-</xsl:stylesheet>
diff --git a/Documentation/manpage-base.xsl b/Documentation/manpage-base.xsl
deleted file mode 100644
index a264fa6..0000000
--- a/Documentation/manpage-base.xsl
+++ /dev/null
@@ -1,35 +0,0 @@
-<!-- manpage-base.xsl:
-     special formatting for manpages rendered from asciidoc+docbook -->
-<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-		version="1.0">
-
-<!-- these params silence some output from xmlto -->
-<xsl:param name="man.output.quietly" select="1"/>
-<xsl:param name="refentry.meta.get.quietly" select="1"/>
-
-<!-- convert asciidoc callouts to man page format;
-     git.docbook.backslash and git.docbook.dot params
-     must be supplied by another XSL file or other means -->
-<xsl:template match="co">
-	<xsl:value-of select="concat(
-			      $git.docbook.backslash,'fB(',
-			      substring-after(@id,'-'),')',
-			      $git.docbook.backslash,'fR')"/>
-</xsl:template>
-<xsl:template match="calloutlist">
-	<xsl:value-of select="$git.docbook.dot"/>
-	<xsl:text>sp&#10;</xsl:text>
-	<xsl:apply-templates/>
-	<xsl:text>&#10;</xsl:text>
-</xsl:template>
-<xsl:template match="callout">
-	<xsl:value-of select="concat(
-			      $git.docbook.backslash,'fB',
-			      substring-after(@arearefs,'-'),
-			      '. ',$git.docbook.backslash,'fR')"/>
-	<xsl:apply-templates/>
-	<xsl:value-of select="$git.docbook.dot"/>
-	<xsl:text>br&#10;</xsl:text>
-</xsl:template>
-
-</xsl:stylesheet>
diff --git a/Documentation/manpage-bold-literal.xsl b/Documentation/manpage-bold-literal.xsl
index 94d6c1b..e13db85 100644
--- a/Documentation/manpage-bold-literal.xsl
+++ b/Documentation/manpage-bold-literal.xsl
@@ -8,11 +8,9 @@
      this makes literal text easier to distinguish in manpages
      viewed on a tty -->
 <xsl:template match="literal|d:literal">
-	<xsl:value-of select="$git.docbook.backslash"/>
-	<xsl:text>fB</xsl:text>
+	<xsl:text>\fB</xsl:text>
 	<xsl:apply-templates/>
-	<xsl:value-of select="$git.docbook.backslash"/>
-	<xsl:text>fR</xsl:text>
+	<xsl:text>\fR</xsl:text>
 </xsl:template>
 
 </xsl:stylesheet>
diff --git a/Documentation/manpage-normal.xsl b/Documentation/manpage-normal.xsl
index a48f5b1..a9c7ec6 100644
--- a/Documentation/manpage-normal.xsl
+++ b/Documentation/manpage-normal.xsl
@@ -1,13 +1,26 @@
 <!-- manpage-normal.xsl:
-     special settings for manpages rendered from asciidoc+docbook
-     handles anything we want to keep away from docbook-xsl 1.72.0 -->
+     special settings for manpages rendered from asciidoc+docbook -->
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 		version="1.0">
 
-<xsl:import href="manpage-base.xsl"/>
 
-<!-- these are the normal values for the roff control characters -->
-<xsl:param name="git.docbook.backslash">\</xsl:param>
-<xsl:param name="git.docbook.dot"	>.</xsl:param>
+<!-- these params silence some output from xmlto -->
+<xsl:param name="man.output.quietly" select="1"/>
+<xsl:param name="refentry.meta.get.quietly" select="1"/>
+
+<!-- convert asciidoc callouts to man page format -->
+<xsl:template match="co">
+	<xsl:value-of select="concat('\fB(',substring-after(@id,'-'),')\fR')"/>
+</xsl:template>
+<xsl:template match="calloutlist">
+	<xsl:text>.sp&#10;</xsl:text>
+	<xsl:apply-templates/>
+	<xsl:text>&#10;</xsl:text>
+</xsl:template>
+<xsl:template match="callout">
+	<xsl:value-of select="concat('\fB',substring-after(@arearefs,'-'),'. \fR')"/>
+	<xsl:apply-templates/>
+	<xsl:text>.br&#10;</xsl:text>
+</xsl:template>
 
 </xsl:stylesheet>
diff --git a/Documentation/manpage-suppress-sp.xsl b/Documentation/manpage-suppress-sp.xsl
deleted file mode 100644
index a63c763..0000000
--- a/Documentation/manpage-suppress-sp.xsl
+++ /dev/null
@@ -1,21 +0,0 @@
-<!-- manpage-suppress-sp.xsl:
-     special settings for manpages rendered from asciidoc+docbook
-     handles erroneous, inline .sp in manpage output of some
-     versions of docbook-xsl -->
-<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-		version="1.0">
-
-<!-- attempt to work around spurious .sp at the tail of the line
-     that some versions of docbook stylesheets seem to add -->
-<xsl:template match="simpara">
-  <xsl:variable name="content">
-    <xsl:apply-templates/>
-  </xsl:variable>
-  <xsl:value-of select="normalize-space($content)"/>
-  <xsl:if test="not(ancestor::authorblurb) and
-                not(ancestor::personblurb)">
-    <xsl:text>&#10;&#10;</xsl:text>
-  </xsl:if>
-</xsl:template>
-
-</xsl:stylesheet>
diff --git a/Documentation/merge-options.txt b/Documentation/merge-options.txt
index 40dc4f5..80d4831 100644
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@ -61,9 +61,12 @@
 
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
+--no-gpg-sign::
 	GPG-sign the resulting merge commit. The `keyid` argument is
 	optional and defaults to the committer identity; if specified,
-	it must be stuck to the option without a space.
+	it must be stuck to the option without a space. `--no-gpg-sign`
+	is useful to countermand both `commit.gpgSign` configuration variable,
+	and earlier `--gpg-sign`.
 
 --log[=<n>]::
 --no-log::
@@ -157,6 +160,14 @@
 
 endif::git-pull[]
 
+--autostash::
+--no-autostash::
+	Automatically create a temporary stash entry before the operation
+	begins, and apply it after the operation ends.  This means
+	that you can run the operation on a dirty worktree.  However, use
+	with care: the final stash application after a successful
+	merge might result in non-trivial conflicts.
+
 --allow-unrelated-histories::
 	By default, `git merge` command refuses to merge histories
 	that do not share a common ancestor.  This option can be
diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index a4b6f49..547a552 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -83,6 +83,12 @@
 
 	  <full commit message>
 
+* 'mboxrd'
++
+Like 'email', but lines in the commit message starting with "From "
+(preceded by zero or more ">") are quoted with ">" so they aren't
+confused as starting a new commit.
+
 * 'raw'
 +
 The 'raw' format shows the entire commit exactly as
diff --git a/Documentation/pull-fetch-param.txt b/Documentation/pull-fetch-param.txt
index 7d3a60f..95ea849 100644
--- a/Documentation/pull-fetch-param.txt
+++ b/Documentation/pull-fetch-param.txt
@@ -19,7 +19,8 @@
 	(see <<CRTB,CONFIGURED REMOTE-TRACKING BRANCHES>> below).
 endif::git-pull[]
 ifdef::git-pull[]
-	(see linkgit:git-fetch[1]).
+	(see the section "CONFIGURED REMOTE-TRACKING BRANCHES"
+	in linkgit:git-fetch[1]).
 endif::git-pull[]
 +
 The format of a <refspec> parameter is an optional plus
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index bfd02ad..04ad7dd 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -342,6 +342,12 @@
 	branches if the end result is the same (i.e. merging branches
 	with the same content)
 
+--show-pulls::
+	Include all commits from the default mode, but also any merge
+	commits that are not TREESAME to the first parent but are
+	TREESAME to a later parent. This mode is helpful for showing
+	the merge commits that "first introduced" a change to a branch.
+
 --full-history::
 	Same as the default mode, but does not prune some history.
 
@@ -534,7 +540,7 @@
   parent and is TREESAME.
 --
 
-Finally, there is a fifth simplification mode available:
+There is another simplification mode available:
 
 --ancestry-path::
 	Limit the displayed commits to those directly on the ancestry
@@ -573,6 +579,132 @@
 				L--M
 -----------------------------------------------------------------------
 
+Before discussing another option, `--show-pulls`, we need to
+create a new example history.
++
+A common problem users face when looking at simplified history is that a
+commit they know changed a file somehow does not appear in the file's
+simplified history. Let's demonstrate a new example and show how options
+such as `--full-history` and `--simplify-merges` works in that case:
++
+-----------------------------------------------------------------------
+	  .-A---M-----C--N---O---P
+	 /     / \  \  \/   /   /
+	I     B   \  R-'`-Z'   /
+	 \   /     \/         /
+	  \ /      /\        /
+	   `---X--'  `---Y--'
+-----------------------------------------------------------------------
++
+For this example, suppose `I` created `file.txt` which was modified by
+`A`, `B`, and `X` in different ways. The single-parent commits `C`, `Z`,
+and `Y` do not change `file.txt`. The merge commit `M` was created by
+resolving the merge conflict to include both changes from `A` and `B`
+and hence is not TREESAME to either. The merge commit `R`, however, was
+created by ignoring the contents of `file.txt` at `M` and taking only
+the contents of `file.txt` at `X`. Hence, `R` is TREESAME to `X` but not
+`M`. Finally, the natural merge resolution to create `N` is to take the
+contents of `file.txt` at `R`, so `N` is TREESAME to `R` but not `C`.
+The merge commits `O` and `P` are TREESAME to their first parents, but
+not to their second parents, `Z` and `Y` respectively.
++
+When using the default mode, `N` and `R` both have a TREESAME parent, so
+those edges are walked and the others are ignored. The resulting history
+graph is:
++
+-----------------------------------------------------------------------
+	I---X
+-----------------------------------------------------------------------
++
+When using `--full-history`, Git walks every edge. This will discover
+the commits `A` and `B` and the merge `M`, but also will reveal the
+merge commits `O` and `P`. With parent rewriting, the resulting graph is:
++
+-----------------------------------------------------------------------
+	  .-A---M--------N---O---P
+	 /     / \  \  \/   /   /
+	I     B   \  R-'`--'   /
+	 \   /     \/         /
+	  \ /      /\        /
+	   `---X--'  `------'
+-----------------------------------------------------------------------
++
+Here, the merge commits `O` and `P` contribute extra noise, as they did
+not actually contribute a change to `file.txt`. They only merged a topic
+that was based on an older version of `file.txt`. This is a common
+issue in repositories using a workflow where many contributors work in
+parallel and merge their topic branches along a single trunk: manu
+unrelated merges appear in the `--full-history` results.
++
+When using the `--simplify-merges` option, the commits `O` and `P`
+disappear from the results. This is because the rewritten second parents
+of `O` and `P` are reachable from their first parents. Those edges are
+removed and then the commits look like single-parent commits that are
+TREESAME to their parent. This also happens to the commit `N`, resulting
+in a history view as follows:
++
+-----------------------------------------------------------------------
+	  .-A---M--.
+	 /     /    \
+	I     B      R
+	 \   /      /
+	  \ /      /
+	   `---X--'
+-----------------------------------------------------------------------
++
+In this view, we see all of the important single-parent changes from
+`A`, `B`, and `X`. We also see the carefully-resolved merge `M` and the
+not-so-carefully-resolved merge `R`. This is usually enough information
+to determine why the commits `A` and `B` "disappeared" from history in
+the default view. However, there are a few issues with this approach.
++
+The first issue is performance. Unlike any previous option, the
+`--simplify-merges` option requires walking the entire commit history
+before returning a single result. This can make the option difficult to
+use for very large repositories.
++
+The second issue is one of auditing. When many contributors are working
+on the same repository, it is important which merge commits introduced
+a change into an important branch. The problematic merge `R` above is
+not likely to be the merge commit that was used to merge into an
+important branch. Instead, the merge `N` was used to merge `R` and `X`
+into the important branch. This commit may have information about why
+the change `X` came to override the changes from `A` and `B` in its
+commit message.
++
+The `--show-pulls` option helps with both of these issues by adding more
+merge commits to the history results. If a merge is not TREESAME to its
+first parent but is TREESAME to a later parent, then that merge is
+treated as if it "pulled" the change from another branch. When using
+`--show-pulls` on this example (and no other options) the resulting
+graph is:
++
+-----------------------------------------------------------------------
+	I---X---R---N
+-----------------------------------------------------------------------
++
+Here, the merge commits `R` and `N` are included because they pulled
+the commits `X` and `R` into the base branch, respectively. These
+merges are the reason the commits `A` and `B` do not appear in the
+default history.
++
+When `--show-pulls` is paired with `--simplify-merges`, the
+graph includes all of the necessary information:
++
+-----------------------------------------------------------------------
+	  .-A---M--.   N
+	 /     /    \ /
+	I     B      R
+	 \   /      /
+	  \ /      /
+	   `---X--'
+-----------------------------------------------------------------------
++
+Notice that since `M` is reachable from `R`, the edge from `N` to `M`
+was simplified away. However, `N` still appears in the history as an
+important commit because it "pulled" the change `R` into the main
+branch.
+
 The `--simplify-by-decoration` option allows you to view only the
 big picture of the topology of the history, by omitting commits
 that are not referenced by tags.  Commits are marked as !TREESAME
diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
index 97f995e..1ad9506 100644
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@ -233,7 +233,7 @@
 
     A =      = A^0
     B = A^   = A^1     = A~1
-    C = A^2  = A^2
+    C =      = A^2
     D = A^^  = A^1^1   = A~2
     E = B^2  = A^^2
     F = B^3  = A^^3
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 4f07cea..6b60855 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -656,7 +656,8 @@
 ------------
 
 `"def_param"`::
-	This event is generated to log a global parameter.
+	This event is generated to log a global parameter, such as a config
+	setting, command-line flag, or environment variable.
 +
 ------------
 {
diff --git a/Documentation/user-manual.conf b/Documentation/user-manual.conf
index d87294d..0148f12 100644
--- a/Documentation/user-manual.conf
+++ b/Documentation/user-manual.conf
@@ -9,13 +9,3 @@
 
 [linkgit-inlinemacro]
 <ulink url="{target}.html">{target}{0?({0})}</ulink>
-
-ifdef::backend-docbook[]
-# "unbreak" docbook-xsl v1.68 for manpages. v1.69 works with or without this.
-[listingblock]
-<example><title>{title}</title>
-<literallayout class="monospaced">
-|
-</literallayout>
-{title#}</example>
-endif::backend-docbook[]
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 5db483f..21f929e 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.26.0
+DEF_VER=v2.26.GIT
 
 LF='
 '
diff --git a/INSTALL b/INSTALL
index 22c364f..9ba33e6 100644
--- a/INSTALL
+++ b/INSTALL
@@ -206,9 +206,7 @@
    clone two separate git-htmldocs and git-manpages repositories next
    to the clone of git itself.
 
-   It has been reported that docbook-xsl version 1.72 and 1.73 are
-   buggy; 1.72 misformats manual pages for callouts, and 1.73 needs
-   the patch in contrib/patches/docbook-xsl-manpages-charmap.patch
+   The minimum supported version of docbook-xsl is 1.74.
 
    Users attempting to build the documentation on Cygwin may need to ensure
    that the /etc/xml/catalog file looks something like this:
diff --git a/Makefile b/Makefile
index 9804a07..2cf7d8b 100644
--- a/Makefile
+++ b/Makefile
@@ -282,12 +282,6 @@
 # Define NO_ST_BLOCKS_IN_STRUCT_STAT if your platform does not have st_blocks
 # field that counts the on-disk footprint in 512-byte blocks.
 #
-# Define DOCBOOK_XSL_172 if you want to format man pages with DocBook XSL v1.72
-# (not v1.73 or v1.71).
-#
-# Define ASCIIDOC_ROFF if your DocBook XSL does not escape raw roff directives
-# (versions 1.68.1 through v1.72).
-#
 # Define GNU_ROFF if your target system uses GNU groff.  This forces
 # apostrophes to be ASCII so that cut&pasting examples to the shell
 # will work.
@@ -609,7 +603,6 @@
 SCRIPT_SH += git-merge-resolve.sh
 SCRIPT_SH += git-mergetool.sh
 SCRIPT_SH += git-quiltimport.sh
-SCRIPT_SH += git-legacy-stash.sh
 SCRIPT_SH += git-request-pull.sh
 SCRIPT_SH += git-submodule.sh
 SCRIPT_SH += git-web--browse.sh
@@ -617,8 +610,8 @@
 SCRIPT_LIB += git-mergetool--lib
 SCRIPT_LIB += git-parse-remote
 SCRIPT_LIB += git-rebase--preserve-merges
-SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
+SCRIPT_LIB += git-sh-setup
 
 SCRIPT_PERL += git-add--interactive.perl
 SCRIPT_PERL += git-archimport.perl
@@ -686,15 +679,16 @@
 PROGRAM_OBJS += fast-import.o
 PROGRAM_OBJS += http-backend.o
 PROGRAM_OBJS += imap-send.o
+PROGRAM_OBJS += remote-testsvn.o
 PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
-PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
 X =
 
 PROGRAMS += $(patsubst %.o,git-%$X,$(PROGRAM_OBJS))
 
+TEST_BUILTINS_OBJS += test-advise.o
 TEST_BUILTINS_OBJS += test-chmtime.o
 TEST_BUILTINS_OBJS += test-config.o
 TEST_BUILTINS_OBJS += test-ctype.o
@@ -709,15 +703,16 @@
 TEST_BUILTINS_OBJS += test-example-decorate.o
 TEST_BUILTINS_OBJS += test-genrandom.o
 TEST_BUILTINS_OBJS += test-genzeros.o
+TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-hash.o
 TEST_BUILTINS_OBJS += test-hashmap.o
-TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-index-version.o
 TEST_BUILTINS_OBJS += test-json-writer.o
 TEST_BUILTINS_OBJS += test-lazy-init-name-hash.o
 TEST_BUILTINS_OBJS += test-match-trees.o
 TEST_BUILTINS_OBJS += test-mergesort.o
 TEST_BUILTINS_OBJS += test-mktemp.o
+TEST_BUILTINS_OBJS += test-oid-array.o
 TEST_BUILTINS_OBJS += test-oidmap.o
 TEST_BUILTINS_OBJS += test-online-cpus.o
 TEST_BUILTINS_OBJS += test-parse-options.o
@@ -738,7 +733,6 @@
 TEST_BUILTINS_OBJS += test-scrap-cache-tree.o
 TEST_BUILTINS_OBJS += test-serve-v2.o
 TEST_BUILTINS_OBJS += test-sha1.o
-TEST_BUILTINS_OBJS += test-sha1-array.o
 TEST_BUILTINS_OBJS += test-sha256.o
 TEST_BUILTINS_OBJS += test-sigchain.o
 TEST_BUILTINS_OBJS += test-strcmp-offset.o
@@ -748,10 +742,10 @@
 TEST_BUILTINS_OBJS += test-subprocess.o
 TEST_BUILTINS_OBJS += test-trace2.o
 TEST_BUILTINS_OBJS += test-urlmatch-normalization.o
-TEST_BUILTINS_OBJS += test-xml-encode.o
 TEST_BUILTINS_OBJS += test-wildmatch.o
 TEST_BUILTINS_OBJS += test-windows-named-pipe.o
 TEST_BUILTINS_OBJS += test-write-cache.o
+TEST_BUILTINS_OBJS += test-xml-encode.o
 
 # Do not add more tests here unless they have extra dependencies. Add
 # them in TEST_BUILTINS_OBJS above.
@@ -788,10 +782,10 @@
 
 # what test wrappers are needed and 'install' will install, in bindir
 BINDIR_PROGRAMS_NEED_X += git
-BINDIR_PROGRAMS_NEED_X += git-upload-pack
 BINDIR_PROGRAMS_NEED_X += git-receive-pack
-BINDIR_PROGRAMS_NEED_X += git-upload-archive
 BINDIR_PROGRAMS_NEED_X += git-shell
+BINDIR_PROGRAMS_NEED_X += git-upload-archive
+BINDIR_PROGRAMS_NEED_X += git-upload-pack
 
 BINDIR_PROGRAMS_NO_X += git-cvsserver
 
@@ -831,9 +825,9 @@
 LIB_OBJS += alias.o
 LIB_OBJS += alloc.o
 LIB_OBJS += apply.o
-LIB_OBJS += archive.o
 LIB_OBJS += archive-tar.o
 LIB_OBJS += archive-zip.o
+LIB_OBJS += archive.o
 LIB_OBJS += argv-array.o
 LIB_OBJS += attr.o
 LIB_OBJS += base85.o
@@ -849,9 +843,9 @@
 LIB_OBJS += color.o
 LIB_OBJS += column.o
 LIB_OBJS += combine-diff.o
-LIB_OBJS += commit.o
 LIB_OBJS += commit-graph.o
 LIB_OBJS += commit-reach.o
+LIB_OBJS += commit.o
 LIB_OBJS += compat/obstack.o
 LIB_OBJS += compat/terminal.o
 LIB_OBJS += config.o
@@ -865,17 +859,17 @@
 LIB_OBJS += date.o
 LIB_OBJS += decorate.o
 LIB_OBJS += delta-islands.o
+LIB_OBJS += diff-delta.o
+LIB_OBJS += diff-lib.o
+LIB_OBJS += diff-no-index.o
+LIB_OBJS += diff.o
 LIB_OBJS += diffcore-break.o
 LIB_OBJS += diffcore-delta.o
 LIB_OBJS += diffcore-order.o
 LIB_OBJS += diffcore-pickaxe.o
 LIB_OBJS += diffcore-rename.o
-LIB_OBJS += diff-delta.o
-LIB_OBJS += diff-lib.o
-LIB_OBJS += diff-no-index.o
-LIB_OBJS += diff.o
-LIB_OBJS += dir.o
 LIB_OBJS += dir-iterator.o
+LIB_OBJS += dir.o
 LIB_OBJS += editor.o
 LIB_OBJS += entry.o
 LIB_OBJS += environment.o
@@ -886,6 +880,7 @@
 LIB_OBJS += exec-cmd.o
 LIB_OBJS += fetch-negotiator.o
 LIB_OBJS += fetch-pack.o
+LIB_OBJS += fmt-merge-msg.o
 LIB_OBJS += fsck.o
 LIB_OBJS += fsmonitor.o
 LIB_OBJS += gettext.o
@@ -893,7 +888,6 @@
 LIB_OBJS += graph.o
 LIB_OBJS += grep.o
 LIB_OBJS += hashmap.o
-LIB_OBJS += linear-assignment.o
 LIB_OBJS += help.o
 LIB_OBJS += hex.o
 LIB_OBJS += ident.o
@@ -903,9 +897,10 @@
 LIB_OBJS += levenshtein.o
 LIB_OBJS += line-log.o
 LIB_OBJS += line-range.o
-LIB_OBJS += list-objects.o
-LIB_OBJS += list-objects-filter.o
+LIB_OBJS += linear-assignment.o
 LIB_OBJS += list-objects-filter-options.o
+LIB_OBJS += list-objects-filter.o
+LIB_OBJS += list-objects.o
 LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
@@ -914,31 +909,32 @@
 LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
 LIB_OBJS += mem-pool.o
-LIB_OBJS += merge.o
 LIB_OBJS += merge-blobs.o
 LIB_OBJS += merge-recursive.o
+LIB_OBJS += merge.o
 LIB_OBJS += mergesort.o
 LIB_OBJS += midx.o
 LIB_OBJS += name-hash.o
 LIB_OBJS += negotiator/default.o
 LIB_OBJS += negotiator/skipping.o
-LIB_OBJS += notes.o
 LIB_OBJS += notes-cache.o
 LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
+LIB_OBJS += notes.o
 LIB_OBJS += object.o
+LIB_OBJS += oid-array.o
 LIB_OBJS += oidmap.o
 LIB_OBJS += oidset.o
-LIB_OBJS += packfile.o
-LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-bitmap-write.o
+LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-check.o
 LIB_OBJS += pack-objects.o
 LIB_OBJS += pack-revindex.o
 LIB_OBJS += pack-write.o
+LIB_OBJS += packfile.o
 LIB_OBJS += pager.o
-LIB_OBJS += parse-options.o
 LIB_OBJS += parse-options-cb.o
+LIB_OBJS += parse-options.o
 LIB_OBJS += patch-delta.o
 LIB_OBJS += patch-ids.o
 LIB_OBJS += path.o
@@ -951,12 +947,14 @@
 LIB_OBJS += promisor-remote.o
 LIB_OBJS += prompt.o
 LIB_OBJS += protocol.o
+LIB_OBJS += prune-packed.o
 LIB_OBJS += quote.o
 LIB_OBJS += range-diff.o
 LIB_OBJS += reachable.o
 LIB_OBJS += read-cache.o
-LIB_OBJS += rebase.o
 LIB_OBJS += rebase-interactive.o
+LIB_OBJS += rebase.o
+LIB_OBJS += ref-filter.o
 LIB_OBJS += reflog-walk.o
 LIB_OBJS += refs.o
 LIB_OBJS += refs/files-backend.o
@@ -964,12 +962,12 @@
 LIB_OBJS += refs/packed-backend.o
 LIB_OBJS += refs/ref-cache.o
 LIB_OBJS += refspec.o
-LIB_OBJS += ref-filter.o
 LIB_OBJS += remote.o
 LIB_OBJS += replace-object.o
 LIB_OBJS += repo-settings.o
 LIB_OBJS += repository.o
 LIB_OBJS += rerere.o
+LIB_OBJS += reset.o
 LIB_OBJS += resolve-undo.o
 LIB_OBJS += revision.o
 LIB_OBJS += run-command.o
@@ -978,9 +976,8 @@
 LIB_OBJS += serve.o
 LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
-LIB_OBJS += sha1-array.o
-LIB_OBJS += sha1-lookup.o
 LIB_OBJS += sha1-file.o
+LIB_OBJS += sha1-lookup.o
 LIB_OBJS += sha1-name.o
 LIB_OBJS += shallow.o
 LIB_OBJS += sideband.o
@@ -990,9 +987,9 @@
 LIB_OBJS += strbuf.o
 LIB_OBJS += streaming.o
 LIB_OBJS += string-list.o
-LIB_OBJS += submodule.o
-LIB_OBJS += submodule-config.o
 LIB_OBJS += sub-process.o
+LIB_OBJS += submodule-config.o
+LIB_OBJS += submodule.o
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += tempfile.o
@@ -1011,11 +1008,11 @@
 LIB_OBJS += trace2/tr2_tgt_perf.o
 LIB_OBJS += trace2/tr2_tls.o
 LIB_OBJS += trailer.o
-LIB_OBJS += transport.o
 LIB_OBJS += transport-helper.o
+LIB_OBJS += transport.o
 LIB_OBJS += tree-diff.o
-LIB_OBJS += tree.o
 LIB_OBJS += tree-walk.o
+LIB_OBJS += tree.o
 LIB_OBJS += unpack-trees.o
 LIB_OBJS += upload-pack.o
 LIB_OBJS += url.o
@@ -1055,9 +1052,9 @@
 BUILTIN_OBJS += builtin/clean.o
 BUILTIN_OBJS += builtin/clone.o
 BUILTIN_OBJS += builtin/column.o
+BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/commit-tree.o
 BUILTIN_OBJS += builtin/commit.o
-BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/config.o
 BUILTIN_OBJS += builtin/count-objects.o
 BUILTIN_OBJS += builtin/credential.o
@@ -1088,13 +1085,13 @@
 BUILTIN_OBJS += builtin/ls-tree.o
 BUILTIN_OBJS += builtin/mailinfo.o
 BUILTIN_OBJS += builtin/mailsplit.o
-BUILTIN_OBJS += builtin/merge.o
 BUILTIN_OBJS += builtin/merge-base.o
 BUILTIN_OBJS += builtin/merge-file.o
 BUILTIN_OBJS += builtin/merge-index.o
 BUILTIN_OBJS += builtin/merge-ours.o
 BUILTIN_OBJS += builtin/merge-recursive.o
 BUILTIN_OBJS += builtin/merge-tree.o
+BUILTIN_OBJS += builtin/merge.o
 BUILTIN_OBJS += builtin/mktag.o
 BUILTIN_OBJS += builtin/mktree.o
 BUILTIN_OBJS += builtin/multi-pack-index.o
@@ -1114,9 +1111,9 @@
 BUILTIN_OBJS += builtin/rebase.o
 BUILTIN_OBJS += builtin/receive-pack.o
 BUILTIN_OBJS += builtin/reflog.o
-BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/remote-ext.o
 BUILTIN_OBJS += builtin/remote-fd.o
+BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/repack.o
 BUILTIN_OBJS += builtin/replace.o
 BUILTIN_OBJS += builtin/rerere.o
@@ -1358,17 +1355,22 @@
 else
 	ifdef CURLDIR
 		# Try "-Wl,-rpath=$(CURLDIR)/$(lib)" in such a case.
-		BASIC_CFLAGS += -I$(CURLDIR)/include
+		CURL_CFLAGS = -I$(CURLDIR)/include
 		CURL_LIBCURL = -L$(CURLDIR)/$(lib) $(CC_LD_DYNPATH)$(CURLDIR)/$(lib)
 	else
+		CURL_CFLAGS =
 		CURL_LIBCURL =
 	endif
 
-ifdef CURL_LDFLAGS
+	ifndef CURL_LDFLAGS
+		CURL_LDFLAGS = $(eval CURL_LDFLAGS := $$(shell $$(CURL_CONFIG) --libs))$(CURL_LDFLAGS)
+	endif
 	CURL_LIBCURL += $(CURL_LDFLAGS)
-else
-	CURL_LIBCURL += $(shell $(CURL_CONFIG) --libs)
-endif
+
+	ifndef CURL_CFLAGS
+		CURL_CFLAGS = $(eval CURL_CFLAGS := $$(shell $$(CURL_CONFIG) --cflags))$(CURL_CFLAGS)
+	endif
+	BASIC_CFLAGS += $(CURL_CFLAGS)
 
 	REMOTE_CURL_PRIMARY = git-remote-http$X
 	REMOTE_CURL_ALIASES = git-remote-https$X git-remote-ftp$X git-remote-ftps$X
@@ -2335,16 +2337,16 @@
 endif
 
 XDIFF_OBJS += xdiff/xdiffi.o
-XDIFF_OBJS += xdiff/xprepare.o
-XDIFF_OBJS += xdiff/xutils.o
 XDIFF_OBJS += xdiff/xemit.o
+XDIFF_OBJS += xdiff/xhistogram.o
 XDIFF_OBJS += xdiff/xmerge.o
 XDIFF_OBJS += xdiff/xpatience.o
-XDIFF_OBJS += xdiff/xhistogram.o
+XDIFF_OBJS += xdiff/xprepare.o
+XDIFF_OBJS += xdiff/xutils.o
 
+VCSSVN_OBJS += vcs-svn/fast_export.o
 VCSSVN_OBJS += vcs-svn/line_buffer.o
 VCSSVN_OBJS += vcs-svn/sliding_window.o
-VCSSVN_OBJS += vcs-svn/fast_export.o
 VCSSVN_OBJS += vcs-svn/svndiff.o
 VCSSVN_OBJS += vcs-svn/svndump.o
 
@@ -3152,9 +3154,10 @@
 #
 ALL_COMMANDS = $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS)
 ALL_COMMANDS += git
+ALL_COMMANDS += git-citool
+ALL_COMMANDS += git-gui
 ALL_COMMANDS += gitk
 ALL_COMMANDS += gitweb
-ALL_COMMANDS += git-gui git-citool
 
 .PHONY: check-docs
 check-docs::
diff --git a/README.md b/README.md
index 9d4564c..eb8115e 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-[![Build Status](https://dev.azure.com/git/git/_apis/build/status/git.git)](https://dev.azure.com/git/git/_build/latest?definitionId=11)
+[![Build status](https://github.com/git/git/workflows/CI/PR/badge.svg)](https://github.com/git/git/actions?query=branch%3Amaster+event%3Apush)
 
 Git - fast, scalable, distributed revision control system
 =========================================================
diff --git a/RelNotes b/RelNotes
index 370269d..f3d8527 120000
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/2.26.0.txt
\ No newline at end of file
+Documentation/RelNotes/2.27.0.txt
\ No newline at end of file
diff --git a/abspath.c b/abspath.c
index 9857985..6f15a41 100644
--- a/abspath.c
+++ b/abspath.c
@@ -202,22 +202,6 @@ char *strbuf_realpath(struct strbuf *resolved, const char *path,
 	return retval;
 }
 
-/*
- * Resolve `path` into an absolute, cleaned-up path. The return value
- * comes from a shared buffer.
- */
-const char *real_path(const char *path)
-{
-	static struct strbuf realpath = STRBUF_INIT;
-	return strbuf_realpath(&realpath, path, 1);
-}
-
-const char *real_path_if_valid(const char *path)
-{
-	static struct strbuf realpath = STRBUF_INIT;
-	return strbuf_realpath(&realpath, path, 0);
-}
-
 char *real_pathdup(const char *path, int die_on_error)
 {
 	struct strbuf realpath = STRBUF_INIT;
@@ -233,7 +217,7 @@ char *real_pathdup(const char *path, int die_on_error)
 
 /*
  * Use this to get an absolute path from a relative one. If you want
- * to resolve links, you should use real_path.
+ * to resolve links, you should use strbuf_realpath.
  */
 const char *absolute_path(const char *path)
 {
diff --git a/add-interactive.c b/add-interactive.c
index 4a9bf85..29cd2fe 100644
--- a/add-interactive.c
+++ b/add-interactive.c
@@ -9,6 +9,7 @@
 #include "lockfile.h"
 #include "dir.h"
 #include "run-command.h"
+#include "prompt.h"
 
 static void init_color(struct repository *r, struct add_i_state *s,
 		       const char *slot_name, char *dst,
@@ -289,13 +290,12 @@ static ssize_t list_and_choose(struct add_i_state *s,
 		fputs(singleton ? "> " : ">> ", stdout);
 		fflush(stdout);
 
-		if (strbuf_getline(&input, stdin) == EOF) {
+		if (git_read_line_interactively(&input) == EOF) {
 			putchar('\n');
 			if (immediate)
 				res = LIST_AND_CHOOSE_QUIT;
 			break;
 		}
-		strbuf_trim(&input);
 
 		if (!input.len)
 			break;
diff --git a/add-patch.c b/add-patch.c
index d8dafa8..d8bfe37 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -7,6 +7,7 @@
 #include "color.h"
 #include "diff.h"
 #include "compat/terminal.h"
+#include "prompt.h"
 
 enum prompt_mode_type {
 	PROMPT_MODE_CHANGE = 0, PROMPT_DELETION, PROMPT_HUNK,
@@ -1158,9 +1159,8 @@ static int read_single_character(struct add_p_state *s)
 		return res;
 	}
 
-	if (strbuf_getline(&s->answer, stdin) == EOF)
+	if (git_read_line_interactively(&s->answer) == EOF)
 		return EOF;
-	strbuf_trim_trailing_newline(&s->answer);
 	return 0;
 }
 
diff --git a/advice.c b/advice.c
index 97f3f98..f0a3d32 100644
--- a/advice.c
+++ b/advice.c
@@ -29,7 +29,6 @@ int advice_ignored_hook = 1;
 int advice_waiting_for_editor = 1;
 int advice_graft_file_deprecated = 1;
 int advice_checkout_ambiguous_remote_branch_name = 1;
-int advice_nested_tag = 1;
 int advice_submodule_alternate_error_strategy_die = 1;
 int advice_add_ignored_file = 1;
 int advice_add_empty_pathspec = 1;
@@ -82,7 +81,7 @@ static struct {
 	{ "sequencerInUse", &advice_sequencer_in_use },
 	{ "implicitIdentity", &advice_implicit_identity },
 	{ "detachedHead", &advice_detached_head },
-	{ "setupStreamFailure", &advice_set_upstream_failure },
+	{ "setUpstreamFailure", &advice_set_upstream_failure },
 	{ "objectNameWarning", &advice_object_name_warning },
 	{ "amWorkDir", &advice_amworkdir },
 	{ "rmHints", &advice_rm_hints },
@@ -91,7 +90,6 @@ static struct {
 	{ "waitingForEditor", &advice_waiting_for_editor },
 	{ "graftFileDeprecated", &advice_graft_file_deprecated },
 	{ "checkoutAmbiguousRemoteBranchName", &advice_checkout_ambiguous_remote_branch_name },
-	{ "nestedTag", &advice_nested_tag },
 	{ "submoduleAlternateErrorStrategyDie", &advice_submodule_alternate_error_strategy_die },
 	{ "addIgnoredFile", &advice_add_ignored_file },
 	{ "addEmptyPathspec", &advice_add_empty_pathspec },
@@ -100,15 +98,58 @@ static struct {
 	{ "pushNonFastForward", &advice_push_update_rejected }
 };
 
-void advise(const char *advice, ...)
+static struct {
+	const char *key;
+	int enabled;
+} advice_setting[] = {
+	[ADVICE_ADD_EMBEDDED_REPO]			= { "addEmbeddedRepo", 1 },
+	[ADVICE_AM_WORK_DIR] 				= { "amWorkDir", 1 },
+	[ADVICE_CHECKOUT_AMBIGUOUS_REMOTE_BRANCH_NAME] 	= { "checkoutAmbiguousRemoteBranchName", 1 },
+	[ADVICE_COMMIT_BEFORE_MERGE]			= { "commitBeforeMerge", 1 },
+	[ADVICE_DETACHED_HEAD]				= { "detachedHead", 1 },
+	[ADVICE_FETCH_SHOW_FORCED_UPDATES]		= { "fetchShowForcedUpdates", 1 },
+	[ADVICE_GRAFT_FILE_DEPRECATED]			= { "graftFileDeprecated", 1 },
+	[ADVICE_IGNORED_HOOK]				= { "ignoredHook", 1 },
+	[ADVICE_IMPLICIT_IDENTITY]			= { "implicitIdentity", 1 },
+	[ADVICE_NESTED_TAG]				= { "nestedTag", 1 },
+	[ADVICE_OBJECT_NAME_WARNING]			= { "objectNameWarning", 1 },
+	[ADVICE_PUSH_ALREADY_EXISTS]			= { "pushAlreadyExists", 1 },
+	[ADVICE_PUSH_FETCH_FIRST]			= { "pushFetchFirst", 1 },
+	[ADVICE_PUSH_NEEDS_FORCE]			= { "pushNeedsForce", 1 },
+
+	/* make this an alias for backward compatibility */
+	[ADVICE_PUSH_UPDATE_REJECTED_ALIAS]		= { "pushNonFastForward", 1 },
+
+	[ADVICE_PUSH_NON_FF_CURRENT]			= { "pushNonFFCurrent", 1 },
+	[ADVICE_PUSH_NON_FF_MATCHING]			= { "pushNonFFMatching", 1 },
+	[ADVICE_PUSH_UNQUALIFIED_REF_NAME]		= { "pushUnqualifiedRefName", 1 },
+	[ADVICE_PUSH_UPDATE_REJECTED]			= { "pushUpdateRejected", 1 },
+	[ADVICE_RESET_QUIET_WARNING]			= { "resetQuiet", 1 },
+	[ADVICE_RESOLVE_CONFLICT]			= { "resolveConflict", 1 },
+	[ADVICE_RM_HINTS]				= { "rmHints", 1 },
+	[ADVICE_SEQUENCER_IN_USE]			= { "sequencerInUse", 1 },
+	[ADVICE_SET_UPSTREAM_FAILURE]			= { "setUpstreamFailure", 1 },
+	[ADVICE_STATUS_AHEAD_BEHIND_WARNING]		= { "statusAheadBehindWarning", 1 },
+	[ADVICE_STATUS_HINTS]				= { "statusHints", 1 },
+	[ADVICE_STATUS_U_OPTION]			= { "statusUoption", 1 },
+	[ADVICE_SUBMODULE_ALTERNATE_ERROR_STRATEGY_DIE] = { "submoduleAlternateErrorStrategyDie", 1 },
+	[ADVICE_WAITING_FOR_EDITOR]			= { "waitingForEditor", 1 },
+};
+
+static const char turn_off_instructions[] =
+N_("\n"
+   "Disable this message with \"git config advice.%s false\"");
+
+static void vadvise(const char *advice, int display_instructions,
+		    const char *key, va_list params)
 {
 	struct strbuf buf = STRBUF_INIT;
-	va_list params;
 	const char *cp, *np;
 
-	va_start(params, advice);
 	strbuf_vaddf(&buf, advice, params);
-	va_end(params);
+
+	if (display_instructions)
+		strbuf_addf(&buf, turn_off_instructions, key);
 
 	for (cp = buf.buf; *cp; cp = np) {
 		np = strchrnul(cp, '\n');
@@ -122,6 +163,37 @@ void advise(const char *advice, ...)
 	strbuf_release(&buf);
 }
 
+void advise(const char *advice, ...)
+{
+	va_list params;
+	va_start(params, advice);
+	vadvise(advice, 0, "", params);
+	va_end(params);
+}
+
+int advice_enabled(enum advice_type type)
+{
+	switch(type) {
+	case ADVICE_PUSH_UPDATE_REJECTED:
+		return advice_setting[ADVICE_PUSH_UPDATE_REJECTED].enabled &&
+		       advice_setting[ADVICE_PUSH_UPDATE_REJECTED_ALIAS].enabled;
+	default:
+		return advice_setting[type].enabled;
+	}
+}
+
+void advise_if_enabled(enum advice_type type, const char *advice, ...)
+{
+	va_list params;
+
+	if (!advice_enabled(type))
+		return;
+
+	va_start(params, advice);
+	vadvise(advice, 1, advice_setting[type].key, params);
+	va_end(params);
+}
+
 int git_default_advice_config(const char *var, const char *value)
 {
 	const char *k, *slot_name;
@@ -148,6 +220,13 @@ int git_default_advice_config(const char *var, const char *value)
 		if (strcasecmp(k, advice_config[i].name))
 			continue;
 		*advice_config[i].preference = git_config_bool(var, value);
+		break;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(advice_setting); i++) {
+		if (strcasecmp(k, advice_setting[i].key))
+			continue;
+		advice_setting[i].enabled = git_config_bool(var, value);
 		return 0;
 	}
 
@@ -158,8 +237,8 @@ void list_config_advices(struct string_list *list, const char *prefix)
 {
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(advice_config); i++)
-		list_config_item(list, prefix, advice_config[i].name);
+	for (i = 0; i < ARRAY_SIZE(advice_setting); i++)
+		list_config_item(list, prefix, advice_setting[i].key);
 }
 
 int error_resolve_conflict(const char *me)
diff --git a/advice.h b/advice.h
index 0e6e58d..16f2c11 100644
--- a/advice.h
+++ b/advice.h
@@ -29,14 +29,64 @@ extern int advice_ignored_hook;
 extern int advice_waiting_for_editor;
 extern int advice_graft_file_deprecated;
 extern int advice_checkout_ambiguous_remote_branch_name;
-extern int advice_nested_tag;
 extern int advice_submodule_alternate_error_strategy_die;
 extern int advice_add_ignored_file;
 extern int advice_add_empty_pathspec;
 
+/*
+ * To add a new advice, you need to:
+ * Define a new advice_type.
+ * Add a new entry to advice_setting array.
+ * Add the new config variable to Documentation/config/advice.txt.
+ * Call advise_if_enabled to print your advice.
+ */
+ enum advice_type {
+	ADVICE_ADD_EMBEDDED_REPO,
+	ADVICE_AM_WORK_DIR,
+	ADVICE_CHECKOUT_AMBIGUOUS_REMOTE_BRANCH_NAME,
+	ADVICE_COMMIT_BEFORE_MERGE,
+	ADVICE_DETACHED_HEAD,
+	ADVICE_FETCH_SHOW_FORCED_UPDATES,
+	ADVICE_GRAFT_FILE_DEPRECATED,
+	ADVICE_IGNORED_HOOK,
+	ADVICE_IMPLICIT_IDENTITY,
+	ADVICE_NESTED_TAG,
+	ADVICE_OBJECT_NAME_WARNING,
+	ADVICE_PUSH_ALREADY_EXISTS,
+	ADVICE_PUSH_FETCH_FIRST,
+	ADVICE_PUSH_NEEDS_FORCE,
+	ADVICE_PUSH_NON_FF_CURRENT,
+	ADVICE_PUSH_NON_FF_MATCHING,
+	ADVICE_PUSH_UNQUALIFIED_REF_NAME,
+	ADVICE_PUSH_UPDATE_REJECTED_ALIAS,
+	ADVICE_PUSH_UPDATE_REJECTED,
+	ADVICE_RESET_QUIET_WARNING,
+	ADVICE_RESOLVE_CONFLICT,
+	ADVICE_RM_HINTS,
+	ADVICE_SEQUENCER_IN_USE,
+	ADVICE_SET_UPSTREAM_FAILURE,
+	ADVICE_STATUS_AHEAD_BEHIND_WARNING,
+	ADVICE_STATUS_HINTS,
+	ADVICE_STATUS_U_OPTION,
+	ADVICE_SUBMODULE_ALTERNATE_ERROR_STRATEGY_DIE,
+	ADVICE_WAITING_FOR_EDITOR,
+};
+
 int git_default_advice_config(const char *var, const char *value);
 __attribute__((format (printf, 1, 2)))
 void advise(const char *advice, ...);
+
+/**
+ * Checks if advice type is enabled (can be printed to the user).
+ * Should be called before advise().
+ */
+int advice_enabled(enum advice_type type);
+
+/**
+ * Checks the visibility of the advice before printing.
+ */
+void advise_if_enabled(enum advice_type type, const char *advice, ...);
+
 int error_resolve_conflict(const char *me);
 void NORETURN die_resolve_conflict(const char *me);
 void NORETURN die_conclude_merge(void);
diff --git a/apply.c b/apply.c
index bdc008f..144c19a 100644
--- a/apply.c
+++ b/apply.c
@@ -4349,7 +4349,7 @@ static int try_create_file(struct apply_state *state, const char *path,
 	if (fd < 0)
 		return 1;
 
-	if (convert_to_working_tree(state->repo->index, path, buf, size, &nbuf)) {
+	if (convert_to_working_tree(state->repo->index, path, buf, size, &nbuf, NULL)) {
 		size = nbuf.len;
 		buf  = nbuf.buf;
 	}
diff --git a/archive-tar.c b/archive-tar.c
index 5a77701..5ceec36 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -364,7 +364,7 @@ static struct archiver **tar_filters;
 static int nr_tar_filters;
 static int alloc_tar_filters;
 
-static struct archiver *find_tar_filter(const char *name, int len)
+static struct archiver *find_tar_filter(const char *name, size_t len)
 {
 	int i;
 	for (i = 0; i < nr_tar_filters; i++) {
@@ -380,7 +380,7 @@ static int tar_filter_config(const char *var, const char *value, void *data)
 	struct archiver *ar;
 	const char *name;
 	const char *type;
-	int namelen;
+	size_t namelen;
 
 	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
 		return 0;
diff --git a/archive.c b/archive.c
index a8da0fc..fb39706 100644
--- a/archive.c
+++ b/archive.c
@@ -77,6 +77,11 @@ void *object_file_to_archive(const struct archiver_args *args,
 {
 	void *buffer;
 	const struct commit *commit = args->convert ? args->commit : NULL;
+	struct checkout_metadata meta;
+
+	init_checkout_metadata(&meta, args->refname,
+			       args->commit_oid ? args->commit_oid :
+			       (args->tree ? &args->tree->object.oid : NULL), oid);
 
 	path += args->baselen;
 	buffer = read_object_file(oid, type, sizep);
@@ -85,7 +90,7 @@ void *object_file_to_archive(const struct archiver_args *args,
 		size_t size = 0;
 
 		strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
-		convert_to_working_tree(args->repo->index, path, buf.buf, buf.len, &buf);
+		convert_to_working_tree(args->repo->index, path, buf.buf, buf.len, &buf, &meta);
 		if (commit)
 			format_subst(commit, buf.buf, buf.len, &buf);
 		buffer = strbuf_detach(&buf, &size);
@@ -385,16 +390,17 @@ static void parse_treeish_arg(const char **argv,
 	struct tree *tree;
 	const struct commit *commit;
 	struct object_id oid;
+	char *ref = NULL;
 
 	/* Remotes are only allowed to fetch actual refs */
 	if (remote && !remote_allow_unreachable) {
-		char *ref = NULL;
 		const char *colon = strchrnul(name, ':');
 		int refnamelen = colon - name;
 
 		if (!dwim_ref(name, refnamelen, &oid, &ref))
 			die(_("no such ref: %.*s"), refnamelen, name);
-		free(ref);
+	} else {
+		dwim_ref(name, strlen(name), &oid, &ref);
 	}
 
 	if (get_oid(name, &oid))
@@ -427,6 +433,7 @@ static void parse_treeish_arg(const char **argv,
 
 		tree = parse_tree_indirect(&tree_oid);
 	}
+	ar_args->refname = ref;
 	ar_args->tree = tree;
 	ar_args->commit_oid = commit_oid;
 	ar_args->commit = commit;
diff --git a/archive.h b/archive.h
index e60e3dd..3bd96bf 100644
--- a/archive.h
+++ b/archive.h
@@ -8,6 +8,7 @@ struct repository;
 
 struct archiver_args {
 	struct repository *repo;
+	const char *refname;
 	const char *base;
 	size_t baselen;
 	struct tree *tree;
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
deleted file mode 100644
index 675c3a4..0000000
--- a/azure-pipelines.yml
+++ /dev/null
@@ -1,558 +0,0 @@
-variables:
-  Agent.Source.Git.ShallowFetchDepth: 1
-
-jobs:
-- job: windows_build
-  displayName: Windows Build
-  condition: succeeded()
-  pool:
-    vmImage: windows-latest
-  timeoutInMinutes: 240
-  steps:
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        net use s: \\gitfileshare.file.core.windows.net\test-cache "$GITFILESHAREPWD" /user:AZURE\gitfileshare /persistent:no
-        cmd /c mklink /d "$(Build.SourcesDirectory)\test-cache" S:\
-      }
-    displayName: 'Mount test-cache'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - powershell: |
-      $urlbase = "https://dev.azure.com/git-for-windows/git/_apis/build/builds"
-      $id = ((Invoke-WebRequest -UseBasicParsing "${urlbase}?definitions=22&statusFilter=completed&resultFilter=succeeded&`$top=1").content | ConvertFrom-JSON).value[0].id
-      $downloadUrl = ((Invoke-WebRequest -UseBasicParsing "${urlbase}/$id/artifacts").content | ConvertFrom-JSON).value[1].resource.downloadUrl
-      (New-Object Net.WebClient).DownloadFile($downloadUrl,"git-sdk-64-minimal.zip")
-      Expand-Archive git-sdk-64-minimal.zip -DestinationPath . -Force
-      Remove-Item git-sdk-64-minimal.zip
-
-      # Let Git ignore the SDK and the test-cache
-      "/git-sdk-64-minimal/`n/test-cache/`n" | Out-File -NoNewLine -Encoding ascii -Append "$(Build.SourcesDirectory)\.git\info\exclude"
-    displayName: 'Download git-sdk-64-minimal'
-  - powershell: |
-      & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
-        ci/make-test-artifacts.sh artifacts
-      "@
-      if (!$?) { exit(1) }
-    displayName: Build
-    env:
-      HOME: $(Build.SourcesDirectory)
-      MSYSTEM: MINGW64
-      DEVELOPER: 1
-      NO_PERL: 1
-  - task: PublishPipelineArtifact@0
-    displayName: 'Publish Pipeline Artifact: test artifacts'
-    inputs:
-      artifactName: 'windows-artifacts'
-      targetPath: '$(Build.SourcesDirectory)\artifacts'
-  - task: PublishPipelineArtifact@0
-    displayName: 'Publish Pipeline Artifact: git-sdk-64-minimal'
-    inputs:
-      artifactName: 'git-sdk-64-minimal'
-      targetPath: '$(Build.SourcesDirectory)\git-sdk-64-minimal'
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        cmd /c rmdir "$(Build.SourcesDirectory)\test-cache"
-      }
-    displayName: 'Unmount test-cache'
-    condition: true
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-
-- job: windows_test
-  displayName: Windows Test
-  dependsOn: windows_build
-  condition: succeeded()
-  pool:
-    vmImage: windows-latest
-  timeoutInMinutes: 240
-  strategy:
-    parallel: 10
-  steps:
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        net use s: \\gitfileshare.file.core.windows.net\test-cache "$GITFILESHAREPWD" /user:AZURE\gitfileshare /persistent:no
-        cmd /c mklink /d "$(Build.SourcesDirectory)\test-cache" S:\
-      }
-    displayName: 'Mount test-cache'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: DownloadPipelineArtifact@0
-    displayName: 'Download Pipeline Artifact: test artifacts'
-    inputs:
-      artifactName: 'windows-artifacts'
-      targetPath: '$(Build.SourcesDirectory)'
-  - task: DownloadPipelineArtifact@0
-    displayName: 'Download Pipeline Artifact: git-sdk-64-minimal'
-    inputs:
-      artifactName: 'git-sdk-64-minimal'
-      targetPath: '$(Build.SourcesDirectory)\git-sdk-64-minimal'
-  - powershell: |
-      & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
-        test -f artifacts.tar.gz || {
-          echo No test artifacts found\; skipping >&2
-          exit 0
-        }
-        tar xf artifacts.tar.gz || exit 1
-
-        # Let Git ignore the SDK and the test-cache
-        printf '%s\n' /git-sdk-64-minimal/ /test-cache/ >>.git/info/exclude
-
-        ci/run-test-slice.sh `$SYSTEM_JOBPOSITIONINPHASE `$SYSTEM_TOTALJOBSINPHASE || {
-          ci/print-test-failures.sh
-          exit 1
-        }
-      "@
-      if (!$?) { exit(1) }
-    displayName: 'Test (parallel)'
-    env:
-      HOME: $(Build.SourcesDirectory)
-      MSYSTEM: MINGW64
-      NO_SVN_TESTS: 1
-      GIT_TEST_SKIP_REBASE_P: 1
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        cmd /c rmdir "$(Build.SourcesDirectory)\test-cache"
-      }
-    displayName: 'Unmount test-cache'
-    condition: true
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'windows'
-      platform: Windows
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: vs_build
-  displayName: Visual Studio Build
-  condition: succeeded()
-  pool:
-    vmImage: windows-latest
-  timeoutInMinutes: 240
-  steps:
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        net use s: \\gitfileshare.file.core.windows.net\test-cache "$GITFILESHAREPWD" /user:AZURE\gitfileshare /persistent:no
-        cmd /c mklink /d "$(Build.SourcesDirectory)\test-cache" S:\
-      }
-    displayName: 'Mount test-cache'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - powershell: |
-      $urlbase = "https://dev.azure.com/git-for-windows/git/_apis/build/builds"
-      $id = ((Invoke-WebRequest -UseBasicParsing "${urlbase}?definitions=22&statusFilter=completed&resultFilter=succeeded&`$top=1").content | ConvertFrom-JSON).value[0].id
-      $downloadUrl = ((Invoke-WebRequest -UseBasicParsing "${urlbase}/$id/artifacts").content | ConvertFrom-JSON).value[1].resource.downloadUrl
-      (New-Object Net.WebClient).DownloadFile($downloadUrl,"git-sdk-64-minimal.zip")
-      Expand-Archive git-sdk-64-minimal.zip -DestinationPath . -Force
-      Remove-Item git-sdk-64-minimal.zip
-
-      # Let Git ignore the SDK and the test-cache
-      "/git-sdk-64-minimal/`n/test-cache/`n" | Out-File -NoNewLine -Encoding ascii -Append "$(Build.SourcesDirectory)\.git\info\exclude"
-    displayName: 'Download git-sdk-64-minimal'
-  - powershell: |
-      & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
-        make NDEBUG=1 DEVELOPER=1 vcxproj
-      "@
-      if (!$?) { exit(1) }
-    displayName: Generate Visual Studio Solution
-    env:
-      HOME: $(Build.SourcesDirectory)
-      MSYSTEM: MINGW64
-      DEVELOPER: 1
-      NO_PERL: 1
-      GIT_CONFIG_PARAMETERS: "'user.name=CI' 'user.email=ci@git'"
-  - powershell: |
-      $urlbase = "https://dev.azure.com/git/git/_apis/build/builds"
-      $id = ((Invoke-WebRequest -UseBasicParsing "${urlbase}?definitions=9&statusFilter=completed&resultFilter=succeeded&`$top=1").content | ConvertFrom-JSON).value[0].id
-      $downloadUrl = ((Invoke-WebRequest -UseBasicParsing "${urlbase}/$id/artifacts").content | ConvertFrom-JSON).value[0].resource.downloadUrl
-      (New-Object Net.WebClient).DownloadFile($downloadUrl, "compat.zip")
-      Expand-Archive compat.zip -DestinationPath . -Force
-      Remove-Item compat.zip
-    displayName: 'Download vcpkg artifacts'
-  - task: MSBuild@1
-    inputs:
-      solution: git.sln
-      platform: x64
-      configuration: Release
-      maximumCpuCount: 4
-      msbuildArguments: /p:PlatformToolset=v142
-  - powershell: |
-      & compat\vcbuild\vcpkg_copy_dlls.bat release
-      if (!$?) { exit(1) }
-      & git-sdk-64-minimal\usr\bin\bash.exe -lc @"
-        mkdir -p artifacts &&
-        eval \"`$(make -n artifacts-tar INCLUDE_DLLS_IN_ARTIFACTS=YesPlease ARTIFACTS_DIRECTORY=artifacts | grep ^tar)\"
-      "@
-      if (!$?) { exit(1) }
-    displayName: Bundle artifact tar
-    env:
-      HOME: $(Build.SourcesDirectory)
-      MSYSTEM: MINGW64
-      DEVELOPER: 1
-      NO_PERL: 1
-      MSVC: 1
-      VCPKG_ROOT: $(Build.SourcesDirectory)\compat\vcbuild\vcpkg
-  - powershell: |
-      $tag = (Invoke-WebRequest -UseBasicParsing "https://gitforwindows.org/latest-tag.txt").content
-      $version = (Invoke-WebRequest -UseBasicParsing "https://gitforwindows.org/latest-version.txt").content
-      $url = "https://github.com/git-for-windows/git/releases/download/${tag}/PortableGit-${version}-64-bit.7z.exe"
-      (New-Object Net.WebClient).DownloadFile($url,"PortableGit.exe")
-      & .\PortableGit.exe -y -oartifacts\PortableGit
-      # Wait until it is unpacked
-      while (-not @(Remove-Item -ErrorAction SilentlyContinue PortableGit.exe; $?)) { sleep 1 }
-    displayName: Download & extract portable Git
-  - task: PublishPipelineArtifact@0
-    displayName: 'Publish Pipeline Artifact: MSVC test artifacts'
-    inputs:
-      artifactName: 'vs-artifacts'
-      targetPath: '$(Build.SourcesDirectory)\artifacts'
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        cmd /c rmdir "$(Build.SourcesDirectory)\test-cache"
-      }
-    displayName: 'Unmount test-cache'
-    condition: true
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-
-- job: vs_test
-  displayName: Visual Studio Test
-  dependsOn: vs_build
-  condition: succeeded()
-  pool:
-    vmImage: windows-latest
-  timeoutInMinutes: 240
-  strategy:
-    parallel: 10
-  steps:
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        net use s: \\gitfileshare.file.core.windows.net\test-cache "$GITFILESHAREPWD" /user:AZURE\gitfileshare /persistent:no
-        cmd /c mklink /d "$(Build.SourcesDirectory)\test-cache" S:\
-      }
-    displayName: 'Mount test-cache'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: DownloadPipelineArtifact@0
-    displayName: 'Download Pipeline Artifact: VS test artifacts'
-    inputs:
-      artifactName: 'vs-artifacts'
-      targetPath: '$(Build.SourcesDirectory)'
-  - powershell: |
-      & PortableGit\git-cmd.exe --command=usr\bin\bash.exe -lc @"
-        test -f artifacts.tar.gz || {
-          echo No test artifacts found\; skipping >&2
-          exit 0
-        }
-        tar xf artifacts.tar.gz || exit 1
-
-        # Let Git ignore the SDK and the test-cache
-        printf '%s\n' /PortableGit/ /test-cache/ >>.git/info/exclude
-
-        cd t &&
-        PATH=\"`$PWD/helper:`$PATH\" &&
-        test-tool.exe run-command testsuite --jobs=10 -V -x --write-junit-xml \
-                `$(test-tool.exe path-utils slice-tests \
-                        `$SYSTEM_JOBPOSITIONINPHASE `$SYSTEM_TOTALJOBSINPHASE t[0-9]*.sh)
-      "@
-      if (!$?) { exit(1) }
-    displayName: 'Test (parallel)'
-    env:
-      HOME: $(Build.SourcesDirectory)
-      MSYSTEM: MINGW64
-      NO_SVN_TESTS: 1
-      GIT_TEST_SKIP_REBASE_P: 1
-  - powershell: |
-      if ("$GITFILESHAREPWD" -ne "" -and "$GITFILESHAREPWD" -ne "`$`(gitfileshare.pwd)") {
-        cmd /c rmdir "$(Build.SourcesDirectory)\test-cache"
-      }
-    displayName: 'Unmount test-cache'
-    condition: true
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'vs'
-      platform: Windows
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-vs-test-artifacts
-
-- job: linux_clang
-  displayName: linux-clang
-  condition: succeeded()
-  pool:
-    vmImage: ubuntu-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       sudo apt-get update &&
-       sudo apt-get -y install git gcc make libssl-dev libcurl4-openssl-dev libexpat-dev tcl tk gettext git-email zlib1g-dev apache2-bin &&
-
-       export CC=clang || exit 1
-
-       ci/install-dependencies.sh || exit 1
-       ci/run-build-and-tests.sh || {
-           ci/print-test-failures.sh
-           exit 1
-       }
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/run-build-and-tests.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'linux-clang'
-      platform: Linux
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: linux_gcc
-  displayName: linux-gcc
-  condition: succeeded()
-  pool:
-    vmImage: ubuntu-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       sudo add-apt-repository ppa:ubuntu-toolchain-r/test &&
-       sudo apt-get update &&
-       sudo apt-get -y install git gcc make libssl-dev libcurl4-openssl-dev libexpat-dev tcl tk gettext git-email zlib1g-dev apache2 language-pack-is git-svn gcc-8 || exit 1
-
-       ci/install-dependencies.sh || exit 1
-       ci/run-build-and-tests.sh || {
-           ci/print-test-failures.sh
-           exit 1
-       }
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/run-build-and-tests.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'linux-gcc'
-      platform: Linux
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: osx_clang
-  displayName: osx-clang
-  condition: succeeded()
-  pool:
-    vmImage: macOS-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       export CC=clang
-
-       ci/install-dependencies.sh || exit 1
-       ci/run-build-and-tests.sh || {
-           ci/print-test-failures.sh
-           exit 1
-       }
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/run-build-and-tests.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'osx-clang'
-      platform: macOS
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: osx_gcc
-  displayName: osx-gcc
-  condition: succeeded()
-  pool:
-    vmImage: macOS-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       ci/install-dependencies.sh || exit 1
-       ci/run-build-and-tests.sh || {
-           ci/print-test-failures.sh
-           exit 1
-       }
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/run-build-and-tests.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'osx-gcc'
-      platform: macOS
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: gettext_poison
-  displayName: GETTEXT_POISON
-  condition: succeeded()
-  pool:
-    vmImage: ubuntu-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       sudo apt-get update &&
-       sudo apt-get -y install git gcc make libssl-dev libcurl4-openssl-dev libexpat-dev tcl tk gettext git-email zlib1g-dev &&
-
-       export jobname=GETTEXT_POISON || exit 1
-
-       ci/run-build-and-tests.sh || {
-           ci/print-test-failures.sh
-           exit 1
-       }
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/run-build-and-tests.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'gettext-poison'
-      platform: Linux
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: linux32
-  displayName: Linux32
-  condition: succeeded()
-  pool:
-    vmImage: ubuntu-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       res=0
-       sudo AGENT_OS="$AGENT_OS" BUILD_BUILDNUMBER="$BUILD_BUILDNUMBER" BUILD_REPOSITORY_URI="$BUILD_REPOSITORY_URI" BUILD_SOURCEBRANCH="$BUILD_SOURCEBRANCH" BUILD_SOURCEVERSION="$BUILD_SOURCEVERSION" SYSTEM_PHASENAME="$SYSTEM_PHASENAME" SYSTEM_TASKDEFINITIONSURI="$SYSTEM_TASKDEFINITIONSURI" SYSTEM_TEAMPROJECT="$SYSTEM_TEAMPROJECT" CC=$CC MAKEFLAGS="$MAKEFLAGS" bash -lxc ci/run-linux32-docker.sh || res=1
-
-       sudo chmod a+r t/out/TEST-*.xml
-       test ! -d t/failed-test-artifacts || sudo chmod a+r t/failed-test-artifacts
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || res=1
-       exit $res
-    displayName: 'ci/run-linux32-docker.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-  - task: PublishTestResults@2
-    displayName: 'Publish Test Results **/TEST-*.xml'
-    inputs:
-      mergeTestResults: true
-      testRunTitle: 'linux32'
-      platform: Linux
-      publishRunAttachments: false
-    condition: succeededOrFailed()
-  - task: PublishBuildArtifacts@1
-    displayName: 'Publish trash directories of failed tests'
-    condition: failed()
-    inputs:
-      PathtoPublish: t/failed-test-artifacts
-      ArtifactName: failed-test-artifacts
-
-- job: static_analysis
-  displayName: StaticAnalysis
-  condition: succeeded()
-  pool:
-    vmImage: ubuntu-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       sudo apt-get update &&
-       sudo apt-get install -y coccinelle libcurl4-openssl-dev libssl-dev libexpat-dev gettext &&
-
-       export jobname=StaticAnalysis &&
-
-       ci/run-static-analysis.sh || exit 1
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/run-static-analysis.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
-
-- job: documentation
-  displayName: Documentation
-  condition: succeeded()
-  pool:
-    vmImage: ubuntu-latest
-  steps:
-  - bash: |
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || ci/mount-fileshare.sh //gitfileshare.file.core.windows.net/test-cache gitfileshare "$GITFILESHAREPWD" "$HOME/test-cache" || exit 1
-
-       sudo apt-get update &&
-       sudo apt-get install -y asciidoc xmlto asciidoctor docbook-xsl-ns &&
-
-       export ALREADY_HAVE_ASCIIDOCTOR=yes. &&
-       export jobname=Documentation &&
-
-       ci/test-documentation.sh || exit 1
-
-       test "$GITFILESHAREPWD" = '$(gitfileshare.pwd)' || sudo umount "$HOME/test-cache" || exit 1
-    displayName: 'ci/test-documentation.sh'
-    env:
-      GITFILESHAREPWD: $(gitfileshare.pwd)
diff --git a/bisect.c b/bisect.c
index 9154f81..d5e8304 100644
--- a/bisect.c
+++ b/bisect.c
@@ -10,7 +10,7 @@
 #include "run-command.h"
 #include "log-tree.h"
 #include "bisect.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "argv-array.h"
 #include "commit-slab.h"
 #include "commit-reach.h"
@@ -473,7 +473,7 @@ static void read_bisect_paths(struct argv_array *array)
 	fclose(fp);
 }
 
-static char *join_sha1_array_hex(struct oid_array *array, char delim)
+static char *join_oid_array_hex(struct oid_array *array, char delim)
 {
 	struct strbuf joined_hexs = STRBUF_INIT;
 	int i;
@@ -765,7 +765,7 @@ static enum bisect_error handle_bad_merge_base(void)
 {
 	if (is_expected_rev(current_bad_oid)) {
 		char *bad_hex = oid_to_hex(current_bad_oid);
-		char *good_hex = join_sha1_array_hex(&good_revs, ' ');
+		char *good_hex = join_oid_array_hex(&good_revs, ' ');
 		if (!strcmp(term_bad, "bad") && !strcmp(term_good, "good")) {
 			fprintf(stderr, _("The merge base %s is bad.\n"
 				"This means the bug has been fixed "
@@ -796,7 +796,7 @@ static void handle_skipped_merge_base(const struct object_id *mb)
 {
 	char *mb_hex = oid_to_hex(mb);
 	char *bad_hex = oid_to_hex(current_bad_oid);
-	char *good_hex = join_sha1_array_hex(&good_revs, ' ');
+	char *good_hex = join_oid_array_hex(&good_revs, ' ');
 
 	warning(_("the merge base between %s and [%s] "
 		"must be skipped.\n"
diff --git a/branch.c b/branch.c
index 5794947..2d9e767 100644
--- a/branch.c
+++ b/branch.c
@@ -344,6 +344,7 @@ void remove_merge_branch_state(struct repository *r)
 	unlink(git_path_merge_rr(r));
 	unlink(git_path_merge_msg(r));
 	unlink(git_path_merge_mode(r));
+	save_autostash(git_path_merge_autostash(r));
 }
 
 void remove_branch_state(struct repository *r, int verbose)
diff --git a/builtin.h b/builtin.h
index 2b25a80..a5ae15b 100644
--- a/builtin.h
+++ b/builtin.h
@@ -94,25 +94,9 @@
  * command.
  */
 
-#define DEFAULT_MERGE_LOG_LEN 20
-
 extern const char git_usage_string[];
 extern const char git_more_info_string[];
 
-#define PRUNE_PACKED_DRY_RUN 01
-#define PRUNE_PACKED_VERBOSE 02
-
-void prune_packed_objects(int);
-
-struct fmt_merge_msg_opts {
-	unsigned add_title:1,
-		credit_people:1;
-	int shortlog_len;
-};
-
-int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
-		  struct fmt_merge_msg_opts *);
-
 /**
  * If a built-in has DELAY_PAGER_CONFIG set, the built-in should call this early
  * when it wishes to respect the `pager.foo`-config. The `cmd` is the name of
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 272f9fc..0d03fda 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -12,7 +12,7 @@
 #include "userdiff.h"
 #include "streaming.h"
 #include "tree-walk.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "packfile.h"
 #include "object-store.h"
 #include "promisor-remote.h"
@@ -42,7 +42,10 @@ static int filter_object(const char *path, unsigned mode,
 			     oid_to_hex(oid), path);
 	if ((type == OBJ_BLOB) && S_ISREG(mode)) {
 		struct strbuf strbuf = STRBUF_INIT;
-		if (convert_to_working_tree(&the_index, path, *buf, *size, &strbuf)) {
+		struct checkout_metadata meta;
+
+		init_checkout_metadata(&meta, NULL, NULL, oid);
+		if (convert_to_working_tree(&the_index, path, *buf, *size, &strbuf, &meta)) {
 			free(*buf);
 			*size = strbuf.len;
 			*buf = strbuf_detach(&strbuf, NULL);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index d677381..8bc94d3 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -88,6 +88,19 @@ struct checkout_opts {
 	struct tree *source_tree;
 };
 
+struct branch_info {
+	const char *name; /* The short name used */
+	const char *path; /* The full name of a real branch */
+	struct commit *commit; /* The named commit */
+	char *refname; /* The full name of the ref being checked out. */
+	struct object_id oid; /* The object ID of the commit being checked out. */
+	/*
+	 * if not null the branch is detached because it's already
+	 * checked out in this checkout
+	 */
+	char *checkout;
+};
+
 static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
 			      int changed)
 {
@@ -337,7 +350,8 @@ static void mark_ce_for_checkout_no_overlay(struct cache_entry *ce,
 	}
 }
 
-static int checkout_worktree(const struct checkout_opts *opts)
+static int checkout_worktree(const struct checkout_opts *opts,
+			     const struct branch_info *info)
 {
 	struct checkout state = CHECKOUT_INIT;
 	int nr_checkouts = 0, nr_unmerged = 0;
@@ -348,6 +362,10 @@ static int checkout_worktree(const struct checkout_opts *opts)
 	state.refresh_cache = 1;
 	state.istate = &the_index;
 
+	init_checkout_metadata(&state.meta, info->refname,
+			       info->commit ? &info->commit->object.oid : &info->oid,
+			       NULL);
+
 	enable_delayed_checkout(&state);
 	for (pos = 0; pos < active_nr; pos++) {
 		struct cache_entry *ce = active_cache[pos];
@@ -396,7 +414,7 @@ static int checkout_worktree(const struct checkout_opts *opts)
 }
 
 static int checkout_paths(const struct checkout_opts *opts,
-			  const char *revision)
+			  const struct branch_info *new_branch_info)
 {
 	int pos;
 	static char *ps_matched;
@@ -462,7 +480,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 		else
 			BUG("either flag must have been set, worktree=%d, index=%d",
 			    opts->checkout_worktree, opts->checkout_index);
-		return run_add_interactive(revision, patch_mode, &opts->pathspec);
+		return run_add_interactive(new_branch_info->name, patch_mode, &opts->pathspec);
 	}
 
 	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
@@ -523,7 +541,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 
 	/* Now we are committed to check them out */
 	if (opts->checkout_worktree)
-		errs |= checkout_worktree(opts);
+		errs |= checkout_worktree(opts, new_branch_info);
 	else
 		remove_marked_cache_entries(&the_index, 1);
 
@@ -586,7 +604,8 @@ static void describe_detached_head(const char *msg, struct commit *commit)
 }
 
 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
-		      int worktree, int *writeout_error)
+		      int worktree, int *writeout_error,
+		      struct branch_info *info)
 {
 	struct unpack_trees_options opts;
 	struct tree_desc tree_desc;
@@ -601,6 +620,11 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 	opts.verbose_update = o->show_progress;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
+	init_checkout_metadata(&opts.meta, info->refname,
+			       info->commit ? &info->commit->object.oid :
+			       is_null_oid(&info->oid) ? &tree->object.oid :
+			       &info->oid,
+			       NULL);
 	parse_tree(tree);
 	init_tree_desc(&tree_desc, tree->buffer, tree->size);
 	switch (unpack_trees(1, &tree_desc, &opts)) {
@@ -620,21 +644,17 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 	}
 }
 
-struct branch_info {
-	const char *name; /* The short name used */
-	const char *path; /* The full name of a real branch */
-	struct commit *commit; /* The named commit */
-	/*
-	 * if not null the branch is detached because it's already
-	 * checked out in this checkout
-	 */
-	char *checkout;
-};
-
 static void setup_branch_path(struct branch_info *branch)
 {
 	struct strbuf buf = STRBUF_INIT;
 
+	/*
+	 * If this is a ref, resolve it; otherwise, look up the OID for our
+	 * expression.  Failure here is okay.
+	 */
+	if (!dwim_ref(branch->name, strlen(branch->name), &branch->oid, &branch->refname))
+		repo_get_oid_committish(the_repository, branch->name, &branch->oid);
+
 	strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
 	if (strcmp(buf.buf, branch->name))
 		branch->name = xstrdup(buf.buf);
@@ -663,7 +683,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 	} else
 		new_tree = get_commit_tree(new_branch_info->commit);
 	if (opts->discard_changes) {
-		ret = reset_tree(new_tree, opts, 1, writeout_error);
+		ret = reset_tree(new_tree, opts, 1, writeout_error, new_branch_info);
 		if (ret)
 			return ret;
 	} else {
@@ -692,6 +712,10 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		topts.quiet = opts->merge && old_branch_info->commit;
 		topts.verbose_update = opts->show_progress;
 		topts.fn = twoway_merge;
+		init_checkout_metadata(&topts.meta, new_branch_info->refname,
+				       new_branch_info->commit ?
+				       &new_branch_info->commit->object.oid :
+				       &new_branch_info->oid, NULL);
 		if (opts->overwrite_ignore) {
 			topts.dir = xcalloc(1, sizeof(*topts.dir));
 			topts.dir->flags |= DIR_SHOW_IGNORED;
@@ -762,7 +786,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 
 			ret = reset_tree(new_tree,
 					 opts, 1,
-					 writeout_error);
+					 writeout_error, new_branch_info);
 			if (ret)
 				return ret;
 			o.ancestor = old_branch_info->name;
@@ -782,7 +806,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 				exit(128);
 			ret = reset_tree(new_tree,
 					 opts, 0,
-					 writeout_error);
+					 writeout_error, new_branch_info);
 			strbuf_release(&o.obuf);
 			strbuf_release(&old_commit_shortname);
 			if (ret)
@@ -1710,7 +1734,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 
 	UNLEAK(opts);
 	if (opts->patch_mode || opts->pathspec.nr)
-		return checkout_paths(opts, new_branch_info.name);
+		return checkout_paths(opts, &new_branch_info);
 	else
 		return checkout_branch(opts, &new_branch_info);
 }
diff --git a/builtin/clean.c b/builtin/clean.c
index 5abf087..f14c21b 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -18,6 +18,7 @@
 #include "color.h"
 #include "pathspec.h"
 #include "help.h"
+#include "prompt.h"
 
 static int force = -1; /* unset */
 static int interactive;
@@ -420,7 +421,6 @@ static int find_unique(const char *choice, struct menu_stuff *menu_stuff)
 	return found;
 }
 
-
 /*
  * Parse user input, and return choice(s) for menu (menu_stuff).
  *
@@ -580,9 +580,7 @@ static int *list_and_choose(struct menu_opts *opts, struct menu_stuff *stuff)
 			       clean_get_color(CLEAN_COLOR_RESET));
 		}
 
-		if (strbuf_getline_lf(&choice, stdin) != EOF) {
-			strbuf_trim(&choice);
-		} else {
+		if (git_read_line_interactively(&choice) == EOF) {
 			eof = 1;
 			break;
 		}
@@ -662,9 +660,7 @@ static int filter_by_patterns_cmd(void)
 		clean_print_color(CLEAN_COLOR_PROMPT);
 		printf(_("Input ignore patterns>> "));
 		clean_print_color(CLEAN_COLOR_RESET);
-		if (strbuf_getline_lf(&confirm, stdin) != EOF)
-			strbuf_trim(&confirm);
-		else
+		if (git_read_line_interactively(&confirm) == EOF)
 			putchar('\n');
 
 		/* quit filter_by_pattern mode if press ENTER or Ctrl-D */
@@ -760,9 +756,7 @@ static int ask_each_cmd(void)
 			qname = quote_path_relative(item->string, NULL, &buf);
 			/* TRANSLATORS: Make sure to keep [y/N] as is */
 			printf(_("Remove %s [y/N]? "), qname);
-			if (strbuf_getline_lf(&confirm, stdin) != EOF) {
-				strbuf_trim(&confirm);
-			} else {
+			if (git_read_line_interactively(&confirm) == EOF) {
 				putchar('\n');
 				eof = 1;
 			}
@@ -989,12 +983,6 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		if (!cache_name_is_other(ent->name, ent->len))
 			continue;
 
-		if (pathspec.nr)
-			matches = dir_path_match(&the_index, ent, &pathspec, 0, NULL);
-
-		if (pathspec.nr && !matches)
-			continue;
-
 		if (lstat(ent->name, &st))
 			die_errno("Cannot lstat '%s'", ent->name);
 
diff --git a/builtin/clone.c b/builtin/clone.c
index 1ad26f4..cb48a29 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -102,10 +102,10 @@ static struct option builtin_clone_options[] = {
 		    N_("don't use local hardlinks, always copy")),
 	OPT_BOOL('s', "shared", &option_shared,
 		    N_("setup as shared repository")),
-	OPT_ALIAS(0, "recursive", "recurse-submodules"),
 	{ OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
 	  N_("pathspec"), N_("initialize submodules in the clone"),
 	  PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
+	OPT_ALIAS(0, "recursive", "recurse-submodules"),
 	OPT_INTEGER('j', "jobs", &max_jobs,
 		    N_("number of submodules cloned in parallel")),
 	OPT_STRING(0, "template", &option_template, N_("template-directory"),
@@ -420,6 +420,7 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 	struct dir_iterator *iter;
 	int iter_status;
 	unsigned int flags;
+	struct strbuf realpath = STRBUF_INIT;
 
 	mkdir_if_missing(dest->buf, 0777);
 
@@ -454,7 +455,8 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 		if (unlink(dest->buf) && errno != ENOENT)
 			die_errno(_("failed to unlink '%s'"), dest->buf);
 		if (!option_no_hardlinks) {
-			if (!link(real_path(src->buf), dest->buf))
+			strbuf_realpath(&realpath, src->buf, 1);
+			if (!link(realpath.buf, dest->buf))
 				continue;
 			if (option_local > 0)
 				die_errno(_("failed to create link '%s'"), dest->buf);
@@ -468,6 +470,8 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 		strbuf_setlen(src, src_len);
 		die(_("failed to iterate over '%s'"), src->buf);
 	}
+
+	strbuf_release(&realpath);
 }
 
 static void clone_local(const char *src_repo, const char *dest_repo)
@@ -639,7 +643,9 @@ static void write_followtags(const struct ref *refs, const char *msg)
 			continue;
 		if (ends_with(ref->name, "^{}"))
 			continue;
-		if (!has_object_file(&ref->old_oid))
+		if (!has_object_file_with_flags(&ref->old_oid,
+						OBJECT_INFO_QUICK |
+						OBJECT_INFO_SKIP_FETCH_OBJECT))
 			continue;
 		update_ref(msg, ref->name, &ref->old_oid, NULL, 0,
 			   UPDATE_REFS_DIE_ON_ERR);
@@ -672,8 +678,7 @@ static void update_remote_refs(const struct ref *refs,
 			       const char *branch_top,
 			       const char *msg,
 			       struct transport *transport,
-			       int check_connectivity,
-			       int check_refs_are_promisor_objects_only)
+			       int check_connectivity)
 {
 	const struct ref *rm = mapped_refs;
 
@@ -682,8 +687,6 @@ static void update_remote_refs(const struct ref *refs,
 
 		opt.transport = transport;
 		opt.progress = transport->progress;
-		opt.check_refs_are_promisor_objects_only =
-			!!check_refs_are_promisor_objects_only;
 
 		if (check_connected(iterate_ref_map, &rm, &opt))
 			die(_("remote did not send all necessary objects"));
@@ -780,11 +783,11 @@ static int checkout(int submodule_progress)
 	if (!strcmp(head, "HEAD")) {
 		if (advice_detached_head)
 			detach_advice(oid_to_hex(&oid));
+		FREE_AND_NULL(head);
 	} else {
 		if (!starts_with(head, "refs/heads/"))
 			die(_("HEAD not found below refs/heads!"));
 	}
-	free(head);
 
 	/* We need to be in the new work tree for the checkout */
 	setup_work_tree();
@@ -799,6 +802,7 @@ static int checkout(int submodule_progress)
 	opts.verbose_update = (option_verbosity >= 0);
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
+	init_checkout_metadata(&opts.meta, head, &oid, NULL);
 
 	tree = parse_tree_indirect(&oid);
 	parse_tree(tree);
@@ -806,6 +810,8 @@ static int checkout(int submodule_progress)
 	if (unpack_trees(1, &t, &opts) < 0)
 		die(_("unable to checkout working tree"));
 
+	free(head);
+
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 
@@ -1102,7 +1108,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	init_db(git_dir, real_git_dir, option_template, INIT_DB_QUIET);
+	init_db(git_dir, real_git_dir, option_template, GIT_HASH_UNKNOWN, INIT_DB_QUIET);
 
 	if (real_git_dir)
 		git_dir = real_git_dir;
@@ -1275,7 +1281,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	update_remote_refs(refs, mapped_refs, remote_head_points_at,
 			   branch_top.buf, reflog_msg.buf, transport,
-			   !is_local, filter_options.choice);
+			   !is_local);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 4a70b33..03a8331 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -39,14 +39,17 @@ static struct object_directory *find_odb(struct repository *r,
 {
 	struct object_directory *odb;
 	char *obj_dir_real = real_pathdup(obj_dir, 1);
+	struct strbuf odb_path_real = STRBUF_INIT;
 
 	prepare_alt_odb(r);
 	for (odb = r->objects->odb; odb; odb = odb->next) {
-		if (!strcmp(obj_dir_real, real_path(odb->path)))
+		strbuf_realpath(&odb_path_real, odb->path, 1);
+		if (!strcmp(obj_dir_real, odb_path_real.buf))
 			break;
 	}
 
 	free(obj_dir_real);
+	strbuf_release(&odb_path_real);
 
 	if (!odb)
 		die(_("could not find object directory matching %s"), obj_dir);
@@ -140,7 +143,7 @@ static int graph_write(int argc, const char **argv)
 		OPT_INTEGER(0, "size-multiple", &split_opts.size_multiple,
 			N_("maximum ratio between two levels of a split commit-graph")),
 		OPT_EXPIRY_DATE(0, "expire-time", &split_opts.expire_time,
-			N_("maximum number of commits in a non-base split commit-graph")),
+			N_("only expire files older than a given date-time")),
 		OPT_END(),
 	};
 
diff --git a/builtin/commit.c b/builtin/commit.c
index 7ba33a3..09170f5 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -59,6 +59,9 @@ N_("The previous cherry-pick is now empty, possibly due to conflict resolution.\
 "    git commit --allow-empty\n"
 "\n");
 
+static const char empty_rebase_pick_advice[] =
+N_("Otherwise, please use 'git rebase --skip'\n");
+
 static const char empty_cherry_pick_advice_single[] =
 N_("Otherwise, please use 'git cherry-pick --skip'\n");
 
@@ -122,7 +125,6 @@ static enum commit_msg_cleanup_mode cleanup_mode;
 static const char *cleanup_arg;
 
 static enum commit_whence whence;
-static int sequencer_in_use;
 static int use_editor = 1, include_status = 1;
 static int have_option_m;
 static struct strbuf message = STRBUF_INIT;
@@ -179,12 +181,7 @@ static void determine_whence(struct wt_status *s)
 {
 	if (file_exists(git_path_merge_head(the_repository)))
 		whence = FROM_MERGE;
-	else if (file_exists(git_path_cherry_pick_head(the_repository))) {
-		whence = FROM_CHERRY_PICK;
-		if (file_exists(git_path_seq_dir()))
-			sequencer_in_use = 1;
-	}
-	else
+	else if (!sequencer_determine_whence(the_repository, &whence))
 		whence = FROM_COMMIT;
 	if (s)
 		s->whence = whence;
@@ -477,8 +474,10 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 	if (whence != FROM_COMMIT) {
 		if (whence == FROM_MERGE)
 			die(_("cannot do a partial commit during a merge."));
-		else if (whence == FROM_CHERRY_PICK)
+		else if (is_from_cherry_pick(whence))
 			die(_("cannot do a partial commit during a cherry-pick."));
+		else if (is_from_rebase(whence))
+			die(_("cannot do a partial commit during a rebase."));
 	}
 
 	if (list_paths(&partial, !current_head ? NULL : "HEAD", &pathspec))
@@ -795,7 +794,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	 */
 	else if (whence == FROM_MERGE)
 		hook_arg1 = "merge";
-	else if (whence == FROM_CHERRY_PICK) {
+	else if (is_from_cherry_pick(whence) || whence == FROM_REBASE_PICK) {
 		hook_arg1 = "commit";
 		hook_arg2 = "CHERRY_PICK_HEAD";
 	}
@@ -973,12 +972,15 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		run_status(stdout, index_file, prefix, 0, s);
 		if (amend)
 			fputs(_(empty_amend_advice), stderr);
-		else if (whence == FROM_CHERRY_PICK) {
+		else if (is_from_cherry_pick(whence) ||
+			 whence == FROM_REBASE_PICK) {
 			fputs(_(empty_cherry_pick_advice), stderr);
-			if (!sequencer_in_use)
+			if (whence == FROM_CHERRY_PICK_SINGLE)
 				fputs(_(empty_cherry_pick_advice_single), stderr);
-			else
+			else if (whence == FROM_CHERRY_PICK_MULTI)
 				fputs(_(empty_cherry_pick_advice_multi), stderr);
+			else
+				fputs(_(empty_rebase_pick_advice), stderr);
 		}
 		return 0;
 	}
@@ -1181,8 +1183,10 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	if (amend && whence != FROM_COMMIT) {
 		if (whence == FROM_MERGE)
 			die(_("You are in the middle of a merge -- cannot amend."));
-		else if (whence == FROM_CHERRY_PICK)
+		else if (is_from_cherry_pick(whence))
 			die(_("You are in the middle of a cherry-pick -- cannot amend."));
+		else if (whence == FROM_REBASE_PICK)
+			die(_("You are in the middle of a rebase -- cannot amend."));
 	}
 	if (fixup_message && squash_message)
 		die(_("Options --squash and --fixup cannot be used together"));
@@ -1204,7 +1208,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 		use_message = edit_message;
 	if (amend && !use_message && !fixup_message)
 		use_message = "HEAD";
-	if (!use_message && whence != FROM_CHERRY_PICK && renew_authorship)
+	if (!use_message && !is_from_cherry_pick(whence) &&
+	    !is_from_rebase(whence) && renew_authorship)
 		die(_("--reset-author can be used only with -C, -c or --amend."));
 	if (use_message) {
 		use_message_buffer = read_commit_message(use_message);
@@ -1213,7 +1218,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 			author_message_buffer = use_message_buffer;
 		}
 	}
-	if (whence == FROM_CHERRY_PICK && !renew_authorship) {
+	if ((is_from_cherry_pick(whence) || whence == FROM_REBASE_PICK) &&
+	    !renew_authorship) {
 		author_message = "CHERRY_PICK_HEAD";
 		author_message_buffer = read_commit_message(author_message);
 	}
@@ -1631,8 +1637,10 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 			reduce_heads_replace(&parents);
 	} else {
 		if (!reflog_msg)
-			reflog_msg = (whence == FROM_CHERRY_PICK)
+			reflog_msg = is_from_cherry_pick(whence)
 					? "commit (cherry-pick)"
+					: is_from_rebase(whence)
+					? "commit (rebase)"
 					: "commit";
 		commit_list_insert(current_head, &parents);
 	}
@@ -1659,7 +1667,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	}
 
 	if (amend) {
-		const char *exclude_gpgsig[2] = { "gpgsig", NULL };
+		const char *exclude_gpgsig[3] = { "gpgsig", "gpgsig-sha256", NULL };
 		extra = read_commit_extra_headers(current_head, exclude_gpgsig);
 	} else {
 		struct commit_extra_header **tail = &extra;
@@ -1713,6 +1721,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 				     &oid, flags);
 	}
 
+	apply_autostash(git_path_merge_autostash(the_repository));
+
 	UNLEAK(err);
 	UNLEAK(sb);
 	return 0;
diff --git a/builtin/describe.c b/builtin/describe.c
index 420f4c6..21d2cb9 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -54,6 +54,7 @@ struct commit_name {
 	struct tag *tag;
 	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
 	unsigned name_checked:1;
+	unsigned misnamed:1;
 	struct object_id oid;
 	char *path;
 };
@@ -132,6 +133,7 @@ static void add_to_known_names(const char *path,
 		e->tag = tag;
 		e->prio = prio;
 		e->name_checked = 0;
+		e->misnamed = 0;
 		oidcpy(&e->oid, oid);
 		free(e->path);
 		e->path = xstrdup(path);
@@ -275,10 +277,11 @@ static void append_name(struct commit_name *n, struct strbuf *dst)
 			die(_("annotated tag %s not available"), n->path);
 	}
 	if (n->tag && !n->name_checked) {
-		if (!n->tag->tag)
-			die(_("annotated tag %s has no embedded name"), n->path);
-		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
-			warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
+		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path)) {
+			warning(_("tag '%s' is externally known as '%s'"),
+				n->path, n->tag->tag);
+			n->misnamed = 1;
+		}
 		n->name_checked = 1;
 	}
 
@@ -314,7 +317,7 @@ static void describe_commit(struct object_id *oid, struct strbuf *dst)
 		 * Exact match to an existing ref.
 		 */
 		append_name(n, dst);
-		if (longformat)
+		if (n->misnamed || longformat)
 			append_suffix(0, n->tag ? get_tagged_oid(n->tag) : oid, dst);
 		if (suffix)
 			strbuf_addstr(dst, suffix);
@@ -463,7 +466,7 @@ static void describe_commit(struct object_id *oid, struct strbuf *dst)
 	}
 
 	append_name(all_matches[0].name, dst);
-	if (abbrev)
+	if (all_matches[0].name->misnamed || abbrev)
 		append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
 	if (suffix)
 		strbuf_addstr(dst, suffix);
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index cb9ea79..802363d 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -109,6 +109,7 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 	struct object *tree1, *tree2;
 	static struct rev_info *opt = &log_tree_opt;
 	struct setup_revision_opt s_r_opt;
+	struct userformat_want w;
 	int read_stdin = 0;
 
 	if (argc == 2 && !strcmp(argv[1], "-h"))
@@ -127,6 +128,14 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 	precompose_argv(argc, argv);
 	argc = setup_revisions(argc, argv, opt, &s_r_opt);
 
+	memset(&w, 0, sizeof(w));
+	userformat_find_requirements(NULL, &w);
+
+	if (!opt->show_notes_given && w.notes)
+		opt->show_notes = 1;
+	if (opt->show_notes)
+		load_display_notes(&opt->notes_opt);
+
 	while (--argc > 0) {
 		const char *arg = *++argv;
 
diff --git a/builtin/diff.c b/builtin/diff.c
index 42ac803..8537b17 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -17,7 +17,7 @@
 #include "log-tree.h"
 #include "builtin.h"
 #include "submodule.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 
 #define DIFF_NO_INDEX_EXPLICIT 1
 #define DIFF_NO_INDEX_IMPLICIT 2
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index dc1485c..4771100 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -3,7 +3,7 @@
 #include "fetch-pack.h"
 #include "remote.h"
 #include "connect.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "protocol.h"
 
 static const char fetch_pack_usage[] =
diff --git a/builtin/fetch.c b/builtin/fetch.c
index bf6bab8..1097e1e 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -908,13 +908,6 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 	if (!connectivity_checked) {
 		struct check_connected_options opt = CHECK_CONNECTED_INIT;
 
-		if (filter_options.choice)
-			/*
-			 * Since a filter is specified, objects indirectly
-			 * referenced by refs are allowed to be absent.
-			 */
-			opt.check_refs_are_promisor_objects_only = 1;
-
 		rm = ref_map;
 		if (check_connected(iterate_ref_map, &rm, &opt)) {
 			rc = error(_("%s did not send all necessary objects\n"), url);
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 736f666..48a8699 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -1,666 +1,13 @@
 #include "builtin.h"
-#include "cache.h"
 #include "config.h"
-#include "refs.h"
-#include "object-store.h"
-#include "commit.h"
-#include "diff.h"
-#include "revision.h"
-#include "tag.h"
-#include "string-list.h"
-#include "branch.h"
 #include "fmt-merge-msg.h"
-#include "gpg-interface.h"
-#include "repository.h"
-#include "commit-reach.h"
+#include "parse-options.h"
 
 static const char * const fmt_merge_msg_usage[] = {
 	N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
 	NULL
 };
 
-static int use_branch_desc;
-
-int fmt_merge_msg_config(const char *key, const char *value, void *cb)
-{
-	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
-		int is_bool;
-		merge_log_config = git_config_bool_or_int(key, value, &is_bool);
-		if (!is_bool && merge_log_config < 0)
-			return error("%s: negative length %s", key, value);
-		if (is_bool && merge_log_config)
-			merge_log_config = DEFAULT_MERGE_LOG_LEN;
-	} else if (!strcmp(key, "merge.branchdesc")) {
-		use_branch_desc = git_config_bool(key, value);
-	} else {
-		return git_default_config(key, value, cb);
-	}
-	return 0;
-}
-
-/* merge data per repository where the merged tips came from */
-struct src_data {
-	struct string_list branch, tag, r_branch, generic;
-	int head_status;
-};
-
-struct origin_data {
-	struct object_id oid;
-	unsigned is_local_branch:1;
-};
-
-static void init_src_data(struct src_data *data)
-{
-	data->branch.strdup_strings = 1;
-	data->tag.strdup_strings = 1;
-	data->r_branch.strdup_strings = 1;
-	data->generic.strdup_strings = 1;
-}
-
-static struct string_list srcs = STRING_LIST_INIT_DUP;
-static struct string_list origins = STRING_LIST_INIT_DUP;
-
-struct merge_parents {
-	int alloc, nr;
-	struct merge_parent {
-		struct object_id given;
-		struct object_id commit;
-		unsigned char used;
-	} *item;
-};
-
-/*
- * I know, I know, this is inefficient, but you won't be pulling and merging
- * hundreds of heads at a time anyway.
- */
-static struct merge_parent *find_merge_parent(struct merge_parents *table,
-					      struct object_id *given,
-					      struct object_id *commit)
-{
-	int i;
-	for (i = 0; i < table->nr; i++) {
-		if (given && !oideq(&table->item[i].given, given))
-			continue;
-		if (commit && !oideq(&table->item[i].commit, commit))
-			continue;
-		return &table->item[i];
-	}
-	return NULL;
-}
-
-static void add_merge_parent(struct merge_parents *table,
-			     struct object_id *given,
-			     struct object_id *commit)
-{
-	if (table->nr && find_merge_parent(table, given, commit))
-		return;
-	ALLOC_GROW(table->item, table->nr + 1, table->alloc);
-	oidcpy(&table->item[table->nr].given, given);
-	oidcpy(&table->item[table->nr].commit, commit);
-	table->item[table->nr].used = 0;
-	table->nr++;
-}
-
-static int handle_line(char *line, struct merge_parents *merge_parents)
-{
-	int i, len = strlen(line);
-	struct origin_data *origin_data;
-	char *src;
-	const char *origin, *tag_name;
-	struct src_data *src_data;
-	struct string_list_item *item;
-	int pulling_head = 0;
-	struct object_id oid;
-	const unsigned hexsz = the_hash_algo->hexsz;
-
-	if (len < hexsz + 3 || line[hexsz] != '\t')
-		return 1;
-
-	if (starts_with(line + hexsz + 1, "not-for-merge"))
-		return 0;
-
-	if (line[hexsz + 1] != '\t')
-		return 2;
-
-	i = get_oid_hex(line, &oid);
-	if (i)
-		return 3;
-
-	if (!find_merge_parent(merge_parents, &oid, NULL))
-		return 0; /* subsumed by other parents */
-
-	origin_data = xcalloc(1, sizeof(struct origin_data));
-	oidcpy(&origin_data->oid, &oid);
-
-	if (line[len - 1] == '\n')
-		line[len - 1] = 0;
-	line += hexsz + 2;
-
-	/*
-	 * At this point, line points at the beginning of comment e.g.
-	 * "branch 'frotz' of git://that/repository.git".
-	 * Find the repository name and point it with src.
-	 */
-	src = strstr(line, " of ");
-	if (src) {
-		*src = 0;
-		src += 4;
-		pulling_head = 0;
-	} else {
-		src = line;
-		pulling_head = 1;
-	}
-
-	item = unsorted_string_list_lookup(&srcs, src);
-	if (!item) {
-		item = string_list_append(&srcs, src);
-		item->util = xcalloc(1, sizeof(struct src_data));
-		init_src_data(item->util);
-	}
-	src_data = item->util;
-
-	if (pulling_head) {
-		origin = src;
-		src_data->head_status |= 1;
-	} else if (skip_prefix(line, "branch ", &origin)) {
-		origin_data->is_local_branch = 1;
-		string_list_append(&src_data->branch, origin);
-		src_data->head_status |= 2;
-	} else if (skip_prefix(line, "tag ", &tag_name)) {
-		origin = line;
-		string_list_append(&src_data->tag, tag_name);
-		src_data->head_status |= 2;
-	} else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
-		string_list_append(&src_data->r_branch, origin);
-		src_data->head_status |= 2;
-	} else {
-		origin = src;
-		string_list_append(&src_data->generic, line);
-		src_data->head_status |= 2;
-	}
-
-	if (!strcmp(".", src) || !strcmp(src, origin)) {
-		int len = strlen(origin);
-		if (origin[0] == '\'' && origin[len - 1] == '\'')
-			origin = xmemdupz(origin + 1, len - 2);
-	} else
-		origin = xstrfmt("%s of %s", origin, src);
-	if (strcmp(".", src))
-		origin_data->is_local_branch = 0;
-	string_list_append(&origins, origin)->util = origin_data;
-	return 0;
-}
-
-static void print_joined(const char *singular, const char *plural,
-		struct string_list *list, struct strbuf *out)
-{
-	if (list->nr == 0)
-		return;
-	if (list->nr == 1) {
-		strbuf_addf(out, "%s%s", singular, list->items[0].string);
-	} else {
-		int i;
-		strbuf_addstr(out, plural);
-		for (i = 0; i < list->nr - 1; i++)
-			strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
-				    list->items[i].string);
-		strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
-	}
-}
-
-static void add_branch_desc(struct strbuf *out, const char *name)
-{
-	struct strbuf desc = STRBUF_INIT;
-
-	if (!read_branch_desc(&desc, name)) {
-		const char *bp = desc.buf;
-		while (*bp) {
-			const char *ep = strchrnul(bp, '\n');
-			if (*ep)
-				ep++;
-			strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
-			bp = ep;
-		}
-		strbuf_complete_line(out);
-	}
-	strbuf_release(&desc);
-}
-
-#define util_as_integral(elem) ((intptr_t)((elem)->util))
-
-static void record_person_from_buf(int which, struct string_list *people,
-				   const char *buffer)
-{
-	char *name_buf, *name, *name_end;
-	struct string_list_item *elem;
-	const char *field;
-
-	field = (which == 'a') ? "\nauthor " : "\ncommitter ";
-	name = strstr(buffer, field);
-	if (!name)
-		return;
-	name += strlen(field);
-	name_end = strchrnul(name, '<');
-	if (*name_end)
-		name_end--;
-	while (isspace(*name_end) && name <= name_end)
-		name_end--;
-	if (name_end < name)
-		return;
-	name_buf = xmemdupz(name, name_end - name + 1);
-
-	elem = string_list_lookup(people, name_buf);
-	if (!elem) {
-		elem = string_list_insert(people, name_buf);
-		elem->util = (void *)0;
-	}
-	elem->util = (void*)(util_as_integral(elem) + 1);
-	free(name_buf);
-}
-
-
-static void record_person(int which, struct string_list *people,
-			  struct commit *commit)
-{
-	const char *buffer = get_commit_buffer(commit, NULL);
-	record_person_from_buf(which, people, buffer);
-	unuse_commit_buffer(commit, buffer);
-}
-
-static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
-{
-	const struct string_list_item *a = a_, *b = b_;
-	return util_as_integral(b) - util_as_integral(a);
-}
-
-static void add_people_count(struct strbuf *out, struct string_list *people)
-{
-	if (people->nr == 1)
-		strbuf_addstr(out, people->items[0].string);
-	else if (people->nr == 2)
-		strbuf_addf(out, "%s (%d) and %s (%d)",
-			    people->items[0].string,
-			    (int)util_as_integral(&people->items[0]),
-			    people->items[1].string,
-			    (int)util_as_integral(&people->items[1]));
-	else if (people->nr)
-		strbuf_addf(out, "%s (%d) and others",
-			    people->items[0].string,
-			    (int)util_as_integral(&people->items[0]));
-}
-
-static void credit_people(struct strbuf *out,
-			  struct string_list *them,
-			  int kind)
-{
-	const char *label;
-	const char *me;
-
-	if (kind == 'a') {
-		label = "By";
-		me = git_author_info(IDENT_NO_DATE);
-	} else {
-		label = "Via";
-		me = git_committer_info(IDENT_NO_DATE);
-	}
-
-	if (!them->nr ||
-	    (them->nr == 1 &&
-	     me &&
-	     skip_prefix(me, them->items->string, &me) &&
-	     starts_with(me, " <")))
-		return;
-	strbuf_addf(out, "\n%c %s ", comment_line_char, label);
-	add_people_count(out, them);
-}
-
-static void add_people_info(struct strbuf *out,
-			    struct string_list *authors,
-			    struct string_list *committers)
-{
-	QSORT(authors->items, authors->nr,
-	      cmp_string_list_util_as_integral);
-	QSORT(committers->items, committers->nr,
-	      cmp_string_list_util_as_integral);
-
-	credit_people(out, authors, 'a');
-	credit_people(out, committers, 'c');
-}
-
-static void shortlog(const char *name,
-		     struct origin_data *origin_data,
-		     struct commit *head,
-		     struct rev_info *rev,
-		     struct fmt_merge_msg_opts *opts,
-		     struct strbuf *out)
-{
-	int i, count = 0;
-	struct commit *commit;
-	struct object *branch;
-	struct string_list subjects = STRING_LIST_INIT_DUP;
-	struct string_list authors = STRING_LIST_INIT_DUP;
-	struct string_list committers = STRING_LIST_INIT_DUP;
-	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
-	struct strbuf sb = STRBUF_INIT;
-	const struct object_id *oid = &origin_data->oid;
-	int limit = opts->shortlog_len;
-
-	branch = deref_tag(the_repository, parse_object(the_repository, oid),
-			   oid_to_hex(oid),
-			   the_hash_algo->hexsz);
-	if (!branch || branch->type != OBJ_COMMIT)
-		return;
-
-	setup_revisions(0, NULL, rev, NULL);
-	add_pending_object(rev, branch, name);
-	add_pending_object(rev, &head->object, "^HEAD");
-	head->object.flags |= UNINTERESTING;
-	if (prepare_revision_walk(rev))
-		die("revision walk setup failed");
-	while ((commit = get_revision(rev)) != NULL) {
-		struct pretty_print_context ctx = {0};
-
-		if (commit->parents && commit->parents->next) {
-			/* do not list a merge but count committer */
-			if (opts->credit_people)
-				record_person('c', &committers, commit);
-			continue;
-		}
-		if (!count && opts->credit_people)
-			/* the 'tip' committer */
-			record_person('c', &committers, commit);
-		if (opts->credit_people)
-			record_person('a', &authors, commit);
-		count++;
-		if (subjects.nr > limit)
-			continue;
-
-		format_commit_message(commit, "%s", &sb, &ctx);
-		strbuf_ltrim(&sb);
-
-		if (!sb.len)
-			string_list_append(&subjects,
-					   oid_to_hex(&commit->object.oid));
-		else
-			string_list_append_nodup(&subjects,
-						 strbuf_detach(&sb, NULL));
-	}
-
-	if (opts->credit_people)
-		add_people_info(out, &authors, &committers);
-	if (count > limit)
-		strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
-	else
-		strbuf_addf(out, "\n* %s:\n", name);
-
-	if (origin_data->is_local_branch && use_branch_desc)
-		add_branch_desc(out, name);
-
-	for (i = 0; i < subjects.nr; i++)
-		if (i >= limit)
-			strbuf_addstr(out, "  ...\n");
-		else
-			strbuf_addf(out, "  %s\n", subjects.items[i].string);
-
-	clear_commit_marks((struct commit *)branch, flags);
-	clear_commit_marks(head, flags);
-	free_commit_list(rev->commits);
-	rev->commits = NULL;
-	rev->pending.nr = 0;
-
-	string_list_clear(&authors, 0);
-	string_list_clear(&committers, 0);
-	string_list_clear(&subjects, 0);
-}
-
-static void fmt_merge_msg_title(struct strbuf *out,
-				const char *current_branch)
-{
-	int i = 0;
-	char *sep = "";
-
-	strbuf_addstr(out, "Merge ");
-	for (i = 0; i < srcs.nr; i++) {
-		struct src_data *src_data = srcs.items[i].util;
-		const char *subsep = "";
-
-		strbuf_addstr(out, sep);
-		sep = "; ";
-
-		if (src_data->head_status == 1) {
-			strbuf_addstr(out, srcs.items[i].string);
-			continue;
-		}
-		if (src_data->head_status == 3) {
-			subsep = ", ";
-			strbuf_addstr(out, "HEAD");
-		}
-		if (src_data->branch.nr) {
-			strbuf_addstr(out, subsep);
-			subsep = ", ";
-			print_joined("branch ", "branches ", &src_data->branch,
-					out);
-		}
-		if (src_data->r_branch.nr) {
-			strbuf_addstr(out, subsep);
-			subsep = ", ";
-			print_joined("remote-tracking branch ", "remote-tracking branches ",
-					&src_data->r_branch, out);
-		}
-		if (src_data->tag.nr) {
-			strbuf_addstr(out, subsep);
-			subsep = ", ";
-			print_joined("tag ", "tags ", &src_data->tag, out);
-		}
-		if (src_data->generic.nr) {
-			strbuf_addstr(out, subsep);
-			print_joined("commit ", "commits ", &src_data->generic,
-					out);
-		}
-		if (strcmp(".", srcs.items[i].string))
-			strbuf_addf(out, " of %s", srcs.items[i].string);
-	}
-
-	if (!strcmp("master", current_branch))
-		strbuf_addch(out, '\n');
-	else
-		strbuf_addf(out, " into %s\n", current_branch);
-}
-
-static void fmt_tag_signature(struct strbuf *tagbuf,
-			      struct strbuf *sig,
-			      const char *buf,
-			      unsigned long len)
-{
-	const char *tag_body = strstr(buf, "\n\n");
-	if (tag_body) {
-		tag_body += 2;
-		strbuf_add(tagbuf, tag_body, buf + len - tag_body);
-	}
-	strbuf_complete_line(tagbuf);
-	if (sig->len) {
-		strbuf_addch(tagbuf, '\n');
-		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
-	}
-}
-
-static void fmt_merge_msg_sigs(struct strbuf *out)
-{
-	int i, tag_number = 0, first_tag = 0;
-	struct strbuf tagbuf = STRBUF_INIT;
-
-	for (i = 0; i < origins.nr; i++) {
-		struct object_id *oid = origins.items[i].util;
-		enum object_type type;
-		unsigned long size, len;
-		char *buf = read_object_file(oid, &type, &size);
-		struct strbuf sig = STRBUF_INIT;
-
-		if (!buf || type != OBJ_TAG)
-			goto next;
-		len = parse_signature(buf, size);
-
-		if (size == len)
-			; /* merely annotated */
-		else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
-			if (!sig.len)
-				strbuf_addstr(&sig, "gpg verification failed.\n");
-		}
-
-		if (!tag_number++) {
-			fmt_tag_signature(&tagbuf, &sig, buf, len);
-			first_tag = i;
-		} else {
-			if (tag_number == 2) {
-				struct strbuf tagline = STRBUF_INIT;
-				strbuf_addch(&tagline, '\n');
-				strbuf_add_commented_lines(&tagline,
-						origins.items[first_tag].string,
-						strlen(origins.items[first_tag].string));
-				strbuf_insert(&tagbuf, 0, tagline.buf,
-					      tagline.len);
-				strbuf_release(&tagline);
-			}
-			strbuf_addch(&tagbuf, '\n');
-			strbuf_add_commented_lines(&tagbuf,
-					origins.items[i].string,
-					strlen(origins.items[i].string));
-			fmt_tag_signature(&tagbuf, &sig, buf, len);
-		}
-		strbuf_release(&sig);
-	next:
-		free(buf);
-	}
-	if (tagbuf.len) {
-		strbuf_addch(out, '\n');
-		strbuf_addbuf(out, &tagbuf);
-	}
-	strbuf_release(&tagbuf);
-}
-
-static void find_merge_parents(struct merge_parents *result,
-			       struct strbuf *in, struct object_id *head)
-{
-	struct commit_list *parents;
-	struct commit *head_commit;
-	int pos = 0, i, j;
-
-	parents = NULL;
-	while (pos < in->len) {
-		int len;
-		char *p = in->buf + pos;
-		char *newline = strchr(p, '\n');
-		const char *q;
-		struct object_id oid;
-		struct commit *parent;
-		struct object *obj;
-
-		len = newline ? newline - p : strlen(p);
-		pos += len + !!newline;
-
-		if (parse_oid_hex(p, &oid, &q) ||
-		    q[0] != '\t' ||
-		    q[1] != '\t')
-			continue; /* skip not-for-merge */
-		/*
-		 * Do not use get_merge_parent() here; we do not have
-		 * "name" here and we do not want to contaminate its
-		 * util field yet.
-		 */
-		obj = parse_object(the_repository, &oid);
-		parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
-		if (!parent)
-			continue;
-		commit_list_insert(parent, &parents);
-		add_merge_parent(result, &obj->oid, &parent->object.oid);
-	}
-	head_commit = lookup_commit(the_repository, head);
-	if (head_commit)
-		commit_list_insert(head_commit, &parents);
-	reduce_heads_replace(&parents);
-
-	while (parents) {
-		struct commit *cmit = pop_commit(&parents);
-		for (i = 0; i < result->nr; i++)
-			if (oideq(&result->item[i].commit, &cmit->object.oid))
-				result->item[i].used = 1;
-	}
-
-	for (i = j = 0; i < result->nr; i++) {
-		if (result->item[i].used) {
-			if (i != j)
-				result->item[j] = result->item[i];
-			j++;
-		}
-	}
-	result->nr = j;
-}
-
-int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
-		  struct fmt_merge_msg_opts *opts)
-{
-	int i = 0, pos = 0;
-	struct object_id head_oid;
-	const char *current_branch;
-	void *current_branch_to_free;
-	struct merge_parents merge_parents;
-
-	memset(&merge_parents, 0, sizeof(merge_parents));
-
-	/* get current branch */
-	current_branch = current_branch_to_free =
-		resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
-	if (!current_branch)
-		die("No current branch");
-	if (starts_with(current_branch, "refs/heads/"))
-		current_branch += 11;
-
-	find_merge_parents(&merge_parents, in, &head_oid);
-
-	/* get a line */
-	while (pos < in->len) {
-		int len;
-		char *newline, *p = in->buf + pos;
-
-		newline = strchr(p, '\n');
-		len = newline ? newline - p : strlen(p);
-		pos += len + !!newline;
-		i++;
-		p[len] = 0;
-		if (handle_line(p, &merge_parents))
-			die("error in line %d: %.*s", i, len, p);
-	}
-
-	if (opts->add_title && srcs.nr)
-		fmt_merge_msg_title(out, current_branch);
-
-	if (origins.nr)
-		fmt_merge_msg_sigs(out);
-
-	if (opts->shortlog_len) {
-		struct commit *head;
-		struct rev_info rev;
-
-		head = lookup_commit_or_die(&head_oid, "HEAD");
-		repo_init_revisions(the_repository, &rev, NULL);
-		rev.commit_format = CMIT_FMT_ONELINE;
-		rev.ignore_merges = 1;
-		rev.limited = 1;
-
-		strbuf_complete_line(out);
-
-		for (i = 0; i < origins.nr; i++)
-			shortlog(origins.items[i].string,
-				 origins.items[i].util,
-				 head, &rev, opts, out);
-	}
-
-	strbuf_complete_line(out);
-	free(current_branch_to_free);
-	free(merge_parents.item);
-	return 0;
-}
-
 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 {
 	const char *inpath = NULL;
diff --git a/builtin/grep.c b/builtin/grep.c
index 99e2685..5e150f5 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -295,6 +295,38 @@ static int grep_cmd_config(const char *var, const char *value, void *cb)
 	return st;
 }
 
+static void grep_source_name(struct grep_opt *opt, const char *filename,
+			     int tree_name_len, struct strbuf *out)
+{
+	strbuf_reset(out);
+
+	if (opt->null_following_name) {
+		if (opt->relative && opt->prefix_length) {
+			struct strbuf rel_buf = STRBUF_INIT;
+			const char *rel_name =
+				relative_path(filename + tree_name_len,
+					      opt->prefix, &rel_buf);
+
+			if (tree_name_len)
+				strbuf_add(out, filename, tree_name_len);
+
+			strbuf_addstr(out, rel_name);
+			strbuf_release(&rel_buf);
+		} else {
+			strbuf_addstr(out, filename);
+		}
+		return;
+	}
+
+	if (opt->relative && opt->prefix_length)
+		quote_path_relative(filename + tree_name_len, opt->prefix, out);
+	else
+		quote_c_style(filename + tree_name_len, out, NULL, 0);
+
+	if (tree_name_len)
+		strbuf_insert(out, 0, filename, tree_name_len);
+}
+
 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 		     const char *filename, int tree_name_len,
 		     const char *path)
@@ -302,13 +334,7 @@ static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 	struct strbuf pathbuf = STRBUF_INIT;
 	struct grep_source gs;
 
-	if (opt->relative && opt->prefix_length) {
-		quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
-		strbuf_insert(&pathbuf, 0, filename, tree_name_len);
-	} else {
-		strbuf_addstr(&pathbuf, filename);
-	}
-
+	grep_source_name(opt, filename, tree_name_len, &pathbuf);
 	grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
 	strbuf_release(&pathbuf);
 
@@ -334,11 +360,7 @@ static int grep_file(struct grep_opt *opt, const char *filename)
 	struct strbuf buf = STRBUF_INIT;
 	struct grep_source gs;
 
-	if (opt->relative && opt->prefix_length)
-		quote_path_relative(filename, opt->prefix, &buf);
-	else
-		strbuf_addstr(&buf, filename);
-
+	grep_source_name(opt, filename, 0, &buf);
 	grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 	strbuf_release(&buf);
 
@@ -679,8 +701,6 @@ static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 
 	fill_directory(&dir, opt->repo->index, pathspec);
 	for (i = 0; i < dir.nr; i++) {
-		if (!dir_path_match(opt->repo->index, dir.entries[i], pathspec, 0, NULL))
-			continue;
 		hit |= grep_file(opt, dir.entries[i]->name);
 		if (hit && opt->status_only)
 			break;
diff --git a/builtin/help.c b/builtin/help.c
index e5590d7..c024110 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -242,7 +242,7 @@ static int add_man_viewer_cmd(const char *name,
 static int add_man_viewer_info(const char *var, const char *value)
 {
 	const char *name, *subkey;
-	int namelen;
+	size_t namelen;
 
 	if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 		return 0;
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index d967d18..f176dd2 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1368,9 +1368,8 @@ static void fix_unresolved_deltas(struct hashfile *f)
 				continue;
 			oid_array_append(&to_fetch, &d->oid);
 		}
-		if (to_fetch.nr)
-			promisor_remote_get_direct(the_repository,
-						   to_fetch.oid, to_fetch.nr);
+		promisor_remote_get_direct(the_repository,
+					   to_fetch.oid, to_fetch.nr);
 		oid_array_clear(&to_fetch);
 	}
 
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 944ec77..0b7222e 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -20,6 +20,8 @@
 #define TEST_FILEMODE 1
 #endif
 
+#define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"
+
 static int init_is_bare_repository = 0;
 static int init_shared_repository = -1;
 static const char *init_db_template_dir;
@@ -176,13 +178,36 @@ static int needs_work_tree_config(const char *git_dir, const char *work_tree)
 	return 1;
 }
 
+void initialize_repository_version(int hash_algo)
+{
+	char repo_version_string[10];
+	int repo_version = GIT_REPO_VERSION;
+
+#ifndef ENABLE_SHA256
+	if (hash_algo != GIT_HASH_SHA1)
+		die(_("The hash algorithm %s is not supported in this build."), hash_algos[hash_algo].name);
+#endif
+
+	if (hash_algo != GIT_HASH_SHA1)
+		repo_version = GIT_REPO_VERSION_READ;
+
+	/* This forces creation of new config file */
+	xsnprintf(repo_version_string, sizeof(repo_version_string),
+		  "%d", repo_version);
+	git_config_set("core.repositoryformatversion", repo_version_string);
+
+	if (hash_algo != GIT_HASH_SHA1)
+		git_config_set("extensions.objectformat",
+			       hash_algos[hash_algo].name);
+}
+
 static int create_default_files(const char *template_path,
-				const char *original_git_dir)
+				const char *original_git_dir,
+				const struct repository_format *fmt)
 {
 	struct stat st1;
 	struct strbuf buf = STRBUF_INIT;
 	char *path;
-	char repo_version_string[10];
 	char junk[2];
 	int reinit;
 	int filemode;
@@ -244,10 +269,7 @@ static int create_default_files(const char *template_path,
 			exit(1);
 	}
 
-	/* This forces creation of new config file */
-	xsnprintf(repo_version_string, sizeof(repo_version_string),
-		  "%d", GIT_REPO_VERSION);
-	git_config_set("core.repositoryformatversion", repo_version_string);
+	initialize_repository_version(fmt->hash_algo);
 
 	/* Check filemode trustability */
 	path = git_path_buf(&buf, "config");
@@ -340,12 +362,33 @@ static void separate_git_dir(const char *git_dir, const char *git_link)
 	write_file(git_link, "gitdir: %s", git_dir);
 }
 
+static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
+{
+	const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
+	/*
+	 * If we already have an initialized repo, don't allow the user to
+	 * specify a different algorithm, as that could cause corruption.
+	 * Otherwise, if the user has specified one on the command line, use it.
+	 */
+	if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
+		die(_("attempt to reinitialize repository with different hash"));
+	else if (hash != GIT_HASH_UNKNOWN)
+		repo_fmt->hash_algo = hash;
+	else if (env) {
+		int env_algo = hash_algo_by_name(env);
+		if (env_algo == GIT_HASH_UNKNOWN)
+			die(_("unknown hash algorithm '%s'"), env);
+		repo_fmt->hash_algo = env_algo;
+	}
+}
+
 int init_db(const char *git_dir, const char *real_git_dir,
-	    const char *template_dir, unsigned int flags)
+	    const char *template_dir, int hash, unsigned int flags)
 {
 	int reinit;
 	int exist_ok = flags & INIT_DB_EXIST_OK;
 	char *original_git_dir = real_pathdup(git_dir, 1);
+	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 
 	if (real_git_dir) {
 		struct stat st;
@@ -356,12 +399,12 @@ int init_db(const char *git_dir, const char *real_git_dir,
 		if (!exist_ok && !stat(real_git_dir, &st))
 			die(_("%s already exists"), real_git_dir);
 
-		set_git_dir(real_path(real_git_dir));
+		set_git_dir(real_git_dir, 1);
 		git_dir = get_git_dir();
 		separate_git_dir(git_dir, original_git_dir);
 	}
 	else {
-		set_git_dir(real_path(git_dir));
+		set_git_dir(git_dir, 1);
 		git_dir = get_git_dir();
 	}
 	startup_info->have_repository = 1;
@@ -378,9 +421,11 @@ int init_db(const char *git_dir, const char *real_git_dir,
 	 * config file, so this will not fail.  What we are catching
 	 * is an attempt to reinitialize new repository with an old tool.
 	 */
-	check_repository_format();
+	check_repository_format(&repo_fmt);
 
-	reinit = create_default_files(template_dir, original_git_dir);
+	validate_hash_algorithm(&repo_fmt, hash);
+
+	reinit = create_default_files(template_dir, original_git_dir, &repo_fmt);
 
 	create_object_directory();
 
@@ -482,6 +527,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	const char *work_tree;
 	const char *template_dir = NULL;
 	unsigned int flags = 0;
+	const char *object_format = NULL;
+	int hash_algo = GIT_HASH_UNKNOWN;
 	const struct option init_db_options[] = {
 		OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 				N_("directory from which templates will be used")),
@@ -494,6 +541,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 		OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 			   N_("separate git dir from working tree")),
+		OPT_STRING(0, "object-format", &object_format, N_("hash"),
+			   N_("specify the hash algorithm to use")),
 		OPT_END()
 	};
 
@@ -546,6 +595,12 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		free(cwd);
 	}
 
+	if (object_format) {
+		hash_algo = hash_algo_by_name(object_format);
+		if (hash_algo == GIT_HASH_UNKNOWN)
+			die(_("unknown hash algorithm '%s'"), object_format);
+	}
+
 	if (init_shared_repository != -1)
 		set_shared_repository(init_shared_repository);
 
@@ -597,5 +652,5 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 	UNLEAK(work_tree);
 
 	flags |= INIT_DB_EXIST_OK;
-	return init_db(git_dir, real_git_dir, template_dir, flags);
+	return init_db(git_dir, real_git_dir, template_dir, hash_algo, flags);
 }
diff --git a/builtin/log.c b/builtin/log.c
index 83a4a61..bef7403 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -46,6 +46,7 @@ static int default_abbrev_commit;
 static int default_show_root = 1;
 static int default_follow;
 static int default_show_signature;
+static int default_encode_email_headers = 1;
 static int decoration_style;
 static int decoration_given;
 static int use_mailmap_config = 1;
@@ -151,6 +152,7 @@ static void cmd_log_init_defaults(struct rev_info *rev)
 	rev->show_root_diff = default_show_root;
 	rev->subject_prefix = fmt_patch_subject_prefix;
 	rev->show_signature = default_show_signature;
+	rev->encode_email_headers = default_encode_email_headers;
 	rev->diffopt.flags.allow_textconv = 1;
 
 	if (default_date_mode)
@@ -164,15 +166,18 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	int quiet = 0, source = 0, mailmap;
 	static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
 	static struct string_list decorate_refs_exclude = STRING_LIST_INIT_NODUP;
+	static struct string_list decorate_refs_exclude_config = STRING_LIST_INIT_NODUP;
 	static struct string_list decorate_refs_include = STRING_LIST_INIT_NODUP;
 	struct decoration_filter decoration_filter = {&decorate_refs_include,
-						      &decorate_refs_exclude};
+						      &decorate_refs_exclude,
+						      &decorate_refs_exclude_config};
 	static struct revision_sources revision_sources;
 
 	const struct option builtin_log_options[] = {
 		OPT__QUIET(&quiet, N_("suppress diff output")),
 		OPT_BOOL(0, "source", &source, N_("show source")),
 		OPT_BOOL(0, "use-mailmap", &mailmap, N_("Use mail map file")),
+		OPT_ALIAS(0, "mailmap", "use-mailmap"),
 		OPT_STRING_LIST(0, "decorate-refs", &decorate_refs_include,
 				N_("pattern"), N_("only decorate refs that match <pattern>")),
 		OPT_STRING_LIST(0, "decorate-refs-exclude", &decorate_refs_exclude,
@@ -236,7 +241,19 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	}
 
 	if (decoration_style) {
+		const struct string_list *config_exclude =
+			repo_config_get_value_multi(the_repository,
+						    "log.excludeDecoration");
+
+		if (config_exclude) {
+			struct string_list_item *item;
+			for_each_string_list_item(item, config_exclude)
+				string_list_append(&decorate_refs_exclude_config,
+						   item->string);
+		}
+
 		rev->show_decorations = 1;
+
 		load_ref_decorations(&decoration_filter, decoration_style);
 	}
 
@@ -438,6 +455,10 @@ static int git_log_config(const char *var, const char *value, void *cb)
 		return git_config_string(&fmt_pretty, var, value);
 	if (!strcmp(var, "format.subjectprefix"))
 		return git_config_string(&fmt_patch_subject_prefix, var, value);
+	if (!strcmp(var, "format.encodeemailheaders")) {
+		default_encode_email_headers = git_config_bool(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "log.abbrevcommit")) {
 		default_abbrev_commit = git_config_bool(var, value);
 		return 0;
@@ -1719,6 +1740,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.show_notes = show_notes;
 	memcpy(&rev.notes_opt, &notes_opt, sizeof(notes_opt));
 	rev.commit_format = CMIT_FMT_EMAIL;
+	rev.encode_email_headers = default_encode_email_headers;
 	rev.expand_tabs_in_log_default = 0;
 	rev.verbose_header = 1;
 	rev.diff = 1;
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index f069a02..b87c22a 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -128,8 +128,9 @@ static void show_dir_entry(const struct index_state *istate,
 	if (len > ent->len)
 		die("git ls-files: internal error - directory entry not superset of prefix");
 
-	if (!dir_path_match(istate, ent, &pathspec, len, ps_matched))
-		return;
+	/* If ps_matches is non-NULL, figure out which pathspec(s) match. */
+	if (ps_matched)
+		dir_path_match(istate, ent, &pathspec, len, ps_matched);
 
 	fputs(tag, stdout);
 	write_eolinfo(istate, NULL, ent->name);
diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index e3f8da1..6719ac1 100644
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -114,26 +114,16 @@ static int handle_is_ancestor(int argc, const char **argv)
 static int handle_fork_point(int argc, const char **argv)
 {
 	struct object_id oid;
-	char *refname;
 	struct commit *derived, *fork_point;
 	const char *commitname;
 
-	switch (dwim_ref(argv[0], strlen(argv[0]), &oid, &refname)) {
-	case 0:
-		die("No such ref: '%s'", argv[0]);
-	case 1:
-		break; /* good */
-	default:
-		die("Ambiguous refname: '%s'", argv[0]);
-	}
-
 	commitname = (argc == 2) ? argv[1] : "HEAD";
 	if (get_oid(commitname, &oid))
 		die("Not a valid object name: '%s'", commitname);
 
 	derived = lookup_commit_reference(the_repository, &oid);
 
-	fork_point = get_fork_point(refname, derived);
+	fork_point = get_fork_point(argv[0], derived);
 
 	if (!fork_point)
 		return 1;
diff --git a/builtin/merge.c b/builtin/merge.c
index d127d22..f78ac75 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -82,6 +82,7 @@ static int show_progress = -1;
 static int default_to_upstream = 1;
 static int signoff;
 static const char *sign_commit;
+static int autostash;
 static int no_verify;
 
 static struct strategy all_strategy[] = {
@@ -286,6 +287,7 @@ static struct option builtin_merge_options[] = {
 	OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
 	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
 	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+	OPT_AUTOSTASH(&autostash),
 	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
 	OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
 	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass pre-merge-commit and commit-msg hooks")),
@@ -475,6 +477,7 @@ static void finish(struct commit *head_commit,
 	/* Run a post-merge hook */
 	run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
 
+	apply_autostash(git_path_merge_autostash(the_repository));
 	strbuf_release(&reflog_message);
 }
 
@@ -597,10 +600,12 @@ static void parse_branch_merge_options(char *bmo)
 static int git_merge_config(const char *k, const char *v, void *cb)
 {
 	int status;
+	const char *str;
 
-	if (branch && starts_with(k, "branch.") &&
-		starts_with(k + 7, branch) &&
-		!strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
+	if (branch &&
+	    skip_prefix(k, "branch.", &str) &&
+	    skip_prefix(str, branch, &str) &&
+	    !strcmp(str, ".mergeoptions")) {
 		free(branch_mergeoptions);
 		branch_mergeoptions = xstrdup(v);
 		return 0;
@@ -634,6 +639,9 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		return 0;
 	} else if (!strcmp(k, "gpg.mintrustlevel")) {
 		check_trust_level = 0;
+	} else if (!strcmp(k, "merge.autostash")) {
+		autostash = git_config_bool(k, v);
+		return 0;
 	}
 
 	status = fmt_merge_msg_config(k, v, cb);
@@ -1281,6 +1289,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (abort_current_merge) {
 		int nargc = 2;
 		const char *nargv[] = {"reset", "--merge", NULL};
+		struct strbuf stash_oid = STRBUF_INIT;
 
 		if (orig_argc != 2)
 			usage_msg_opt(_("--abort expects no arguments"),
@@ -1289,8 +1298,17 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		if (!file_exists(git_path_merge_head(the_repository)))
 			die(_("There is no merge to abort (MERGE_HEAD missing)."));
 
+		if (read_oneliner(&stash_oid, git_path_merge_autostash(the_repository),
+		    READ_ONELINER_SKIP_IF_EMPTY))
+			unlink(git_path_merge_autostash(the_repository));
+
 		/* Invoke 'git reset --merge' */
 		ret = cmd_reset(nargc, nargv, prefix);
+
+		if (stash_oid.len)
+			apply_autostash_oid(stash_oid.buf);
+
+		strbuf_release(&stash_oid);
 		goto done;
 	}
 
@@ -1513,6 +1531,10 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			goto done;
 		}
 
+		if (autostash)
+			create_autostash(the_repository,
+					 git_path_merge_autostash(the_repository),
+					 "merge");
 		if (checkout_fast_forward(the_repository,
 					  &head_commit->object.oid,
 					  &commit->object.oid,
@@ -1579,6 +1601,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (fast_forward == FF_ONLY)
 		die(_("Not possible to fast-forward, aborting."));
 
+	if (autostash)
+		create_autostash(the_repository,
+				 git_path_merge_autostash(the_repository),
+				 "merge");
+
 	/* We are going to make a new commit. */
 	git_committer_info(IDENT_STRICT);
 
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 02aa6ee..fdd18c7 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -26,7 +26,7 @@
 #include "pack-bitmap.h"
 #include "delta-islands.h"
 #include "reachable.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "argv-array.h"
 #include "list.h"
 #include "packfile.h"
@@ -880,7 +880,7 @@ static void write_reused_pack_one(size_t pos, struct hashfile *out,
 			len = encode_in_pack_object_header(header, sizeof(header),
 							   OBJ_REF_DELTA, size);
 			hashwrite(out, header, len);
-			hashwrite(out, base_oid.hash, 20);
+			hashwrite(out, base_oid.hash, the_hash_algo->rawsz);
 			copy_pack_data(out, reuse_packfile, w_curs, cur, next - cur);
 			return;
 		}
@@ -3469,9 +3469,9 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 
 	read_replace_refs = 0;
 
-	sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
+	sparse = git_env_bool("GIT_TEST_PACK_SPARSE", -1);
 	prepare_repo_settings(the_repository);
-	if (!sparse && the_repository->settings.pack_use_sparse != -1)
+	if (sparse < 0)
 		sparse = the_repository->settings.pack_use_sparse;
 
 	reset_pack_idx_option(&pack_idx_opts);
diff --git a/builtin/prune-packed.c b/builtin/prune-packed.c
index 48c5e78..b7b9281 100644
--- a/builtin/prune-packed.c
+++ b/builtin/prune-packed.c
@@ -1,54 +1,12 @@
 #include "builtin.h"
-#include "cache.h"
-#include "progress.h"
 #include "parse-options.h"
-#include "packfile.h"
-#include "object-store.h"
+#include "prune-packed.h"
 
 static const char * const prune_packed_usage[] = {
 	N_("git prune-packed [-n | --dry-run] [-q | --quiet]"),
 	NULL
 };
 
-static struct progress *progress;
-
-static int prune_subdir(unsigned int nr, const char *path, void *data)
-{
-	int *opts = data;
-	display_progress(progress, nr + 1);
-	if (!(*opts & PRUNE_PACKED_DRY_RUN))
-		rmdir(path);
-	return 0;
-}
-
-static int prune_object(const struct object_id *oid, const char *path,
-			 void *data)
-{
-	int *opts = data;
-
-	if (!has_object_pack(oid))
-		return 0;
-
-	if (*opts & PRUNE_PACKED_DRY_RUN)
-		printf("rm -f %s\n", path);
-	else
-		unlink_or_warn(path);
-	return 0;
-}
-
-void prune_packed_objects(int opts)
-{
-	if (opts & PRUNE_PACKED_VERBOSE)
-		progress = start_delayed_progress(_("Removing duplicate objects"), 256);
-
-	for_each_loose_file_in_objdir(get_object_directory(),
-				      prune_object, NULL, prune_subdir, &opts);
-
-	/* Ensure we show 100% before finishing progress */
-	display_progress(progress, 256);
-	stop_progress(&progress);
-}
-
 int cmd_prune_packed(int argc, const char **argv, const char *prefix)
 {
 	int opts = isatty(2) ? PRUNE_PACKED_VERBOSE : 0;
diff --git a/builtin/prune.c b/builtin/prune.c
index 2b76872..fd9acc7 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -6,6 +6,7 @@
 #include "reachable.h"
 #include "parse-options.h"
 #include "progress.h"
+#include "prune-packed.h"
 #include "object-store.h"
 
 static const char * const prune_usage[] = {
diff --git a/builtin/pull.c b/builtin/pull.c
index 3e624d1..f1fa6db 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -12,7 +12,7 @@
 #include "parse-options.h"
 #include "exec-cmd.h"
 #include "run-command.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "remote.h"
 #include "dir.h"
 #include "rebase.h"
@@ -110,6 +110,7 @@ static char *opt_ipv4;
 static char *opt_ipv6;
 static int opt_show_forced_updates = -1;
 static char *set_upstream;
+static struct argv_array opt_fetch = ARGV_ARRAY_INIT;
 
 static struct option pull_options[] = {
 	/* Shared options */
@@ -163,7 +164,7 @@ static struct option pull_options[] = {
 		N_("verify that the named commit has a valid GPG signature"),
 		PARSE_OPT_NOARG),
 	OPT_BOOL(0, "autostash", &opt_autostash,
-		N_("automatically stash/stash pop before and after rebase")),
+		N_("automatically stash/stash pop before and after")),
 	OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
 		N_("merge strategy to use"),
 		0),
@@ -207,6 +208,15 @@ static struct option pull_options[] = {
 	OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
 		N_("deepen history of shallow clone"),
 		0),
+	OPT_PASSTHRU_ARGV(0, "shallow-since", &opt_fetch, N_("time"),
+		N_("deepen history of shallow repository based on time"),
+		0),
+	OPT_PASSTHRU_ARGV(0, "shallow-exclude", &opt_fetch, N_("revision"),
+		N_("deepen history of shallow clone, excluding rev"),
+		0),
+	OPT_PASSTHRU_ARGV(0, "deepen", &opt_fetch, N_("n"),
+		N_("deepen history of shallow clone"),
+		0),
 	OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
 		N_("convert to a complete repository"),
 		PARSE_OPT_NONEG | PARSE_OPT_NOARG),
@@ -216,12 +226,19 @@ static struct option pull_options[] = {
 	OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
 		N_("specify fetch refmap"),
 		PARSE_OPT_NONEG),
+	OPT_PASSTHRU_ARGV('o', "server-option", &opt_fetch,
+		N_("server-specific"),
+		N_("option to transmit"),
+		0),
 	OPT_PASSTHRU('4',  "ipv4", &opt_ipv4, NULL,
 		N_("use IPv4 addresses only"),
 		PARSE_OPT_NOARG),
 	OPT_PASSTHRU('6',  "ipv6", &opt_ipv6, NULL,
 		N_("use IPv6 addresses only"),
 		PARSE_OPT_NOARG),
+	OPT_PASSTHRU_ARGV(0, "negotiation-tip", &opt_fetch, N_("revision"),
+		N_("report that we have only objects reachable from this object"),
+		0),
 	OPT_BOOL(0, "show-forced-updates", &opt_show_forced_updates,
 		 N_("check for forced-updates on all updated branches")),
 	OPT_PASSTHRU(0, "set-upstream", &set_upstream, NULL,
@@ -327,6 +344,22 @@ static enum rebase_type config_get_rebase(void)
 	if (!git_config_get_value("pull.rebase", &value))
 		return parse_config_rebase("pull.rebase", value, 1);
 
+	if (opt_verbosity >= 0 &&
+	    (!opt_ff || strcmp(opt_ff, "--ff-only"))) {
+		warning(_("Pulling without specifying how to reconcile divergent branches is\n"
+			"discouraged. You can squelch this message by running one of the following\n"
+			"commands sometime before your next pull:\n"
+			"\n"
+			"  git config pull.rebase false  # merge (the default strategy)\n"
+			"  git config pull.rebase true   # rebase\n"
+			"  git config pull.ff only       # fast-forward only\n"
+			"\n"
+			"You can replace \"git config\" with \"git config --global\" to set a default\n"
+			"preference for all repositories. You can also pass --rebase, --no-rebase,\n"
+			"or --ff-only on the command line to override the configured default per\n"
+			"invocation.\n"));
+	}
+
 	return REBASE_FALSE;
 }
 
@@ -551,6 +584,7 @@ static int run_fetch(const char *repo, const char **refspecs)
 		argv_array_push(&args, "--no-show-forced-updates");
 	if (set_upstream)
 		argv_array_push(&args, set_upstream);
+	argv_array_pushv(&args, opt_fetch.argv);
 
 	if (repo) {
 		argv_array_push(&args, repo);
@@ -661,6 +695,10 @@ static int run_merge(void)
 	argv_array_pushv(&args, opt_strategy_opts.argv);
 	if (opt_gpg_sign)
 		argv_array_push(&args, opt_gpg_sign);
+	if (opt_autostash == 0)
+		argv_array_push(&args, "--no-autostash");
+	else if (opt_autostash == 1)
+		argv_array_push(&args, "--autostash");
 	if (opt_allow_unrelated_histories > 0)
 		argv_array_push(&args, "--allow-unrelated-histories");
 
@@ -908,9 +946,6 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (get_oid("HEAD", &orig_head))
 		oidclr(&orig_head);
 
-	if (!opt_rebase && opt_autostash != -1)
-		die(_("--[no-]autostash option is only valid with --rebase."));
-
 	autostash = config_autostash;
 	if (opt_rebase) {
 		if (opt_autostash != -1)
@@ -976,6 +1011,7 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 
 	if (opt_rebase) {
 		int ret = 0;
+		int ran_ff = 0;
 		if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
 		     recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
 		    submodule_touches_in_range(the_repository, &rebase_fork_point, &curr_head))
@@ -992,10 +1028,12 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 			if (is_descendant_of(merge_head, list)) {
 				/* we can fast-forward this without invoking rebase */
 				opt_ff = "--ff-only";
+				ran_ff = 1;
 				ret = run_merge();
 			}
 		}
-		ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
+		if (!ran_ff)
+			ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
 
 		if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
 			     recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
diff --git a/builtin/rebase.c b/builtin/rebase.c
index bff53d5..1c0a49c 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -27,6 +27,9 @@
 #include "branch.h"
 #include "sequencer.h"
 #include "rebase-interactive.h"
+#include "reset.h"
+
+#define DEFAULT_REFLOG_ACTION "rebase"
 
 static char const * const builtin_rebase_usage[] = {
 	N_("git rebase [-i] [options] [--exec <cmd>] "
@@ -85,6 +88,7 @@ struct rebase_options {
 	const char *action;
 	int signoff;
 	int allow_rerere_autoupdate;
+	int keep_empty;
 	int autosquash;
 	char *gpg_sign_opt;
 	int autostash;
@@ -95,11 +99,13 @@ struct rebase_options {
 	struct strbuf git_format_patch_opt;
 	int reschedule_failed_exec;
 	int use_legacy_rebase;
+	int reapply_cherry_picks;
 };
 
 #define REBASE_OPTIONS_INIT {			  	\
 		.type = REBASE_UNSPECIFIED,	  	\
 		.empty = EMPTY_UNSPECIFIED,	  	\
+		.keep_empty = 1,			\
 		.default_backend = "merge",	  	\
 		.flags = REBASE_NO_QUIET, 		\
 		.git_am_opts = ARGV_ARRAY_INIT,		\
@@ -379,11 +385,13 @@ static int run_sequencer_rebase(struct rebase_options *opts,
 
 	git_config_get_bool("rebase.abbreviatecommands", &abbreviate_commands);
 
+	flags |= opts->keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 	flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 	flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 	flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 	flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 	flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
+	flags |= opts->reapply_cherry_picks ? TODO_LIST_REAPPLY_CHERRY_PICKS : 0;
 
 	switch (command) {
 	case ACTION_NONE: {
@@ -442,6 +450,7 @@ static int run_sequencer_rebase(struct rebase_options *opts,
 	return ret;
 }
 
+static void imply_merge(struct rebase_options *opts, const char *option);
 static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 				int unset)
 {
@@ -449,10 +458,8 @@ static int parse_opt_keep_empty(const struct option *opt, const char *arg,
 
 	BUG_ON_OPT_ARG(arg);
 
-	/*
-	 * If we ever want to remap --keep-empty to --empty=keep, insert:
-	 * 	opts->empty = unset ? EMPTY_UNSPECIFIED : EMPTY_KEEP;
-	 */
+	imply_merge(opts, unset ? "--no-keep-empty" : "--keep-empty");
+	opts->keep_empty = !unset;
 	opts->type = REBASE_MERGE;
 	return 0;
 }
@@ -471,7 +478,7 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 		OPT_NEGBIT(0, "ff", &opts.flags, N_("allow fast-forward"),
 			   REBASE_FORCE),
 		{ OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
-			N_("(DEPRECATED) keep empty commits"),
+			N_("keep commits which start empty"),
 			PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 			parse_opt_keep_empty },
 		OPT_BOOL_F(0, "allow-empty-message", &opts.allow_empty_message,
@@ -559,7 +566,7 @@ static void imply_merge(struct rebase_options *opts, const char *option)
 {
 	switch (opts->type) {
 	case REBASE_APPLY:
-		die(_("%s requires an interactive rebase"), option);
+		die(_("%s requires the merge backend"), option);
 		break;
 	case REBASE_MERGE:
 	case REBASE_PRESERVE_MERGES:
@@ -586,15 +593,6 @@ static const char *state_dir_path(const char *filename, struct rebase_options *o
 	return path.buf;
 }
 
-/* Read one file, then strip line endings */
-static int read_one(const char *path, struct strbuf *buf)
-{
-	if (strbuf_read_file(buf, path, 0) < 0)
-		return error_errno(_("could not read '%s'"), path);
-	strbuf_trim_trailing_newline(buf);
-	return 0;
-}
-
 /* Initialize the rebase options from the state directory. */
 static int read_basic_state(struct rebase_options *opts)
 {
@@ -602,8 +600,10 @@ static int read_basic_state(struct rebase_options *opts)
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id oid;
 
-	if (read_one(state_dir_path("head-name", opts), &head_name) ||
-	    read_one(state_dir_path("onto", opts), &buf))
+	if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
+			   READ_ONELINER_WARN_MISSING) ||
+	    !read_oneliner(&buf, state_dir_path("onto", opts),
+			   READ_ONELINER_WARN_MISSING))
 		return -1;
 	opts->head_name = starts_with(head_name.buf, "refs/") ?
 		xstrdup(head_name.buf) : NULL;
@@ -619,9 +619,11 @@ static int read_basic_state(struct rebase_options *opts)
 	 */
 	strbuf_reset(&buf);
 	if (file_exists(state_dir_path("orig-head", opts))) {
-		if (read_one(state_dir_path("orig-head", opts), &buf))
+		if (!read_oneliner(&buf, state_dir_path("orig-head", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
-	} else if (read_one(state_dir_path("head", opts), &buf))
+	} else if (!read_oneliner(&buf, state_dir_path("head", opts),
+				  READ_ONELINER_WARN_MISSING))
 		return -1;
 	if (get_oid(buf.buf, &opts->orig_head))
 		return error(_("invalid orig-head: '%s'"), buf.buf);
@@ -641,8 +643,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
-			    &buf))
+		if (!read_oneliner(&buf, state_dir_path("allow_rerere_autoupdate", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		if (!strcmp(buf.buf, "--rerere-autoupdate"))
 			opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
@@ -655,8 +657,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("gpg_sign_opt", opts),
-			    &buf))
+		if (!read_oneliner(&buf, state_dir_path("gpg_sign_opt", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		free(opts->gpg_sign_opt);
 		opts->gpg_sign_opt = xstrdup(buf.buf);
@@ -664,7 +666,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("strategy", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("strategy", opts), &buf))
+		if (!read_oneliner(&buf, state_dir_path("strategy", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		free(opts->strategy);
 		opts->strategy = xstrdup(buf.buf);
@@ -672,7 +675,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("strategy_opts", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("strategy_opts", opts), &buf))
+		if (!read_oneliner(&buf, state_dir_path("strategy_opts", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		free(opts->strategy_opts);
 		opts->strategy_opts = xstrdup(buf.buf);
@@ -715,51 +719,6 @@ static int rebase_write_basic_state(struct rebase_options *opts)
 	return 0;
 }
 
-static int apply_autostash(struct rebase_options *opts)
-{
-	const char *path = state_dir_path("autostash", opts);
-	struct strbuf autostash = STRBUF_INIT;
-	struct child_process stash_apply = CHILD_PROCESS_INIT;
-
-	if (!file_exists(path))
-		return 0;
-
-	if (read_one(path, &autostash))
-		return error(_("Could not read '%s'"), path);
-	/* Ensure that the hash is not mistaken for a number */
-	strbuf_addstr(&autostash, "^0");
-	argv_array_pushl(&stash_apply.args,
-			 "stash", "apply", autostash.buf, NULL);
-	stash_apply.git_cmd = 1;
-	stash_apply.no_stderr = stash_apply.no_stdout =
-		stash_apply.no_stdin = 1;
-	if (!run_command(&stash_apply))
-		printf(_("Applied autostash.\n"));
-	else {
-		struct argv_array args = ARGV_ARRAY_INIT;
-		int res = 0;
-
-		argv_array_pushl(&args,
-				 "stash", "store", "-m", "autostash", "-q",
-				 autostash.buf, NULL);
-		if (run_command_v_opt(args.argv, RUN_GIT_CMD))
-			res = error(_("Cannot store %s"), autostash.buf);
-		argv_array_clear(&args);
-		strbuf_release(&autostash);
-		if (res)
-			return res;
-
-		fprintf(stderr,
-			_("Applying autostash resulted in conflicts.\n"
-			  "Your changes are safe in the stash.\n"
-			  "You can run \"git stash pop\" or \"git stash drop\" "
-			  "at any time.\n"));
-	}
-
-	strbuf_release(&autostash);
-	return 0;
-}
-
 static int finish_rebase(struct rebase_options *opts)
 {
 	struct strbuf dir = STRBUF_INIT;
@@ -767,7 +726,7 @@ static int finish_rebase(struct rebase_options *opts)
 	int ret = 0;
 
 	delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
-	apply_autostash(opts);
+	apply_autostash(state_dir_path("autostash", opts));
 	close_object_store(the_repository->objects);
 	/*
 	 * We ignore errors in 'gc --auto', since the
@@ -812,143 +771,6 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
 	}
 }
 
-#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
-
-#define RESET_HEAD_DETACH (1<<0)
-#define RESET_HEAD_HARD (1<<1)
-#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
-#define RESET_HEAD_REFS_ONLY (1<<3)
-#define RESET_ORIG_HEAD (1<<4)
-
-static int reset_head(struct object_id *oid, const char *action,
-		      const char *switch_to_branch, unsigned flags,
-		      const char *reflog_orig_head, const char *reflog_head)
-{
-	unsigned detach_head = flags & RESET_HEAD_DETACH;
-	unsigned reset_hard = flags & RESET_HEAD_HARD;
-	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
-	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
-	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
-	struct object_id head_oid;
-	struct tree_desc desc[2] = { { NULL }, { NULL } };
-	struct lock_file lock = LOCK_INIT;
-	struct unpack_trees_options unpack_tree_opts;
-	struct tree *tree;
-	const char *reflog_action;
-	struct strbuf msg = STRBUF_INIT;
-	size_t prefix_len;
-	struct object_id *orig = NULL, oid_orig,
-		*old_orig = NULL, oid_old_orig;
-	int ret = 0, nr = 0;
-
-	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
-		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
-
-	if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
-		ret = -1;
-		goto leave_reset_head;
-	}
-
-	if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
-		ret = error(_("could not determine HEAD revision"));
-		goto leave_reset_head;
-	}
-
-	if (!oid)
-		oid = &head_oid;
-
-	if (refs_only)
-		goto reset_head_refs;
-
-	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
-	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
-	unpack_tree_opts.head_idx = 1;
-	unpack_tree_opts.src_index = the_repository->index;
-	unpack_tree_opts.dst_index = the_repository->index;
-	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
-	unpack_tree_opts.update = 1;
-	unpack_tree_opts.merge = 1;
-	if (!detach_head)
-		unpack_tree_opts.reset = 1;
-
-	if (repo_read_index_unmerged(the_repository) < 0) {
-		ret = error(_("could not read index"));
-		goto leave_reset_head;
-	}
-
-	if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
-		ret = error(_("failed to find tree of %s"),
-			    oid_to_hex(&head_oid));
-		goto leave_reset_head;
-	}
-
-	if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
-		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
-		goto leave_reset_head;
-	}
-
-	if (unpack_trees(nr, desc, &unpack_tree_opts)) {
-		ret = -1;
-		goto leave_reset_head;
-	}
-
-	tree = parse_tree_indirect(oid);
-	prime_cache_tree(the_repository, the_repository->index, tree);
-
-	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
-		ret = error(_("could not write index"));
-		goto leave_reset_head;
-	}
-
-reset_head_refs:
-	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
-	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
-	prefix_len = msg.len;
-
-	if (update_orig_head) {
-		if (!get_oid("ORIG_HEAD", &oid_old_orig))
-			old_orig = &oid_old_orig;
-		if (!get_oid("HEAD", &oid_orig)) {
-			orig = &oid_orig;
-			if (!reflog_orig_head) {
-				strbuf_addstr(&msg, "updating ORIG_HEAD");
-				reflog_orig_head = msg.buf;
-			}
-			update_ref(reflog_orig_head, "ORIG_HEAD", orig,
-				   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
-		} else if (old_orig)
-			delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
-	}
-
-	if (!reflog_head) {
-		strbuf_setlen(&msg, prefix_len);
-		strbuf_addstr(&msg, "updating HEAD");
-		reflog_head = msg.buf;
-	}
-	if (!switch_to_branch)
-		ret = update_ref(reflog_head, "HEAD", oid, orig,
-				 detach_head ? REF_NO_DEREF : 0,
-				 UPDATE_REFS_MSG_ON_ERR);
-	else {
-		ret = update_ref(reflog_head, switch_to_branch, oid,
-				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
-		if (!ret)
-			ret = create_symref("HEAD", switch_to_branch,
-					    reflog_head);
-	}
-	if (run_hook)
-		run_hook_le(NULL, "post-checkout",
-			    oid_to_hex(orig ? orig : &null_oid),
-			    oid_to_hex(oid), "1", NULL);
-
-leave_reset_head:
-	strbuf_release(&msg);
-	rollback_lock_file(&lock);
-	while (nr)
-		free((void *)desc[--nr].buffer);
-	return ret;
-}
-
 static int move_to_original_branch(struct rebase_options *opts)
 {
 	struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
@@ -964,8 +786,10 @@ static int move_to_original_branch(struct rebase_options *opts)
 		    opts->head_name, oid_to_hex(&opts->onto->object.oid));
 	strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 		    opts->head_name);
-	ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
-			 orig_head_reflog.buf, head_reflog.buf);
+	ret = reset_head(the_repository, NULL, "", opts->head_name,
+			 RESET_HEAD_REFS_ONLY,
+			 orig_head_reflog.buf, head_reflog.buf,
+			 DEFAULT_REFLOG_ACTION);
 
 	strbuf_release(&orig_head_reflog);
 	strbuf_release(&head_reflog);
@@ -1053,8 +877,9 @@ static int run_am(struct rebase_options *opts)
 		free(rebased_patches);
 		argv_array_clear(&am.args);
 
-		reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
-			   "HEAD", NULL);
+		reset_head(the_repository, &opts->orig_head, "checkout",
+			   opts->head_name, 0,
+			   "HEAD", NULL, DEFAULT_REFLOG_ACTION);
 		error(_("\ngit encountered an error while preparing the "
 			"patches to replay\n"
 			"these revisions:\n"
@@ -1162,6 +987,7 @@ static int run_specific_rebase(struct rebase_options *opts, enum action action)
 		opts->allow_rerere_autoupdate ?
 			opts->allow_rerere_autoupdate == RERERE_AUTOUPDATE ?
 			"--rerere-autoupdate" : "--no-rerere-autoupdate" : "");
+	add_var(&script_snippet, "keep_empty", opts->keep_empty ? "yes" : "");
 	add_var(&script_snippet, "autosquash", opts->autosquash ? "t" : "");
 	add_var(&script_snippet, "gpg_sign_opt", opts->gpg_sign_opt);
 	add_var(&script_snippet, "cmd", opts->cmd);
@@ -1212,7 +1038,7 @@ static int run_specific_rebase(struct rebase_options *opts, enum action action)
 	} else if (status == 2) {
 		struct strbuf dir = STRBUF_INIT;
 
-		apply_autostash(opts);
+		apply_autostash(state_dir_path("autostash", opts));
 		strbuf_addstr(&dir, opts->state_dir);
 		remove_dir_recursively(&dir, 0);
 		strbuf_release(&dir);
@@ -1453,7 +1279,6 @@ static int check_exec_cmd(const char *cmd)
 	return 0;
 }
 
-
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
 	struct rebase_options options = REBASE_OPTIONS_INIT;
@@ -1547,7 +1372,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			       N_("how to handle commits that become empty"),
 			       PARSE_OPT_NONEG, parse_opt_empty),
 		{ OPTION_CALLBACK, 'k', "keep-empty", &options, NULL,
-			N_("(DEPRECATED) keep empty commits"),
+			N_("keep commits which start empty"),
 			PARSE_OPT_NOARG | PARSE_OPT_HIDDEN,
 			parse_opt_keep_empty },
 		OPT_BOOL(0, "autosquash", &options.autosquash,
@@ -1556,8 +1381,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		{ OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 			N_("GPG-sign commits"),
 			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
-		OPT_BOOL(0, "autostash", &options.autostash,
-			 N_("automatically stash/stash pop before and after")),
+		OPT_AUTOSTASH(&options.autostash),
 		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 				N_("add exec lines after each commit of the "
 				   "editable list")),
@@ -1582,6 +1406,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "reschedule-failed-exec",
 			 &reschedule_failed_exec,
 			 N_("automatically re-schedule any `exec` that fails")),
+		OPT_BOOL(0, "reapply-cherry-picks", &options.reapply_cherry_picks,
+			 N_("apply all changes, even those already present upstream")),
 		OPT_END(),
 	};
 	int i;
@@ -1592,6 +1418,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	options.allow_empty_message = 1;
 	git_config(rebase_config, &options);
+	/* options.gpg_sign_opt will be either "-S" or NULL */
+	gpg_sign = options.gpg_sign_opt ? "" : NULL;
+	FREE_AND_NULL(options.gpg_sign_opt);
 
 	if (options.use_legacy_rebase ||
 	    !git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1))
@@ -1709,8 +1538,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		rerere_clear(the_repository, &merge_rr);
 		string_list_clear(&merge_rr, 1);
 
-		if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
-			       NULL, NULL) < 0)
+		if (reset_head(the_repository, NULL, "reset", NULL, RESET_HEAD_HARD,
+			       NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
 			die(_("could not discard worktree changes"));
 		remove_branch_state(the_repository, 0);
 		if (read_basic_state(&options))
@@ -1727,9 +1556,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 		if (read_basic_state(&options))
 			exit(1);
-		if (reset_head(&options.orig_head, "reset",
+		if (reset_head(the_repository, &options.orig_head, "reset",
 			       options.head_name, RESET_HEAD_HARD,
-			       NULL, NULL) < 0)
+			       NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
 			die(_("could not move back to %s"),
 			    oid_to_hex(&options.orig_head));
 		remove_branch_state(the_repository, 0);
@@ -1737,6 +1566,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		goto cleanup;
 	}
 	case ACTION_QUIT: {
+		save_autostash(state_dir_path("autostash", &options));
 		if (options.type == REBASE_MERGE) {
 			struct replay_opts replay = REPLAY_OPTS_INIT;
 
@@ -1822,10 +1652,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	if (options.empty != EMPTY_UNSPECIFIED)
 		imply_merge(&options, "--empty");
 
-	if (gpg_sign) {
-		free(options.gpg_sign_opt);
+	if (options.reapply_cherry_picks)
+		imply_merge(&options, "--reapply-cherry-picks");
+
+	if (gpg_sign)
 		options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
-	}
 
 	if (exec.nr) {
 		int i;
@@ -2086,49 +1917,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		die(_("could not read index"));
 
 	if (options.autostash) {
-		struct lock_file lock_file = LOCK_INIT;
-		int fd;
-
-		fd = hold_locked_index(&lock_file, 0);
-		refresh_cache(REFRESH_QUIET);
-		if (0 <= fd)
-			repo_update_index_if_able(the_repository, &lock_file);
-		rollback_lock_file(&lock_file);
-
-		if (has_unstaged_changes(the_repository, 1) ||
-		    has_uncommitted_changes(the_repository, 1)) {
-			const char *autostash =
-				state_dir_path("autostash", &options);
-			struct child_process stash = CHILD_PROCESS_INIT;
-			struct object_id oid;
-
-			argv_array_pushl(&stash.args,
-					 "stash", "create", "autostash", NULL);
-			stash.git_cmd = 1;
-			stash.no_stdin = 1;
-			strbuf_reset(&buf);
-			if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
-				die(_("Cannot autostash"));
-			strbuf_trim_trailing_newline(&buf);
-			if (get_oid(buf.buf, &oid))
-				die(_("Unexpected stash response: '%s'"),
-				    buf.buf);
-			strbuf_reset(&buf);
-			strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
-
-			if (safe_create_leading_directories_const(autostash))
-				die(_("Could not create directory for '%s'"),
-				    options.state_dir);
-			write_file(autostash, "%s", oid_to_hex(&oid));
-			printf(_("Created autostash: %s\n"), buf.buf);
-			if (reset_head(NULL, "reset --hard",
-				       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
-				die(_("could not reset --hard"));
-
-			if (discard_index(the_repository->index) < 0 ||
-				repo_read_index(the_repository) < 0)
-				die(_("could not read index"));
-		}
+		create_autostash(the_repository, state_dir_path("autostash", &options),
+				 DEFAULT_REFLOG_ACTION);
 	}
 
 	if (require_clean_work_tree(the_repository, "rebase",
@@ -2162,10 +1952,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 				strbuf_addf(&buf, "%s: checkout %s",
 					    getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
 					    options.switch_to);
-				if (reset_head(&options.orig_head, "checkout",
+				if (reset_head(the_repository,
+					       &options.orig_head, "checkout",
 					       options.head_name,
 					       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
-					       NULL, buf.buf) < 0) {
+					       NULL, buf.buf,
+					       DEFAULT_REFLOG_ACTION) < 0) {
 					ret = !!error(_("could not switch to "
 							"%s"),
 						      options.switch_to);
@@ -2237,10 +2029,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	strbuf_addf(&msg, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
-	if (reset_head(&options.onto->object.oid, "checkout", NULL,
+	if (reset_head(the_repository, &options.onto->object.oid, "checkout", NULL,
 		       RESET_HEAD_DETACH | RESET_ORIG_HEAD |
 		       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
-		       NULL, msg.buf))
+		       NULL, msg.buf, DEFAULT_REFLOG_ACTION))
 		die(_("Could not detach HEAD"));
 	strbuf_release(&msg);
 
@@ -2255,8 +2047,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		strbuf_addf(&msg, "rebase finished: %s onto %s",
 			options.head_name ? options.head_name : "detached HEAD",
 			oid_to_hex(&options.onto->object.oid));
-		reset_head(NULL, "Fast-forwarded", options.head_name,
-			   RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
+		reset_head(the_repository, NULL, "Fast-forwarded", options.head_name,
+			   RESET_HEAD_REFS_ONLY, "HEAD", msg.buf,
+			   DEFAULT_REFLOG_ACTION);
 		strbuf_release(&msg);
 		ret = !!finish_rebase(&options);
 		goto cleanup;
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 652661f..a00f91c 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -13,7 +13,7 @@
 #include "remote.h"
 #include "connect.h"
 #include "string-list.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "connected.h"
 #include "argv-array.h"
 #include "version.h"
@@ -499,12 +499,27 @@ static char *find_header(const char *msg, size_t len, const char *key,
 	return NULL;
 }
 
+/*
+ * Return zero if a and b are equal up to n bytes and nonzero if they are not.
+ * This operation is guaranteed to run in constant time to avoid leaking data.
+ */
+static int constant_memequal(const char *a, const char *b, size_t n)
+{
+	int res = 0;
+	size_t i;
+
+	for (i = 0; i < n; i++)
+		res |= a[i] ^ b[i];
+	return res;
+}
+
 static const char *check_nonce(const char *buf, size_t len)
 {
 	char *nonce = find_header(buf, len, "nonce", NULL);
 	timestamp_t stamp, ostamp;
 	char *bohmac, *expect = NULL;
 	const char *retval = NONCE_BAD;
+	size_t noncelen;
 
 	if (!nonce) {
 		retval = NONCE_MISSING;
@@ -546,8 +561,14 @@ static const char *check_nonce(const char *buf, size_t len)
 		goto leave;
 	}
 
+	noncelen = strlen(nonce);
 	expect = prepare_push_cert_nonce(service_dir, stamp);
-	if (strcmp(expect, nonce)) {
+	if (noncelen != strlen(expect)) {
+		/* This is not even the right size. */
+		retval = NONCE_BAD;
+		goto leave;
+	}
+	if (constant_memequal(expect, nonce, noncelen)) {
 		/* Not what we would have signed earlier */
 		retval = NONCE_BAD;
 		goto leave;
diff --git a/builtin/reflog.c b/builtin/reflog.c
index 81dfd56..52ecf6d 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -459,7 +459,7 @@ static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 static int reflog_expire_config(const char *var, const char *value, void *cb)
 {
 	const char *pattern, *key;
-	int pattern_len;
+	size_t pattern_len;
 	timestamp_t expire;
 	int slot;
 	struct reflog_expire_cfg *ent;
diff --git a/builtin/repack.c b/builtin/repack.c
index 0781763..1b686ee 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -10,6 +10,7 @@
 #include "argv-array.h"
 #include "midx.h"
 #include "packfile.h"
+#include "prune-packed.h"
 #include "object-store.h"
 #include "promisor-remote.h"
 
diff --git a/builtin/reset.c b/builtin/reset.c
index 18228c3..4c63411 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -46,7 +46,7 @@ static inline int is_merge(void)
 	return !access(git_path_merge_head(the_repository), F_OK);
 }
 
-static int reset_index(const struct object_id *oid, int reset_type, int quiet)
+static int reset_index(const char *ref, const struct object_id *oid, int reset_type, int quiet)
 {
 	int i, nr = 0;
 	struct tree_desc desc[2];
@@ -60,6 +60,7 @@ static int reset_index(const struct object_id *oid, int reset_type, int quiet)
 	opts.dst_index = &the_index;
 	opts.fn = oneway_merge;
 	opts.merge = 1;
+	init_checkout_metadata(&opts.meta, ref, oid, NULL);
 	if (!quiet)
 		opts.verbose_update = 1;
 	switch (reset_type) {
@@ -418,11 +419,20 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 				}
 			}
 		} else {
-			int err = reset_index(&oid, reset_type, quiet);
+			struct object_id dummy;
+			char *ref = NULL;
+			int err;
+
+			dwim_ref(rev, strlen(rev), &dummy, &ref);
+			if (ref && !starts_with(ref, "refs/"))
+				ref = NULL;
+
+			err = reset_index(ref, &oid, reset_type, quiet);
 			if (reset_type == KEEP && !err)
-				err = reset_index(&oid, MIXED, quiet);
+				err = reset_index(ref, &oid, MIXED, quiet);
 			if (err)
 				die(_("Could not reset index file to revision '%s'."), rev);
+			free(ref);
 		}
 
 		if (write_locked_index(&the_index, &lock, COMMIT_LOCK))
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 7a00da8..0605643 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -808,9 +808,10 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				continue;
 			}
 			if (!strcmp(arg, "--show-superproject-working-tree")) {
-				const char *superproject = get_superproject_working_tree();
-				if (superproject)
-					puts(superproject);
+				struct strbuf superproject = STRBUF_INIT;
+				if (get_superproject_working_tree(&superproject))
+					puts(superproject.buf);
+				strbuf_release(&superproject);
 				continue;
 			}
 			if (!strcmp(arg, "--show-prefix")) {
@@ -857,7 +858,10 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 					if (!gitdir && !prefix)
 						gitdir = ".git";
 					if (gitdir) {
-						puts(real_path(gitdir));
+						struct strbuf realpath = STRBUF_INIT;
+						strbuf_realpath(&realpath, gitdir, 1);
+						puts(realpath.buf);
+						strbuf_release(&realpath);
 						continue;
 					}
 				}
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 098ebf2..f2c5a34 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -11,7 +11,7 @@
 #include "quote.h"
 #include "transport.h"
 #include "version.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "gpg-interface.h"
 #include "gettext.h"
 #include "protocol.h"
diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 740da4b..95d0882 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -18,7 +18,7 @@
 static const char *empty_base = "";
 
 static char const * const builtin_sparse_checkout_usage[] = {
-	N_("git sparse-checkout (init|list|set|add|disable) <options>"),
+	N_("git sparse-checkout (init|list|set|add|reapply|disable) <options>"),
 	NULL
 };
 
@@ -94,50 +94,37 @@ static int sparse_checkout_list(int argc, const char **argv)
 
 static int update_working_directory(struct pattern_list *pl)
 {
-	int result = 0;
+	enum update_sparsity_result result;
 	struct unpack_trees_options o;
 	struct lock_file lock_file = LOCK_INIT;
-	struct object_id oid;
-	struct tree *tree;
-	struct tree_desc t;
 	struct repository *r = the_repository;
 
-	if (repo_read_index_unmerged(r))
-		die(_("you need to resolve your current index first"));
-
-	if (get_oid("HEAD", &oid))
-		return 0;
-
-	tree = parse_tree_indirect(&oid);
-	parse_tree(tree);
-	init_tree_desc(&t, tree->buffer, tree->size);
-
 	memset(&o, 0, sizeof(o));
 	o.verbose_update = isatty(2);
-	o.merge = 1;
 	o.update = 1;
-	o.fn = oneway_merge;
 	o.head_idx = -1;
 	o.src_index = r->index;
 	o.dst_index = r->index;
 	o.skip_sparse_checkout = 0;
 	o.pl = pl;
-	o.keep_pattern_list = !!pl;
 
-	resolve_undo_clear_index(r->index);
 	setup_work_tree();
 
-	cache_tree_free(&r->index->cache_tree);
-
 	repo_hold_locked_index(r, &lock_file, LOCK_DIE_ON_ERROR);
 
-	core_apply_sparse_checkout = 1;
-	result = unpack_trees(1, &t, &o);
+	setup_unpack_trees_porcelain(&o, "sparse-checkout");
+	result = update_sparsity(&o);
+	clear_unpack_trees_porcelain(&o);
 
-	if (!result) {
-		prime_cache_tree(r, r->index, tree);
+	if (result == UPDATE_SPARSITY_WARNINGS)
+		/*
+		 * We don't do any special handling of warnings from untracked
+		 * files in the way or dirty entries that can't be removed.
+		 */
+		result = UPDATE_SPARSITY_SUCCESS;
+	if (result == UPDATE_SPARSITY_SUCCESS)
 		write_locked_index(r->index, &lock_file, COMMIT_LOCK);
-	} else
+	else
 		rollback_lock_file(&lock_file);
 
 	return result;
@@ -304,8 +291,6 @@ static int sparse_checkout_init(int argc, const char **argv)
 	};
 
 	repo_read_index(the_repository);
-	require_clean_work_tree(the_repository,
-				N_("initialize sparse-checkout"), NULL, 1, 0);
 
 	argc = parse_options(argc, argv, NULL,
 			     builtin_sparse_checkout_init_options,
@@ -560,8 +545,6 @@ static int sparse_checkout_set(int argc, const char **argv, const char *prefix,
 	};
 
 	repo_read_index(the_repository);
-	require_clean_work_tree(the_repository,
-				N_("set sparse-checkout patterns"), NULL, 1, 0);
 
 	argc = parse_options(argc, argv, prefix,
 			     builtin_sparse_checkout_set_options,
@@ -571,14 +554,18 @@ static int sparse_checkout_set(int argc, const char **argv, const char *prefix,
 	return modify_pattern_list(argc, argv, m);
 }
 
+static int sparse_checkout_reapply(int argc, const char **argv)
+{
+	repo_read_index(the_repository);
+	return update_working_directory(NULL);
+}
+
 static int sparse_checkout_disable(int argc, const char **argv)
 {
 	struct pattern_list pl;
 	struct strbuf match_all = STRBUF_INIT;
 
 	repo_read_index(the_repository);
-	require_clean_work_tree(the_repository,
-				N_("disable sparse-checkout"), NULL, 1, 0);
 
 	memset(&pl, 0, sizeof(pl));
 	hashmap_init(&pl.recursive_hashmap, pl_hashmap_cmp, NULL, 0);
@@ -622,6 +609,8 @@ int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
 			return sparse_checkout_set(argc, argv, prefix, REPLACE);
 		if (!strcmp(argv[0], "add"))
 			return sparse_checkout_set(argc, argv, prefix, ADD);
+		if (!strcmp(argv[0], "reapply"))
+			return sparse_checkout_reapply(argc, argv);
 		if (!strcmp(argv[0], "disable"))
 			return sparse_checkout_disable(argc, argv);
 	}
diff --git a/builtin/stash.c b/builtin/stash.c
index 78af6ce..0c52a3b 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -702,6 +702,7 @@ static int list_stash(int argc, const char **argv, const char *prefix)
 
 static int show_stat = 1;
 static int show_patch;
+static int use_legacy_stash;
 
 static int git_stash_config(const char *var, const char *value, void *cb)
 {
@@ -713,7 +714,11 @@ static int git_stash_config(const char *var, const char *value, void *cb)
 		show_patch = git_config_bool(var, value);
 		return 0;
 	}
-	return git_default_config(var, value, cb);
+	if (!strcmp(var, "stash.usebuiltin")) {
+		use_legacy_stash = !git_config_bool(var, value);
+		return 0;
+	}
+	return git_diff_basic_config(var, value, cb);
 }
 
 static int show_stash(int argc, const char **argv, const char *prefix)
@@ -750,7 +755,6 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	 * any options.
 	 */
 	if (revision_args.argc == 1) {
-		git_config(git_stash_config, NULL);
 		if (show_stat)
 			rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT;
 
@@ -857,30 +861,23 @@ static int get_untracked_files(const struct pathspec *ps, int include_untracked,
 			       struct strbuf *untracked_files)
 {
 	int i;
-	int max_len;
 	int found = 0;
-	char *seen;
 	struct dir_struct dir;
 
 	memset(&dir, 0, sizeof(dir));
 	if (include_untracked != INCLUDE_ALL_FILES)
 		setup_standard_excludes(&dir);
 
-	seen = xcalloc(ps->nr, 1);
-
-	max_len = fill_directory(&dir, the_repository->index, ps);
+	fill_directory(&dir, the_repository->index, ps);
 	for (i = 0; i < dir.nr; i++) {
 		struct dir_entry *ent = dir.entries[i];
-		if (dir_path_match(&the_index, ent, ps, max_len, seen)) {
-			found++;
-			strbuf_addstr(untracked_files, ent->name);
-			/* NUL-terminate: will be fed to update-index -z */
-			strbuf_addch(untracked_files, '\0');
-		}
+		found++;
+		strbuf_addstr(untracked_files, ent->name);
+		/* NUL-terminate: will be fed to update-index -z */
+		strbuf_addch(untracked_files, '\0');
 		free(ent);
 	}
 
-	free(seen);
 	free(dir.entries);
 	free(dir.ignored);
 	clear_directory(&dir);
@@ -1037,7 +1034,7 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 	}
 
 	cp_diff_tree.git_cmd = 1;
-	argv_array_pushl(&cp_diff_tree.args, "diff-tree", "-p", "HEAD",
+	argv_array_pushl(&cp_diff_tree.args, "diff-tree", "-p", "-U1", "HEAD",
 			 oid_to_hex(&info->w_tree), "--", NULL);
 	if (pipe_command(&cp_diff_tree, NULL, 0, out_patch, 0, NULL, 0)) {
 		ret = -1;
@@ -1559,29 +1556,6 @@ static int save_stash(int argc, const char **argv, const char *prefix)
 	return ret;
 }
 
-static int use_builtin_stash(void)
-{
-	struct child_process cp = CHILD_PROCESS_INIT;
-	struct strbuf out = STRBUF_INIT;
-	int ret, env = git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1);
-
-	if (env != -1)
-		return env;
-
-	argv_array_pushl(&cp.args,
-			 "config", "--bool", "stash.usebuiltin", NULL);
-	cp.git_cmd = 1;
-	if (capture_command(&cp, &out, 6)) {
-		strbuf_release(&out);
-		return 1;
-	}
-
-	strbuf_trim(&out);
-	ret = !strcmp("true", out.buf);
-	strbuf_release(&out);
-	return ret;
-}
-
 int cmd_stash(int argc, const char **argv, const char *prefix)
 {
 	pid_t pid = getpid();
@@ -1592,21 +1566,12 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	if (!use_builtin_stash()) {
-		const char *path = mkpath("%s/git-legacy-stash",
-					  git_exec_path());
+	git_config(git_stash_config, NULL);
 
-		if (sane_execvp(path, (char **)argv) < 0)
-			die_errno(_("could not exec %s"), path);
-		else
-			BUG("sane_execvp() returned???");
-	}
-
-	prefix = setup_git_directory();
-	trace_repo_setup(prefix);
-	setup_work_tree();
-
-	git_config(git_diff_basic_config, NULL);
+	if (use_legacy_stash ||
+	    !git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1))
+		warning(_("the stash.useBuiltin support has been removed!\n"
+			  "See its entry in 'git help config' for details."));
 
 	argc = parse_options(argc, argv, prefix, options, git_stash_usage,
 			     PARSE_OPT_KEEP_UNKNOWN | PARSE_OPT_KEEP_DASHDASH);
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 86a608e..1a4b391 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -444,19 +444,19 @@ static void for_each_listed_submodule(const struct module_list *list,
 		fn(list->entries[i], cb_data);
 }
 
-struct cb_foreach {
+struct foreach_cb {
 	int argc;
 	const char **argv;
 	const char *prefix;
 	int quiet;
 	int recursive;
 };
-#define CB_FOREACH_INIT { 0 }
+#define FOREACH_CB_INIT { 0 }
 
 static void runcommand_in_submodule_cb(const struct cache_entry *list_item,
 				       void *cb_data)
 {
-	struct cb_foreach *info = cb_data;
+	struct foreach_cb *info = cb_data;
 	const char *path = list_item->name;
 	const struct object_id *ce_oid = &list_item->oid;
 
@@ -557,7 +557,7 @@ static void runcommand_in_submodule_cb(const struct cache_entry *list_item,
 
 static int module_foreach(int argc, const char **argv, const char *prefix)
 {
-	struct cb_foreach info = CB_FOREACH_INIT;
+	struct foreach_cb info = FOREACH_CB_INIT;
 	struct pathspec pathspec;
 	struct module_list list = MODULE_LIST_INIT;
 
diff --git a/builtin/tag.c b/builtin/tag.c
index e0a4c25..dd160b4 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -17,7 +17,7 @@
 #include "diff.h"
 #include "revision.h"
 #include "gpg-interface.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "column.h"
 #include "ref-filter.h"
 
@@ -231,8 +231,9 @@ static void create_tag(const struct object_id *object, const char *object_ref,
 	if (type <= OBJ_NONE)
 		die(_("bad object type."));
 
-	if (type == OBJ_TAG && advice_nested_tag)
-		advise(_(message_advice_nested_tag), tag, object_ref);
+	if (type == OBJ_TAG)
+		advise_if_enabled(ADVICE_NESTED_TAG, _(message_advice_nested_tag),
+				  tag, object_ref);
 
 	strbuf_addf(&header,
 		    "object %s\n"
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 2d8f7f0..b74dd9a6 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -50,7 +50,7 @@ static const char *parse_arg(const char *next, struct strbuf *arg)
  * the argument.  Die if C-quoting is malformed or the reference name
  * is invalid.
  */
-static char *parse_refname(struct strbuf *input, const char **next)
+static char *parse_refname(const char **next)
 {
 	struct strbuf ref = STRBUF_INIT;
 
@@ -95,7 +95,7 @@ static char *parse_refname(struct strbuf *input, const char **next)
  * provided but cannot be converted to a SHA-1, die.  flags can
  * include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY.
  */
-static int parse_next_oid(struct strbuf *input, const char **next,
+static int parse_next_oid(const char **next, const char *end,
 			  struct object_id *oid,
 			  const char *command, const char *refname,
 			  int flags)
@@ -103,7 +103,7 @@ static int parse_next_oid(struct strbuf *input, const char **next,
 	struct strbuf arg = STRBUF_INIT;
 	int ret = 0;
 
-	if (*next == input->buf + input->len)
+	if (*next == end)
 		goto eof;
 
 	if (line_termination) {
@@ -128,7 +128,7 @@ static int parse_next_oid(struct strbuf *input, const char **next,
 			die("%s %s: expected NUL but got: %s",
 			    command, refname, *next);
 		(*next)++;
-		if (*next == input->buf + input->len)
+		if (*next == end)
 			goto eof;
 		strbuf_addstr(&arg, *next);
 		*next += arg.len;
@@ -178,23 +178,23 @@ static int parse_next_oid(struct strbuf *input, const char **next,
  * depending on how line_termination is set.
  */
 
-static const char *parse_cmd_update(struct ref_transaction *transaction,
-				    struct strbuf *input, const char *next)
+static void parse_cmd_update(struct ref_transaction *transaction,
+			     const char *next, const char *end)
 {
 	struct strbuf err = STRBUF_INIT;
 	char *refname;
 	struct object_id new_oid, old_oid;
 	int have_old;
 
-	refname = parse_refname(input, &next);
+	refname = parse_refname(&next);
 	if (!refname)
 		die("update: missing <ref>");
 
-	if (parse_next_oid(input, &next, &new_oid, "update", refname,
+	if (parse_next_oid(&next, end, &new_oid, "update", refname,
 			   PARSE_SHA1_ALLOW_EMPTY))
 		die("update %s: missing <newvalue>", refname);
 
-	have_old = !parse_next_oid(input, &next, &old_oid, "update", refname,
+	have_old = !parse_next_oid(&next, end, &old_oid, "update", refname,
 				   PARSE_SHA1_OLD);
 
 	if (*next != line_termination)
@@ -209,22 +209,20 @@ static const char *parse_cmd_update(struct ref_transaction *transaction,
 	update_flags = default_flags;
 	free(refname);
 	strbuf_release(&err);
-
-	return next;
 }
 
-static const char *parse_cmd_create(struct ref_transaction *transaction,
-				    struct strbuf *input, const char *next)
+static void parse_cmd_create(struct ref_transaction *transaction,
+			     const char *next, const char *end)
 {
 	struct strbuf err = STRBUF_INIT;
 	char *refname;
 	struct object_id new_oid;
 
-	refname = parse_refname(input, &next);
+	refname = parse_refname(&next);
 	if (!refname)
 		die("create: missing <ref>");
 
-	if (parse_next_oid(input, &next, &new_oid, "create", refname, 0))
+	if (parse_next_oid(&next, end, &new_oid, "create", refname, 0))
 		die("create %s: missing <newvalue>", refname);
 
 	if (is_null_oid(&new_oid))
@@ -241,23 +239,21 @@ static const char *parse_cmd_create(struct ref_transaction *transaction,
 	update_flags = default_flags;
 	free(refname);
 	strbuf_release(&err);
-
-	return next;
 }
 
-static const char *parse_cmd_delete(struct ref_transaction *transaction,
-				    struct strbuf *input, const char *next)
+static void parse_cmd_delete(struct ref_transaction *transaction,
+			     const char *next, const char *end)
 {
 	struct strbuf err = STRBUF_INIT;
 	char *refname;
 	struct object_id old_oid;
 	int have_old;
 
-	refname = parse_refname(input, &next);
+	refname = parse_refname(&next);
 	if (!refname)
 		die("delete: missing <ref>");
 
-	if (parse_next_oid(input, &next, &old_oid, "delete", refname,
+	if (parse_next_oid(&next, end, &old_oid, "delete", refname,
 			   PARSE_SHA1_OLD)) {
 		have_old = 0;
 	} else {
@@ -277,22 +273,20 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction,
 	update_flags = default_flags;
 	free(refname);
 	strbuf_release(&err);
-
-	return next;
 }
 
-static const char *parse_cmd_verify(struct ref_transaction *transaction,
-				    struct strbuf *input, const char *next)
+static void parse_cmd_verify(struct ref_transaction *transaction,
+			     const char *next, const char *end)
 {
 	struct strbuf err = STRBUF_INIT;
 	char *refname;
 	struct object_id old_oid;
 
-	refname = parse_refname(input, &next);
+	refname = parse_refname(&next);
 	if (!refname)
 		die("verify: missing <ref>");
 
-	if (parse_next_oid(input, &next, &old_oid, "verify", refname,
+	if (parse_next_oid(&next, end, &old_oid, "verify", refname,
 			   PARSE_SHA1_OLD))
 		oidclr(&old_oid);
 
@@ -306,50 +300,179 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction,
 	update_flags = default_flags;
 	free(refname);
 	strbuf_release(&err);
-
-	return next;
 }
 
-static const char *parse_cmd_option(struct strbuf *input, const char *next)
+static void parse_cmd_option(struct ref_transaction *transaction,
+			     const char *next, const char *end)
 {
 	const char *rest;
 	if (skip_prefix(next, "no-deref", &rest) && *rest == line_termination)
 		update_flags |= REF_NO_DEREF;
 	else
 		die("option unknown: %s", next);
-	return rest;
 }
 
-static void update_refs_stdin(struct ref_transaction *transaction)
+static void parse_cmd_start(struct ref_transaction *transaction,
+			    const char *next, const char *end)
 {
-	struct strbuf input = STRBUF_INIT;
-	const char *next;
+	if (*next != line_termination)
+		die("start: extra input: %s", next);
+	puts("start: ok");
+}
 
-	if (strbuf_read(&input, 0, 1000) < 0)
-		die_errno("could not read from stdin");
-	next = input.buf;
+static void parse_cmd_prepare(struct ref_transaction *transaction,
+			      const char *next, const char *end)
+{
+	struct strbuf error = STRBUF_INIT;
+	if (*next != line_termination)
+		die("prepare: extra input: %s", next);
+	if (ref_transaction_prepare(transaction, &error))
+		die("prepare: %s", error.buf);
+	puts("prepare: ok");
+}
+
+static void parse_cmd_abort(struct ref_transaction *transaction,
+			    const char *next, const char *end)
+{
+	struct strbuf error = STRBUF_INIT;
+	if (*next != line_termination)
+		die("abort: extra input: %s", next);
+	if (ref_transaction_abort(transaction, &error))
+		die("abort: %s", error.buf);
+	puts("abort: ok");
+}
+
+static void parse_cmd_commit(struct ref_transaction *transaction,
+			     const char *next, const char *end)
+{
+	struct strbuf error = STRBUF_INIT;
+	if (*next != line_termination)
+		die("commit: extra input: %s", next);
+	if (ref_transaction_commit(transaction, &error))
+		die("commit: %s", error.buf);
+	puts("commit: ok");
+	ref_transaction_free(transaction);
+}
+
+enum update_refs_state {
+	/* Non-transactional state open for updates. */
+	UPDATE_REFS_OPEN,
+	/* A transaction has been started. */
+	UPDATE_REFS_STARTED,
+	/* References are locked and ready for commit */
+	UPDATE_REFS_PREPARED,
+	/* Transaction has been committed or closed. */
+	UPDATE_REFS_CLOSED,
+};
+
+static const struct parse_cmd {
+	const char *prefix;
+	void (*fn)(struct ref_transaction *, const char *, const char *);
+	unsigned args;
+	enum update_refs_state state;
+} command[] = {
+	{ "update",  parse_cmd_update,  3, UPDATE_REFS_OPEN },
+	{ "create",  parse_cmd_create,  2, UPDATE_REFS_OPEN },
+	{ "delete",  parse_cmd_delete,  2, UPDATE_REFS_OPEN },
+	{ "verify",  parse_cmd_verify,  2, UPDATE_REFS_OPEN },
+	{ "option",  parse_cmd_option,  1, UPDATE_REFS_OPEN },
+	{ "start",   parse_cmd_start,   0, UPDATE_REFS_STARTED },
+	{ "prepare", parse_cmd_prepare, 0, UPDATE_REFS_PREPARED },
+	{ "abort",   parse_cmd_abort,   0, UPDATE_REFS_CLOSED },
+	{ "commit",  parse_cmd_commit,  0, UPDATE_REFS_CLOSED },
+};
+
+static void update_refs_stdin(void)
+{
+	struct strbuf input = STRBUF_INIT, err = STRBUF_INIT;
+	enum update_refs_state state = UPDATE_REFS_OPEN;
+	struct ref_transaction *transaction;
+	int i, j;
+
+	transaction = ref_transaction_begin(&err);
+	if (!transaction)
+		die("%s", err.buf);
+
 	/* Read each line dispatch its command */
-	while (next < input.buf + input.len) {
-		if (*next == line_termination)
-			die("empty command in input");
-		else if (isspace(*next))
-			die("whitespace before command: %s", next);
-		else if (skip_prefix(next, "update ", &next))
-			next = parse_cmd_update(transaction, &input, next);
-		else if (skip_prefix(next, "create ", &next))
-			next = parse_cmd_create(transaction, &input, next);
-		else if (skip_prefix(next, "delete ", &next))
-			next = parse_cmd_delete(transaction, &input, next);
-		else if (skip_prefix(next, "verify ", &next))
-			next = parse_cmd_verify(transaction, &input, next);
-		else if (skip_prefix(next, "option ", &next))
-			next = parse_cmd_option(&input, next);
-		else
-			die("unknown command: %s", next);
+	while (!strbuf_getwholeline(&input, stdin, line_termination)) {
+		const struct parse_cmd *cmd = NULL;
 
-		next++;
+		if (*input.buf == line_termination)
+			die("empty command in input");
+		else if (isspace(*input.buf))
+			die("whitespace before command: %s", input.buf);
+
+		for (i = 0; i < ARRAY_SIZE(command); i++) {
+			const char *prefix = command[i].prefix;
+			char c;
+
+			if (!starts_with(input.buf, prefix))
+				continue;
+
+			/*
+			 * If the command has arguments, verify that it's
+			 * followed by a space. Otherwise, it shall be followed
+			 * by a line terminator.
+			 */
+			c = command[i].args ? ' ' : line_termination;
+			if (input.buf[strlen(prefix)] != c)
+				continue;
+
+			cmd = &command[i];
+			break;
+		}
+		if (!cmd)
+			die("unknown command: %s", input.buf);
+
+		/*
+		 * Read additional arguments if NUL-terminated. Do not raise an
+		 * error in case there is an early EOF to let the command
+		 * handle missing arguments with a proper error message.
+		 */
+		for (j = 1; line_termination == '\0' && j < cmd->args; j++)
+			if (strbuf_appendwholeline(&input, stdin, line_termination))
+				break;
+
+		switch (state) {
+		case UPDATE_REFS_OPEN:
+		case UPDATE_REFS_STARTED:
+			/* Do not downgrade a transaction to a non-transaction. */
+			if (cmd->state >= state)
+				state = cmd->state;
+			break;
+		case UPDATE_REFS_PREPARED:
+			if (cmd->state != UPDATE_REFS_CLOSED)
+				die("prepared transactions can only be closed");
+			state = cmd->state;
+			break;
+		case UPDATE_REFS_CLOSED:
+			die("transaction is closed");
+			break;
+		}
+
+		cmd->fn(transaction, input.buf + strlen(cmd->prefix) + !!cmd->args,
+			input.buf + input.len);
 	}
 
+	switch (state) {
+	case UPDATE_REFS_OPEN:
+		/* Commit by default if no transaction was requested. */
+		if (ref_transaction_commit(transaction, &err))
+			die("%s", err.buf);
+		ref_transaction_free(transaction);
+		break;
+	case UPDATE_REFS_STARTED:
+	case UPDATE_REFS_PREPARED:
+		/* If using a transaction, we want to abort it. */
+		if (ref_transaction_abort(transaction, &err))
+			die("%s", err.buf);
+		break;
+	case UPDATE_REFS_CLOSED:
+		/* Otherwise no need to do anything, the transaction was closed already. */
+		break;
+	}
+
+	strbuf_release(&err);
 	strbuf_release(&input);
 }
 
@@ -384,21 +507,11 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 	}
 
 	if (read_stdin) {
-		struct strbuf err = STRBUF_INIT;
-		struct ref_transaction *transaction;
-
-		transaction = ref_transaction_begin(&err);
-		if (!transaction)
-			die("%s", err.buf);
 		if (delete || argc > 0)
 			usage_with_options(git_update_ref_usage, options);
 		if (end_null)
 			line_termination = '\0';
-		update_refs_stdin(transaction);
-		if (ref_transaction_commit(transaction, &err))
-			die("%s", err.buf);
-		ref_transaction_free(transaction);
-		strbuf_release(&err);
+		update_refs_stdin();
 		return 0;
 	}
 
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 24f2280..d99db35 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -258,7 +258,7 @@ static int add_worktree(const char *path, const char *refname,
 			const struct add_opts *opts)
 {
 	struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT;
-	struct strbuf sb = STRBUF_INIT;
+	struct strbuf sb = STRBUF_INIT, realpath = STRBUF_INIT;
 	const char *name;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct argv_array child_env = ARGV_ARRAY_INIT;
@@ -330,9 +330,11 @@ static int add_worktree(const char *path, const char *refname,
 
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
-	write_file(sb.buf, "%s", real_path(sb_git.buf));
+	strbuf_realpath(&realpath, sb_git.buf, 1);
+	write_file(sb.buf, "%s", realpath.buf);
+	strbuf_realpath(&realpath, get_git_common_dir(), 1);
 	write_file(sb_git.buf, "gitdir: %s/worktrees/%s",
-		   real_path(get_git_common_dir()), name);
+		   realpath.buf, name);
 	/*
 	 * This is to keep resolve_ref() happy. We need a valid HEAD
 	 * or is_git_directory() will reject the directory. Any value which
@@ -418,6 +420,7 @@ static int add_worktree(const char *path, const char *refname,
 	strbuf_release(&sb_repo);
 	strbuf_release(&sb_git);
 	strbuf_release(&sb_name);
+	strbuf_release(&realpath);
 	return ret;
 }
 
diff --git a/cache.h b/cache.h
index 37c899b..0f0485e 100644
--- a/cache.h
+++ b/cache.h
@@ -14,7 +14,7 @@
 #include "pack-revindex.h"
 #include "hash.h"
 #include "path.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "repository.h"
 #include "mem-pool.h"
 
@@ -543,7 +543,7 @@ const char *get_git_common_dir(void);
 char *get_object_directory(void);
 char *get_index_file(void);
 char *get_graft_file(struct repository *r);
-void set_git_dir(const char *path);
+void set_git_dir(const char *path, int make_realpath);
 int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
 int get_common_dir(struct strbuf *sb, const char *gitdir);
 const char *get_git_namespace(void);
@@ -627,7 +627,9 @@ int path_inside_repo(const char *prefix, const char *path);
 #define INIT_DB_EXIST_OK 0x0002
 
 int init_db(const char *git_dir, const char *real_git_dir,
-	    const char *template_dir, unsigned int flags);
+	    const char *template_dir, int hash_algo,
+	    unsigned int flags);
+void initialize_repository_version(int hash_algo);
 
 void sanitize_stdfds(void);
 int daemonize(void);
@@ -1086,8 +1088,10 @@ int verify_repository_format(const struct repository_format *format,
  * and die if it is a version we don't understand. Generally one would
  * set_git_dir() before calling this, and use it only for "are we in a valid
  * repo?".
+ *
+ * If successful and fmt is not NULL, fill fmt with data.
  */
-void check_repository_format(void);
+void check_repository_format(struct repository_format *fmt);
 
 #define MTIME_CHANGED	0x0001
 #define CTIME_CHANGED	0x0002
@@ -1314,8 +1318,6 @@ static inline int is_absolute_path(const char *path)
 int is_directory(const char *);
 char *strbuf_realpath(struct strbuf *resolved, const char *path,
 		      int die_on_error);
-const char *real_path(const char *path);
-const char *real_path_if_valid(const char *path);
 char *real_pathdup(const char *path, int die_on_error);
 const char *absolute_path(const char *path);
 char *absolute_pathdup(const char *path);
@@ -1481,6 +1483,9 @@ int set_disambiguate_hint_config(const char *var, const char *value);
 int get_sha1_hex(const char *hex, unsigned char *sha1);
 int get_oid_hex(const char *hex, struct object_id *sha1);
 
+/* Like get_oid_hex, but for an arbitrary hash algorithm. */
+int get_oid_hex_algop(const char *hex, struct object_id *oid, const struct git_hash_algo *algop);
+
 /*
  * Read `len` pairs of hexadecimal digits from `hex` and write the
  * values to `binary` as `len` bytes. Return 0 on success, or -1 if
@@ -1516,6 +1521,20 @@ char *oid_to_hex(const struct object_id *oid);						/* same static buffer */
  */
 int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
 
+/* Like parse_oid_hex, but for an arbitrary hash algorithm. */
+int parse_oid_hex_algop(const char *hex, struct object_id *oid, const char **end,
+			const struct git_hash_algo *algo);
+
+
+/*
+ * These functions work like get_oid_hex and parse_oid_hex, but they will parse
+ * a hex value for any algorithm. The algorithm is detected based on the length
+ * and the algorithm in use is returned. If this is not a hex object ID in any
+ * algorithm, returns GIT_HASH_UNKNOWN.
+ */
+int get_oid_hex_any(const char *hex, struct object_id *oid);
+int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end);
+
 /*
  * This reads short-hand syntax that not only evaluates to a commit
  * object name, but also can act as if the end user spelled the name
@@ -1679,6 +1698,7 @@ struct checkout {
 	const char *base_dir;
 	int base_dir_len;
 	struct delayed_checkout *delayed_checkout;
+	struct checkout_metadata meta;
 	unsigned force:1,
 		 quiet:1,
 		 not_new:1,
diff --git a/ci/git-problem-matcher.json b/ci/git-problem-matcher.json
new file mode 100644
index 0000000..506dfbd
--- /dev/null
+++ b/ci/git-problem-matcher.json
@@ -0,0 +1,16 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "git-test-suite",
+            "pattern": [
+                {
+                    "regexp": "^([^ :]+\\.sh):(\\d+): (error|warning|info):\\s+(.*)$",
+                    "file": 1,
+                    "line": 2,
+                    "severity": 3,
+                    "message": 4
+                }
+            ]
+        }
+    ]
+}
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 497fd32..0229a77 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -7,12 +7,16 @@
 
 P4WHENCE=http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION
 LFSWHENCE=https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION
+UBUNTU_COMMON_PKGS="make libssl-dev libcurl4-openssl-dev libexpat-dev
+ tcl tk gettext zlib1g-dev perl-modules liberror-perl libauthen-sasl-perl
+ libemail-valid-perl libio-socket-ssl-perl libnet-smtp-ssl-perl"
 
 case "$jobname" in
 linux-clang|linux-gcc)
 	sudo apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
 	sudo apt-get -q update
-	sudo apt-get -q -y install language-pack-is libsvn-perl apache2
+	sudo apt-get -q -y install language-pack-is libsvn-perl apache2 \
+		$UBUNTU_COMMON_PKGS
 	case "$jobname" in
 	linux-gcc)
 		sudo apt-get -q -y install gcc-8
@@ -59,14 +63,18 @@
 StaticAnalysis)
 	sudo apt-get -q update
 	sudo apt-get -q -y install coccinelle libcurl4-openssl-dev libssl-dev \
-		libexpat-dev gettext
+		libexpat-dev gettext make
 	;;
 Documentation)
 	sudo apt-get -q update
-	sudo apt-get -q -y install asciidoc xmlto docbook-xsl-ns
+	sudo apt-get -q -y install asciidoc xmlto docbook-xsl-ns make
 
 	test -n "$ALREADY_HAVE_ASCIIDOCTOR" ||
-	gem install --version 1.5.8 asciidoctor
+	sudo gem install --version 1.5.8 asciidoctor
+	;;
+linux-gcc-4.8|GETTEXT_POISON)
+	sudo apt-get -q update
+	sudo apt-get -q -y install $UBUNTU_COMMON_PKGS
 	;;
 esac
 
diff --git a/ci/install-docker-dependencies.sh b/ci/install-docker-dependencies.sh
new file mode 100755
index 0000000..26a6689
--- /dev/null
+++ b/ci/install-docker-dependencies.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+# Install dependencies required to build and test Git inside container
+#
+
+case "$jobname" in
+Linux32)
+	linux32 --32bit i386 sh -c '
+		apt update >/dev/null &&
+		apt install -y build-essential libcurl4-openssl-dev \
+			libssl-dev libexpat-dev gettext python >/dev/null
+	'
+	;;
+linux-musl)
+	apk add --update build-base curl-dev openssl-dev expat-dev gettext \
+		pcre2-dev python3 musl-libintl perl-utils ncurses >/dev/null
+	;;
+esac
diff --git a/ci/lib.sh b/ci/lib.sh
index a90d0dc..dac3688 100755
--- a/ci/lib.sh
+++ b/ci/lib.sh
@@ -34,7 +34,7 @@
 # successfully before (e.g. because the branch got rebased, changing only
 # the commit messages).
 skip_good_tree () {
-	if test "$TRAVIS_DEBUG_MODE" = true
+	if test "$TRAVIS_DEBUG_MODE" = true || test true = "$GITHUB_ACTIONS"
 	then
 		return
 	fi
@@ -79,6 +79,9 @@
 	}
 }
 
+# GitHub Action doesn't set TERM, which is required by tput
+export TERM=${TERM:-dumb}
+
 # Clear MAKEFLAGS that may come from the outside world.
 export MAKEFLAGS=
 
@@ -136,8 +139,32 @@
 	MAKEFLAGS="$MAKEFLAGS --jobs=10"
 	test windows_nt != "$CI_OS_NAME" ||
 	GIT_TEST_OPTS="--no-chain-lint --no-bin-wrappers $GIT_TEST_OPTS"
+elif test true = "$GITHUB_ACTIONS"
+then
+	CI_TYPE=github-actions
+	CI_BRANCH="$GITHUB_REF"
+	CI_COMMIT="$GITHUB_SHA"
+	CI_OS_NAME="$(echo "$RUNNER_OS" | tr A-Z a-z)"
+	test macos != "$CI_OS_NAME" || CI_OS_NAME=osx
+	CI_REPO_SLUG="$GITHUB_REPOSITORY"
+	CI_JOB_ID="$GITHUB_RUN_ID"
+	CC="${CC:-gcc}"
+
+	cache_dir="$HOME/none"
+
+	export GIT_PROVE_OPTS="--timer --jobs 10"
+	export GIT_TEST_OPTS="--verbose-log -x"
+	MAKEFLAGS="$MAKEFLAGS --jobs=10"
+	test windows != "$CI_OS_NAME" ||
+	GIT_TEST_OPTS="--no-chain-lint --no-bin-wrappers $GIT_TEST_OPTS"
+
+	# https://github.com/actions/toolkit/blob/master/docs/commands.md#problem-matchers
+	echo "::add-matcher::ci/git-problem-matcher.json"
+	test linux-musl = "$jobname" ||
+	MAKEFLAGS="$MAKEFLAGS TEST_SHELL_PATH=/bin/sh"
 else
 	echo "Could not identify CI type" >&2
+	env >&2
 	exit 1
 fi
 
@@ -162,6 +189,9 @@
 	if [ "$jobname" = linux-gcc ]
 	then
 		export CC=gcc-8
+		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=$(which python3)"
+	else
+		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=$(which python2)"
 	fi
 
 	export GIT_TEST_HTTPD=true
@@ -182,6 +212,9 @@
 	if [ "$jobname" = osx-gcc ]
 	then
 		export CC=gcc-9
+		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=$(which python3)"
+	else
+		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=$(which python2)"
 	fi
 
 	# t9810 occasionally fails on Travis CI OS X
@@ -189,9 +222,17 @@
 	# Travis CI OS X
 	export GIT_SKIP_TESTS="t9810 t9816"
 	;;
-GIT_TEST_GETTEXT_POISON)
+GETTEXT_POISON)
 	export GIT_TEST_GETTEXT_POISON=true
 	;;
+Linux32)
+	CC=gcc
+	;;
+linux-musl)
+	CC=gcc
+	MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python3 USE_LIBPCRE2=Yes"
+	MAKEFLAGS="$MAKEFLAGS NO_REGEX=Yes ICONV_OMITS_BOM=Yes"
+	;;
 esac
 
 MAKEFLAGS="$MAKEFLAGS CC=${CC:-cc}"
diff --git a/ci/print-test-failures.sh b/ci/print-test-failures.sh
index e688a26..92a983a 100755
--- a/ci/print-test-failures.sh
+++ b/ci/print-test-failures.sh
@@ -46,6 +46,13 @@
 			mv "$trash_dir" failed-test-artifacts
 			continue
 			;;
+		github-actions)
+			mkdir -p failed-test-artifacts
+			echo "::set-env name=FAILED_TEST_ARTIFACTS::t/failed-test-artifacts"
+			cp "${TEST_EXIT%.exit}.out" failed-test-artifacts/
+			tar czf failed-test-artifacts/"$test_name".trash.tar.gz "$trash_dir"
+			continue
+			;;
 		*)
 			echo "Unhandled CI type: $CI_TYPE" >&2
 			exit 1
diff --git a/ci/run-linux32-build.sh b/ci/run-docker-build.sh
similarity index 63%
rename from ci/run-linux32-build.sh
rename to ci/run-docker-build.sh
index e3a193a..8d47a5f 100755
--- a/ci/run-linux32-build.sh
+++ b/ci/run-docker-build.sh
@@ -1,25 +1,33 @@
 #!/bin/sh
 #
-# Build and test Git in a 32-bit environment
+# Build and test Git inside container
 #
 # Usage:
-#   run-linux32-build.sh <host-user-id>
+#   run-docker-build.sh <host-user-id>
 #
 
 set -ex
 
 if test $# -ne 1 || test -z "$1"
 then
-	echo >&2 "usage: run-linux32-build.sh <host-user-id>"
+	echo >&2 "usage: run-docker-build.sh <host-user-id>"
 	exit 1
 fi
 
-# Update packages to the latest available versions
-linux32 --32bit i386 sh -c '
-    apt update >/dev/null &&
-    apt install -y build-essential libcurl4-openssl-dev libssl-dev \
-	libexpat-dev gettext python >/dev/null
-'
+case "$jobname" in
+Linux32)
+	switch_cmd="linux32 --32bit i386"
+	;;
+linux-musl)
+	switch_cmd=
+	useradd () { adduser -D "$@"; }
+	;;
+*)
+	exit 1
+	;;
+esac
+
+"${0%/*}/install-docker-dependencies.sh"
 
 # If this script runs inside a docker container, then all commands are
 # usually executed as root. Consequently, the host user might not be
@@ -51,10 +59,17 @@
 fi
 
 # Build and test
-linux32 --32bit i386 su -m -l $CI_USER -c '
+command $switch_cmd su -m -l $CI_USER -c "
 	set -ex
+	export DEVELOPER='$DEVELOPER'
+	export DEFAULT_TEST_TARGET='$DEFAULT_TEST_TARGET'
+	export GIT_PROVE_OPTS='$GIT_PROVE_OPTS'
+	export GIT_TEST_OPTS='$GIT_TEST_OPTS'
+	export GIT_TEST_CLONE_2GB='$GIT_TEST_CLONE_2GB'
+	export MAKEFLAGS='$MAKEFLAGS'
+	export cache_dir='$cache_dir'
 	cd /usr/src/git
-	test -n "$cache_dir" && ln -s "$cache_dir/.prove" t/.prove
+	test -n '$cache_dir' && ln -s '$cache_dir/.prove' t/.prove
 	make
 	make test
-'
+"
diff --git a/ci/run-docker.sh b/ci/run-docker.sh
new file mode 100755
index 0000000..37fa372
--- /dev/null
+++ b/ci/run-docker.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+#
+# Download and run Docker image to build and test Git
+#
+
+. ${0%/*}/lib.sh
+
+case "$jobname" in
+Linux32)
+	CI_CONTAINER="daald/ubuntu32:xenial"
+	;;
+linux-musl)
+	CI_CONTAINER=alpine
+	;;
+*)
+	exit 1
+	;;
+esac
+
+docker pull "$CI_CONTAINER"
+
+# Use the following command to debug the docker build locally:
+# <host-user-id> must be 0 if podman is used as drop-in replacement for docker
+# $ docker run -itv "${PWD}:/usr/src/git" --entrypoint /bin/sh "$CI_CONTAINER"
+# root@container:/# export jobname=<jobname>
+# root@container:/# /usr/src/git/ci/run-docker-build.sh <host-user-id>
+
+container_cache_dir=/tmp/travis-cache
+
+docker run \
+	--interactive \
+	--env DEVELOPER \
+	--env DEFAULT_TEST_TARGET \
+	--env GIT_PROVE_OPTS \
+	--env GIT_TEST_OPTS \
+	--env GIT_TEST_CLONE_2GB \
+	--env MAKEFLAGS \
+	--env jobname \
+	--env cache_dir="$container_cache_dir" \
+	--volume "${PWD}:/usr/src/git" \
+	--volume "$cache_dir:$container_cache_dir" \
+	"$CI_CONTAINER" \
+	/usr/src/git/ci/run-docker-build.sh $(id -u $USER)
+
+check_unignored_build_artifacts
+
+save_good_tree
diff --git a/ci/run-linux32-docker.sh b/ci/run-linux32-docker.sh
deleted file mode 100755
index 751acfc..0000000
--- a/ci/run-linux32-docker.sh
+++ /dev/null
@@ -1,31 +0,0 @@
-#!/bin/sh
-#
-# Download and run Docker image to build and test 32-bit Git
-#
-
-. ${0%/*}/lib.sh
-
-docker pull daald/ubuntu32:xenial
-
-# Use the following command to debug the docker build locally:
-# $ docker run -itv "${PWD}:/usr/src/git" --entrypoint /bin/bash daald/ubuntu32:xenial
-# root@container:/# /usr/src/git/ci/run-linux32-build.sh <host-user-id>
-
-container_cache_dir=/tmp/travis-cache
-
-docker run \
-	--interactive \
-	--env DEVELOPER \
-	--env DEFAULT_TEST_TARGET \
-	--env GIT_PROVE_OPTS \
-	--env GIT_TEST_OPTS \
-	--env GIT_TEST_CLONE_2GB \
-	--env cache_dir="$container_cache_dir" \
-	--volume "${PWD}:/usr/src/git" \
-	--volume "$cache_dir:$container_cache_dir" \
-	daald/ubuntu32:xenial \
-	/usr/src/git/ci/run-linux32-build.sh $(id -u $USER)
-
-check_unignored_build_artifacts
-
-save_good_tree
diff --git a/combine-diff.c b/combine-diff.c
index d5c4d83..002e0e5 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -10,7 +10,7 @@
 #include "log-tree.h"
 #include "refs.h"
 #include "userdiff.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "revision.h"
 
 static int compare_paths(const struct combine_diff_path *one,
diff --git a/commit-graph.c b/commit-graph.c
index f013a84..0d0d377 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -1707,7 +1707,7 @@ static void expire_commit_graphs(struct write_commit_graph_context *ctx)
 	timestamp_t expire_time = time(NULL);
 
 	if (ctx->split_opts && ctx->split_opts->expire_time)
-		expire_time -= ctx->split_opts->expire_time;
+		expire_time = ctx->split_opts->expire_time;
 	if (!ctx->split) {
 		char *chain_file_name = get_chain_filename(ctx->odb);
 		unlink(chain_file_name);
diff --git a/commit-slab.h b/commit-slab.h
index 69bf0c8..05b3f28 100644
--- a/commit-slab.h
+++ b/commit-slab.h
@@ -24,7 +24,12 @@
  * - int *indegree_peek(struct indegree *, struct commit *);
  *
  *   This function is similar to indegree_at(), but it will return NULL
- *   until a call to indegree_at() was made for the commit.
+ *   if the location to store the data associated with the given commit
+ *   has not been allocated yet.
+ *   Note that the location to store the data might have already been
+ *   allocated even if no indegree_at() call has been made for that commit
+ *   yet; in this case this function returns a pointer to a
+ *   zero-initialized location.
  *
  * - void init_indegree(struct indegree *);
  *   void init_indegree_with_stride(struct indegree *, int);
diff --git a/commit.c b/commit.c
index a6cfa41..c7099da 100644
--- a/commit.c
+++ b/commit.c
@@ -927,12 +927,22 @@ struct commit *get_fork_point(const char *refname, struct commit *commit)
 	struct commit_list *bases;
 	int i;
 	struct commit *ret = NULL;
+	char *full_refname;
+
+	switch (dwim_ref(refname, strlen(refname), &oid, &full_refname)) {
+	case 0:
+		die("No such ref: '%s'", refname);
+	case 1:
+		break; /* good */
+	default:
+		die("Ambiguous refname: '%s'", refname);
+	}
 
 	memset(&revs, 0, sizeof(revs));
 	revs.initial = 1;
-	for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
+	for_each_reflog_ent(full_refname, collect_one_reflog_ent, &revs);
 
-	if (!revs.nr && !get_oid(refname, &oid))
+	if (!revs.nr)
 		add_one_commit(&oid, &revs);
 
 	for (i = 0; i < revs.nr; i++)
@@ -958,17 +968,26 @@ struct commit *get_fork_point(const char *refname, struct commit *commit)
 
 cleanup_return:
 	free_commit_list(bases);
+	free(full_refname);
 	return ret;
 }
 
-static const char gpg_sig_header[] = "gpgsig";
-static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
+/*
+ * Indexed by hash algorithm identifier.
+ */
+static const char *gpg_sig_headers[] = {
+	NULL,
+	"gpgsig",
+	"gpgsig-sha256",
+};
 
 static int do_sign_commit(struct strbuf *buf, const char *keyid)
 {
 	struct strbuf sig = STRBUF_INIT;
 	int inspos, copypos;
 	const char *eoh;
+	const char *gpg_sig_header = gpg_sig_headers[hash_algo_by_ptr(the_hash_algo)];
+	int gpg_sig_header_len = strlen(gpg_sig_header);
 
 	/* find the end of the header */
 	eoh = strstr(buf->buf, "\n\n");
@@ -1010,6 +1029,8 @@ int parse_signed_commit(const struct commit *commit,
 	const char *buffer = get_commit_buffer(commit, &size);
 	int in_signature, saw_signature = -1;
 	const char *line, *tail;
+	const char *gpg_sig_header = gpg_sig_headers[hash_algo_by_ptr(the_hash_algo)];
+	int gpg_sig_header_len = strlen(gpg_sig_header);
 
 	line = buffer;
 	tail = buffer + size;
@@ -1056,11 +1077,17 @@ int remove_signature(struct strbuf *buf)
 
 		if (in_signature && line[0] == ' ')
 			sig_end = next;
-		else if (starts_with(line, gpg_sig_header) &&
-			 line[gpg_sig_header_len] == ' ') {
-			sig_start = line;
-			sig_end = next;
-			in_signature = 1;
+		else if (starts_with(line, "gpgsig")) {
+			int i;
+			for (i = 1; i < GIT_HASH_NALGOS; i++) {
+				const char *p;
+				if (skip_prefix(line, gpg_sig_headers[i], &p) &&
+				    *p == ' ') {
+					sig_start = line;
+					sig_end = next;
+					in_signature = 1;
+				}
+			}
 		} else {
 			if (*line == '\n')
 				/* dump the whole remainder of the buffer */
diff --git a/compat/mingw.c b/compat/mingw.c
index d14065d..8ee0b64 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -460,8 +460,21 @@ static int mingw_open_append(wchar_t const *wfilename, int oflags, ...)
 	handle = CreateFileW(wfilename, FILE_APPEND_DATA,
 			FILE_SHARE_WRITE | FILE_SHARE_READ,
 			NULL, create, FILE_ATTRIBUTE_NORMAL, NULL);
-	if (handle == INVALID_HANDLE_VALUE)
-		return errno = err_win_to_posix(GetLastError()), -1;
+	if (handle == INVALID_HANDLE_VALUE) {
+		DWORD err = GetLastError();
+
+		/*
+		 * Some network storage solutions (e.g. Isilon) might return
+		 * ERROR_INVALID_PARAMETER instead of expected error
+		 * ERROR_PATH_NOT_FOUND, which results in an unknown error. If
+		 * so, let's turn the error to ERROR_PATH_NOT_FOUND instead.
+		 */
+		if (err == ERROR_INVALID_PARAMETER)
+			err = ERROR_PATH_NOT_FOUND;
+
+		errno = err_win_to_posix(err);
+		return -1;
+	}
 
 	/*
 	 * No O_APPEND here, because the CRT uses it only to reset the
@@ -964,7 +977,16 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
 size_t mingw_strftime(char *s, size_t max,
 		      const char *format, const struct tm *tm)
 {
-	size_t ret = strftime(s, max, format, tm);
+	/* a pointer to the original strftime in case we can't find the UCRT version */
+	static size_t (*fallback)(char *, size_t, const char *, const struct tm *) = strftime;
+	size_t ret;
+	DECLARE_PROC_ADDR(ucrtbase.dll, size_t, strftime, char *, size_t,
+		const char *, const struct tm *);
+
+	if (INIT_PROC_ADDR(strftime))
+		ret = strftime(s, max, format, tm);
+	else
+		ret = fallback(s, max, format, tm);
 
 	if (!ret && errno == EINVAL)
 		die("invalid strftime format: '%s'", format);
@@ -1479,6 +1501,7 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	const char *(*quote_arg)(const char *arg) =
 		is_msys2_sh(cmd ? cmd : *argv) ?
 		quote_arg_msys2 : quote_arg_msvc;
+	const char *strace_env;
 
 	/* Make sure to override previous errors, if any */
 	errno = 0;
@@ -1562,6 +1585,31 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 			free(quoted);
 	}
 
+	strace_env = getenv("GIT_STRACE_COMMANDS");
+	if (strace_env) {
+		char *p = path_lookup("strace.exe", 1);
+		if (!p)
+			return error("strace not found!");
+		if (xutftowcs_path(wcmd, p) < 0) {
+			free(p);
+			return -1;
+		}
+		free(p);
+		if (!strcmp("1", strace_env) ||
+		    !strcasecmp("yes", strace_env) ||
+		    !strcasecmp("true", strace_env))
+			strbuf_insert(&args, 0, "strace ", 7);
+		else {
+			const char *quoted = quote_arg(strace_env);
+			struct strbuf buf = STRBUF_INIT;
+			strbuf_addf(&buf, "strace -o %s ", quoted);
+			if (quoted != strace_env)
+				free((char *)quoted);
+			strbuf_insert(&args, 0, buf.buf, buf.len);
+			strbuf_release(&buf);
+		}
+	}
+
 	ALLOC_ARRAY(wargs, st_add(st_mult(2, args.len), 1));
 	xutftowcs(wargs, args.buf, 2 * args.len + 1);
 	strbuf_release(&args);
@@ -2581,12 +2629,14 @@ int is_valid_win32_path(const char *path, int allow_literal_nul)
 					continue;
 				}
 				break;
-			case 'c': case 'C': /* COM<N>, CON, CONIN$, CONOUT$ */
+			case 'c': case 'C':
+				/* COM1 ... COM9, CON, CONIN$, CONOUT$ */
 				if ((c = path[++i]) != 'o' && c != 'O')
 					goto not_a_reserved_name;
 				c = path[++i];
-				if (c == 'm' || c == 'M') { /* COM<N> */
-					if (!isdigit(path[++i]))
+				if (c == 'm' || c == 'M') { /* COM1 ... COM9 */
+					c = path[++i];
+					if (c < '1' || c > '9')
 						goto not_a_reserved_name;
 				} else if (c == 'n' || c == 'N') { /* CON */
 					c = path[i + 1];
diff --git a/compat/win32/path-utils.h b/compat/win32/path-utils.h
index f2e7087..bba2b64 100644
--- a/compat/win32/path-utils.h
+++ b/compat/win32/path-utils.h
@@ -20,6 +20,17 @@ static inline char *win32_find_last_dir_sep(const char *path)
 	return ret;
 }
 #define find_last_dir_sep win32_find_last_dir_sep
+static inline int win32_has_dir_sep(const char *path)
+{
+	/*
+	 * See how long the non-separator part of the given path is, and
+	 * if and only if it covers the whole path (i.e. path[len] is NUL),
+	 * there is no separator in the path---otherwise there is a separator.
+	 */
+	size_t len = strcspn(path, "/\\");
+	return !!path[len];
+}
+#define has_dir_sep(path) win32_has_dir_sep(path)
 int win32_offset_1st_component(const char *path);
 #define offset_1st_component win32_offset_1st_component
 
diff --git a/config.c b/config.c
index d17d2bd..8db9c77 100644
--- a/config.c
+++ b/config.c
@@ -37,6 +37,7 @@ struct config_source {
 	enum config_error_action default_error_action;
 	int linenr;
 	int eof;
+	size_t total_len;
 	struct strbuf value;
 	struct strbuf var;
 	unsigned subsection_case_sensitive : 1;
@@ -309,7 +310,7 @@ int git_config_include(const char *var, const char *value, void *data)
 {
 	struct config_include_data *inc = data;
 	const char *cond, *key;
-	int cond_len;
+	size_t cond_len;
 	int ret;
 
 	/*
@@ -358,12 +359,13 @@ static inline int iskeychar(int c)
  *
  * store_key - pointer to char* which will hold a copy of the key with
  *             lowercase section and variable name
- * baselen - pointer to int which will hold the length of the
+ * baselen - pointer to size_t which will hold the length of the
  *           section + subsection part, can be NULL
  */
-static int git_config_parse_key_1(const char *key, char **store_key, int *baselen_, int quiet)
+static int git_config_parse_key_1(const char *key, char **store_key, size_t *baselen_, int quiet)
 {
-	int i, dot, baselen;
+	size_t i, baselen;
+	int dot;
 	const char *last_dot = strrchr(key, '.');
 
 	/*
@@ -425,7 +427,7 @@ static int git_config_parse_key_1(const char *key, char **store_key, int *basele
 	return -CONFIG_INVALID_KEY;
 }
 
-int git_config_parse_key(const char *key, char **store_key, int *baselen)
+int git_config_parse_key(const char *key, char **store_key, size_t *baselen)
 {
 	return git_config_parse_key_1(key, store_key, baselen, 0);
 }
@@ -523,6 +525,19 @@ static int get_next_char(void)
 			c = '\r';
 		}
 	}
+
+	if (c != EOF && ++cf->total_len > INT_MAX) {
+		/*
+		 * This is an absurdly long config file; refuse to parse
+		 * further in order to protect downstream code from integer
+		 * overflows. Note that we can't return an error specifically,
+		 * but we can mark EOF and put trash in the return value,
+		 * which will trigger a parse error.
+		 */
+		cf->eof = 1;
+		return 0;
+	}
+
 	if (c == '\n')
 		cf->linenr++;
 	if (c == EOF) {
@@ -728,7 +743,7 @@ static int git_parse_source(config_fn_t fn, void *data,
 			    const struct config_options *opts)
 {
 	int comment = 0;
-	int baselen = 0;
+	size_t baselen = 0;
 	struct strbuf *var = &cf->var;
 	int error_return = 0;
 	char *error_msg = NULL;
@@ -1539,6 +1554,7 @@ static int do_config_from(struct config_source *top, config_fn_t fn, void *data,
 	top->prev = cf;
 	top->linenr = 1;
 	top->eof = 0;
+	top->total_len = 0;
 	strbuf_init(&top->value, 1024);
 	strbuf_init(&top->var, 1024);
 	cf = top;
@@ -2383,7 +2399,7 @@ void git_die_config(const char *key, const char *err, ...)
  */
 
 struct config_store_data {
-	int baselen;
+	size_t baselen;
 	char *key;
 	int do_not_match;
 	regex_t *value_regex;
@@ -2509,7 +2525,7 @@ static struct strbuf store_create_section(const char *key,
 					  const struct config_store_data *store)
 {
 	const char *dot;
-	int i;
+	size_t i;
 	struct strbuf sb = STRBUF_INIT;
 
 	dot = memchr(key, '.', store->baselen);
@@ -2522,7 +2538,9 @@ static struct strbuf store_create_section(const char *key,
 		}
 		strbuf_addstr(&sb, "\"]\n");
 	} else {
-		strbuf_addf(&sb, "[%.*s]\n", store->baselen, key);
+		strbuf_addch(&sb, '[');
+		strbuf_add(&sb, key, store->baselen);
+		strbuf_addstr(&sb, "]\n");
 	}
 
 	return sb;
@@ -2545,7 +2563,6 @@ static ssize_t write_pair(int fd, const char *key, const char *value,
 {
 	int i;
 	ssize_t ret;
-	int length = strlen(key + store->baselen + 1);
 	const char *quote = "";
 	struct strbuf sb = STRBUF_INIT;
 
@@ -2564,8 +2581,7 @@ static ssize_t write_pair(int fd, const char *key, const char *value,
 	if (i && value[i - 1] == ' ')
 		quote = "\"";
 
-	strbuf_addf(&sb, "\t%.*s = %s",
-		    length, key + store->baselen + 1, quote);
+	strbuf_addf(&sb, "\t%s = %s", key + store->baselen + 1, quote);
 
 	for (i = 0; value[i]; i++)
 		switch (value[i]) {
@@ -3238,7 +3254,7 @@ int config_error_nonbool(const char *var)
 
 int parse_config_key(const char *var,
 		     const char *section,
-		     const char **subsection, int *subsection_len,
+		     const char **subsection, size_t *subsection_len,
 		     const char **key)
 {
 	const char *dot;
diff --git a/config.h b/config.h
index 9b3773f..0608744 100644
--- a/config.h
+++ b/config.h
@@ -254,7 +254,7 @@ int git_config_set_gently(const char *, const char *);
  */
 void git_config_set(const char *, const char *);
 
-int git_config_parse_key(const char *, char **, int *);
+int git_config_parse_key(const char *, char **, size_t *);
 int git_config_key_is_valid(const char *key);
 int git_config_set_multivar_gently(const char *, const char *, const char *, int);
 void git_config_set_multivar(const char *, const char *, const char *, int);
@@ -359,7 +359,7 @@ int git_config_include(const char *name, const char *value, void *data);
  */
 int parse_config_key(const char *var,
 		     const char *section,
-		     const char **subsection, int *subsection_len,
+		     const char **subsection, size_t *subsection_len,
 		     const char **key);
 
 /**
diff --git a/config.mak.dev b/config.mak.dev
index 89b218d..cd4a82a 100644
--- a/config.mak.dev
+++ b/config.mak.dev
@@ -16,6 +16,8 @@
 DEVELOPER_CFLAGS += -Wunused
 DEVELOPER_CFLAGS += -Wvla
 
+DEVELOPER_CFLAGS += -DENABLE_SHA256
+
 ifndef COMPILER_FEATURES
 COMPILER_FEATURES := $(shell ./detect-compiler $(CC))
 endif
diff --git a/config.mak.uname b/config.mak.uname
index 0ab8e00..3e526f6 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -308,6 +308,7 @@
 	NO_STRLCPY = YesPlease
 	HAVE_PATHS_H = YesPlease
 	LIBC_CONTAINS_LIBINTL = YesPlease
+	FREAD_READS_DIRECTORIES = UnfortunatelyYes
 endif
 ifeq ($(uname_S),IRIX)
 	NO_SETENV = YesPlease
diff --git a/connect.c b/connect.c
index b6451ab..23013c6 100644
--- a/connect.c
+++ b/connect.c
@@ -9,7 +9,7 @@
 #include "connect.h"
 #include "url.h"
 #include "string-list.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "transport.h"
 #include "strbuf.h"
 #include "version.h"
diff --git a/connected.c b/connected.c
index 7e9bd1b..3135b71 100644
--- a/connected.c
+++ b/connected.c
@@ -52,7 +52,7 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 		strbuf_release(&idx_file);
 	}
 
-	if (opt->check_refs_are_promisor_objects_only) {
+	if (has_promisor_remote()) {
 		/*
 		 * For partial clones, we don't want to have to do a regular
 		 * connectivity check because we have to enumerate and exclude
@@ -61,7 +61,11 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 		 * object is a promisor object. Instead, just make sure we
 		 * received, in a promisor packfile, the objects pointed to by
 		 * each wanted ref.
+		 *
+		 * Before checking for promisor packs, be sure we have the
+		 * latest pack-files loaded into memory.
 		 */
+		reprepare_packed_git(the_repository);
 		do {
 			struct packed_git *p;
 
@@ -71,13 +75,18 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 				if (find_pack_entry_one(oid.hash, p))
 					goto promisor_pack_found;
 			}
-			return 1;
+			/*
+			 * Fallback to rev-list with oid and the rest of the
+			 * object IDs provided by fn.
+			 */
+			goto no_promisor_pack_found;
 promisor_pack_found:
 			;
 		} while (!fn(cb_data, &oid));
 		return 0;
 	}
 
+no_promisor_pack_found:
 	if (opt->shallow_file) {
 		argv_array_push(&rev_list.args, "--shallow-file");
 		argv_array_push(&rev_list.args, opt->shallow_file);
diff --git a/connected.h b/connected.h
index eba5c26..8d5a6b3 100644
--- a/connected.h
+++ b/connected.h
@@ -46,15 +46,6 @@ struct check_connected_options {
 	 * during a fetch.
 	 */
 	unsigned is_deepening_fetch : 1;
-
-	/*
-	 * If non-zero, only check that the top-level objects referenced by the
-	 * wanted refs (passed in as cb_data) are promisor objects. This is
-	 * useful for partial clones, where enumerating and excluding all
-	 * promisor objects is very slow and the commit-walk itself becomes a
-	 * no-op.
-	 */
-	unsigned check_refs_are_promisor_objects_only : 1;
 };
 
 #define CHECK_CONNECTED_INIT { 0 }
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index c21786f..b1d6e5e 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -504,7 +504,7 @@
 {
 	local root="$2" match="$3"
 
-	__git_ls_files_helper "$root" "$1" "$match" |
+	__git_ls_files_helper "$root" "$1" "${match:-?}" |
 	awk -F / -v pfx="${2//\\/\\\\}" '{
 		paths[$1] = 1
 	}
diff --git a/contrib/completion/git-completion.zsh b/contrib/completion/git-completion.zsh
index eef4eff..ce47e86 100644
--- a/contrib/completion/git-completion.zsh
+++ b/contrib/completion/git-completion.zsh
@@ -150,9 +150,11 @@
 	push:'update remote refs along with associated objects'
 	rebase:'forward-port local commits to the updated upstream head'
 	reset:'reset current HEAD to the specified state'
+	restore:'restore working tree files'
 	rm:'remove files from the working tree and from the index'
 	show:'show various types of objects'
 	status:'show the working tree status'
+	switch:'switch branches'
 	tag:'create, list, delete or verify a tag object signed with GPG')
 	_describe -t common-commands 'common commands' list && _ret=0
 }
diff --git a/contrib/fast-import/import-tars.perl b/contrib/fast-import/import-tars.perl
index e800d9f..d50ce26 100755
--- a/contrib/fast-import/import-tars.perl
+++ b/contrib/fast-import/import-tars.perl
@@ -139,6 +139,8 @@
 			print FI "\n";
 		}
 
+		next if ($typeflag eq 'g'); # ignore global header
+
 		my $path;
 		if ($prefix) {
 			$path = "$prefix/$name";
diff --git a/contrib/subtree/Makefile b/contrib/subtree/Makefile
index 6906aae..6fa7496 100644
--- a/contrib/subtree/Makefile
+++ b/contrib/subtree/Makefile
@@ -25,14 +25,16 @@
 ASCIIDOC_DOCBOOK = docbook
 ASCIIDOC_EXTRA   =
 XMLTO            = xmlto
+XMLTO_EXTRA      =
 
 ifdef USE_ASCIIDOCTOR
 ASCIIDOC         = asciidoctor
 ASCIIDOC_CONF    =
 ASCIIDOC_HTML    = xhtml5
-ASCIIDOC_DOCBOOK = docbook45
+ASCIIDOC_DOCBOOK = docbook
 ASCIIDOC_EXTRA  += -I../../Documentation -rasciidoctor-extensions
 ASCIIDOC_EXTRA  += -alitdd='&\#x2d;&\#x2d;'
+XMLTO_EXTRA     += --skip-validation
 endif
 
 ifndef SHELL_PATH
@@ -78,7 +80,7 @@
 	$(INSTALL) -m 644 $^ $(DESTDIR)$(htmldir)
 
 $(GIT_SUBTREE_DOC): $(GIT_SUBTREE_XML)
-	$(XMLTO) -m $(MANPAGE_XSL) man $^
+	$(XMLTO) -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $^
 
 $(GIT_SUBTREE_XML): $(GIT_SUBTREE_TXT)
 	$(ASCIIDOC) -b $(ASCIIDOC_DOCBOOK) -d manpage $(ASCIIDOC_CONF) \
diff --git a/convert.c b/convert.c
index 5ead3ce..5724498 100644
--- a/convert.c
+++ b/convert.c
@@ -797,6 +797,7 @@ static void handle_filter_error(const struct strbuf *filter_status,
 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
 				   int fd, struct strbuf *dst, const char *cmd,
 				   const unsigned int wanted_capability,
+				   const struct checkout_metadata *meta,
 				   struct delayed_checkout *dco)
 {
 	int err;
@@ -855,6 +856,24 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
 	if (err)
 		goto done;
 
+	if (meta && meta->refname) {
+		err = packet_write_fmt_gently(process->in, "ref=%s\n", meta->refname);
+		if (err)
+			goto done;
+	}
+
+	if (meta && !is_null_oid(&meta->treeish)) {
+		err = packet_write_fmt_gently(process->in, "treeish=%s\n", oid_to_hex(&meta->treeish));
+		if (err)
+			goto done;
+	}
+
+	if (meta && !is_null_oid(&meta->blob)) {
+		err = packet_write_fmt_gently(process->in, "blob=%s\n", oid_to_hex(&meta->blob));
+		if (err)
+			goto done;
+	}
+
 	if ((entry->supported_capabilities & CAP_DELAY) &&
 	    dco && dco->state == CE_CAN_DELAY) {
 		can_delay = 1;
@@ -971,6 +990,7 @@ static struct convert_driver {
 static int apply_filter(const char *path, const char *src, size_t len,
 			int fd, struct strbuf *dst, struct convert_driver *drv,
 			const unsigned int wanted_capability,
+			const struct checkout_metadata *meta,
 			struct delayed_checkout *dco)
 {
 	const char *cmd = NULL;
@@ -990,7 +1010,7 @@ static int apply_filter(const char *path, const char *src, size_t len,
 		return apply_single_file_filter(path, src, len, fd, dst, cmd);
 	else if (drv->process && *drv->process)
 		return apply_multi_file_filter(path, src, len, fd, dst,
-			drv->process, wanted_capability, dco);
+			drv->process, wanted_capability, meta, dco);
 
 	return 0;
 }
@@ -998,7 +1018,7 @@ static int apply_filter(const char *path, const char *src, size_t len,
 static int read_convert_config(const char *var, const char *value, void *cb)
 {
 	const char *key, *name;
-	int namelen;
+	size_t namelen;
 	struct convert_driver *drv;
 
 	/*
@@ -1368,7 +1388,7 @@ int would_convert_to_git_filter_fd(const struct index_state *istate, const char
 	if (!ca.drv->required)
 		return 0;
 
-	return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL);
+	return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL, NULL);
 }
 
 const char *get_convert_attr_ascii(const struct index_state *istate, const char *path)
@@ -1406,7 +1426,7 @@ int convert_to_git(const struct index_state *istate,
 
 	convert_attrs(istate, &ca, path);
 
-	ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL);
+	ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL, NULL);
 	if (!ret && ca.drv && ca.drv->required)
 		die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
 
@@ -1441,7 +1461,7 @@ void convert_to_git_filter_fd(const struct index_state *istate,
 	assert(ca.drv);
 	assert(ca.drv->clean || ca.drv->process);
 
-	if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
+	if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL, NULL))
 		die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
 
 	encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
@@ -1452,7 +1472,9 @@ void convert_to_git_filter_fd(const struct index_state *istate,
 static int convert_to_working_tree_internal(const struct index_state *istate,
 					    const char *path, const char *src,
 					    size_t len, struct strbuf *dst,
-					    int normalizing, struct delayed_checkout *dco)
+					    int normalizing,
+					    const struct checkout_metadata *meta,
+					    struct delayed_checkout *dco)
 {
 	int ret = 0, ret_filter = 0;
 	struct conv_attrs ca;
@@ -1484,7 +1506,7 @@ static int convert_to_working_tree_internal(const struct index_state *istate,
 	}
 
 	ret_filter = apply_filter(
-		path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco);
+		path, src, len, -1, dst, ca.drv, CAP_SMUDGE, meta, dco);
 	if (!ret_filter && ca.drv && ca.drv->required)
 		die(_("%s: smudge filter %s failed"), path, ca.drv->name);
 
@@ -1494,22 +1516,24 @@ static int convert_to_working_tree_internal(const struct index_state *istate,
 int async_convert_to_working_tree(const struct index_state *istate,
 				  const char *path, const char *src,
 				  size_t len, struct strbuf *dst,
+				  const struct checkout_metadata *meta,
 				  void *dco)
 {
-	return convert_to_working_tree_internal(istate, path, src, len, dst, 0, dco);
+	return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, dco);
 }
 
 int convert_to_working_tree(const struct index_state *istate,
 			    const char *path, const char *src,
-			    size_t len, struct strbuf *dst)
+			    size_t len, struct strbuf *dst,
+			    const struct checkout_metadata *meta)
 {
-	return convert_to_working_tree_internal(istate, path, src, len, dst, 0, NULL);
+	return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, NULL);
 }
 
 int renormalize_buffer(const struct index_state *istate, const char *path,
 		       const char *src, size_t len, struct strbuf *dst)
 {
-	int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL);
+	int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL, NULL);
 	if (ret) {
 		src = dst->buf;
 		len = dst->len;
@@ -1982,3 +2006,25 @@ int stream_filter(struct stream_filter *filter,
 {
 	return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
 }
+
+void init_checkout_metadata(struct checkout_metadata *meta, const char *refname,
+			    const struct object_id *treeish,
+			    const struct object_id *blob)
+{
+	memset(meta, 0, sizeof(*meta));
+	if (refname)
+		meta->refname = refname;
+	if (treeish)
+		oidcpy(&meta->treeish, treeish);
+	if (blob)
+		oidcpy(&meta->blob, blob);
+}
+
+void clone_checkout_metadata(struct checkout_metadata *dst,
+			     const struct checkout_metadata *src,
+			     const struct object_id *blob)
+{
+	memcpy(dst, src, sizeof(*dst));
+	if (blob)
+		oidcpy(&dst->blob, blob);
+}
diff --git a/convert.h b/convert.h
index 3710969..e29d102 100644
--- a/convert.h
+++ b/convert.h
@@ -4,10 +4,10 @@
 #ifndef CONVERT_H
 #define CONVERT_H
 
+#include "hash.h"
 #include "string-list.h"
 
 struct index_state;
-struct object_id;
 struct strbuf;
 
 #define CONV_EOL_RNDTRP_DIE   (1<<0) /* Die if CRLF to LF to CRLF is different */
@@ -57,6 +57,12 @@ struct delayed_checkout {
 	struct string_list paths;
 };
 
+struct checkout_metadata {
+	const char *refname;
+	struct object_id treeish;
+	struct object_id blob;
+};
+
 extern enum eol core_eol;
 extern char *check_roundtrip_encoding;
 const char *get_cached_convert_stats_ascii(const struct index_state *istate,
@@ -71,10 +77,12 @@ int convert_to_git(const struct index_state *istate,
 		   struct strbuf *dst, int conv_flags);
 int convert_to_working_tree(const struct index_state *istate,
 			    const char *path, const char *src,
-			    size_t len, struct strbuf *dst);
+			    size_t len, struct strbuf *dst,
+			    const struct checkout_metadata *meta);
 int async_convert_to_working_tree(const struct index_state *istate,
 				  const char *path, const char *src,
 				  size_t len, struct strbuf *dst,
+				  const struct checkout_metadata *meta,
 				  void *dco);
 int async_query_available_blobs(const char *cmd,
 				struct string_list *available_paths);
@@ -95,6 +103,23 @@ int would_convert_to_git_filter_fd(const struct index_state *istate,
 				   const char *path);
 
 /*
+ * Initialize the checkout metadata with the given values.  Any argument may be
+ * NULL if it is not applicable.  The treeish should be a commit if that is
+ * available, and a tree otherwise.
+ *
+ * The refname is not copied and must be valid for the lifetime of the struct.
+ * THe object IDs are copied.
+ */
+void init_checkout_metadata(struct checkout_metadata *meta, const char *refname,
+			    const struct object_id *treeish,
+			    const struct object_id *blob);
+
+/* Copy the metadata from src to dst, updating the blob. */
+void clone_checkout_metadata(struct checkout_metadata *dst,
+			     const struct checkout_metadata *src,
+			     const struct object_id *blob);
+
+/*
  * Reset the internal list of attributes used by convert_to_git and
  * convert_to_working_tree.
  */
diff --git a/credential.c b/credential.c
index 77dfde4..064e25e 100644
--- a/credential.c
+++ b/credential.c
@@ -88,6 +88,11 @@ static void credential_apply_config(struct credential *c)
 	struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 	struct strbuf url = STRBUF_INIT;
 
+	if (!c->host)
+		die(_("refusing to work with credential missing host field"));
+	if (!c->protocol)
+		die(_("refusing to work with credential missing protocol field"));
+
 	if (c->configured)
 		return;
 
@@ -222,20 +227,25 @@ int credential_read(struct credential *c, FILE *fp)
 	return 0;
 }
 
-static void credential_write_item(FILE *fp, const char *key, const char *value)
+static void credential_write_item(FILE *fp, const char *key, const char *value,
+				  int required)
 {
+	if (!value && required)
+		BUG("credential value for %s is missing", key);
 	if (!value)
 		return;
+	if (strchr(value, '\n'))
+		die("credential value for %s contains newline", key);
 	fprintf(fp, "%s=%s\n", key, value);
 }
 
 void credential_write(const struct credential *c, FILE *fp)
 {
-	credential_write_item(fp, "protocol", c->protocol);
-	credential_write_item(fp, "host", c->host);
-	credential_write_item(fp, "path", c->path);
-	credential_write_item(fp, "username", c->username);
-	credential_write_item(fp, "password", c->password);
+	credential_write_item(fp, "protocol", c->protocol, 1);
+	credential_write_item(fp, "host", c->host, 1);
+	credential_write_item(fp, "path", c->path, 0);
+	credential_write_item(fp, "username", c->username, 0);
+	credential_write_item(fp, "password", c->password, 0);
 }
 
 static int run_credential_helper(struct credential *c,
@@ -353,7 +363,22 @@ void credential_reject(struct credential *c)
 	c->approved = 0;
 }
 
-void credential_from_url(struct credential *c, const char *url)
+static int check_url_component(const char *url, int quiet,
+			       const char *name, const char *value)
+{
+	if (!value)
+		return 0;
+	if (!strchr(value, '\n'))
+		return 0;
+
+	if (!quiet)
+		warning(_("url contains a newline in its %s component: %s"),
+			name, url);
+	return -1;
+}
+
+int credential_from_url_gently(struct credential *c, const char *url,
+			       int quiet)
 {
 	const char *at, *colon, *cp, *slash, *host, *proto_end;
 
@@ -366,12 +391,22 @@ void credential_from_url(struct credential *c, const char *url)
 	 *   (3) proto://<user>:<pass>@<host>/...
 	 */
 	proto_end = strstr(url, "://");
-	if (!proto_end)
-		return;
+	if (!proto_end || proto_end == url) {
+		if (!quiet)
+			warning(_("url has no scheme: %s"), url);
+		return -1;
+	}
 	cp = proto_end + 3;
 	at = strchr(cp, '@');
 	colon = strchr(cp, ':');
-	slash = strchrnul(cp, '/');
+
+	/*
+	 * A query or fragment marker before the slash ends the host portion.
+	 * We'll just continue to call this "slash" for simplicity. Notably our
+	 * "trim leading slashes" part won't skip over this part of the path,
+	 * but that's what we'd want.
+	 */
+	slash = cp + strcspn(cp, "/?#");
 
 	if (!at || slash <= at) {
 		/* Case (1) */
@@ -392,10 +427,8 @@ void credential_from_url(struct credential *c, const char *url)
 		host = at + 1;
 	}
 
-	if (proto_end - url > 0)
-		c->protocol = xmemdupz(url, proto_end - url);
-	if (slash - host > 0)
-		c->host = url_decode_mem(host, slash - host);
+	c->protocol = xmemdupz(url, proto_end - url);
+	c->host = url_decode_mem(host, slash - host);
 	/* Trim leading and trailing slashes from path */
 	while (*slash == '/')
 		slash++;
@@ -406,4 +439,19 @@ void credential_from_url(struct credential *c, const char *url)
 		while (p > c->path && *p == '/')
 			*p-- = '\0';
 	}
+
+	if (check_url_component(url, quiet, "username", c->username) < 0 ||
+	    check_url_component(url, quiet, "password", c->password) < 0 ||
+	    check_url_component(url, quiet, "protocol", c->protocol) < 0 ||
+	    check_url_component(url, quiet, "host", c->host) < 0 ||
+	    check_url_component(url, quiet, "path", c->path) < 0)
+		return -1;
+
+	return 0;
+}
+
+void credential_from_url(struct credential *c, const char *url)
+{
+	if (credential_from_url_gently(c, url, 0) < 0)
+		die(_("credential url cannot be parsed: %s"), url);
 }
diff --git a/credential.h b/credential.h
index fec7815..d99ec42 100644
--- a/credential.h
+++ b/credential.h
@@ -173,8 +173,21 @@ void credential_reject(struct credential *);
 int credential_read(struct credential *, FILE *);
 void credential_write(const struct credential *, FILE *);
 
-/* Parse a URL into broken-down credential fields. */
+/*
+ * Parse a url into a credential struct, replacing any existing contents.
+ *
+ * If the url can't be parsed (e.g., a missing "proto://" component), the
+ * resulting credential will be empty but we'll still return success from the
+ * "gently" form.
+ *
+ * If we encounter a component which cannot be represented as a credential
+ * value (e.g., because it contains a newline), the "gently" form will return
+ * an error but leave the broken state in the credential object for further
+ * examination.  The non-gentle form will issue a warning to stderr and return
+ * an empty credential.
+ */
 void credential_from_url(struct credential *, const char *url);
+int credential_from_url_gently(struct credential *, const char *url, int quiet);
 
 int credential_match(const struct credential *have,
 		     const struct credential *want);
diff --git a/csum-file.c b/csum-file.c
index 53ce37f..0f35fa5 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -157,7 +157,7 @@ void hashfile_checkpoint(struct hashfile *f, struct hashfile_checkpoint *checkpo
 {
 	hashflush(f);
 	checkpoint->offset = f->total;
-	checkpoint->ctx = f->ctx;
+	the_hash_algo->clone_fn(&checkpoint->ctx, &f->ctx);
 }
 
 int hashfile_truncate(struct hashfile *f, struct hashfile_checkpoint *checkpoint)
diff --git a/delta-islands.c b/delta-islands.c
index 09dbd3c..aa98b2e 100644
--- a/delta-islands.c
+++ b/delta-islands.c
@@ -17,7 +17,7 @@
 #include "pack-bitmap.h"
 #include "pack-objects.h"
 #include "delta-islands.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "config.h"
 
 KHASH_INIT(str, const char *, void *, 1, kh_str_hash_func, kh_str_hash_equal)
diff --git a/diff.c b/diff.c
index f2cfbf2..d1ad6a3 100644
--- a/diff.c
+++ b/diff.c
@@ -573,7 +573,7 @@ static int fill_mmfile(struct repository *r, mmfile_t *mf,
 		mf->size = 0;
 		return 0;
 	}
-	else if (diff_populate_filespec(r, one, 0))
+	else if (diff_populate_filespec(r, one, NULL))
 		return -1;
 
 	mf->ptr = one->data;
@@ -585,9 +585,13 @@ static int fill_mmfile(struct repository *r, mmfile_t *mf,
 static unsigned long diff_filespec_size(struct repository *r,
 					struct diff_filespec *one)
 {
+	struct diff_populate_filespec_options dpf_options = {
+		.check_size_only = 1,
+	};
+
 	if (!DIFF_FILE_VALID(one))
 		return 0;
-	diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
+	diff_populate_filespec(r, one, &dpf_options);
 	return one->size;
 }
 
@@ -3020,6 +3024,9 @@ static void show_dirstat(struct diff_options *options)
 		struct diff_filepair *p = q->queue[i];
 		const char *name;
 		unsigned long copied, added, damage;
+		struct diff_populate_filespec_options dpf_options = {
+			.check_size_only = 1,
+		};
 
 		name = p->two->path ? p->two->path : p->one->path;
 
@@ -3047,19 +3054,19 @@ static void show_dirstat(struct diff_options *options)
 		}
 
 		if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
-			diff_populate_filespec(options->repo, p->one, 0);
-			diff_populate_filespec(options->repo, p->two, 0);
+			diff_populate_filespec(options->repo, p->one, NULL);
+			diff_populate_filespec(options->repo, p->two, NULL);
 			diffcore_count_changes(options->repo,
 					       p->one, p->two, NULL, NULL,
 					       &copied, &added);
 			diff_free_filespec_data(p->one);
 			diff_free_filespec_data(p->two);
 		} else if (DIFF_FILE_VALID(p->one)) {
-			diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
+			diff_populate_filespec(options->repo, p->one, &dpf_options);
 			copied = added = 0;
 			diff_free_filespec_data(p->one);
 		} else if (DIFF_FILE_VALID(p->two)) {
-			diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
+			diff_populate_filespec(options->repo, p->two, &dpf_options);
 			copied = 0;
 			added = p->two->size;
 			diff_free_filespec_data(p->two);
@@ -3339,13 +3346,17 @@ static void emit_binary_diff(struct diff_options *o,
 int diff_filespec_is_binary(struct repository *r,
 			    struct diff_filespec *one)
 {
+	struct diff_populate_filespec_options dpf_options = {
+		.check_binary = 1,
+	};
+
 	if (one->is_binary == -1) {
 		diff_filespec_load_driver(one, r->index);
 		if (one->driver->binary != -1)
 			one->is_binary = one->driver->binary;
 		else {
 			if (!one->data && DIFF_FILE_VALID(one))
-				diff_populate_filespec(r, one, CHECK_BINARY);
+				diff_populate_filespec(r, one, &dpf_options);
 			if (one->is_binary == -1 && one->data)
 				one->is_binary = buffer_is_binary(one->data,
 						one->size);
@@ -3677,8 +3688,8 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
 	}
 
 	else if (complete_rewrite) {
-		diff_populate_filespec(o->repo, one, 0);
-		diff_populate_filespec(o->repo, two, 0);
+		diff_populate_filespec(o->repo, one, NULL);
+		diff_populate_filespec(o->repo, two, NULL);
 		data->deleted = count_lines(one->data, one->size);
 		data->added = count_lines(two->data, two->size);
 	}
@@ -3914,9 +3925,10 @@ static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
  */
 int diff_populate_filespec(struct repository *r,
 			   struct diff_filespec *s,
-			   unsigned int flags)
+			   const struct diff_populate_filespec_options *options)
 {
-	int size_only = flags & CHECK_SIZE_ONLY;
+	int size_only = options ? options->check_size_only : 0;
+	int check_binary = options ? options->check_binary : 0;
 	int err = 0;
 	int conv_flags = global_conv_flags_eol;
 	/*
@@ -3986,7 +3998,7 @@ int diff_populate_filespec(struct repository *r,
 		 * opening the file and inspecting the contents, this
 		 * is probably fine.
 		 */
-		if ((flags & CHECK_BINARY) &&
+		if (check_binary &&
 		    s->size > big_file_threshold && s->is_binary == -1) {
 			s->is_binary = 1;
 			return 0;
@@ -4011,12 +4023,30 @@ int diff_populate_filespec(struct repository *r,
 		}
 	}
 	else {
-		enum object_type type;
-		if (size_only || (flags & CHECK_BINARY)) {
-			type = oid_object_info(r, &s->oid, &s->size);
-			if (type < 0)
-				die("unable to read %s",
-				    oid_to_hex(&s->oid));
+		struct object_info info = {
+			.sizep = &s->size
+		};
+
+		if (!(size_only || check_binary))
+			/*
+			 * Set contentp, since there is no chance that merely
+			 * the size is sufficient.
+			 */
+			info.contentp = &s->data;
+
+		if (options && options->missing_object_cb) {
+			if (!oid_object_info_extended(r, &s->oid, &info,
+						      OBJECT_INFO_LOOKUP_REPLACE |
+						      OBJECT_INFO_SKIP_FETCH_OBJECT))
+				goto object_read;
+			options->missing_object_cb(options->missing_object_data);
+		}
+		if (oid_object_info_extended(r, &s->oid, &info,
+					     OBJECT_INFO_LOOKUP_REPLACE))
+			die("unable to read %s", oid_to_hex(&s->oid));
+
+object_read:
+		if (size_only || check_binary) {
 			if (size_only)
 				return 0;
 			if (s->size > big_file_threshold && s->is_binary == -1) {
@@ -4024,9 +4054,12 @@ int diff_populate_filespec(struct repository *r,
 				return 0;
 			}
 		}
-		s->data = repo_read_object_file(r, &s->oid, &type, &s->size);
-		if (!s->data)
-			die("unable to read %s", oid_to_hex(&s->oid));
+		if (!info.contentp) {
+			info.contentp = &s->data;
+			if (oid_object_info_extended(r, &s->oid, &info,
+						     OBJECT_INFO_LOOKUP_REPLACE))
+				die("unable to read %s", oid_to_hex(&s->oid));
+		}
 		s->should_free = 1;
 	}
 	return 0;
@@ -4062,6 +4095,9 @@ static void prep_temp_blob(struct index_state *istate,
 	struct strbuf tempfile = STRBUF_INIT;
 	char *path_dup = xstrdup(path);
 	const char *base = basename(path_dup);
+	struct checkout_metadata meta;
+
+	init_checkout_metadata(&meta, NULL, NULL, oid);
 
 	/* Generate "XXXXXX_basename.ext" */
 	strbuf_addstr(&tempfile, "XXXXXX_");
@@ -4071,7 +4107,7 @@ static void prep_temp_blob(struct index_state *istate,
 	if (!temp->tempfile)
 		die_errno("unable to create temp-file");
 	if (convert_to_working_tree(istate, path,
-			(const char *)blob, (size_t)size, &buf)) {
+			(const char *)blob, (size_t)size, &buf, &meta)) {
 		blob = buf.buf;
 		size = buf.len;
 	}
@@ -4141,7 +4177,7 @@ static struct diff_tempfile *prepare_temp_file(struct repository *r,
 		return temp;
 	}
 	else {
-		if (diff_populate_filespec(r, one, 0))
+		if (diff_populate_filespec(r, one, NULL))
 			die("cannot read data blob for %s", one->path);
 		prep_temp_blob(r->index, name, temp,
 			       one->data, one->size,
@@ -6407,9 +6443,9 @@ static int diff_filespec_is_identical(struct repository *r,
 {
 	if (S_ISGITLINK(one->mode))
 		return 0;
-	if (diff_populate_filespec(r, one, 0))
+	if (diff_populate_filespec(r, one, NULL))
 		return 0;
-	if (diff_populate_filespec(r, two, 0))
+	if (diff_populate_filespec(r, two, NULL))
 		return 0;
 	return !memcmp(one->data, two->data, one->size);
 }
@@ -6417,6 +6453,12 @@ static int diff_filespec_is_identical(struct repository *r,
 static int diff_filespec_check_stat_unmatch(struct repository *r,
 					    struct diff_filepair *p)
 {
+	struct diff_populate_filespec_options dpf_options = {
+		.check_size_only = 1,
+		.missing_object_cb = diff_queued_diff_prefetch,
+		.missing_object_data = r,
+	};
+
 	if (p->done_skip_stat_unmatch)
 		return p->skip_stat_unmatch_result;
 
@@ -6439,8 +6481,8 @@ static int diff_filespec_check_stat_unmatch(struct repository *r,
 	    !DIFF_FILE_VALID(p->two) ||
 	    (p->one->oid_valid && p->two->oid_valid) ||
 	    (p->one->mode != p->two->mode) ||
-	    diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
-	    diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
+	    diff_populate_filespec(r, p->one, &dpf_options) ||
+	    diff_populate_filespec(r, p->two, &dpf_options) ||
 	    (p->one->size != p->two->size) ||
 	    !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
 		p->skip_stat_unmatch_result = 1;
@@ -6491,9 +6533,9 @@ void diffcore_fix_diff_index(void)
 	QSORT(q->queue, q->nr, diffnamecmp);
 }
 
-static void add_if_missing(struct repository *r,
-			   struct oid_array *to_fetch,
-			   const struct diff_filespec *filespec)
+void diff_add_if_missing(struct repository *r,
+			 struct oid_array *to_fetch,
+			 const struct diff_filespec *filespec)
 {
 	if (filespec && filespec->oid_valid &&
 	    !S_ISGITLINK(filespec->mode) &&
@@ -6502,29 +6544,47 @@ static void add_if_missing(struct repository *r,
 		oid_array_append(to_fetch, &filespec->oid);
 }
 
+void diff_queued_diff_prefetch(void *repository)
+{
+	struct repository *repo = repository;
+	int i;
+	struct diff_queue_struct *q = &diff_queued_diff;
+	struct oid_array to_fetch = OID_ARRAY_INIT;
+
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		diff_add_if_missing(repo, &to_fetch, p->one);
+		diff_add_if_missing(repo, &to_fetch, p->two);
+	}
+
+	/*
+	 * NEEDSWORK: Consider deduplicating the OIDs sent.
+	 */
+	promisor_remote_get_direct(repo, to_fetch.oid, to_fetch.nr);
+
+	oid_array_clear(&to_fetch);
+}
+
 void diffcore_std(struct diff_options *options)
 {
-	if (options->repo == the_repository && has_promisor_remote()) {
-		/*
-		 * Prefetch the diff pairs that are about to be flushed.
-		 */
-		int i;
-		struct diff_queue_struct *q = &diff_queued_diff;
-		struct oid_array to_fetch = OID_ARRAY_INIT;
+	int output_formats_to_prefetch = DIFF_FORMAT_DIFFSTAT |
+		DIFF_FORMAT_NUMSTAT |
+		DIFF_FORMAT_PATCH |
+		DIFF_FORMAT_SHORTSTAT |
+		DIFF_FORMAT_DIRSTAT;
 
-		for (i = 0; i < q->nr; i++) {
-			struct diff_filepair *p = q->queue[i];
-			add_if_missing(options->repo, &to_fetch, p->one);
-			add_if_missing(options->repo, &to_fetch, p->two);
-		}
-		if (to_fetch.nr)
-			/*
-			 * NEEDSWORK: Consider deduplicating the OIDs sent.
-			 */
-			promisor_remote_get_direct(options->repo,
-						   to_fetch.oid, to_fetch.nr);
-		oid_array_clear(&to_fetch);
-	}
+	/*
+	 * Check if the user requested a blob-data-requiring diff output and/or
+	 * break-rewrite detection (which requires blob data). If yes, prefetch
+	 * the diff pairs.
+	 *
+	 * If no prefetching occurs, diffcore_rename() will prefetch if it
+	 * decides that it needs inexact rename detection.
+	 */
+	if (options->repo == the_repository && has_promisor_remote() &&
+	    (options->output_format & output_formats_to_prefetch ||
+	     options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
+		diff_queued_diff_prefetch(options->repo);
 
 	/* NOTE please keep the following in sync with diff_tree_combined() */
 	if (options->skip_stat_unmatch)
@@ -6771,7 +6831,7 @@ size_t fill_textconv(struct repository *r,
 			*outbuf = "";
 			return 0;
 		}
-		if (diff_populate_filespec(r, df, 0))
+		if (diff_populate_filespec(r, df, NULL))
 			die("unable to read files to diff");
 		*outbuf = df->data;
 		return df->size;
diff --git a/diffcore-break.c b/diffcore-break.c
index 9d20a6a..0d4a149 100644
--- a/diffcore-break.c
+++ b/diffcore-break.c
@@ -4,6 +4,7 @@
 #include "cache.h"
 #include "diff.h"
 #include "diffcore.h"
+#include "promisor-remote.h"
 
 static int should_break(struct repository *r,
 			struct diff_filespec *src,
@@ -49,6 +50,8 @@ static int should_break(struct repository *r,
 	unsigned long delta_size, max_size;
 	unsigned long src_copied, literal_added, src_removed;
 
+	struct diff_populate_filespec_options options = { 0 };
+
 	*merge_score_p = 0; /* assume no deletion --- "do not break"
 			     * is the default.
 			     */
@@ -62,8 +65,13 @@ static int should_break(struct repository *r,
 	    oideq(&src->oid, &dst->oid))
 		return 0; /* they are the same */
 
-	if (diff_populate_filespec(r, src, 0) ||
-	    diff_populate_filespec(r, dst, 0))
+	if (r == the_repository && has_promisor_remote()) {
+		options.missing_object_cb = diff_queued_diff_prefetch;
+		options.missing_object_data = r;
+	}
+
+	if (diff_populate_filespec(r, src, &options) ||
+	    diff_populate_filespec(r, dst, &options))
 		return 0; /* error but caught downstream */
 
 	max_size = ((src->size > dst->size) ? src->size : dst->size);
diff --git a/diffcore-rename.c b/diffcore-rename.c
index e189f40..99e63e9 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -1,4 +1,5 @@
 /*
+ *
  * Copyright (C) 2005 Junio C Hamano
  */
 #include "cache.h"
@@ -7,6 +8,7 @@
 #include "object-store.h"
 #include "hashmap.h"
 #include "progress.h"
+#include "promisor-remote.h"
 
 /* Table of rename/copy destinations */
 
@@ -128,10 +130,46 @@ struct diff_score {
 	short name_score;
 };
 
+struct prefetch_options {
+	struct repository *repo;
+	int skip_unmodified;
+};
+static void prefetch(void *prefetch_options)
+{
+	struct prefetch_options *options = prefetch_options;
+	int i;
+	struct oid_array to_fetch = OID_ARRAY_INIT;
+
+	for (i = 0; i < rename_dst_nr; i++) {
+		if (rename_dst[i].pair)
+			/*
+			 * The loop in diffcore_rename() will not need these
+			 * blobs, so skip prefetching.
+			 */
+			continue; /* already found exact match */
+		diff_add_if_missing(options->repo, &to_fetch,
+				    rename_dst[i].two);
+	}
+	for (i = 0; i < rename_src_nr; i++) {
+		if (options->skip_unmodified &&
+		    diff_unmodified_pair(rename_src[i].p))
+			/*
+			 * The loop in diffcore_rename() will not need these
+			 * blobs, so skip prefetching.
+			 */
+			continue;
+		diff_add_if_missing(options->repo, &to_fetch,
+				    rename_src[i].p->one);
+	}
+	promisor_remote_get_direct(options->repo, to_fetch.oid, to_fetch.nr);
+	oid_array_clear(&to_fetch);
+}
+
 static int estimate_similarity(struct repository *r,
 			       struct diff_filespec *src,
 			       struct diff_filespec *dst,
-			       int minimum_score)
+			       int minimum_score,
+			       int skip_unmodified)
 {
 	/* src points at a file that existed in the original tree (or
 	 * optionally a file in the destination tree) and dst points
@@ -148,6 +186,15 @@ static int estimate_similarity(struct repository *r,
 	 */
 	unsigned long max_size, delta_size, base_size, src_copied, literal_added;
 	int score;
+	struct diff_populate_filespec_options dpf_options = {
+		.check_size_only = 1
+	};
+	struct prefetch_options prefetch_options = {r, skip_unmodified};
+
+	if (r == the_repository && has_promisor_remote()) {
+		dpf_options.missing_object_cb = prefetch;
+		dpf_options.missing_object_data = &prefetch_options;
+	}
 
 	/* We deal only with regular files.  Symlink renames are handled
 	 * only when they are exact matches --- in other words, no edits
@@ -166,10 +213,10 @@ static int estimate_similarity(struct repository *r,
 	 * say whether the size is valid or not!)
 	 */
 	if (!src->cnt_data &&
-	    diff_populate_filespec(r, src, CHECK_SIZE_ONLY))
+	    diff_populate_filespec(r, src, &dpf_options))
 		return 0;
 	if (!dst->cnt_data &&
-	    diff_populate_filespec(r, dst, CHECK_SIZE_ONLY))
+	    diff_populate_filespec(r, dst, &dpf_options))
 		return 0;
 
 	max_size = ((src->size > dst->size) ? src->size : dst->size);
@@ -187,9 +234,11 @@ static int estimate_similarity(struct repository *r,
 	if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
 		return 0;
 
-	if (!src->cnt_data && diff_populate_filespec(r, src, 0))
+	dpf_options.check_size_only = 0;
+
+	if (!src->cnt_data && diff_populate_filespec(r, src, &dpf_options))
 		return 0;
-	if (!dst->cnt_data && diff_populate_filespec(r, dst, 0))
+	if (!dst->cnt_data && diff_populate_filespec(r, dst, &dpf_options))
 		return 0;
 
 	if (diffcore_count_changes(r, src, dst,
@@ -261,7 +310,7 @@ static unsigned int hash_filespec(struct repository *r,
 				  struct diff_filespec *filespec)
 {
 	if (!filespec->oid_valid) {
-		if (diff_populate_filespec(r, filespec, 0))
+		if (diff_populate_filespec(r, filespec, NULL))
 			return 0;
 		hash_object_file(r->hash_algo, filespec->data, filespec->size,
 				 "blob", &filespec->oid);
@@ -566,7 +615,8 @@ void diffcore_rename(struct diff_options *options)
 
 			this_src.score = estimate_similarity(options->repo,
 							     one, two,
-							     minimum_score);
+							     minimum_score,
+							     skip_unmodified);
 			this_src.name_score = basename_same(one, two);
 			this_src.dst = i;
 			this_src.src = j;
diff --git a/diffcore.h b/diffcore.h
index 7c07347..d2a63c5 100644
--- a/diffcore.h
+++ b/diffcore.h
@@ -65,9 +65,25 @@ void free_filespec(struct diff_filespec *);
 void fill_filespec(struct diff_filespec *, const struct object_id *,
 		   int, unsigned short);
 
-#define CHECK_SIZE_ONLY 1
-#define CHECK_BINARY    2
-int diff_populate_filespec(struct repository *, struct diff_filespec *, unsigned int);
+/*
+ * Prefetch the entries in diff_queued_diff. The parameter is a pointer to a
+ * struct repository.
+ */
+void diff_queued_diff_prefetch(void *repository);
+
+struct diff_populate_filespec_options {
+	unsigned check_size_only : 1;
+	unsigned check_binary : 1;
+
+	/*
+	 * If an object is missing, diff_populate_filespec() will invoke this
+	 * callback before attempting to read that object again.
+	 */
+	void (*missing_object_cb)(void *);
+	void *missing_object_data;
+};
+int diff_populate_filespec(struct repository *, struct diff_filespec *,
+			   const struct diff_populate_filespec_options *);
 void diff_free_filespec_data(struct diff_filespec *);
 void diff_free_filespec_blob(struct diff_filespec *);
 int diff_filespec_is_binary(struct repository *, struct diff_filespec *);
@@ -182,4 +198,12 @@ int diffcore_count_changes(struct repository *r,
 			   unsigned long *src_copied,
 			   unsigned long *literal_added);
 
+/*
+ * If filespec contains an OID and if that object is missing from the given
+ * repository, add that OID to to_fetch.
+ */
+void diff_add_if_missing(struct repository *r,
+			 struct oid_array *to_fetch,
+			 const struct diff_filespec *filespec);
+
 #endif
diff --git a/dir.c b/dir.c
index 0ffb1b3..d97e955 100644
--- a/dir.c
+++ b/dir.c
@@ -1727,36 +1727,59 @@ static enum exist_status directory_exists_in_index(struct index_state *istate,
 static enum path_treatment treat_directory(struct dir_struct *dir,
 	struct index_state *istate,
 	struct untracked_cache_dir *untracked,
-	const char *dirname, int len, int baselen, int exclude,
+	const char *dirname, int len, int baselen, int excluded,
 	const struct pathspec *pathspec)
 {
-	int nested_repo = 0;
-
+	/*
+	 * WARNING: From this function, you can return path_recurse or you
+	 *          can call read_directory_recursive() (or neither), but
+	 *          you CAN'T DO BOTH.
+	 */
+	enum path_treatment state;
+	int matches_how = 0;
+	int nested_repo = 0, check_only, stop_early;
+	int old_ignored_nr, old_untracked_nr;
 	/* The "len-1" is to strip the final '/' */
-	switch (directory_exists_in_index(istate, dirname, len-1)) {
-	case index_directory:
+	enum exist_status status = directory_exists_in_index(istate, dirname, len-1);
+
+	if (status == index_directory)
 		return path_recurse;
-
-	case index_gitdir:
+	if (status == index_gitdir)
 		return path_none;
+	if (status != index_nonexistent)
+		BUG("Unhandled value for directory_exists_in_index: %d\n", status);
 
-	case index_nonexistent:
-		if ((dir->flags & DIR_SKIP_NESTED_GIT) ||
-		    !(dir->flags & DIR_NO_GITLINKS)) {
-			struct strbuf sb = STRBUF_INIT;
-			strbuf_addstr(&sb, dirname);
-			nested_repo = is_nonbare_repository_dir(&sb);
-			strbuf_release(&sb);
-		}
-		if (nested_repo)
-			return ((dir->flags & DIR_SKIP_NESTED_GIT) ? path_none :
-				(exclude ? path_excluded : path_untracked));
+	/*
+	 * We don't want to descend into paths that don't match the necessary
+	 * patterns.  Clearly, if we don't have a pathspec, then we can't check
+	 * for matching patterns.  Also, if (excluded) then we know we matched
+	 * the exclusion patterns so as an optimization we can skip checking
+	 * for matching patterns.
+	 */
+	if (pathspec && !excluded) {
+		matches_how = do_match_pathspec(istate, pathspec, dirname, len,
+						0 /* prefix */, NULL /* seen */,
+						DO_MATCH_LEADING_PATHSPEC);
+		if (!matches_how)
+			return path_none;
+	}
 
-		if (dir->flags & DIR_SHOW_OTHER_DIRECTORIES)
-			break;
-		if (exclude &&
-			(dir->flags & DIR_SHOW_IGNORED_TOO) &&
-			(dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING)) {
+
+	if ((dir->flags & DIR_SKIP_NESTED_GIT) ||
+		!(dir->flags & DIR_NO_GITLINKS)) {
+		struct strbuf sb = STRBUF_INIT;
+		strbuf_addstr(&sb, dirname);
+		nested_repo = is_nonbare_repository_dir(&sb);
+		strbuf_release(&sb);
+	}
+	if (nested_repo)
+		return ((dir->flags & DIR_SKIP_NESTED_GIT) ? path_none :
+			(excluded ? path_excluded : path_untracked));
+
+	if (!(dir->flags & DIR_SHOW_OTHER_DIRECTORIES)) {
+		if (excluded &&
+		    (dir->flags & DIR_SHOW_IGNORED_TOO) &&
+		    (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING)) {
 
 			/*
 			 * This is an excluded directory and we are
@@ -1783,18 +1806,134 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 
 	/* This is the "show_other_directories" case */
 
-	if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
-		return exclude ? path_excluded : path_untracked;
-
-	untracked = lookup_untracked(dir->untracked, untracked,
-				     dirname + baselen, len - baselen);
+	/*
+	 * If we have a pathspec which could match something _below_ this
+	 * directory (e.g. when checking 'subdir/' having a pathspec like
+	 * 'subdir/some/deep/path/file' or 'subdir/widget-*.c'), then we
+	 * need to recurse.
+	 */
+	if (matches_how == MATCHED_RECURSIVELY_LEADING_PATHSPEC)
+		return path_recurse;
 
 	/*
-	 * If this is an excluded directory, then we only need to check if
-	 * the directory contains any files.
+	 * Other than the path_recurse case immediately above, we only need
+	 * to recurse into untracked/ignored directories if either of the
+	 * following bits is set:
+	 *   - DIR_SHOW_IGNORED_TOO (because then we need to determine if
+	 *                           there are ignored directories below)
+	 *   - DIR_HIDE_EMPTY_DIRECTORIES (because we have to determine if
+	 *                                 the directory is empty)
 	 */
-	return read_directory_recursive(dir, istate, dirname, len,
-					untracked, 1, exclude, pathspec);
+	if (!(dir->flags & (DIR_SHOW_IGNORED_TOO | DIR_HIDE_EMPTY_DIRECTORIES)))
+		return excluded ? path_excluded : path_untracked;
+
+	/*
+	 * ...and even if DIR_SHOW_IGNORED_TOO is set, we can still avoid
+	 * recursing into ignored directories if the path is excluded and
+	 * DIR_SHOW_IGNORED_TOO_MODE_MATCHING is also set.
+	 */
+	if (excluded &&
+	    (dir->flags & DIR_SHOW_IGNORED_TOO) &&
+	    (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING))
+		return path_excluded;
+
+	/*
+	 * If we have we don't want to know the all the paths under an
+	 * untracked or ignored directory, we still need to go into the
+	 * directory to determine if it is empty (because an empty directory
+	 * should be path_none instead of path_excluded or path_untracked).
+	 */
+	check_only = ((dir->flags & DIR_HIDE_EMPTY_DIRECTORIES) &&
+		      !(dir->flags & DIR_SHOW_IGNORED_TOO));
+
+	/*
+	 * However, there's another optimization possible as a subset of
+	 * check_only, based on the cases we have to consider:
+	 *   A) Directory matches no exclude patterns:
+	 *     * Directory is empty => path_none
+	 *     * Directory has an untracked file under it => path_untracked
+	 *     * Directory has only ignored files under it => path_excluded
+	 *   B) Directory matches an exclude pattern:
+	 *     * Directory is empty => path_none
+	 *     * Directory has an untracked file under it => path_excluded
+	 *     * Directory has only ignored files under it => path_excluded
+	 * In case A, we can exit as soon as we've found an untracked
+	 * file but otherwise have to walk all files.  In case B, though,
+	 * we can stop at the first file we find under the directory.
+	 */
+	stop_early = check_only && excluded;
+
+	/*
+	 * If /every/ file within an untracked directory is ignored, then
+	 * we want to treat the directory as ignored (for e.g. status
+	 * --porcelain), without listing the individual ignored files
+	 * underneath.  To do so, we'll save the current ignored_nr, and
+	 * pop all the ones added after it if it turns out the entire
+	 * directory is ignored.  Also, when DIR_SHOW_IGNORED_TOO and
+	 * !DIR_KEEP_UNTRACKED_CONTENTS then we don't want to show
+	 * untracked paths so will need to pop all those off the last
+	 * after we traverse.
+	 */
+	old_ignored_nr = dir->ignored_nr;
+	old_untracked_nr = dir->nr;
+
+	/* Actually recurse into dirname now, we'll fixup the state later. */
+	untracked = lookup_untracked(dir->untracked, untracked,
+				     dirname + baselen, len - baselen);
+	state = read_directory_recursive(dir, istate, dirname, len, untracked,
+					 check_only, stop_early, pathspec);
+
+	/* There are a variety of reasons we may need to fixup the state... */
+	if (state == path_excluded) {
+		/* state == path_excluded implies all paths under
+		 * dirname were ignored...
+		 *
+		 * if running e.g. `git status --porcelain --ignored=matching`,
+		 * then we want to see the subpaths that are ignored.
+		 *
+		 * if running e.g. just `git status --porcelain`, then
+		 * we just want the directory itself to be listed as ignored
+		 * and not the individual paths underneath.
+		 */
+		int want_ignored_subpaths =
+			((dir->flags & DIR_SHOW_IGNORED_TOO) &&
+			 (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING));
+
+		if (want_ignored_subpaths) {
+			/*
+			 * with --ignored=matching, we want the subpaths
+			 * INSTEAD of the directory itself.
+			 */
+			state = path_none;
+		} else {
+			int i;
+			for (i = old_ignored_nr + 1; i<dir->ignored_nr; ++i)
+				FREE_AND_NULL(dir->ignored[i]);
+			dir->ignored_nr = old_ignored_nr;
+		}
+	}
+
+	/*
+	 * We may need to ignore some of the untracked paths we found while
+	 * traversing subdirectories.
+	 */
+	if ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
+	    !(dir->flags & DIR_KEEP_UNTRACKED_CONTENTS)) {
+		int i;
+		for (i = old_untracked_nr + 1; i<dir->nr; ++i)
+			FREE_AND_NULL(dir->entries[i]);
+		dir->nr = old_untracked_nr;
+	}
+
+	/*
+	 * If there is nothing under the current directory and we are not
+	 * hiding empty directories, then we need to report on the
+	 * untracked or ignored status of the directory itself.
+	 */
+	if (state == path_none && !(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
+		state = excluded ? path_excluded : path_untracked;
+
+	return state;
 }
 
 /*
@@ -1934,85 +2073,6 @@ static int resolve_dtype(int dtype, struct index_state *istate,
 	return dtype;
 }
 
-static enum path_treatment treat_one_path(struct dir_struct *dir,
-					  struct untracked_cache_dir *untracked,
-					  struct index_state *istate,
-					  struct strbuf *path,
-					  int baselen,
-					  const struct pathspec *pathspec,
-					  int dtype)
-{
-	int exclude;
-	int has_path_in_index = !!index_file_exists(istate, path->buf, path->len, ignore_case);
-	enum path_treatment path_treatment;
-
-	dtype = resolve_dtype(dtype, istate, path->buf, path->len);
-
-	/* Always exclude indexed files */
-	if (dtype != DT_DIR && has_path_in_index)
-		return path_none;
-
-	/*
-	 * When we are looking at a directory P in the working tree,
-	 * there are three cases:
-	 *
-	 * (1) P exists in the index.  Everything inside the directory P in
-	 * the working tree needs to go when P is checked out from the
-	 * index.
-	 *
-	 * (2) P does not exist in the index, but there is P/Q in the index.
-	 * We know P will stay a directory when we check out the contents
-	 * of the index, but we do not know yet if there is a directory
-	 * P/Q in the working tree to be killed, so we need to recurse.
-	 *
-	 * (3) P does not exist in the index, and there is no P/Q in the index
-	 * to require P to be a directory, either.  Only in this case, we
-	 * know that everything inside P will not be killed without
-	 * recursing.
-	 */
-	if ((dir->flags & DIR_COLLECT_KILLED_ONLY) &&
-	    (dtype == DT_DIR) &&
-	    !has_path_in_index &&
-	    (directory_exists_in_index(istate, path->buf, path->len) == index_nonexistent))
-		return path_none;
-
-	exclude = is_excluded(dir, istate, path->buf, &dtype);
-
-	/*
-	 * Excluded? If we don't explicitly want to show
-	 * ignored files, ignore it
-	 */
-	if (exclude && !(dir->flags & (DIR_SHOW_IGNORED|DIR_SHOW_IGNORED_TOO)))
-		return path_excluded;
-
-	switch (dtype) {
-	default:
-		return path_none;
-	case DT_DIR:
-		strbuf_addch(path, '/');
-		path_treatment = treat_directory(dir, istate, untracked,
-						 path->buf, path->len,
-						 baselen, exclude, pathspec);
-		/*
-		 * If 1) we only want to return directories that
-		 * match an exclude pattern and 2) this directory does
-		 * not match an exclude pattern but all of its
-		 * contents are excluded, then indicate that we should
-		 * recurse into this directory (instead of marking the
-		 * directory itself as an ignored path).
-		 */
-		if (!exclude &&
-		    path_treatment == path_excluded &&
-		    (dir->flags & DIR_SHOW_IGNORED_TOO) &&
-		    (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING))
-			return path_recurse;
-		return path_treatment;
-	case DT_REG:
-	case DT_LNK:
-		return exclude ? path_excluded : path_untracked;
-	}
-}
-
 static enum path_treatment treat_path_fast(struct dir_struct *dir,
 					   struct untracked_cache_dir *untracked,
 					   struct cached_dir *cdir,
@@ -2021,6 +2081,11 @@ static enum path_treatment treat_path_fast(struct dir_struct *dir,
 					   int baselen,
 					   const struct pathspec *pathspec)
 {
+	/*
+	 * WARNING: From this function, you can return path_recurse or you
+	 *          can call read_directory_recursive() (or neither), but
+	 *          you CAN'T DO BOTH.
+	 */
 	strbuf_setlen(path, baselen);
 	if (!cdir->ucd) {
 		strbuf_addstr(path, cdir->file);
@@ -2054,6 +2119,8 @@ static enum path_treatment treat_path(struct dir_struct *dir,
 				      int baselen,
 				      const struct pathspec *pathspec)
 {
+	int has_path_in_index, dtype, excluded;
+
 	if (!cdir->d_name)
 		return treat_path_fast(dir, untracked, cdir, istate, path,
 				       baselen, pathspec);
@@ -2064,8 +2131,72 @@ static enum path_treatment treat_path(struct dir_struct *dir,
 	if (simplify_away(path->buf, path->len, pathspec))
 		return path_none;
 
-	return treat_one_path(dir, untracked, istate, path, baselen, pathspec,
-			      cdir->d_type);
+	dtype = resolve_dtype(cdir->d_type, istate, path->buf, path->len);
+
+	/* Always exclude indexed files */
+	has_path_in_index = !!index_file_exists(istate, path->buf, path->len,
+						ignore_case);
+	if (dtype != DT_DIR && has_path_in_index)
+		return path_none;
+
+	/*
+	 * When we are looking at a directory P in the working tree,
+	 * there are three cases:
+	 *
+	 * (1) P exists in the index.  Everything inside the directory P in
+	 * the working tree needs to go when P is checked out from the
+	 * index.
+	 *
+	 * (2) P does not exist in the index, but there is P/Q in the index.
+	 * We know P will stay a directory when we check out the contents
+	 * of the index, but we do not know yet if there is a directory
+	 * P/Q in the working tree to be killed, so we need to recurse.
+	 *
+	 * (3) P does not exist in the index, and there is no P/Q in the index
+	 * to require P to be a directory, either.  Only in this case, we
+	 * know that everything inside P will not be killed without
+	 * recursing.
+	 */
+	if ((dir->flags & DIR_COLLECT_KILLED_ONLY) &&
+	    (dtype == DT_DIR) &&
+	    !has_path_in_index &&
+	    (directory_exists_in_index(istate, path->buf, path->len) == index_nonexistent))
+		return path_none;
+
+	excluded = is_excluded(dir, istate, path->buf, &dtype);
+
+	/*
+	 * Excluded? If we don't explicitly want to show
+	 * ignored files, ignore it
+	 */
+	if (excluded && !(dir->flags & (DIR_SHOW_IGNORED|DIR_SHOW_IGNORED_TOO)))
+		return path_excluded;
+
+	switch (dtype) {
+	default:
+		return path_none;
+	case DT_DIR:
+		/*
+		 * WARNING: Do not ignore/amend the return value from
+		 * treat_directory(), and especially do not change it to return
+		 * path_recurse as that can cause exponential slowdown.
+		 * Instead, modify treat_directory() to return the right value.
+		 */
+		strbuf_addch(path, '/');
+		return treat_directory(dir, istate, untracked,
+				       path->buf, path->len,
+				       baselen, excluded, pathspec);
+	case DT_REG:
+	case DT_LNK:
+		if (excluded)
+			return path_excluded;
+		if (pathspec &&
+		    !do_match_pathspec(istate, pathspec, path->buf, path->len,
+				       0 /* prefix */, NULL /* seen */,
+				       0 /* flags */))
+			return path_none;
+		return path_untracked;
+	}
 }
 
 static void add_untracked(struct untracked_cache_dir *dir, const char *name)
@@ -2245,7 +2376,7 @@ static void add_path_to_appropriate_result_list(struct dir_struct *dir,
  * If 'stop_at_first_file' is specified, 'path_excluded' is returned
  * to signal that a file was found. This is the least significant value that
  * indicates that a file was encountered that does not depend on the order of
- * whether an untracked or exluded path was encountered first.
+ * whether an untracked or excluded path was encountered first.
  *
  * Returns the most significant path_treatment value encountered in the scan.
  * If 'stop_at_first_file' is specified, `path_excluded` is the most
@@ -2258,14 +2389,10 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 	int stop_at_first_file, const struct pathspec *pathspec)
 {
 	/*
-	 * WARNING WARNING WARNING:
-	 *
-	 * Any updates to the traversal logic here may need corresponding
-	 * updates in treat_leading_path().  See the commit message for the
-	 * commit adding this warning as well as the commit preceding it
-	 * for details.
+	 * WARNING: Do NOT recurse unless path_recurse is returned from
+	 *          treat_path().  Recursing on any other return value
+	 *          can result in exponential slowdown.
 	 */
-
 	struct cached_dir cdir;
 	enum path_treatment state, subdir_state, dir_state = path_none;
 	struct strbuf path = STRBUF_INIT;
@@ -2287,13 +2414,7 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 			dir_state = state;
 
 		/* recurse into subdir if instructed by treat_path */
-		if ((state == path_recurse) ||
-			((state == path_untracked) &&
-			 (resolve_dtype(cdir.d_type, istate, path.buf, path.len) == DT_DIR) &&
-			 ((dir->flags & DIR_SHOW_IGNORED_TOO) ||
-			  (pathspec &&
-			   do_match_pathspec(istate, pathspec, path.buf, path.len,
-					     baselen, NULL, DO_MATCH_LEADING_PATHSPEC) == MATCHED_RECURSIVELY_LEADING_PATHSPEC)))) {
+		if (state == path_recurse) {
 			struct untracked_cache_dir *ud;
 			ud = lookup_untracked(dir->untracked, untracked,
 					      path.buf + baselen,
@@ -2341,7 +2462,7 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 					add_untracked(untracked, path.buf + baselen);
 				break;
 			}
-			/* skip the dir_add_* part */
+			/* skip the add_path_to_appropriate_result_list() */
 			continue;
 		}
 
@@ -2377,15 +2498,6 @@ static int treat_leading_path(struct dir_struct *dir,
 			      const char *path, int len,
 			      const struct pathspec *pathspec)
 {
-	/*
-	 * WARNING WARNING WARNING:
-	 *
-	 * Any updates to the traversal logic here may need corresponding
-	 * updates in read_directory_recursive().  See 777b420347 (dir:
-	 * synchronize treat_leading_path() and read_directory_recursive(),
-	 * 2019-12-19) and its parent commit for details.
-	 */
-
 	struct strbuf sb = STRBUF_INIT;
 	struct strbuf subdir = STRBUF_INIT;
 	int prevlen, baselen;
@@ -2436,23 +2548,7 @@ static int treat_leading_path(struct dir_struct *dir,
 		strbuf_reset(&subdir);
 		strbuf_add(&subdir, path+prevlen, baselen-prevlen);
 		cdir.d_name = subdir.buf;
-		state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen,
-				    pathspec);
-		if (state == path_untracked &&
-		    resolve_dtype(cdir.d_type, istate, sb.buf, sb.len) == DT_DIR &&
-		    (dir->flags & DIR_SHOW_IGNORED_TOO ||
-		     do_match_pathspec(istate, pathspec, sb.buf, sb.len,
-				       baselen, NULL, DO_MATCH_LEADING_PATHSPEC) == MATCHED_RECURSIVELY_LEADING_PATHSPEC)) {
-			if (!match_pathspec(istate, pathspec, sb.buf, sb.len,
-					    0 /* prefix */, NULL,
-					    0 /* do NOT special case dirs */))
-				state = path_none;
-			add_path_to_appropriate_result_list(dir, NULL, &cdir,
-							    istate,
-							    &sb, baselen,
-							    pathspec, state);
-			state = path_recurse;
-		}
+		state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen, pathspec);
 
 		if (state != path_recurse)
 			break; /* do not recurse into it */
@@ -2652,28 +2748,6 @@ int read_directory(struct dir_struct *dir, struct index_state *istate,
 	QSORT(dir->entries, dir->nr, cmp_dir_entry);
 	QSORT(dir->ignored, dir->ignored_nr, cmp_dir_entry);
 
-	/*
-	 * If DIR_SHOW_IGNORED_TOO is set, read_directory_recursive() will
-	 * also pick up untracked contents of untracked dirs; by default
-	 * we discard these, but given DIR_KEEP_UNTRACKED_CONTENTS we do not.
-	 */
-	if ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
-		     !(dir->flags & DIR_KEEP_UNTRACKED_CONTENTS)) {
-		int i, j;
-
-		/* remove from dir->entries untracked contents of untracked dirs */
-		for (i = j = 0; j < dir->nr; j++) {
-			if (i &&
-			    check_dir_entry_contains(dir->entries[i - 1], dir->entries[j])) {
-				FREE_AND_NULL(dir->entries[j]);
-			} else {
-				dir->entries[i++] = dir->entries[j];
-			}
-		}
-
-		dir->nr = i;
-	}
-
 	trace_performance_leave("read directory %.*s", len, path);
 	if (dir->untracked) {
 		static int force_untracked_cache = -1;
diff --git a/editor.c b/editor.c
index f079abb..91989ee 100644
--- a/editor.c
+++ b/editor.c
@@ -54,7 +54,8 @@ static int launch_specified_editor(const char *editor, const char *path,
 		return error("Terminal is dumb, but EDITOR unset");
 
 	if (strcmp(editor, ":")) {
-		const char *args[] = { editor, real_path(path), NULL };
+		struct strbuf realpath = STRBUF_INIT;
+		const char *args[] = { editor, NULL, NULL };
 		struct child_process p = CHILD_PROCESS_INIT;
 		int ret, sig;
 		int print_waiting_for_editor = advice_waiting_for_editor && isatty(2);
@@ -75,16 +76,22 @@ static int launch_specified_editor(const char *editor, const char *path,
 			fflush(stderr);
 		}
 
+		strbuf_realpath(&realpath, path, 1);
+		args[1] = realpath.buf;
+
 		p.argv = args;
 		p.env = env;
 		p.use_shell = 1;
 		p.trace2_child_class = "editor";
-		if (start_command(&p) < 0)
+		if (start_command(&p) < 0) {
+			strbuf_release(&realpath);
 			return error("unable to start editor '%s'", editor);
+		}
 
 		sigchain_push(SIGINT, SIG_IGN);
 		sigchain_push(SIGQUIT, SIG_IGN);
 		ret = finish_command(&p);
+		strbuf_release(&realpath);
 		sig = ret - 128;
 		sigchain_pop(SIGINT);
 		sigchain_pop(SIGQUIT);
diff --git a/entry.c b/entry.c
index 53380bb..00b4903 100644
--- a/entry.c
+++ b/entry.c
@@ -264,6 +264,9 @@ static int write_entry(struct cache_entry *ce,
 	size_t newsize = 0;
 	struct stat st;
 	const struct submodule *sub;
+	struct checkout_metadata meta;
+
+	clone_checkout_metadata(&meta, &state->meta, &ce->oid);
 
 	if (ce_mode_s_ifmt == S_IFREG) {
 		struct stream_filter *filter = get_stream_filter(state->istate, ce->name,
@@ -315,13 +318,13 @@ static int write_entry(struct cache_entry *ce,
 		 */
 		if (dco && dco->state != CE_NO_DELAY) {
 			ret = async_convert_to_working_tree(state->istate, ce->name, new_blob,
-							    size, &buf, dco);
+							    size, &buf, &meta, dco);
 			if (ret && string_list_has_string(&dco->paths, ce->name)) {
 				free(new_blob);
 				goto delayed;
 			}
 		} else
-			ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf);
+			ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf, &meta);
 
 		if (ret) {
 			free(new_blob);
diff --git a/environment.c b/environment.c
index e72a02d..10c9061 100644
--- a/environment.c
+++ b/environment.c
@@ -254,8 +254,11 @@ static int git_work_tree_initialized;
  */
 void set_git_work_tree(const char *new_work_tree)
 {
+	struct strbuf realpath = STRBUF_INIT;
+
 	if (git_work_tree_initialized) {
-		new_work_tree = real_path(new_work_tree);
+		strbuf_realpath(&realpath, new_work_tree, 1);
+		new_work_tree = realpath.buf;
 		if (strcmp(new_work_tree, the_repository->worktree))
 			die("internal error: work tree has already been set\n"
 			    "Current worktree: %s\nNew worktree: %s",
@@ -264,6 +267,8 @@ void set_git_work_tree(const char *new_work_tree)
 	}
 	git_work_tree_initialized = 1;
 	repo_set_worktree(the_repository, new_work_tree);
+
+	strbuf_release(&realpath);
 }
 
 const char *get_git_work_tree(void)
@@ -345,11 +350,20 @@ static void update_relative_gitdir(const char *name,
 	free(path);
 }
 
-void set_git_dir(const char *path)
+void set_git_dir(const char *path, int make_realpath)
 {
+	struct strbuf realpath = STRBUF_INIT;
+
+	if (make_realpath) {
+		strbuf_realpath(&realpath, path, 1);
+		path = realpath.buf;
+	}
+
 	set_git_dir_1(path);
 	if (!is_absolute_path(path))
 		chdir_notify_register(NULL, update_relative_gitdir, NULL);
+
+	strbuf_release(&realpath);
 }
 
 const char *get_log_output_encoding(void)
diff --git a/fast-import.c b/fast-import.c
index b8b65a8..c989702 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -18,6 +18,7 @@
 #include "object-store.h"
 #include "mem-pool.h"
 #include "commit-reach.h"
+#include "khash.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
@@ -38,12 +39,28 @@
 
 struct object_entry {
 	struct pack_idx_entry idx;
-	struct object_entry *next;
+	struct hashmap_entry ent;
 	uint32_t type : TYPE_BITS,
 		pack_id : PACK_ID_BITS,
 		depth : DEPTH_BITS;
 };
 
+static int object_entry_hashcmp(const void *map_data,
+				const struct hashmap_entry *eptr,
+				const struct hashmap_entry *entry_or_key,
+				const void *keydata)
+{
+	const struct object_id *oid = keydata;
+	const struct object_entry *e1, *e2;
+
+	e1 = container_of(eptr, const struct object_entry, ent);
+	if (oid)
+		return oidcmp(&e1->idx.oid, oid);
+
+	e2 = container_of(entry_or_key, const struct object_entry, ent);
+	return oidcmp(&e1->idx.oid, &e2->idx.oid);
+}
+
 struct object_entry_pool {
 	struct object_entry_pool *next_pool;
 	struct object_entry *next_free;
@@ -53,6 +70,7 @@ struct object_entry_pool {
 
 struct mark_set {
 	union {
+		struct object_id *oids[1024];
 		struct object_entry *marked[1024];
 		struct mark_set *sets[1024];
 	} data;
@@ -131,6 +149,9 @@ struct recent_command {
 	char *buf;
 };
 
+typedef void (*mark_set_inserter_t)(struct mark_set *s, struct object_id *oid, uintmax_t mark);
+typedef void (*each_mark_fn_t)(uintmax_t mark, void *obj, void *cbp);
+
 /* Configured limits on output */
 static unsigned long max_depth = 50;
 static off_t max_packsize;
@@ -173,7 +194,7 @@ static off_t pack_size;
 /* Table of objects we've written. */
 static unsigned int object_entry_alloc = 5000;
 static struct object_entry_pool *blocks;
-static struct object_entry *object_table[1 << 16];
+static struct hashmap object_table;
 static struct mark_set *marks;
 static const char *export_marks_file;
 static const char *import_marks_file;
@@ -222,6 +243,11 @@ static int allow_unsafe_features;
 /* Signal handling */
 static volatile sig_atomic_t checkpoint_requested;
 
+/* Submodule marks */
+static struct string_list sub_marks_from = STRING_LIST_INIT_DUP;
+static struct string_list sub_marks_to = STRING_LIST_INIT_DUP;
+static kh_oid_map_t *sub_oid_map;
+
 /* Where to write output of cat-blob commands */
 static int cat_blob_fd = STDOUT_FILENO;
 
@@ -230,6 +256,29 @@ static void parse_get_mark(const char *p);
 static void parse_cat_blob(const char *p);
 static void parse_ls(const char *p, struct branch *b);
 
+static void for_each_mark(struct mark_set *m, uintmax_t base, each_mark_fn_t callback, void *p)
+{
+	uintmax_t k;
+	if (m->shift) {
+		for (k = 0; k < 1024; k++) {
+			if (m->data.sets[k])
+				for_each_mark(m->data.sets[k], base + (k << m->shift), callback, p);
+		}
+	} else {
+		for (k = 0; k < 1024; k++) {
+			if (m->data.marked[k])
+				callback(base + k, m->data.marked[k], p);
+		}
+	}
+}
+
+static void dump_marks_fn(uintmax_t mark, void *object, void *cbp) {
+	struct object_entry *e = object;
+	FILE *f = cbp;
+
+	fprintf(f, ":%" PRIuMAX " %s\n", mark, oid_to_hex(&e->idx.oid));
+}
+
 static void write_branch_report(FILE *rpt, struct branch *b)
 {
 	fprintf(rpt, "%s:\n", b->name);
@@ -258,8 +307,6 @@ static void write_branch_report(FILE *rpt, struct branch *b)
 	fputc('\n', rpt);
 }
 
-static void dump_marks_helper(FILE *, uintmax_t, struct mark_set *);
-
 static void write_crash_report(const char *err)
 {
 	char *loc = git_pathdup("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
@@ -338,7 +385,7 @@ static void write_crash_report(const char *err)
 	if (export_marks_file)
 		fprintf(rpt, "  exported to %s\n", export_marks_file);
 	else
-		dump_marks_helper(rpt, 0, marks);
+		for_each_mark(marks, 0, dump_marks_fn, rpt);
 
 	fputc('\n', rpt);
 	fputs("-------------------\n", rpt);
@@ -424,44 +471,37 @@ static struct object_entry *new_object(struct object_id *oid)
 
 static struct object_entry *find_object(struct object_id *oid)
 {
-	unsigned int h = oid->hash[0] << 8 | oid->hash[1];
-	struct object_entry *e;
-	for (e = object_table[h]; e; e = e->next)
-		if (oideq(oid, &e->idx.oid))
-			return e;
-	return NULL;
+	return hashmap_get_entry_from_hash(&object_table, oidhash(oid), oid,
+					   struct object_entry, ent);
 }
 
 static struct object_entry *insert_object(struct object_id *oid)
 {
-	unsigned int h = oid->hash[0] << 8 | oid->hash[1];
-	struct object_entry *e = object_table[h];
+	struct object_entry *e;
+	unsigned int hash = oidhash(oid);
 
-	while (e) {
-		if (oideq(oid, &e->idx.oid))
-			return e;
-		e = e->next;
+	e = hashmap_get_entry_from_hash(&object_table, hash, oid,
+					struct object_entry, ent);
+	if (!e) {
+		e = new_object(oid);
+		e->idx.offset = 0;
+		hashmap_entry_init(&e->ent, hash);
+		hashmap_add(&object_table, &e->ent);
 	}
 
-	e = new_object(oid);
-	e->next = object_table[h];
-	e->idx.offset = 0;
-	object_table[h] = e;
 	return e;
 }
 
 static void invalidate_pack_id(unsigned int id)
 {
-	unsigned int h;
 	unsigned long lu;
 	struct tag *t;
+	struct hashmap_iter iter;
+	struct object_entry *e;
 
-	for (h = 0; h < ARRAY_SIZE(object_table); h++) {
-		struct object_entry *e;
-
-		for (e = object_table[h]; e; e = e->next)
-			if (e->pack_id == id)
-				e->pack_id = MAX_PACK_ID;
+	hashmap_for_each_entry(&object_table, &iter, e, ent) {
+		if (e->pack_id == id)
+			e->pack_id = MAX_PACK_ID;
 	}
 
 	for (lu = 0; lu < branch_table_sz; lu++) {
@@ -493,9 +533,8 @@ static char *pool_strdup(const char *s)
 	return r;
 }
 
-static void insert_mark(uintmax_t idnum, struct object_entry *oe)
+static void insert_mark(struct mark_set *s, uintmax_t idnum, struct object_entry *oe)
 {
-	struct mark_set *s = marks;
 	while ((idnum >> s->shift) >= 1024) {
 		s = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
 		s->shift = marks->shift + 10;
@@ -516,10 +555,9 @@ static void insert_mark(uintmax_t idnum, struct object_entry *oe)
 	s->data.marked[idnum] = oe;
 }
 
-static struct object_entry *find_mark(uintmax_t idnum)
+static void *find_mark(struct mark_set *s, uintmax_t idnum)
 {
 	uintmax_t orig_idnum = idnum;
-	struct mark_set *s = marks;
 	struct object_entry *oe = NULL;
 	if ((idnum >> s->shift) < 1024) {
 		while (s && s->shift) {
@@ -919,7 +957,7 @@ static int store_object(
 
 	e = insert_object(&oid);
 	if (mark)
-		insert_mark(mark, e);
+		insert_mark(marks, mark, e);
 	if (e->idx.offset) {
 		duplicate_count_by_type[type]++;
 		return 1;
@@ -1117,7 +1155,7 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 	e = insert_object(&oid);
 
 	if (mark)
-		insert_mark(mark, e);
+		insert_mark(marks, mark, e);
 
 	if (e->idx.offset) {
 		duplicate_count_by_type[OBJ_BLOB]++;
@@ -1655,26 +1693,6 @@ static void dump_tags(void)
 	strbuf_release(&err);
 }
 
-static void dump_marks_helper(FILE *f,
-	uintmax_t base,
-	struct mark_set *m)
-{
-	uintmax_t k;
-	if (m->shift) {
-		for (k = 0; k < 1024; k++) {
-			if (m->data.sets[k])
-				dump_marks_helper(f, base + (k << m->shift),
-					m->data.sets[k]);
-		}
-	} else {
-		for (k = 0; k < 1024; k++) {
-			if (m->data.marked[k])
-				fprintf(f, ":%" PRIuMAX " %s\n", base + k,
-					oid_to_hex(&m->data.marked[k]->idx.oid));
-		}
-	}
-}
-
 static void dump_marks(void)
 {
 	struct lock_file mark_lock = LOCK_INIT;
@@ -1704,7 +1722,7 @@ static void dump_marks(void)
 		return;
 	}
 
-	dump_marks_helper(f, 0, marks);
+	for_each_mark(marks, 0, dump_marks_fn, f);
 	if (commit_lock_file(&mark_lock)) {
 		failure |= error_errno("Unable to write file %s",
 				       export_marks_file);
@@ -1712,21 +1730,38 @@ static void dump_marks(void)
 	}
 }
 
-static void read_marks(void)
+static void insert_object_entry(struct mark_set *s, struct object_id *oid, uintmax_t mark)
+{
+	struct object_entry *e;
+	e = find_object(oid);
+	if (!e) {
+		enum object_type type = oid_object_info(the_repository,
+							oid, NULL);
+		if (type < 0)
+			die("object not found: %s", oid_to_hex(oid));
+		e = insert_object(oid);
+		e->type = type;
+		e->pack_id = MAX_PACK_ID;
+		e->idx.offset = 1; /* just not zero! */
+	}
+	insert_mark(s, mark, e);
+}
+
+static void insert_oid_entry(struct mark_set *s, struct object_id *oid, uintmax_t mark)
+{
+	insert_mark(s, mark, xmemdupz(oid, sizeof(*oid)));
+}
+
+static void read_mark_file(struct mark_set *s, FILE *f, mark_set_inserter_t inserter)
 {
 	char line[512];
-	FILE *f = fopen(import_marks_file, "r");
-	if (f)
-		;
-	else if (import_marks_file_ignore_missing && errno == ENOENT)
-		goto done; /* Marks file does not exist */
-	else
-		die_errno("cannot read '%s'", import_marks_file);
 	while (fgets(line, sizeof(line), f)) {
 		uintmax_t mark;
 		char *end;
 		struct object_id oid;
-		struct object_entry *e;
+
+		/* Ensure SHA-1 objects are padded with zeros. */
+		memset(oid.hash, 0, sizeof(oid.hash));
 
 		end = strchr(line, '\n');
 		if (line[0] != ':' || !end)
@@ -1734,21 +1769,23 @@ static void read_marks(void)
 		*end = 0;
 		mark = strtoumax(line + 1, &end, 10);
 		if (!mark || end == line + 1
-			|| *end != ' ' || get_oid_hex(end + 1, &oid))
+			|| *end != ' '
+			|| get_oid_hex_any(end + 1, &oid) == GIT_HASH_UNKNOWN)
 			die("corrupt mark line: %s", line);
-		e = find_object(&oid);
-		if (!e) {
-			enum object_type type = oid_object_info(the_repository,
-								&oid, NULL);
-			if (type < 0)
-				die("object not found: %s", oid_to_hex(&oid));
-			e = insert_object(&oid);
-			e->type = type;
-			e->pack_id = MAX_PACK_ID;
-			e->idx.offset = 1; /* just not zero! */
-		}
-		insert_mark(mark, e);
+		inserter(s, &oid, mark);
 	}
+}
+
+static void read_marks(void)
+{
+	FILE *f = fopen(import_marks_file, "r");
+	if (f)
+		;
+	else if (import_marks_file_ignore_missing && errno == ENOENT)
+		goto done; /* Marks file does not exist */
+	else
+		die_errno("cannot read '%s'", import_marks_file);
+	read_mark_file(marks, f, insert_object_entry);
 	fclose(f);
 done:
 	import_marks_file_done = 1;
@@ -2134,6 +2171,30 @@ static uintmax_t change_note_fanout(struct tree_entry *root,
 	return do_change_note_fanout(root, root, hex_oid, 0, path, 0, fanout);
 }
 
+static int parse_mapped_oid_hex(const char *hex, struct object_id *oid, const char **end)
+{
+	int algo;
+	khiter_t it;
+
+	/* Make SHA-1 object IDs have all-zero padding. */
+	memset(oid->hash, 0, sizeof(oid->hash));
+
+	algo = parse_oid_hex_any(hex, oid, end);
+	if (algo == GIT_HASH_UNKNOWN)
+		return -1;
+
+	it = kh_get_oid_map(sub_oid_map, *oid);
+	/* No such object? */
+	if (it == kh_end(sub_oid_map)) {
+		/* If we're using the same algorithm, pass it through. */
+		if (hash_algos[algo].format_id == the_hash_algo->format_id)
+			return 0;
+		return -1;
+	}
+	oidcpy(oid, kh_value(sub_oid_map, it));
+	return 0;
+}
+
 /*
  * Given a pointer into a string, parse a mark reference:
  *
@@ -2214,13 +2275,13 @@ static void file_change_m(const char *p, struct branch *b)
 	}
 
 	if (*p == ':') {
-		oe = find_mark(parse_mark_ref_space(&p));
+		oe = find_mark(marks, parse_mark_ref_space(&p));
 		oidcpy(&oid, &oe->idx.oid);
 	} else if (skip_prefix(p, "inline ", &p)) {
 		inline_data = 1;
 		oe = NULL; /* not used with inline_data, but makes gcc happy */
 	} else {
-		if (parse_oid_hex(p, &oid, &p))
+		if (parse_mapped_oid_hex(p, &oid, &p))
 			die("Invalid dataref: %s", command_buf.buf);
 		oe = find_object(&oid);
 		if (*p++ != ' ')
@@ -2388,13 +2449,13 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
 	/* Now parse the notemodify command. */
 	/* <dataref> or 'inline' */
 	if (*p == ':') {
-		oe = find_mark(parse_mark_ref_space(&p));
+		oe = find_mark(marks, parse_mark_ref_space(&p));
 		oidcpy(&oid, &oe->idx.oid);
 	} else if (skip_prefix(p, "inline ", &p)) {
 		inline_data = 1;
 		oe = NULL; /* not used with inline_data, but makes gcc happy */
 	} else {
-		if (parse_oid_hex(p, &oid, &p))
+		if (parse_mapped_oid_hex(p, &oid, &p))
 			die("Invalid dataref: %s", command_buf.buf);
 		oe = find_object(&oid);
 		if (*p++ != ' ')
@@ -2409,7 +2470,7 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
 		oidcpy(&commit_oid, &s->oid);
 	} else if (*p == ':') {
 		uintmax_t commit_mark = parse_mark_ref_eol(p);
-		struct object_entry *commit_oe = find_mark(commit_mark);
+		struct object_entry *commit_oe = find_mark(marks, commit_mark);
 		if (commit_oe->type != OBJ_COMMIT)
 			die("Mark :%" PRIuMAX " not a commit", commit_mark);
 		oidcpy(&commit_oid, &commit_oe->idx.oid);
@@ -2513,7 +2574,7 @@ static int parse_objectish(struct branch *b, const char *objectish)
 		oidcpy(&b->branch_tree.versions[1].oid, t);
 	} else if (*objectish == ':') {
 		uintmax_t idnum = parse_mark_ref_eol(objectish);
-		struct object_entry *oe = find_mark(idnum);
+		struct object_entry *oe = find_mark(marks, idnum);
 		if (oe->type != OBJ_COMMIT)
 			die("Mark :%" PRIuMAX " not a commit", idnum);
 		if (!oideq(&b->oid, &oe->idx.oid)) {
@@ -2577,7 +2638,7 @@ static struct hash_list *parse_merge(unsigned int *count)
 			oidcpy(&n->oid, &s->oid);
 		else if (*from == ':') {
 			uintmax_t idnum = parse_mark_ref_eol(from);
-			struct object_entry *oe = find_mark(idnum);
+			struct object_entry *oe = find_mark(marks, idnum);
 			if (oe->type != OBJ_COMMIT)
 				die("Mark :%" PRIuMAX " not a commit", idnum);
 			oidcpy(&n->oid, &oe->idx.oid);
@@ -2751,7 +2812,7 @@ static void parse_new_tag(const char *arg)
 	} else if (*from == ':') {
 		struct object_entry *oe;
 		from_mark = parse_mark_ref_eol(from);
-		oe = find_mark(from_mark);
+		oe = find_mark(marks, from_mark);
 		type = oe->type;
 		oidcpy(&oid, &oe->idx.oid);
 	} else if (!get_oid(from, &oid)) {
@@ -2909,7 +2970,7 @@ static void parse_get_mark(const char *p)
 	if (*p != ':')
 		die("Not a mark: %s", p);
 
-	oe = find_mark(parse_mark_ref_eol(p));
+	oe = find_mark(marks, parse_mark_ref_eol(p));
 	if (!oe)
 		die("Unknown mark: %s", command_buf.buf);
 
@@ -2924,12 +2985,12 @@ static void parse_cat_blob(const char *p)
 
 	/* cat-blob SP <object> LF */
 	if (*p == ':') {
-		oe = find_mark(parse_mark_ref_eol(p));
+		oe = find_mark(marks, parse_mark_ref_eol(p));
 		if (!oe)
 			die("Unknown mark: %s", command_buf.buf);
 		oidcpy(&oid, &oe->idx.oid);
 	} else {
-		if (parse_oid_hex(p, &oid, &p))
+		if (parse_mapped_oid_hex(p, &oid, &p))
 			die("Invalid dataref: %s", command_buf.buf);
 		if (*p)
 			die("Garbage after SHA1: %s", command_buf.buf);
@@ -2993,18 +3054,54 @@ static struct object_entry *dereference(struct object_entry *oe,
 	return find_object(oid);
 }
 
+static void insert_mapped_mark(uintmax_t mark, void *object, void *cbp)
+{
+	struct object_id *fromoid = object;
+	struct object_id *tooid = find_mark(cbp, mark);
+	int ret;
+	khiter_t it;
+
+	it = kh_put_oid_map(sub_oid_map, *fromoid, &ret);
+	/* We've already seen this object. */
+	if (ret == 0)
+		return;
+	kh_value(sub_oid_map, it) = tooid;
+}
+
+static void build_mark_map_one(struct mark_set *from, struct mark_set *to)
+{
+	for_each_mark(from, 0, insert_mapped_mark, to);
+}
+
+static void build_mark_map(struct string_list *from, struct string_list *to)
+{
+	struct string_list_item *fromp, *top;
+
+	sub_oid_map = kh_init_oid_map();
+
+	for_each_string_list_item(fromp, from) {
+		top = string_list_lookup(to, fromp->string);
+		if (!fromp->util) {
+			die(_("Missing from marks for submodule '%s'"), fromp->string);
+		} else if (!top || !top->util) {
+			die(_("Missing to marks for submodule '%s'"), fromp->string);
+		}
+		build_mark_map_one(fromp->util, top->util);
+	}
+}
+
 static struct object_entry *parse_treeish_dataref(const char **p)
 {
 	struct object_id oid;
 	struct object_entry *e;
 
 	if (**p == ':') {	/* <mark> */
-		e = find_mark(parse_mark_ref_space(p));
+		e = find_mark(marks, parse_mark_ref_space(p));
 		if (!e)
 			die("Unknown mark: %s", command_buf.buf);
 		oidcpy(&oid, &e->idx.oid);
 	} else {	/* <sha1> */
-		if (parse_oid_hex(*p, &oid, p))
+		if (parse_mapped_oid_hex(*p, &oid, p))
 			die("Invalid dataref: %s", command_buf.buf);
 		e = find_object(&oid);
 		if (*(*p)++ != ' ')
@@ -3130,7 +3227,7 @@ static void parse_alias(void)
 		die(_("Expected 'to' command, got %s"), command_buf.buf);
 	e = find_object(&b.oid);
 	assert(e);
-	insert_mark(next_mark, e);
+	insert_mark(marks, next_mark, e);
 }
 
 static char* make_fast_import_path(const char *path)
@@ -3210,6 +3307,26 @@ static void option_export_pack_edges(const char *edges)
 	pack_edges = xfopen(edges, "a");
 }
 
+static void option_rewrite_submodules(const char *arg, struct string_list *list)
+{
+	struct mark_set *ms;
+	FILE *fp;
+	char *s = xstrdup(arg);
+	char *f = strchr(s, ':');
+	if (!f)
+		die(_("Expected format name:filename for submodule rewrite option"));
+	*f = '\0';
+	f++;
+	ms = xcalloc(1, sizeof(*ms));
+	string_list_insert(list, s)->util = ms;
+
+	fp = fopen(f, "r");
+	if (!fp)
+		die_errno("cannot read '%s'", f);
+	read_mark_file(ms, fp, insert_oid_entry);
+	fclose(fp);
+}
+
 static int parse_one_option(const char *option)
 {
 	if (skip_prefix(option, "max-pack-size=", &option)) {
@@ -3272,6 +3389,11 @@ static int parse_one_feature(const char *feature, int from_stream)
 		option_export_marks(arg);
 	} else if (!strcmp(feature, "alias")) {
 		; /* Don't die - this feature is supported */
+	} else if (skip_prefix(feature, "rewrite-submodules-to=", &arg)) {
+		option_rewrite_submodules(arg, &sub_marks_to);
+	} else if (skip_prefix(feature, "rewrite-submodules-from=", &arg)) {
+		option_rewrite_submodules(arg, &sub_marks_from);
+	} else if (skip_prefix(feature, "rewrite-submodules-from=", &arg)) {
 	} else if (!strcmp(feature, "get-mark")) {
 		; /* Don't die - this feature is supported */
 	} else if (!strcmp(feature, "cat-blob")) {
@@ -3377,6 +3499,7 @@ static void parse_argv(void)
 	seen_data_command = 1;
 	if (import_marks_file)
 		read_marks();
+	build_mark_map(&sub_marks_from, &sub_marks_to);
 }
 
 int cmd_main(int argc, const char **argv)
@@ -3397,6 +3520,8 @@ int cmd_main(int argc, const char **argv)
 	avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
 	marks = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
 
+	hashmap_init(&object_table, object_entry_hashcmp, NULL, 0);
+
 	/*
 	 * We don't parse most options until after we've seen the set of
 	 * "feature" lines at the start of the stream (which allows the command
diff --git a/fetch-pack.c b/fetch-pack.c
index a618f3b..8e98b3d 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -15,7 +15,7 @@
 #include "connect.h"
 #include "transport.h"
 #include "version.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "oidset.h"
 #include "packfile.h"
 #include "object-store.h"
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
new file mode 100644
index 0000000..08022ed
--- /dev/null
+++ b/fmt-merge-msg.c
@@ -0,0 +1,656 @@
+#include "config.h"
+#include "refs.h"
+#include "object-store.h"
+#include "diff.h"
+#include "revision.h"
+#include "tag.h"
+#include "string-list.h"
+#include "branch.h"
+#include "fmt-merge-msg.h"
+#include "commit-reach.h"
+
+static int use_branch_desc;
+
+int fmt_merge_msg_config(const char *key, const char *value, void *cb)
+{
+	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
+		int is_bool;
+		merge_log_config = git_config_bool_or_int(key, value, &is_bool);
+		if (!is_bool && merge_log_config < 0)
+			return error("%s: negative length %s", key, value);
+		if (is_bool && merge_log_config)
+			merge_log_config = DEFAULT_MERGE_LOG_LEN;
+	} else if (!strcmp(key, "merge.branchdesc")) {
+		use_branch_desc = git_config_bool(key, value);
+	} else {
+		return git_default_config(key, value, cb);
+	}
+	return 0;
+}
+
+/* merge data per repository where the merged tips came from */
+struct src_data {
+	struct string_list branch, tag, r_branch, generic;
+	int head_status;
+};
+
+struct origin_data {
+	struct object_id oid;
+	unsigned is_local_branch:1;
+};
+
+static void init_src_data(struct src_data *data)
+{
+	data->branch.strdup_strings = 1;
+	data->tag.strdup_strings = 1;
+	data->r_branch.strdup_strings = 1;
+	data->generic.strdup_strings = 1;
+}
+
+static struct string_list srcs = STRING_LIST_INIT_DUP;
+static struct string_list origins = STRING_LIST_INIT_DUP;
+
+struct merge_parents {
+	int alloc, nr;
+	struct merge_parent {
+		struct object_id given;
+		struct object_id commit;
+		unsigned char used;
+	} *item;
+};
+
+/*
+ * I know, I know, this is inefficient, but you won't be pulling and merging
+ * hundreds of heads at a time anyway.
+ */
+static struct merge_parent *find_merge_parent(struct merge_parents *table,
+					      struct object_id *given,
+					      struct object_id *commit)
+{
+	int i;
+	for (i = 0; i < table->nr; i++) {
+		if (given && !oideq(&table->item[i].given, given))
+			continue;
+		if (commit && !oideq(&table->item[i].commit, commit))
+			continue;
+		return &table->item[i];
+	}
+	return NULL;
+}
+
+static void add_merge_parent(struct merge_parents *table,
+			     struct object_id *given,
+			     struct object_id *commit)
+{
+	if (table->nr && find_merge_parent(table, given, commit))
+		return;
+	ALLOC_GROW(table->item, table->nr + 1, table->alloc);
+	oidcpy(&table->item[table->nr].given, given);
+	oidcpy(&table->item[table->nr].commit, commit);
+	table->item[table->nr].used = 0;
+	table->nr++;
+}
+
+static int handle_line(char *line, struct merge_parents *merge_parents)
+{
+	int i, len = strlen(line);
+	struct origin_data *origin_data;
+	char *src;
+	const char *origin, *tag_name;
+	struct src_data *src_data;
+	struct string_list_item *item;
+	int pulling_head = 0;
+	struct object_id oid;
+	const unsigned hexsz = the_hash_algo->hexsz;
+
+	if (len < hexsz + 3 || line[hexsz] != '\t')
+		return 1;
+
+	if (starts_with(line + hexsz + 1, "not-for-merge"))
+		return 0;
+
+	if (line[hexsz + 1] != '\t')
+		return 2;
+
+	i = get_oid_hex(line, &oid);
+	if (i)
+		return 3;
+
+	if (!find_merge_parent(merge_parents, &oid, NULL))
+		return 0; /* subsumed by other parents */
+
+	origin_data = xcalloc(1, sizeof(struct origin_data));
+	oidcpy(&origin_data->oid, &oid);
+
+	if (line[len - 1] == '\n')
+		line[len - 1] = 0;
+	line += hexsz + 2;
+
+	/*
+	 * At this point, line points at the beginning of comment e.g.
+	 * "branch 'frotz' of git://that/repository.git".
+	 * Find the repository name and point it with src.
+	 */
+	src = strstr(line, " of ");
+	if (src) {
+		*src = 0;
+		src += 4;
+		pulling_head = 0;
+	} else {
+		src = line;
+		pulling_head = 1;
+	}
+
+	item = unsorted_string_list_lookup(&srcs, src);
+	if (!item) {
+		item = string_list_append(&srcs, src);
+		item->util = xcalloc(1, sizeof(struct src_data));
+		init_src_data(item->util);
+	}
+	src_data = item->util;
+
+	if (pulling_head) {
+		origin = src;
+		src_data->head_status |= 1;
+	} else if (skip_prefix(line, "branch ", &origin)) {
+		origin_data->is_local_branch = 1;
+		string_list_append(&src_data->branch, origin);
+		src_data->head_status |= 2;
+	} else if (skip_prefix(line, "tag ", &tag_name)) {
+		origin = line;
+		string_list_append(&src_data->tag, tag_name);
+		src_data->head_status |= 2;
+	} else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
+		string_list_append(&src_data->r_branch, origin);
+		src_data->head_status |= 2;
+	} else {
+		origin = src;
+		string_list_append(&src_data->generic, line);
+		src_data->head_status |= 2;
+	}
+
+	if (!strcmp(".", src) || !strcmp(src, origin)) {
+		int len = strlen(origin);
+		if (origin[0] == '\'' && origin[len - 1] == '\'')
+			origin = xmemdupz(origin + 1, len - 2);
+	} else
+		origin = xstrfmt("%s of %s", origin, src);
+	if (strcmp(".", src))
+		origin_data->is_local_branch = 0;
+	string_list_append(&origins, origin)->util = origin_data;
+	return 0;
+}
+
+static void print_joined(const char *singular, const char *plural,
+		struct string_list *list, struct strbuf *out)
+{
+	if (list->nr == 0)
+		return;
+	if (list->nr == 1) {
+		strbuf_addf(out, "%s%s", singular, list->items[0].string);
+	} else {
+		int i;
+		strbuf_addstr(out, plural);
+		for (i = 0; i < list->nr - 1; i++)
+			strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
+				    list->items[i].string);
+		strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
+	}
+}
+
+static void add_branch_desc(struct strbuf *out, const char *name)
+{
+	struct strbuf desc = STRBUF_INIT;
+
+	if (!read_branch_desc(&desc, name)) {
+		const char *bp = desc.buf;
+		while (*bp) {
+			const char *ep = strchrnul(bp, '\n');
+			if (*ep)
+				ep++;
+			strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
+			bp = ep;
+		}
+		strbuf_complete_line(out);
+	}
+	strbuf_release(&desc);
+}
+
+#define util_as_integral(elem) ((intptr_t)((elem)->util))
+
+static void record_person_from_buf(int which, struct string_list *people,
+				   const char *buffer)
+{
+	char *name_buf, *name, *name_end;
+	struct string_list_item *elem;
+	const char *field;
+
+	field = (which == 'a') ? "\nauthor " : "\ncommitter ";
+	name = strstr(buffer, field);
+	if (!name)
+		return;
+	name += strlen(field);
+	name_end = strchrnul(name, '<');
+	if (*name_end)
+		name_end--;
+	while (isspace(*name_end) && name <= name_end)
+		name_end--;
+	if (name_end < name)
+		return;
+	name_buf = xmemdupz(name, name_end - name + 1);
+
+	elem = string_list_lookup(people, name_buf);
+	if (!elem) {
+		elem = string_list_insert(people, name_buf);
+		elem->util = (void *)0;
+	}
+	elem->util = (void*)(util_as_integral(elem) + 1);
+	free(name_buf);
+}
+
+
+static void record_person(int which, struct string_list *people,
+			  struct commit *commit)
+{
+	const char *buffer = get_commit_buffer(commit, NULL);
+	record_person_from_buf(which, people, buffer);
+	unuse_commit_buffer(commit, buffer);
+}
+
+static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
+{
+	const struct string_list_item *a = a_, *b = b_;
+	return util_as_integral(b) - util_as_integral(a);
+}
+
+static void add_people_count(struct strbuf *out, struct string_list *people)
+{
+	if (people->nr == 1)
+		strbuf_addstr(out, people->items[0].string);
+	else if (people->nr == 2)
+		strbuf_addf(out, "%s (%d) and %s (%d)",
+			    people->items[0].string,
+			    (int)util_as_integral(&people->items[0]),
+			    people->items[1].string,
+			    (int)util_as_integral(&people->items[1]));
+	else if (people->nr)
+		strbuf_addf(out, "%s (%d) and others",
+			    people->items[0].string,
+			    (int)util_as_integral(&people->items[0]));
+}
+
+static void credit_people(struct strbuf *out,
+			  struct string_list *them,
+			  int kind)
+{
+	const char *label;
+	const char *me;
+
+	if (kind == 'a') {
+		label = "By";
+		me = git_author_info(IDENT_NO_DATE);
+	} else {
+		label = "Via";
+		me = git_committer_info(IDENT_NO_DATE);
+	}
+
+	if (!them->nr ||
+	    (them->nr == 1 &&
+	     me &&
+	     skip_prefix(me, them->items->string, &me) &&
+	     starts_with(me, " <")))
+		return;
+	strbuf_addf(out, "\n%c %s ", comment_line_char, label);
+	add_people_count(out, them);
+}
+
+static void add_people_info(struct strbuf *out,
+			    struct string_list *authors,
+			    struct string_list *committers)
+{
+	QSORT(authors->items, authors->nr,
+	      cmp_string_list_util_as_integral);
+	QSORT(committers->items, committers->nr,
+	      cmp_string_list_util_as_integral);
+
+	credit_people(out, authors, 'a');
+	credit_people(out, committers, 'c');
+}
+
+static void shortlog(const char *name,
+		     struct origin_data *origin_data,
+		     struct commit *head,
+		     struct rev_info *rev,
+		     struct fmt_merge_msg_opts *opts,
+		     struct strbuf *out)
+{
+	int i, count = 0;
+	struct commit *commit;
+	struct object *branch;
+	struct string_list subjects = STRING_LIST_INIT_DUP;
+	struct string_list authors = STRING_LIST_INIT_DUP;
+	struct string_list committers = STRING_LIST_INIT_DUP;
+	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
+	struct strbuf sb = STRBUF_INIT;
+	const struct object_id *oid = &origin_data->oid;
+	int limit = opts->shortlog_len;
+
+	branch = deref_tag(the_repository, parse_object(the_repository, oid),
+			   oid_to_hex(oid),
+			   the_hash_algo->hexsz);
+	if (!branch || branch->type != OBJ_COMMIT)
+		return;
+
+	setup_revisions(0, NULL, rev, NULL);
+	add_pending_object(rev, branch, name);
+	add_pending_object(rev, &head->object, "^HEAD");
+	head->object.flags |= UNINTERESTING;
+	if (prepare_revision_walk(rev))
+		die("revision walk setup failed");
+	while ((commit = get_revision(rev)) != NULL) {
+		struct pretty_print_context ctx = {0};
+
+		if (commit->parents && commit->parents->next) {
+			/* do not list a merge but count committer */
+			if (opts->credit_people)
+				record_person('c', &committers, commit);
+			continue;
+		}
+		if (!count && opts->credit_people)
+			/* the 'tip' committer */
+			record_person('c', &committers, commit);
+		if (opts->credit_people)
+			record_person('a', &authors, commit);
+		count++;
+		if (subjects.nr > limit)
+			continue;
+
+		format_commit_message(commit, "%s", &sb, &ctx);
+		strbuf_ltrim(&sb);
+
+		if (!sb.len)
+			string_list_append(&subjects,
+					   oid_to_hex(&commit->object.oid));
+		else
+			string_list_append_nodup(&subjects,
+						 strbuf_detach(&sb, NULL));
+	}
+
+	if (opts->credit_people)
+		add_people_info(out, &authors, &committers);
+	if (count > limit)
+		strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
+	else
+		strbuf_addf(out, "\n* %s:\n", name);
+
+	if (origin_data->is_local_branch && use_branch_desc)
+		add_branch_desc(out, name);
+
+	for (i = 0; i < subjects.nr; i++)
+		if (i >= limit)
+			strbuf_addstr(out, "  ...\n");
+		else
+			strbuf_addf(out, "  %s\n", subjects.items[i].string);
+
+	clear_commit_marks((struct commit *)branch, flags);
+	clear_commit_marks(head, flags);
+	free_commit_list(rev->commits);
+	rev->commits = NULL;
+	rev->pending.nr = 0;
+
+	string_list_clear(&authors, 0);
+	string_list_clear(&committers, 0);
+	string_list_clear(&subjects, 0);
+}
+
+static void fmt_merge_msg_title(struct strbuf *out,
+				const char *current_branch)
+{
+	int i = 0;
+	char *sep = "";
+
+	strbuf_addstr(out, "Merge ");
+	for (i = 0; i < srcs.nr; i++) {
+		struct src_data *src_data = srcs.items[i].util;
+		const char *subsep = "";
+
+		strbuf_addstr(out, sep);
+		sep = "; ";
+
+		if (src_data->head_status == 1) {
+			strbuf_addstr(out, srcs.items[i].string);
+			continue;
+		}
+		if (src_data->head_status == 3) {
+			subsep = ", ";
+			strbuf_addstr(out, "HEAD");
+		}
+		if (src_data->branch.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("branch ", "branches ", &src_data->branch,
+					out);
+		}
+		if (src_data->r_branch.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("remote-tracking branch ", "remote-tracking branches ",
+					&src_data->r_branch, out);
+		}
+		if (src_data->tag.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("tag ", "tags ", &src_data->tag, out);
+		}
+		if (src_data->generic.nr) {
+			strbuf_addstr(out, subsep);
+			print_joined("commit ", "commits ", &src_data->generic,
+					out);
+		}
+		if (strcmp(".", srcs.items[i].string))
+			strbuf_addf(out, " of %s", srcs.items[i].string);
+	}
+
+	if (!strcmp("master", current_branch))
+		strbuf_addch(out, '\n');
+	else
+		strbuf_addf(out, " into %s\n", current_branch);
+}
+
+static void fmt_tag_signature(struct strbuf *tagbuf,
+			      struct strbuf *sig,
+			      const char *buf,
+			      unsigned long len)
+{
+	const char *tag_body = strstr(buf, "\n\n");
+	if (tag_body) {
+		tag_body += 2;
+		strbuf_add(tagbuf, tag_body, buf + len - tag_body);
+	}
+	strbuf_complete_line(tagbuf);
+	if (sig->len) {
+		strbuf_addch(tagbuf, '\n');
+		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
+	}
+}
+
+static void fmt_merge_msg_sigs(struct strbuf *out)
+{
+	int i, tag_number = 0, first_tag = 0;
+	struct strbuf tagbuf = STRBUF_INIT;
+
+	for (i = 0; i < origins.nr; i++) {
+		struct object_id *oid = origins.items[i].util;
+		enum object_type type;
+		unsigned long size, len;
+		char *buf = read_object_file(oid, &type, &size);
+		struct signature_check sigc = { 0 };
+		struct strbuf sig = STRBUF_INIT;
+
+		if (!buf || type != OBJ_TAG)
+			goto next;
+		len = parse_signature(buf, size);
+
+		if (size == len)
+			; /* merely annotated */
+		else if (check_signature(buf, len, buf + len, size - len, &sigc) &&
+			!sigc.gpg_output)
+			strbuf_addstr(&sig, "gpg verification failed.\n");
+		else
+			strbuf_addstr(&sig, sigc.gpg_output);
+		signature_check_clear(&sigc);
+
+		if (!tag_number++) {
+			fmt_tag_signature(&tagbuf, &sig, buf, len);
+			first_tag = i;
+		} else {
+			if (tag_number == 2) {
+				struct strbuf tagline = STRBUF_INIT;
+				strbuf_addch(&tagline, '\n');
+				strbuf_add_commented_lines(&tagline,
+						origins.items[first_tag].string,
+						strlen(origins.items[first_tag].string));
+				strbuf_insert(&tagbuf, 0, tagline.buf,
+					      tagline.len);
+				strbuf_release(&tagline);
+			}
+			strbuf_addch(&tagbuf, '\n');
+			strbuf_add_commented_lines(&tagbuf,
+					origins.items[i].string,
+					strlen(origins.items[i].string));
+			fmt_tag_signature(&tagbuf, &sig, buf, len);
+		}
+		strbuf_release(&sig);
+	next:
+		free(buf);
+	}
+	if (tagbuf.len) {
+		strbuf_addch(out, '\n');
+		strbuf_addbuf(out, &tagbuf);
+	}
+	strbuf_release(&tagbuf);
+}
+
+static void find_merge_parents(struct merge_parents *result,
+			       struct strbuf *in, struct object_id *head)
+{
+	struct commit_list *parents;
+	struct commit *head_commit;
+	int pos = 0, i, j;
+
+	parents = NULL;
+	while (pos < in->len) {
+		int len;
+		char *p = in->buf + pos;
+		char *newline = strchr(p, '\n');
+		const char *q;
+		struct object_id oid;
+		struct commit *parent;
+		struct object *obj;
+
+		len = newline ? newline - p : strlen(p);
+		pos += len + !!newline;
+
+		if (parse_oid_hex(p, &oid, &q) ||
+		    q[0] != '\t' ||
+		    q[1] != '\t')
+			continue; /* skip not-for-merge */
+		/*
+		 * Do not use get_merge_parent() here; we do not have
+		 * "name" here and we do not want to contaminate its
+		 * util field yet.
+		 */
+		obj = parse_object(the_repository, &oid);
+		parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
+		if (!parent)
+			continue;
+		commit_list_insert(parent, &parents);
+		add_merge_parent(result, &obj->oid, &parent->object.oid);
+	}
+	head_commit = lookup_commit(the_repository, head);
+	if (head_commit)
+		commit_list_insert(head_commit, &parents);
+	reduce_heads_replace(&parents);
+
+	while (parents) {
+		struct commit *cmit = pop_commit(&parents);
+		for (i = 0; i < result->nr; i++)
+			if (oideq(&result->item[i].commit, &cmit->object.oid))
+				result->item[i].used = 1;
+	}
+
+	for (i = j = 0; i < result->nr; i++) {
+		if (result->item[i].used) {
+			if (i != j)
+				result->item[j] = result->item[i];
+			j++;
+		}
+	}
+	result->nr = j;
+}
+
+
+int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+		  struct fmt_merge_msg_opts *opts)
+{
+	int i = 0, pos = 0;
+	struct object_id head_oid;
+	const char *current_branch;
+	void *current_branch_to_free;
+	struct merge_parents merge_parents;
+
+	memset(&merge_parents, 0, sizeof(merge_parents));
+
+	/* get current branch */
+	current_branch = current_branch_to_free =
+		resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
+	if (!current_branch)
+		die("No current branch");
+	if (starts_with(current_branch, "refs/heads/"))
+		current_branch += 11;
+
+	find_merge_parents(&merge_parents, in, &head_oid);
+
+	/* get a line */
+	while (pos < in->len) {
+		int len;
+		char *newline, *p = in->buf + pos;
+
+		newline = strchr(p, '\n');
+		len = newline ? newline - p : strlen(p);
+		pos += len + !!newline;
+		i++;
+		p[len] = 0;
+		if (handle_line(p, &merge_parents))
+			die("error in line %d: %.*s", i, len, p);
+	}
+
+	if (opts->add_title && srcs.nr)
+		fmt_merge_msg_title(out, current_branch);
+
+	if (origins.nr)
+		fmt_merge_msg_sigs(out);
+
+	if (opts->shortlog_len) {
+		struct commit *head;
+		struct rev_info rev;
+
+		head = lookup_commit_or_die(&head_oid, "HEAD");
+		repo_init_revisions(the_repository, &rev, NULL);
+		rev.commit_format = CMIT_FMT_ONELINE;
+		rev.ignore_merges = 1;
+		rev.limited = 1;
+
+		strbuf_complete_line(out);
+
+		for (i = 0; i < origins.nr; i++)
+			shortlog(origins.items[i].string,
+				 origins.items[i].util,
+				 head, &rev, opts, out);
+	}
+
+	strbuf_complete_line(out);
+	free(current_branch_to_free);
+	free(merge_parents.item);
+	return 0;
+}
diff --git a/fmt-merge-msg.h b/fmt-merge-msg.h
index 01e3aa8..f2ab0e0 100644
--- a/fmt-merge-msg.h
+++ b/fmt-merge-msg.h
@@ -1,7 +1,20 @@
 #ifndef FMT_MERGE_MSG_H
 #define FMT_MERGE_MSG_H
 
+#include "strbuf.h"
+
+#define DEFAULT_MERGE_LOG_LEN 20
+
+struct fmt_merge_msg_opts {
+	unsigned add_title:1,
+		credit_people:1;
+	int shortlog_len;
+};
+
 extern int merge_log_config;
 int fmt_merge_msg_config(const char *key, const char *value, void *cb);
+int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+		  struct fmt_merge_msg_opts *);
+
 
 #endif /* FMT_MERGE_MSG_H */
diff --git a/fsck.c b/fsck.c
index 640d813..087a7f1 100644
--- a/fsck.c
+++ b/fsck.c
@@ -9,12 +9,14 @@
 #include "tag.h"
 #include "fsck.h"
 #include "refs.h"
+#include "url.h"
 #include "utf8.h"
 #include "decorate.h"
 #include "oidset.h"
 #include "packfile.h"
 #include "submodule-config.h"
 #include "config.h"
+#include "credential.h"
 #include "help.h"
 
 static struct oidset gitmodules_found = OIDSET_INIT;
@@ -910,6 +912,149 @@ static int fsck_tag(const struct object_id *oid, const char *buffer,
 	return ret;
 }
 
+/*
+ * Like builtin/submodule--helper.c's starts_with_dot_slash, but without
+ * relying on the platform-dependent is_dir_sep helper.
+ *
+ * This is for use in checking whether a submodule URL is interpreted as
+ * relative to the current directory on any platform, since \ is a
+ * directory separator on Windows but not on other platforms.
+ */
+static int starts_with_dot_slash(const char *str)
+{
+	return str[0] == '.' && (str[1] == '/' || str[1] == '\\');
+}
+
+/*
+ * Like starts_with_dot_slash, this is a variant of submodule--helper's
+ * helper of the same name with the twist that it accepts backslash as a
+ * directory separator even on non-Windows platforms.
+ */
+static int starts_with_dot_dot_slash(const char *str)
+{
+	return str[0] == '.' && starts_with_dot_slash(str + 1);
+}
+
+static int submodule_url_is_relative(const char *url)
+{
+	return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
+}
+
+/*
+ * Count directory components that a relative submodule URL should chop
+ * from the remote_url it is to be resolved against.
+ *
+ * In other words, this counts "../" components at the start of a
+ * submodule URL.
+ *
+ * Returns the number of directory components to chop and writes a
+ * pointer to the next character of url after all leading "./" and
+ * "../" components to out.
+ */
+static int count_leading_dotdots(const char *url, const char **out)
+{
+	int result = 0;
+	while (1) {
+		if (starts_with_dot_dot_slash(url)) {
+			result++;
+			url += strlen("../");
+			continue;
+		}
+		if (starts_with_dot_slash(url)) {
+			url += strlen("./");
+			continue;
+		}
+		*out = url;
+		return result;
+	}
+}
+/*
+ * Check whether a transport is implemented by git-remote-curl.
+ *
+ * If it is, returns 1 and writes the URL that would be passed to
+ * git-remote-curl to the "out" parameter.
+ *
+ * Otherwise, returns 0 and leaves "out" untouched.
+ *
+ * Examples:
+ *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
+ *   https://example.com/repo.git -> 1, https://example.com/repo.git
+ *   git://example.com/repo.git -> 0
+ *
+ * This is for use in checking for previously exploitable bugs that
+ * required a submodule URL to be passed to git-remote-curl.
+ */
+static int url_to_curl_url(const char *url, const char **out)
+{
+	/*
+	 * We don't need to check for case-aliases, "http.exe", and so
+	 * on because in the default configuration, is_transport_allowed
+	 * prevents URLs with those schemes from being cloned
+	 * automatically.
+	 */
+	if (skip_prefix(url, "http::", out) ||
+	    skip_prefix(url, "https::", out) ||
+	    skip_prefix(url, "ftp::", out) ||
+	    skip_prefix(url, "ftps::", out))
+		return 1;
+	if (starts_with(url, "http://") ||
+	    starts_with(url, "https://") ||
+	    starts_with(url, "ftp://") ||
+	    starts_with(url, "ftps://")) {
+		*out = url;
+		return 1;
+	}
+	return 0;
+}
+
+static int check_submodule_url(const char *url)
+{
+	const char *curl_url;
+
+	if (looks_like_command_line_option(url))
+		return -1;
+
+	if (submodule_url_is_relative(url)) {
+		char *decoded;
+		const char *next;
+		int has_nl;
+
+		/*
+		 * This could be appended to an http URL and url-decoded;
+		 * check for malicious characters.
+		 */
+		decoded = url_decode(url);
+		has_nl = !!strchr(decoded, '\n');
+
+		free(decoded);
+		if (has_nl)
+			return -1;
+
+		/*
+		 * URLs which escape their root via "../" can overwrite
+		 * the host field and previous components, resolving to
+		 * URLs like https::example.com/submodule.git and
+		 * https:///example.com/submodule.git that were
+		 * susceptible to CVE-2020-11008.
+		 */
+		if (count_leading_dotdots(url, &next) > 0 &&
+		    (*next == ':' || *next == '/'))
+			return -1;
+	}
+
+	else if (url_to_curl_url(url, &curl_url)) {
+		struct credential c = CREDENTIAL_INIT;
+		int ret = 0;
+		if (credential_from_url_gently(&c, curl_url, 1) ||
+		    !*c.host)
+			ret = -1;
+		credential_clear(&c);
+		return ret;
+	}
+
+	return 0;
+}
+
 struct fsck_gitmodules_data {
 	const struct object_id *oid;
 	struct fsck_options *options;
@@ -920,7 +1065,7 @@ static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
 {
 	struct fsck_gitmodules_data *data = vdata;
 	const char *subsection, *key;
-	int subsection_len;
+	size_t subsection_len;
 	char *name;
 
 	if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
@@ -935,7 +1080,7 @@ static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
 				    "disallowed submodule name: %s",
 				    name);
 	if (!strcmp(key, "url") && value &&
-	    looks_like_command_line_option(value))
+	    check_submodule_url(value) < 0)
 		data->ret |= report(data->options,
 				    data->oid, OBJ_BLOB,
 				    FSCK_MSG_GITMODULES_URL,
diff --git a/git-compat-util.h b/git-compat-util.h
index aed0b5d..8ba576e 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -389,6 +389,14 @@ static inline char *git_find_last_dir_sep(const char *path)
 #define find_last_dir_sep git_find_last_dir_sep
 #endif
 
+#ifndef has_dir_sep
+static inline int git_has_dir_sep(const char *path)
+{
+	return !!strchr(path, '/');
+}
+#define has_dir_sep(path) git_has_dir_sep(path)
+#endif
+
 #ifndef query_user_email
 #define query_user_email() NULL
 #endif
diff --git a/git-legacy-stash.sh b/git-legacy-stash.sh
deleted file mode 100755
index 4d4ebb4..0000000
--- a/git-legacy-stash.sh
+++ /dev/null
@@ -1,798 +0,0 @@
-#!/bin/sh
-# Copyright (c) 2007, Nanako Shiraishi
-
-dashless=$(basename "$0" | sed -e 's/-/ /')
-USAGE="list [<options>]
-   or: $dashless show [<stash>]
-   or: $dashless drop [-q|--quiet] [<stash>]
-   or: $dashless ( pop | apply ) [--index] [-q|--quiet] [<stash>]
-   or: $dashless branch <branchname> [<stash>]
-   or: $dashless save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
-		      [-u|--include-untracked] [-a|--all] [<message>]
-   or: $dashless [push [--patch] [-k|--[no-]keep-index] [-q|--quiet]
-		       [-u|--include-untracked] [-a|--all] [-m <message>]
-		       [-- <pathspec>...]]
-   or: $dashless clear"
-
-SUBDIRECTORY_OK=Yes
-OPTIONS_SPEC=
-START_DIR=$(pwd)
-. git-sh-setup
-require_work_tree
-prefix=$(git rev-parse --show-prefix) || exit 1
-cd_to_toplevel
-
-TMP="$GIT_DIR/.git-stash.$$"
-TMPindex=${GIT_INDEX_FILE-"$(git rev-parse --git-path index)"}.stash.$$
-trap 'rm -f "$TMP-"* "$TMPindex"' 0
-
-ref_stash=refs/stash
-
-if git config --get-colorbool color.interactive; then
-       help_color="$(git config --get-color color.interactive.help 'red bold')"
-       reset_color="$(git config --get-color '' reset)"
-else
-       help_color=
-       reset_color=
-fi
-
-no_changes () {
-	git diff-index --quiet --cached HEAD --ignore-submodules -- "$@" &&
-	git diff-files --quiet --ignore-submodules -- "$@" &&
-	(test -z "$untracked" || test -z "$(untracked_files "$@")")
-}
-
-untracked_files () {
-	if test "$1" = "-z"
-	then
-		shift
-		z=-z
-	else
-		z=
-	fi
-	excl_opt=--exclude-standard
-	test "$untracked" = "all" && excl_opt=
-	git ls-files -o $z $excl_opt -- "$@"
-}
-
-prepare_fallback_ident () {
-	if ! git -c user.useconfigonly=yes var GIT_COMMITTER_IDENT >/dev/null 2>&1
-	then
-		GIT_AUTHOR_NAME="git stash"
-		GIT_AUTHOR_EMAIL=git@stash
-		GIT_COMMITTER_NAME="git stash"
-		GIT_COMMITTER_EMAIL=git@stash
-		export GIT_AUTHOR_NAME
-		export GIT_AUTHOR_EMAIL
-		export GIT_COMMITTER_NAME
-		export GIT_COMMITTER_EMAIL
-	fi
-}
-
-clear_stash () {
-	if test $# != 0
-	then
-		die "$(gettext "git stash clear with parameters is unimplemented")"
-	fi
-	if current=$(git rev-parse --verify --quiet $ref_stash)
-	then
-		git update-ref -d $ref_stash $current
-	fi
-}
-
-maybe_quiet () {
-	case "$1" in
-	--keep-stdout)
-		shift
-		if test -n "$GIT_QUIET"
-		then
-			"$@" 2>/dev/null
-		else
-			"$@"
-		fi
-		;;
-	*)
-		if test -n "$GIT_QUIET"
-		then
-			"$@" >/dev/null 2>&1
-		else
-			"$@"
-		fi
-		;;
-	esac
-}
-
-create_stash () {
-
-	prepare_fallback_ident
-
-	stash_msg=
-	untracked=
-	while test $# != 0
-	do
-		case "$1" in
-		-m|--message)
-			shift
-			stash_msg=${1?"BUG: create_stash () -m requires an argument"}
-			;;
-		-m*)
-			stash_msg=${1#-m}
-			;;
-		--message=*)
-			stash_msg=${1#--message=}
-			;;
-		-u|--include-untracked)
-			shift
-			untracked=${1?"BUG: create_stash () -u requires an argument"}
-			;;
-		--)
-			shift
-			break
-			;;
-		esac
-		shift
-	done
-
-	git update-index -q --refresh
-	if maybe_quiet no_changes "$@"
-	then
-		exit 0
-	fi
-
-	# state of the base commit
-	if b_commit=$(maybe_quiet --keep-stdout git rev-parse --verify HEAD)
-	then
-		head=$(git rev-list --oneline -n 1 HEAD --)
-	elif test -n "$GIT_QUIET"
-	then
-		exit 1
-	else
-		die "$(gettext "You do not have the initial commit yet")"
-	fi
-
-	if branch=$(git symbolic-ref -q HEAD)
-	then
-		branch=${branch#refs/heads/}
-	else
-		branch='(no branch)'
-	fi
-	msg=$(printf '%s: %s' "$branch" "$head")
-
-	# state of the index
-	i_tree=$(git write-tree) &&
-	i_commit=$(printf 'index on %s\n' "$msg" |
-		git commit-tree $i_tree -p $b_commit) ||
-		die "$(gettext "Cannot save the current index state")"
-
-	if test -n "$untracked"
-	then
-		# Untracked files are stored by themselves in a parentless commit, for
-		# ease of unpacking later.
-		u_commit=$(
-			untracked_files -z "$@" | (
-				GIT_INDEX_FILE="$TMPindex" &&
-				export GIT_INDEX_FILE &&
-				rm -f "$TMPindex" &&
-				git update-index -z --add --remove --stdin &&
-				u_tree=$(git write-tree) &&
-				printf 'untracked files on %s\n' "$msg" | git commit-tree $u_tree  &&
-				rm -f "$TMPindex"
-		) ) || die "$(gettext "Cannot save the untracked files")"
-
-		untracked_commit_option="-p $u_commit";
-	else
-		untracked_commit_option=
-	fi
-
-	if test -z "$patch_mode"
-	then
-
-		# state of the working tree
-		w_tree=$( (
-			git read-tree --index-output="$TMPindex" -m $i_tree &&
-			GIT_INDEX_FILE="$TMPindex" &&
-			export GIT_INDEX_FILE &&
-			git diff-index --name-only -z HEAD -- "$@" >"$TMP-stagenames" &&
-			git update-index --ignore-skip-worktree-entries \
-				-z --add --remove --stdin <"$TMP-stagenames" &&
-			git write-tree &&
-			rm -f "$TMPindex"
-		) ) ||
-			die "$(gettext "Cannot save the current worktree state")"
-
-	else
-
-		rm -f "$TMP-index" &&
-		GIT_INDEX_FILE="$TMP-index" git read-tree HEAD &&
-
-		# find out what the user wants
-		GIT_INDEX_FILE="$TMP-index" \
-			git add --legacy-stash-p -- "$@" &&
-
-		# state of the working tree
-		w_tree=$(GIT_INDEX_FILE="$TMP-index" git write-tree) ||
-		die "$(gettext "Cannot save the current worktree state")"
-
-		git diff-tree -p HEAD $w_tree -- >"$TMP-patch" &&
-		test -s "$TMP-patch" ||
-		die "$(gettext "No changes selected")"
-
-		rm -f "$TMP-index" ||
-		die "$(gettext "Cannot remove temporary index (can't happen)")"
-
-	fi
-
-	# create the stash
-	if test -z "$stash_msg"
-	then
-		stash_msg=$(printf 'WIP on %s' "$msg")
-	else
-		stash_msg=$(printf 'On %s: %s' "$branch" "$stash_msg")
-	fi
-	w_commit=$(printf '%s\n' "$stash_msg" |
-	git commit-tree $w_tree -p $b_commit -p $i_commit $untracked_commit_option) ||
-	die "$(gettext "Cannot record working tree state")"
-}
-
-store_stash () {
-	while test $# != 0
-	do
-		case "$1" in
-		-m|--message)
-			shift
-			stash_msg="$1"
-			;;
-		-m*)
-			stash_msg=${1#-m}
-			;;
-		--message=*)
-			stash_msg=${1#--message=}
-			;;
-		-q|--quiet)
-			quiet=t
-			;;
-		*)
-			break
-			;;
-		esac
-		shift
-	done
-	test $# = 1 ||
-	die "$(eval_gettext "\"$dashless store\" requires one <commit> argument")"
-
-	w_commit="$1"
-	if test -z "$stash_msg"
-	then
-		stash_msg="Created via \"git stash store\"."
-	fi
-
-	git update-ref --create-reflog -m "$stash_msg" $ref_stash $w_commit
-	ret=$?
-	test $ret != 0 && test -z "$quiet" &&
-	die "$(eval_gettext "Cannot update \$ref_stash with \$w_commit")"
-	return $ret
-}
-
-push_stash () {
-	keep_index=
-	patch_mode=
-	untracked=
-	stash_msg=
-	while test $# != 0
-	do
-		case "$1" in
-		-k|--keep-index)
-			keep_index=t
-			;;
-		--no-keep-index)
-			keep_index=n
-			;;
-		-p|--patch)
-			patch_mode=t
-			# only default to keep if we don't already have an override
-			test -z "$keep_index" && keep_index=t
-			;;
-		-q|--quiet)
-			GIT_QUIET=t
-			;;
-		-u|--include-untracked)
-			untracked=untracked
-			;;
-		-a|--all)
-			untracked=all
-			;;
-		-m|--message)
-			shift
-			test -z ${1+x} && usage
-			stash_msg=$1
-			;;
-		-m*)
-			stash_msg=${1#-m}
-			;;
-		--message=*)
-			stash_msg=${1#--message=}
-			;;
-		--help)
-			show_help
-			;;
-		--)
-			shift
-			break
-			;;
-		-*)
-			option="$1"
-			eval_gettextln "error: unknown option for 'stash push': \$option"
-			usage
-			;;
-		*)
-			break
-			;;
-		esac
-		shift
-	done
-
-	eval "set $(git rev-parse --sq --prefix "$prefix" -- "$@")"
-
-	if test -n "$patch_mode" && test -n "$untracked"
-	then
-		die "$(gettext "Can't use --patch and --include-untracked or --all at the same time")"
-	fi
-
-	test -n "$untracked" || git ls-files --error-unmatch -- "$@" >/dev/null || exit 1
-
-	git update-index -q --refresh
-	if maybe_quiet no_changes "$@"
-	then
-		say "$(gettext "No local changes to save")"
-		exit 0
-	fi
-
-	git reflog exists $ref_stash ||
-		clear_stash || die "$(gettext "Cannot initialize stash")"
-
-	create_stash -m "$stash_msg" -u "$untracked" -- "$@"
-	store_stash -m "$stash_msg" -q $w_commit ||
-	die "$(gettext "Cannot save the current status")"
-	say "$(eval_gettext "Saved working directory and index state \$stash_msg")"
-
-	if test -z "$patch_mode"
-	then
-		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
-		if test -n "$untracked" && test $# = 0
-		then
-			git clean --force --quiet -d $CLEAN_X_OPTION
-		fi
-
-		if test $# != 0
-		then
-			test -z "$untracked" && UPDATE_OPTION="-u" || UPDATE_OPTION=
-			test "$untracked" = "all" && FORCE_OPTION="--force" || FORCE_OPTION=
-			git add $UPDATE_OPTION $FORCE_OPTION -- "$@"
-			git diff-index -p --cached --binary HEAD -- "$@" |
-			git apply --index -R
-		else
-			git reset --hard -q --no-recurse-submodules
-		fi
-
-		if test "$keep_index" = "t" && test -n "$i_tree"
-		then
-			git read-tree --reset $i_tree
-			git ls-files -z --modified -- "$@" |
-			git checkout-index -z --force --stdin
-		fi
-	else
-		git apply -R < "$TMP-patch" ||
-		die "$(gettext "Cannot remove worktree changes")"
-
-		if test "$keep_index" != "t"
-		then
-			git reset -q -- "$@"
-		fi
-	fi
-}
-
-save_stash () {
-	push_options=
-	while test $# != 0
-	do
-		case "$1" in
-		-q|--quiet)
-			GIT_QUIET=t
-			;;
-		--)
-			shift
-			break
-			;;
-		-*)
-			# pass all options through to push_stash
-			push_options="$push_options $1"
-			;;
-		*)
-			break
-			;;
-		esac
-		shift
-	done
-
-	stash_msg="$*"
-
-	if test -z "$stash_msg"
-	then
-		push_stash $push_options
-	else
-		push_stash $push_options -m "$stash_msg"
-	fi
-}
-
-have_stash () {
-	git rev-parse --verify --quiet $ref_stash >/dev/null
-}
-
-list_stash () {
-	have_stash || return 0
-	git log --format="%gd: %gs" -g --first-parent -m "$@" $ref_stash --
-}
-
-show_stash () {
-	ALLOW_UNKNOWN_FLAGS=t
-	assert_stash_like "$@"
-
-	if test -z "$FLAGS"
-	then
-		if test "$(git config --bool stash.showStat || echo true)" = "true"
-		then
-			FLAGS=--stat
-		fi
-
-		if test "$(git config --bool stash.showPatch || echo false)" = "true"
-		then
-			FLAGS=${FLAGS}${FLAGS:+ }-p
-		fi
-
-		if test -z "$FLAGS"
-		then
-			return 0
-		fi
-	fi
-
-	git diff ${FLAGS} $b_commit $w_commit
-}
-
-show_help () {
-	exec git help stash
-	exit 1
-}
-
-#
-# Parses the remaining options looking for flags and
-# at most one revision defaulting to ${ref_stash}@{0}
-# if none found.
-#
-# Derives related tree and commit objects from the
-# revision, if one is found.
-#
-# stash records the work tree, and is a merge between the
-# base commit (first parent) and the index tree (second parent).
-#
-#   REV is set to the symbolic version of the specified stash-like commit
-#   IS_STASH_LIKE is non-blank if ${REV} looks like a stash
-#   IS_STASH_REF is non-blank if the ${REV} looks like a stash ref
-#   s is set to the SHA1 of the stash commit
-#   w_commit is set to the commit containing the working tree
-#   b_commit is set to the base commit
-#   i_commit is set to the commit containing the index tree
-#   u_commit is set to the commit containing the untracked files tree
-#   w_tree is set to the working tree
-#   b_tree is set to the base tree
-#   i_tree is set to the index tree
-#   u_tree is set to the untracked files tree
-#
-#   GIT_QUIET is set to t if -q is specified
-#   INDEX_OPTION is set to --index if --index is specified.
-#   FLAGS is set to the remaining flags (if allowed)
-#
-# dies if:
-#   * too many revisions specified
-#   * no revision is specified and there is no stash stack
-#   * a revision is specified which cannot be resolve to a SHA1
-#   * a non-existent stash reference is specified
-#   * unknown flags were set and ALLOW_UNKNOWN_FLAGS is not "t"
-#
-
-parse_flags_and_rev()
-{
-	test "$PARSE_CACHE" = "$*" && return 0 # optimisation
-	PARSE_CACHE="$*"
-
-	IS_STASH_LIKE=
-	IS_STASH_REF=
-	INDEX_OPTION=
-	s=
-	w_commit=
-	b_commit=
-	i_commit=
-	u_commit=
-	w_tree=
-	b_tree=
-	i_tree=
-	u_tree=
-
-	FLAGS=
-	REV=
-	for opt
-	do
-		case "$opt" in
-			-q|--quiet)
-				GIT_QUIET=-t
-			;;
-			--index)
-				INDEX_OPTION=--index
-			;;
-			--help)
-				show_help
-			;;
-			-*)
-				test "$ALLOW_UNKNOWN_FLAGS" = t ||
-					die "$(eval_gettext "unknown option: \$opt")"
-				FLAGS="${FLAGS}${FLAGS:+ }$opt"
-			;;
-			*)
-				REV="${REV}${REV:+ }'$opt'"
-			;;
-		esac
-	done
-
-	eval set -- $REV
-
-	case $# in
-		0)
-			have_stash || die "$(gettext "No stash entries found.")"
-			set -- ${ref_stash}@{0}
-		;;
-		1)
-			:
-		;;
-		*)
-			die "$(eval_gettext "Too many revisions specified: \$REV")"
-		;;
-	esac
-
-	case "$1" in
-		*[!0-9]*)
-			:
-		;;
-		*)
-			set -- "${ref_stash}@{$1}"
-		;;
-	esac
-
-	REV=$(git rev-parse --symbolic --verify --quiet "$1") || {
-		reference="$1"
-		die "$(eval_gettext "\$reference is not a valid reference")"
-	}
-
-	i_commit=$(git rev-parse --verify --quiet "$REV^2") &&
-	set -- $(git rev-parse "$REV" "$REV^1" "$REV:" "$REV^1:" "$REV^2:" 2>/dev/null) &&
-	s=$1 &&
-	w_commit=$1 &&
-	b_commit=$2 &&
-	w_tree=$3 &&
-	b_tree=$4 &&
-	i_tree=$5 &&
-	IS_STASH_LIKE=t &&
-	test "$ref_stash" = "$(git rev-parse --symbolic-full-name "${REV%@*}")" &&
-	IS_STASH_REF=t
-
-	u_commit=$(git rev-parse --verify --quiet "$REV^3") &&
-	u_tree=$(git rev-parse "$REV^3:" 2>/dev/null)
-}
-
-is_stash_like()
-{
-	parse_flags_and_rev "$@"
-	test -n "$IS_STASH_LIKE"
-}
-
-assert_stash_like() {
-	is_stash_like "$@" || {
-		args="$*"
-		die "$(eval_gettext "'\$args' is not a stash-like commit")"
-	}
-}
-
-is_stash_ref() {
-	is_stash_like "$@" && test -n "$IS_STASH_REF"
-}
-
-assert_stash_ref() {
-	is_stash_ref "$@" || {
-		args="$*"
-		die "$(eval_gettext "'\$args' is not a stash reference")"
-	}
-}
-
-apply_stash () {
-
-	assert_stash_like "$@"
-
-	git update-index -q --refresh || die "$(gettext "unable to refresh index")"
-
-	# current index state
-	c_tree=$(git write-tree) ||
-		die "$(gettext "Cannot apply a stash in the middle of a merge")"
-
-	unstashed_index_tree=
-	if test -n "$INDEX_OPTION" && test "$b_tree" != "$i_tree" &&
-			test "$c_tree" != "$i_tree"
-	then
-		git diff-tree --binary $s^2^..$s^2 | git apply --cached
-		test $? -ne 0 &&
-			die "$(gettext "Conflicts in index. Try without --index.")"
-		unstashed_index_tree=$(git write-tree) ||
-			die "$(gettext "Could not save index tree")"
-		git reset
-	fi
-
-	if test -n "$u_tree"
-	then
-		GIT_INDEX_FILE="$TMPindex" git read-tree "$u_tree" &&
-		GIT_INDEX_FILE="$TMPindex" git checkout-index --all &&
-		rm -f "$TMPindex" ||
-		die "$(gettext "Could not restore untracked files from stash entry")"
-	fi
-
-	eval "
-		GITHEAD_$w_tree='Stashed changes' &&
-		GITHEAD_$c_tree='Updated upstream' &&
-		GITHEAD_$b_tree='Version stash was based on' &&
-		export GITHEAD_$w_tree GITHEAD_$c_tree GITHEAD_$b_tree
-	"
-
-	if test -n "$GIT_QUIET"
-	then
-		GIT_MERGE_VERBOSITY=0 && export GIT_MERGE_VERBOSITY
-	fi
-	if git merge-recursive $b_tree -- $c_tree $w_tree
-	then
-		# No conflict
-		if test -n "$unstashed_index_tree"
-		then
-			git read-tree "$unstashed_index_tree"
-		else
-			a="$TMP-added" &&
-			git diff-index --cached --name-only --diff-filter=A $c_tree >"$a" &&
-			git read-tree --reset $c_tree &&
-			git update-index --add --stdin <"$a" ||
-				die "$(gettext "Cannot unstage modified files")"
-			rm -f "$a"
-		fi
-		squelch=
-		if test -n "$GIT_QUIET"
-		then
-			squelch='>/dev/null 2>&1'
-		fi
-		(cd "$START_DIR" && eval "git status $squelch") || :
-	else
-		# Merge conflict; keep the exit status from merge-recursive
-		status=$?
-		git rerere
-		if test -n "$INDEX_OPTION"
-		then
-			gettextln "Index was not unstashed." >&2
-		fi
-		exit $status
-	fi
-}
-
-pop_stash() {
-	assert_stash_ref "$@"
-
-	if apply_stash "$@"
-	then
-		drop_stash "$@"
-	else
-		status=$?
-		say "$(gettext "The stash entry is kept in case you need it again.")"
-		exit $status
-	fi
-}
-
-drop_stash () {
-	assert_stash_ref "$@"
-
-	git reflog delete --updateref --rewrite "${REV}" &&
-		say "$(eval_gettext "Dropped \${REV} (\$s)")" ||
-		die "$(eval_gettext "\${REV}: Could not drop stash entry")"
-
-	# clear_stash if we just dropped the last stash entry
-	git rev-parse --verify --quiet "$ref_stash@{0}" >/dev/null ||
-	clear_stash
-}
-
-apply_to_branch () {
-	test -n "$1" || die "$(gettext "No branch name specified")"
-	branch=$1
-	shift 1
-
-	set -- --index "$@"
-	assert_stash_like "$@"
-
-	git checkout -b $branch $REV^ &&
-	apply_stash "$@" && {
-		test -z "$IS_STASH_REF" || drop_stash "$@"
-	}
-}
-
-test "$1" = "-p" && set "push" "$@"
-
-PARSE_CACHE='--not-parsed'
-# The default command is "push" if nothing but options are given
-seen_non_option=
-for opt
-do
-	case "$opt" in
-	--) break ;;
-	-*) ;;
-	*) seen_non_option=t; break ;;
-	esac
-done
-
-test -n "$seen_non_option" || set "push" "$@"
-
-# Main command set
-case "$1" in
-list)
-	shift
-	list_stash "$@"
-	;;
-show)
-	shift
-	show_stash "$@"
-	;;
-save)
-	shift
-	save_stash "$@"
-	;;
-push)
-	shift
-	push_stash "$@"
-	;;
-apply)
-	shift
-	apply_stash "$@"
-	;;
-clear)
-	shift
-	clear_stash "$@"
-	;;
-create)
-	shift
-	create_stash -m "$*" && echo "$w_commit"
-	;;
-store)
-	shift
-	store_stash "$@"
-	;;
-drop)
-	shift
-	drop_stash "$@"
-	;;
-pop)
-	shift
-	pop_stash "$@"
-	;;
-branch)
-	shift
-	apply_to_branch "$@"
-	;;
-*)
-	case $# in
-	0)
-		push_stash &&
-		say "$(gettext "(To restore them type \"git stash apply\")")"
-		;;
-	*)
-		usage
-	esac
-	;;
-esac
diff --git a/git-p4.py b/git-p4.py
index 9a71a66..b8b2a16 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -16,12 +16,12 @@
 # pylint: disable=too-many-branches,too-many-nested-blocks
 #
 import sys
-if sys.hexversion < 0x02040000:
-    # The limiter is the subprocess module
-    sys.stderr.write("git-p4: requires Python 2.4 or later.\n")
+if sys.version_info.major < 3 and sys.version_info.minor < 7:
+    sys.stderr.write("git-p4: requires Python 2.7 or later.\n")
     sys.exit(1)
 import os
 import optparse
+import functools
 import marshal
 import subprocess
 import tempfile
@@ -34,37 +34,17 @@
 import zlib
 import ctypes
 import errno
+import glob
 
+# On python2.7 where raw_input() and input() are both availble,
+# we want raw_input's semantics, but aliased to input for python3
+# compatibility
 # support basestring in python3
 try:
-    unicode = unicode
-except NameError:
-    # 'unicode' is undefined, must be Python 3
-    str = str
-    unicode = str
-    bytes = bytes
-    basestring = (str,bytes)
-else:
-    # 'unicode' exists, must be Python 2
-    str = str
-    unicode = unicode
-    bytes = str
-    basestring = basestring
-
-try:
-    from subprocess import CalledProcessError
-except ImportError:
-    # from python2.7:subprocess.py
-    # Exception classes used by this module.
-    class CalledProcessError(Exception):
-        """This exception is raised when a process run by check_call() returns
-        a non-zero exit status.  The exit status will be stored in the
-        returncode attribute."""
-        def __init__(self, returncode, cmd):
-            self.returncode = returncode
-            self.cmd = cmd
-        def __str__(self):
-            return "Command '%s' returned non-zero exit status %d" % (self.cmd, self.returncode)
+    if raw_input and input:
+        input = raw_input
+except:
+    pass
 
 verbose = False
 
@@ -113,7 +93,7 @@ def p4_build_cmd(cmd):
         # Provide a way to not pass this option by setting git-p4.retries to 0
         real_cmd += ["-r", str(retries)]
 
-    if isinstance(cmd,basestring):
+    if not isinstance(cmd, list):
         real_cmd = ' '.join(real_cmd) + ' ' + cmd
     else:
         real_cmd += cmd
@@ -186,18 +166,118 @@ def prompt(prompt_text):
     """
     choices = set(m.group(1) for m in re.finditer(r"\[(.)\]", prompt_text))
     while True:
-        response = raw_input(prompt_text).strip().lower()
+        sys.stderr.flush()
+        sys.stdout.write(prompt_text)
+        sys.stdout.flush()
+        response=sys.stdin.readline().strip().lower()
         if not response:
             continue
         response = response[0]
         if response in choices:
             return response
 
+# We need different encoding/decoding strategies for text data being passed
+# around in pipes depending on python version
+if bytes is not str:
+    # For python3, always encode and decode as appropriate
+    def decode_text_stream(s):
+        return s.decode() if isinstance(s, bytes) else s
+    def encode_text_stream(s):
+        return s.encode() if isinstance(s, str) else s
+else:
+    # For python2.7, pass read strings as-is, but also allow writing unicode
+    def decode_text_stream(s):
+        return s
+    def encode_text_stream(s):
+        return s.encode('utf_8') if isinstance(s, unicode) else s
+
+def decode_path(path):
+    """Decode a given string (bytes or otherwise) using configured path encoding options
+    """
+    encoding = gitConfig('git-p4.pathEncoding') or 'utf_8'
+    if bytes is not str:
+        return path.decode(encoding, errors='replace') if isinstance(path, bytes) else path
+    else:
+        try:
+            path.decode('ascii')
+        except:
+            path = path.decode(encoding, errors='replace')
+            if verbose:
+                print('Path with non-ASCII characters detected. Used {} to decode: {}'.format(encoding, path))
+        return path
+
+def run_git_hook(cmd, param=[]):
+    """Execute a hook if the hook exists."""
+    if verbose:
+        sys.stderr.write("Looking for hook: %s\n" % cmd)
+        sys.stderr.flush()
+
+    hooks_path = gitConfig("core.hooksPath")
+    if len(hooks_path) <= 0:
+        hooks_path = os.path.join(os.environ["GIT_DIR"], "hooks")
+
+    if not isinstance(param, list):
+        param=[param]
+
+    # resolve hook file name, OS depdenent
+    hook_file = os.path.join(hooks_path, cmd)
+    if platform.system() == 'Windows':
+        if not os.path.isfile(hook_file):
+            # look for the file with an extension
+            files = glob.glob(hook_file + ".*")
+            if not files:
+                return True
+            files.sort()
+            hook_file = files.pop()
+            while hook_file.upper().endswith(".SAMPLE"):
+                # The file is a sample hook. We don't want it
+                if len(files) > 0:
+                    hook_file = files.pop()
+                else:
+                    return True
+
+    if not os.path.isfile(hook_file) or not os.access(hook_file, os.X_OK):
+        return True
+
+    return run_hook_command(hook_file, param) == 0
+
+def run_hook_command(cmd, param):
+    """Executes a git hook command
+       cmd = the command line file to be executed. This can be
+       a file that is run by OS association.
+
+       param = a list of parameters to pass to the cmd command
+
+       On windows, the extension is checked to see if it should
+       be run with the Git for Windows Bash shell.  If there
+       is no file extension, the file is deemed a bash shell
+       and will be handed off to sh.exe. Otherwise, Windows
+       will be called with the shell to handle the file assocation.
+
+       For non Windows operating systems, the file is called
+       as an executable.
+    """
+    cli = [cmd] + param
+    use_shell = False
+    if platform.system() == 'Windows':
+        (root,ext) = os.path.splitext(cmd)
+        if ext == "":
+            exe_path = os.environ.get("EXEPATH")
+            if exe_path is None:
+                exe_path = ""
+            else:
+                exe_path = os.path.join(exe_path, "bin")
+            cli = [os.path.join(exe_path, "SH.EXE")] + cli
+        else:
+            use_shell = True
+    return subprocess.call(cli, shell=use_shell)
+
+
 def write_pipe(c, stdin):
     if verbose:
         sys.stderr.write('Writing pipe: %s\n' % str(c))
 
-    expand = isinstance(c,basestring)
+    expand = not isinstance(c, list)
     p = subprocess.Popen(c, stdin=subprocess.PIPE, shell=expand)
     pipe = p.stdin
     val = pipe.write(stdin)
@@ -209,6 +289,8 @@ def write_pipe(c, stdin):
 
 def p4_write_pipe(c, stdin):
     real_cmd = p4_build_cmd(c)
+    if bytes is not str and isinstance(stdin, str):
+        stdin = encode_text_stream(stdin)
     return write_pipe(real_cmd, stdin)
 
 def read_pipe_full(c):
@@ -219,15 +301,17 @@ def read_pipe_full(c):
     if verbose:
         sys.stderr.write('Reading pipe: %s\n' % str(c))
 
-    expand = isinstance(c,basestring)
+    expand = not isinstance(c, list)
     p = subprocess.Popen(c, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=expand)
     (out, err) = p.communicate()
-    return (p.returncode, out, err)
+    return (p.returncode, out, decode_text_stream(err))
 
-def read_pipe(c, ignore_error=False):
+def read_pipe(c, ignore_error=False, raw=False):
     """ Read output from  command. Returns the output text on
         success. On failure, terminates execution, unless
         ignore_error is True, when it returns an empty string.
+
+        If raw is True, do not attempt to decode output text.
     """
     (retcode, out, err) = read_pipe_full(c)
     if retcode != 0:
@@ -235,6 +319,8 @@ def read_pipe(c, ignore_error=False):
             out = ""
         else:
             die('Command failed: %s\nError: %s' % (str(c), err))
+    if not raw:
+        out = decode_text_stream(out)
     return out
 
 def read_pipe_text(c):
@@ -245,23 +331,22 @@ def read_pipe_text(c):
     if retcode != 0:
         return None
     else:
-        return out.rstrip()
+        return decode_text_stream(out).rstrip()
 
-def p4_read_pipe(c, ignore_error=False):
+def p4_read_pipe(c, ignore_error=False, raw=False):
     real_cmd = p4_build_cmd(c)
-    return read_pipe(real_cmd, ignore_error)
+    return read_pipe(real_cmd, ignore_error, raw=raw)
 
 def read_pipe_lines(c):
     if verbose:
         sys.stderr.write('Reading pipe: %s\n' % str(c))
 
-    expand = isinstance(c, basestring)
+    expand = not isinstance(c, list)
     p = subprocess.Popen(c, stdout=subprocess.PIPE, shell=expand)
     pipe = p.stdout
-    val = pipe.readlines()
+    val = [decode_text_stream(line) for line in pipe.readlines()]
     if pipe.close() or p.wait():
         die('Command failed: %s' % str(c))
-
     return val
 
 def p4_read_pipe_lines(c):
@@ -289,6 +374,7 @@ def p4_has_move_command():
     cmd = p4_build_cmd(["move", "-k", "@from", "@to"])
     p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     (out, err) = p.communicate()
+    err = decode_text_stream(err)
     # return code will be 1 in either case
     if err.find("Invalid option") >= 0:
         return False
@@ -298,7 +384,7 @@ def p4_has_move_command():
     return True
 
 def system(cmd, ignore_error=False):
-    expand = isinstance(cmd,basestring)
+    expand = not isinstance(cmd, list)
     if verbose:
         sys.stderr.write("executing %s\n" % str(cmd))
     retcode = subprocess.call(cmd, shell=expand)
@@ -310,7 +396,7 @@ def system(cmd, ignore_error=False):
 def p4_system(cmd):
     """Specifically invoke p4 as the system command. """
     real_cmd = p4_build_cmd(cmd)
-    expand = isinstance(real_cmd, basestring)
+    expand = not isinstance(real_cmd, list)
     retcode = subprocess.call(real_cmd, shell=expand)
     if retcode:
         raise CalledProcessError(retcode, real_cmd)
@@ -548,7 +634,7 @@ def getP4OpenedType(file):
 # Return the set of all p4 labels
 def getP4Labels(depotPaths):
     labels = set()
-    if isinstance(depotPaths,basestring):
+    if not isinstance(depotPaths, list):
         depotPaths = [depotPaths]
 
     for l in p4CmdList(["labels"] + ["%s..." % p for p in depotPaths]):
@@ -565,12 +651,7 @@ def getGitTags():
         gitTags.add(tag)
     return gitTags
 
-def diffTreePattern():
-    # This is a simple generator for the diff tree regex pattern. This could be
-    # a class variable if this and parseDiffTreeEntry were a part of a class.
-    pattern = re.compile(':(\d+) (\d+) (\w+) (\w+) ([A-Z])(\d+)?\t(.*?)((\t(.*))|$)')
-    while True:
-        yield pattern
+_diff_tree_pattern = None
 
 def parseDiffTreeEntry(entry):
     """Parses a single diff tree entry into its component elements.
@@ -591,7 +672,11 @@ def parseDiffTreeEntry(entry):
 
     If the pattern is not matched, None is returned."""
 
-    match = diffTreePattern().next().match(entry)
+    global _diff_tree_pattern
+    if not _diff_tree_pattern:
+        _diff_tree_pattern = re.compile(':(\d+) (\d+) (\w+) (\w+) ([A-Z])(\d+)?\t(.*?)((\t(.*))|$)')
+
+    match = _diff_tree_pattern.match(entry)
     if match:
         return {
             'src_mode': match.group(1),
@@ -643,7 +728,7 @@ def isModeExecChanged(src_mode, dst_mode):
 def p4CmdList(cmd, stdin=None, stdin_mode='w+b', cb=None, skip_info=False,
         errors_as_exceptions=False):
 
-    if isinstance(cmd,basestring):
+    if not isinstance(cmd, list):
         cmd = "-G " + cmd
         expand = True
     else:
@@ -660,11 +745,12 @@ def p4CmdList(cmd, stdin=None, stdin_mode='w+b', cb=None, skip_info=False,
     stdin_file = None
     if stdin is not None:
         stdin_file = tempfile.TemporaryFile(prefix='p4-stdin', mode=stdin_mode)
-        if isinstance(stdin,basestring):
+        if not isinstance(stdin, list):
             stdin_file.write(stdin)
         else:
             for i in stdin:
-                stdin_file.write(i + '\n')
+                stdin_file.write(encode_text_stream(i))
+                stdin_file.write(b'\n')
         stdin_file.flush()
         stdin_file.seek(0)
 
@@ -677,6 +763,20 @@ def p4CmdList(cmd, stdin=None, stdin_mode='w+b', cb=None, skip_info=False,
     try:
         while True:
             entry = marshal.load(p4.stdout)
+            if bytes is not str:
+                # Decode unmarshalled dict to use str keys and values, except for:
+                #   - `data` which may contain arbitrary binary data
+                #   - `depotFile[0-9]*`, `path`, or `clientFile` which may contain non-UTF8 encoded text
+                decoded_entry = {}
+                for key, value in entry.items():
+                    key = key.decode()
+                    if isinstance(value, bytes) and not (key in ('data', 'path', 'clientFile') or key.startswith('depotFile')):
+                        value = value.decode()
+                    decoded_entry[key] = value
+                # Parse out data if it's an error response
+                if decoded_entry.get('code') == 'error' and 'data' in decoded_entry:
+                    decoded_entry['data'] = decoded_entry['data'].decode()
+                entry = decoded_entry
             if skip_info:
                 if 'code' in entry and entry['code'] == 'info':
                     continue
@@ -727,7 +827,8 @@ def p4Where(depotPath):
         if "depotFile" in entry:
             # Search for the base client side depot path, as long as it starts with the branch's P4 path.
             # The base path always ends with "/...".
-            if entry["depotFile"].find(depotPath) == 0 and entry["depotFile"][-4:] == "/...":
+            entry_path = decode_path(entry['depotFile'])
+            if entry_path.find(depotPath) == 0 and entry_path[-4:] == "/...":
                 output = entry
                 break
         elif "data" in entry:
@@ -742,11 +843,11 @@ def p4Where(depotPath):
         return ""
     clientPath = ""
     if "path" in output:
-        clientPath = output.get("path")
+        clientPath = decode_path(output['path'])
     elif "data" in output:
         data = output.get("data")
-        lastSpace = data.rfind(" ")
-        clientPath = data[lastSpace + 1:]
+        lastSpace = data.rfind(b" ")
+        clientPath = decode_path(data[lastSpace + 1:])
 
     if clientPath.endswith("..."):
         clientPath = clientPath[:-3]
@@ -894,6 +995,7 @@ def branch_exists(branch):
     cmd = [ "git", "rev-parse", "--symbolic", "--verify", branch ]
     p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     out, _ = p.communicate()
+    out = decode_text_stream(out)
     if p.returncode:
         return False
     # expect exactly one line of output: the branch name
@@ -1171,7 +1273,7 @@ def pushFile(self, localLargeFile):
         assert False, "Method 'pushFile' required in " + self.__class__.__name__
 
     def hasLargeFileExtension(self, relPath):
-        return reduce(
+        return functools.reduce(
             lambda a, b: a or b,
             [relPath.endswith('.' + e) for e in gitConfigList('git-p4.largeFileExtensions')],
             False
@@ -1278,7 +1380,7 @@ def generatePointer(self, contentFile):
             ['git', 'lfs', 'pointer', '--file=' + contentFile],
             stdout=subprocess.PIPE
         )
-        pointerFile = pointerProcess.stdout.read()
+        pointerFile = decode_text_stream(pointerProcess.stdout.read())
         if pointerProcess.wait():
             os.remove(contentFile)
             die('git-lfs pointer command failed. Did you install the extension?')
@@ -1414,14 +1516,14 @@ def getUserMapFromPerforceServer(self):
         for (key, val) in self.users.items():
             s += "%s\t%s\n" % (key.expandtabs(1), val.expandtabs(1))
 
-        open(self.getUserCacheFilename(), "wb").write(s)
+        open(self.getUserCacheFilename(), 'w').write(s)
         self.userMapFromPerforceServer = True
 
     def loadUserMapFromCache(self):
         self.users = {}
         self.userMapFromPerforceServer = False
         try:
-            cache = open(self.getUserCacheFilename(), "rb")
+            cache = open(self.getUserCacheFilename(), 'r')
             lines = cache.readlines()
             cache.close()
             for line in lines:
@@ -1536,13 +1638,39 @@ def __init__(self):
                                      "work from a local git branch that is not master"),
                 optparse.make_option("--disable-p4sync", dest="disable_p4sync", action="store_true",
                                      help="Skip Perforce sync of p4/master after submit or shelve"),
+                optparse.make_option("--no-verify", dest="no_verify", action="store_true",
+                                     help="Bypass p4-pre-submit and p4-changelist hooks"),
         ]
         self.description = """Submit changes from git to the perforce depot.\n
-    The `p4-pre-submit` hook is executed if it exists and is executable.
-    The hook takes no parameters and nothing from standard input. Exiting with
-    non-zero status from this script prevents `git-p4 submit` from launching.
+    The `p4-pre-submit` hook is executed if it exists and is executable. It
+    can be bypassed with the `--no-verify` command line option. The hook takes
+    no parameters and nothing from standard input. Exiting with a non-zero status
+    from this script prevents `git-p4 submit` from launching.
 
-    One usage scenario is to run unit tests in the hook."""
+    One usage scenario is to run unit tests in the hook.
+
+    The `p4-prepare-changelist` hook is executed right after preparing the default
+    changelist message and before the editor is started. It takes one parameter,
+    the name of the file that contains the changelist text. Exiting with a non-zero
+    status from the script will abort the process.
+
+    The purpose of the hook is to edit the message file in place, and it is not
+    supressed by the `--no-verify` option. This hook is called even if
+    `--prepare-p4-only` is set.
+
+    The `p4-changelist` hook is executed after the changelist message has been
+    edited by the user. It can be bypassed with the `--no-verify` option. It
+    takes a single parameter, the name of the file that holds the proposed
+    changelist text. Exiting with a non-zero status causes the command to abort.
+
+    The hook is allowed to edit the changelist file and can be used to normalize
+    the text into some project standard format. It can also be used to refuse the
+    Submit after inspect the message file.
+
+    The `p4-post-changelist` hook is invoked after the submit has successfully
+    occured in P4. It takes no parameters and is meant primarily for notification
+    and cannot affect the outcome of the git p4 submit action.
+    """
 
         self.usage += " [name of git branch to submit into perforce depot]"
         self.origin = ""
@@ -1560,6 +1688,7 @@ def __init__(self):
         self.exportLabels = False
         self.p4HasMoveCommand = p4_has_move_command()
         self.branch = None
+        self.no_verify = False
 
         if gitConfig('git-p4.largeFileSystem'):
             die("Large file system not supported for git-p4 submit command. Please remove it from config.")
@@ -1698,7 +1827,8 @@ def modifyChangelistUser(self, changelist, newUser):
         c = changes[0]
         if c['User'] == newUser: return   # nothing to do
         c['User'] = newUser
-        input = marshal.dumps(c)
+        # p4 does not understand format version 3 and above
+        input = marshal.dumps(c, 2)
 
         result = p4CmdList("change -f -i", stdin=input)
         for r in result:
@@ -1762,7 +1892,7 @@ def prepareSubmitTemplate(self, changelist=None):
                 break
         if not change_entry:
             die('Failed to decode output of p4 change -o')
-        for key, value in change_entry.iteritems():
+        for key, value in change_entry.items():
             if key.startswith('File'):
                 if 'depot-paths' in settings:
                     if not [p for p in settings['depot-paths']
@@ -1946,6 +2076,9 @@ def applyCommit(self, id):
         applyPatchCmd = patchcmd + "--check --apply -"
         patch_succeeded = True
 
+        if verbose:
+            print("TryPatch: %s" % tryPatchCmd)
+
         if os.system(tryPatchCmd) != 0:
             fixed_rcs_keywords = False
             patch_succeeded = False
@@ -1985,6 +2118,7 @@ def applyCommit(self, id):
                 print("Retrying the patch with RCS keywords cleaned up")
                 if os.system(tryPatchCmd) == 0:
                     patch_succeeded = True
+                    print("Patch succeesed this time with RCS keywords cleaned")
 
         if not patch_succeeded:
             for f in editedFiles:
@@ -2042,58 +2176,76 @@ def applyCommit(self, id):
         tmpFile = os.fdopen(handle, "w+b")
         if self.isWindows:
             submitTemplate = submitTemplate.replace("\n", "\r\n")
-        tmpFile.write(submitTemplate)
+        tmpFile.write(encode_text_stream(submitTemplate))
         tmpFile.close()
 
-        if self.prepare_p4_only:
-            #
-            # Leave the p4 tree prepared, and the submit template around
-            # and let the user decide what to do next
-            #
-            print()
-            print("P4 workspace prepared for submission.")
-            print("To submit or revert, go to client workspace")
-            print("  " + self.clientPath)
-            print()
-            print("To submit, use \"p4 submit\" to write a new description,")
-            print("or \"p4 submit -i <%s\" to use the one prepared by" \
-                  " \"git p4\"." % fileName)
-            print("You can delete the file \"%s\" when finished." % fileName)
-
-            if self.preserveUser and p4User and not self.p4UserIsMe(p4User):
-                print("To preserve change ownership by user %s, you must\n" \
-                      "do \"p4 change -f <change>\" after submitting and\n" \
-                      "edit the User field.")
-            if pureRenameCopy:
-                print("After submitting, renamed files must be re-synced.")
-                print("Invoke \"p4 sync -f\" on each of these files:")
-                for f in pureRenameCopy:
-                    print("  " + f)
-
-            print()
-            print("To revert the changes, use \"p4 revert ...\", and delete")
-            print("the submit template file \"%s\"" % fileName)
-            if filesToAdd:
-                print("Since the commit adds new files, they must be deleted:")
-                for f in filesToAdd:
-                    print("  " + f)
-            print()
-            return True
-
-        #
-        # Let the user edit the change description, then submit it.
-        #
         submitted = False
 
         try:
+            # Allow the hook to edit the changelist text before presenting it
+            # to the user.
+            if not run_git_hook("p4-prepare-changelist", [fileName]):
+                return False
+
+            if self.prepare_p4_only:
+                #
+                # Leave the p4 tree prepared, and the submit template around
+                # and let the user decide what to do next
+                #
+                submitted = True
+                print("")
+                print("P4 workspace prepared for submission.")
+                print("To submit or revert, go to client workspace")
+                print("  " + self.clientPath)
+                print("")
+                print("To submit, use \"p4 submit\" to write a new description,")
+                print("or \"p4 submit -i <%s\" to use the one prepared by" \
+                      " \"git p4\"." % fileName)
+                print("You can delete the file \"%s\" when finished." % fileName)
+
+                if self.preserveUser and p4User and not self.p4UserIsMe(p4User):
+                    print("To preserve change ownership by user %s, you must\n" \
+                          "do \"p4 change -f <change>\" after submitting and\n" \
+                          "edit the User field.")
+                if pureRenameCopy:
+                    print("After submitting, renamed files must be re-synced.")
+                    print("Invoke \"p4 sync -f\" on each of these files:")
+                    for f in pureRenameCopy:
+                        print("  " + f)
+
+                print("")
+                print("To revert the changes, use \"p4 revert ...\", and delete")
+                print("the submit template file \"%s\"" % fileName)
+                if filesToAdd:
+                    print("Since the commit adds new files, they must be deleted:")
+                    for f in filesToAdd:
+                        print("  " + f)
+                print("")
+                sys.stdout.flush()
+                return True
+
             if self.edit_template(fileName):
+                if not self.no_verify:
+                    if not run_git_hook("p4-changelist", [fileName]):
+                        print("The p4-changelist hook failed.")
+                        sys.stdout.flush()
+                        return False
+
                 # read the edited message and submit
                 tmpFile = open(fileName, "rb")
-                message = tmpFile.read()
+                message = decode_text_stream(tmpFile.read())
                 tmpFile.close()
                 if self.isWindows:
                     message = message.replace("\r\n", "\n")
-                submitTemplate = message[:message.index(separatorLine)]
+                if message.find(separatorLine) != -1:
+                    submitTemplate = message[:message.index(separatorLine)]
+                else:
+                    submitTemplate = message
+
+                if len(submitTemplate.strip()) == 0:
+                    print("Changelist is empty, aborting this changelist.")
+                    sys.stdout.flush()
+                    return False
 
                 if update_shelve:
                     p4_write_pipe(['shelve', '-r', '-i'], submitTemplate)
@@ -2116,20 +2268,23 @@ def applyCommit(self, id):
 
                 submitted = True
 
+                run_git_hook("p4-post-changelist")
         finally:
-            # skip this patch
+            # Revert changes if we skip this patch
             if not submitted or self.shelve:
                 if self.shelve:
                     print ("Reverting shelved files.")
                 else:
                     print ("Submission cancelled, undoing p4 changes.")
+                sys.stdout.flush()
                 for f in editedFiles | filesToDelete:
                     p4_revert(f)
                 for f in filesToAdd:
                     p4_revert(f)
                     os.remove(f)
 
-        os.remove(fileName)
+            if not self.prepare_p4_only:
+                os.remove(fileName)
         return submitted
 
     # Export git tags as p4 labels. Create a p4 label and then tag
@@ -2353,13 +2508,17 @@ def run(self, args):
             sys.exit("number of commits (%d) must match number of shelved changelist (%d)" %
                      (len(commits), num_shelves))
 
-        hooks_path = gitConfig("core.hooksPath")
-        if len(hooks_path) <= 0:
-            hooks_path = os.path.join(os.environ.get("GIT_DIR", ".git"), "hooks")
-
-        hook_file = os.path.join(hooks_path, "p4-pre-submit")
-        if os.path.isfile(hook_file) and os.access(hook_file, os.X_OK) and subprocess.call([hook_file]) != 0:
-            sys.exit(1)
+        if not self.no_verify:
+            try:
+                if not run_git_hook("p4-pre-submit"):
+                    print("\nThe p4-pre-submit hook failed, aborting the submit.\n\nYou can skip " \
+                        "this pre-submission check by adding\nthe command line option '--no-verify', " \
+                        "however,\nthis will also skip the p4-changelist hook as well.")
+                    sys.exit(1)
+            except Exception as e:
+                print("\nThe p4-pre-submit hook failed, aborting the submit.\n\nThe hook failed "\
+                    "with the error '{0}'".format(e.message) )
+                sys.exit(1)
 
         #
         # Apply the commits, one at a time.  On failure, ask if should
@@ -2509,7 +2668,7 @@ def append(self, view_line):
 
     def convert_client_path(self, clientFile):
         # chop off //client/ part to make it relative
-        if not clientFile.startswith(self.client_prefix):
+        if not decode_path(clientFile).startswith(self.client_prefix):
             die("No prefix '%s' on clientFile '%s'" %
                 (self.client_prefix, clientFile))
         return clientFile[len(self.client_prefix):]
@@ -2518,7 +2677,7 @@ def update_client_spec_path_cache(self, files):
         """ Caching file paths by "p4 where" batch query """
 
         # List depot file paths exclude that already cached
-        fileArgs = [f['path'] for f in files if f['path'] not in self.client_spec_path_cache]
+        fileArgs = [f['path'] for f in files if decode_path(f['path']) not in self.client_spec_path_cache]
 
         if len(fileArgs) == 0:
             return  # All files in cache
@@ -2533,16 +2692,18 @@ def update_client_spec_path_cache(self, files):
             if "unmap" in res:
                 # it will list all of them, but only one not unmap-ped
                 continue
+            depot_path = decode_path(res['depotFile'])
             if gitConfigBool("core.ignorecase"):
-                res['depotFile'] = res['depotFile'].lower()
-            self.client_spec_path_cache[res['depotFile']] = self.convert_client_path(res["clientFile"])
+                depot_path = depot_path.lower()
+            self.client_spec_path_cache[depot_path] = self.convert_client_path(res["clientFile"])
 
         # not found files or unmap files set to ""
         for depotFile in fileArgs:
+            depotFile = decode_path(depotFile)
             if gitConfigBool("core.ignorecase"):
                 depotFile = depotFile.lower()
             if depotFile not in self.client_spec_path_cache:
-                self.client_spec_path_cache[depotFile] = ""
+                self.client_spec_path_cache[depotFile] = b''
 
     def map_in_client(self, depot_path):
         """Return the relative location in the client where this
@@ -2647,6 +2808,7 @@ def __init__(self):
     def checkpoint(self):
         self.gitStream.write("checkpoint\n\n")
         self.gitStream.write("progress checkpoint\n\n")
+        self.gitStream.flush()
         out = self.gitOutput.readline()
         if self.verbose:
             print("checkpoint finished: " + out)
@@ -2660,7 +2822,7 @@ def isPathWanted(self, path):
             elif path.lower() == p.lower():
                 return False
         for p in self.depotPaths:
-            if p4PathStartsWith(path, p):
+            if p4PathStartsWith(path, decode_path(p)):
                 return True
         return False
 
@@ -2669,7 +2831,7 @@ def extractFilesFromCommit(self, commit, shelved=False, shelved_cl = 0):
         fnum = 0
         while "depotFile%s" % fnum in commit:
             path =  commit["depotFile%s" % fnum]
-            found = self.isPathWanted(path)
+            found = self.isPathWanted(decode_path(path))
             if not found:
                 fnum = fnum + 1
                 continue
@@ -2703,7 +2865,7 @@ def stripRepoPath(self, path, prefixes):
         if self.useClientSpec:
             # branch detection moves files up a level (the branch name)
             # from what client spec interpretation gives
-            path = self.clientSpecDirs.map_in_client(path)
+            path = decode_path(self.clientSpecDirs.map_in_client(path))
             if self.detectBranches:
                 for b in self.knownBranches:
                     if p4PathStartsWith(path, b + "/"):
@@ -2737,14 +2899,15 @@ def splitFilesIntoBranches(self, commit):
         branches = {}
         fnum = 0
         while "depotFile%s" % fnum in commit:
-            path =  commit["depotFile%s" % fnum]
+            raw_path = commit["depotFile%s" % fnum]
+            path = decode_path(raw_path)
             found = self.isPathWanted(path)
             if not found:
                 fnum = fnum + 1
                 continue
 
             file = {}
-            file["path"] = path
+            file["path"] = raw_path
             file["rev"] = commit["rev%s" % fnum]
             file["action"] = commit["action%s" % fnum]
             file["type"] = commit["type%s" % fnum]
@@ -2753,7 +2916,7 @@ def splitFilesIntoBranches(self, commit):
             # start with the full relative path where this file would
             # go in a p4 client
             if self.useClientSpec:
-                relPath = self.clientSpecDirs.map_in_client(path)
+                relPath = decode_path(self.clientSpecDirs.map_in_client(path))
             else:
                 relPath = self.stripRepoPath(path, self.depotPaths)
 
@@ -2769,7 +2932,7 @@ def splitFilesIntoBranches(self, commit):
         return branches
 
     def writeToGitStream(self, gitMode, relPath, contents):
-        self.gitStream.write('M %s inline %s\n' % (gitMode, relPath))
+        self.gitStream.write(encode_text_stream(u'M {} inline {}\n'.format(gitMode, relPath)))
         self.gitStream.write('data %d\n' % sum(len(d) for d in contents))
         for d in contents:
             self.gitStream.write(d)
@@ -2791,14 +2954,15 @@ def encodeWithUTF8(self, path):
     # - helper for streamP4Files
 
     def streamOneP4File(self, file, contents):
-        relPath = self.stripRepoPath(file['depotFile'], self.branchPrefixes)
-        relPath = self.encodeWithUTF8(relPath)
+        file_path = file['depotFile']
+        relPath = self.stripRepoPath(decode_path(file_path), self.branchPrefixes)
+
         if verbose:
             if 'fileSize' in self.stream_file:
                 size = int(self.stream_file['fileSize'])
             else:
                 size = 0 # deleted files don't get a fileSize apparently
-            sys.stdout.write('\r%s --> %s (%i MB)\n' % (file['depotFile'], relPath, size/1024/1024))
+            sys.stdout.write('\r%s --> %s (%i MB)\n' % (file_path, relPath, size/1024/1024))
             sys.stdout.flush()
 
         (type_base, type_mods) = split_p4_type(file["type"])
@@ -2810,13 +2974,13 @@ def streamOneP4File(self, file, contents):
             git_mode = "120000"
             # p4 print on a symlink sometimes contains "target\n";
             # if it does, remove the newline
-            data = ''.join(contents)
+            data = ''.join(decode_text_stream(c) for c in contents)
             if not data:
                 # Some version of p4 allowed creating a symlink that pointed
                 # to nothing.  This causes p4 errors when checking out such
                 # a change, and errors here too.  Work around it by ignoring
                 # the bad symlink; hopefully a future change fixes it.
-                print("\nIgnoring empty symlink in %s" % file['depotFile'])
+                print("\nIgnoring empty symlink in %s" % file_path)
                 return
             elif data[-1] == '\n':
                 contents = [data[:-1]]
@@ -2835,7 +2999,7 @@ def streamOneP4File(self, file, contents):
             # just the native "NT" type.
             #
             try:
-                text = p4_read_pipe(['print', '-q', '-o', '-', '%s@%s' % (file['depotFile'], file['change'])])
+                text = p4_read_pipe(['print', '-q', '-o', '-', '%s@%s' % (decode_path(file['depotFile']), file['change'])], raw=True)
             except Exception as e:
                 if 'Translation of file content failed' in str(e):
                     type_base = 'binary'
@@ -2843,7 +3007,7 @@ def streamOneP4File(self, file, contents):
                     raise e
             else:
                 if p4_version_string().find('/NT') >= 0:
-                    text = text.replace('\r\n', '\n')
+                    text = text.replace(b'\r\n', b'\n')
                 contents = [ text ]
 
         if type_base == "apple":
@@ -2864,7 +3028,7 @@ def streamOneP4File(self, file, contents):
         pattern = p4_keywords_regexp_for_type(type_base, type_mods)
         if pattern:
             regexp = re.compile(pattern, re.VERBOSE)
-            text = ''.join(contents)
+            text = ''.join(decode_text_stream(c) for c in contents)
             text = regexp.sub(r'$\1$', text)
             contents = [ text ]
 
@@ -2874,12 +3038,11 @@ def streamOneP4File(self, file, contents):
         self.writeToGitStream(git_mode, relPath, contents)
 
     def streamOneP4Deletion(self, file):
-        relPath = self.stripRepoPath(file['path'], self.branchPrefixes)
-        relPath = self.encodeWithUTF8(relPath)
+        relPath = self.stripRepoPath(decode_path(file['path']), self.branchPrefixes)
         if verbose:
             sys.stdout.write("delete %s\n" % relPath)
             sys.stdout.flush()
-        self.gitStream.write("D %s\n" % relPath)
+        self.gitStream.write(encode_text_stream(u'D {}\n'.format(relPath)))
 
         if self.largeFileSystem and self.largeFileSystem.isLargeFile(relPath):
             self.largeFileSystem.removeLargeFile(relPath)
@@ -2979,9 +3142,9 @@ def streamP4FilesCbSelf(entry):
                 if 'shelved_cl' in f:
                     # Handle shelved CLs using the "p4 print file@=N" syntax to print
                     # the contents
-                    fileArg = '%s@=%d' % (f['path'], f['shelved_cl'])
+                    fileArg = f['path'] + encode_text_stream('@={}'.format(f['shelved_cl']))
                 else:
-                    fileArg = '%s#%s' % (f['path'], f['rev'])
+                    fileArg = f['path'] + encode_text_stream('#{}'.format(f['rev']))
 
                 fileArgs.append(fileArg)
 
@@ -3062,8 +3225,8 @@ def commit(self, details, files, branch, parent = "", allow_empty=False):
         if self.clientSpecDirs:
             self.clientSpecDirs.update_client_spec_path_cache(files)
 
-        files = [f for f in files
-            if self.inClientSpec(f['path']) and self.hasBranchPrefix(f['path'])]
+        files = [f for (f, path) in ((f, decode_path(f['path'])) for f in files)
+            if self.inClientSpec(path) and self.hasBranchPrefix(path)]
 
         if gitConfigBool('git-p4.keepEmptyCommits'):
             allow_empty = True
@@ -3635,6 +3798,15 @@ def openStreams(self):
         self.gitStream = self.importProcess.stdin
         self.gitError = self.importProcess.stderr
 
+        if bytes is not str:
+            # Wrap gitStream.write() so that it can be called using `str` arguments
+            def make_encoded_write(write):
+                def encoded_write(s):
+                    return write(s.encode() if isinstance(s, str) else s)
+                return encoded_write
+
+            self.gitStream.write = make_encoded_write(self.gitStream.write)
+
     def closeStreams(self):
         if self.gitStream is None:
             return
@@ -4160,7 +4332,6 @@ def printUsage(commands):
     "unshelve" : P4Unshelve,
 }
 
-
 def main():
     if len(sys.argv[1:]) == 0:
         printUsage(commands.keys())
diff --git a/git-submodule.sh b/git-submodule.sh
index 89f915c..08e0439 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -48,6 +48,8 @@
 progress=
 dissociate=
 single_branch=
+jobs=
+recommend_shallow=
 
 die_if_unmatched ()
 {
diff --git a/git.c b/git.c
index 7be7ad3..2e4efb4 100644
--- a/git.c
+++ b/git.c
@@ -351,6 +351,7 @@ static int handle_alias(int *argcp, const char ***argv)
 
 			trace2_cmd_alias(alias_command, child.args.argv);
 			trace2_cmd_list_config();
+			trace2_cmd_list_env_vars();
 			trace2_cmd_name("_run_shell_alias_");
 
 			ret = run_command(&child);
@@ -388,6 +389,7 @@ static int handle_alias(int *argcp, const char ***argv)
 
 		trace2_cmd_alias(alias_command, new_argv);
 		trace2_cmd_list_config();
+		trace2_cmd_list_env_vars();
 
 		*argv = new_argv;
 		*argcp += count - 1;
@@ -439,6 +441,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 	trace_argv_printf(argv, "trace: built-in: git");
 	trace2_cmd_name(p->cmd);
 	trace2_cmd_list_config();
+	trace2_cmd_list_env_vars();
 
 	validate_cache_entries(the_repository->index);
 	status = p->fn(argc, argv, prefix);
@@ -574,12 +577,7 @@ static struct cmd_struct commands[] = {
 	{ "show-ref", cmd_show_ref, RUN_SETUP },
 	{ "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
 	{ "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
-	/*
-	 * NEEDSWORK: Until the builtin stash is thoroughly robust and no
-	 * longer needs redirection to the stash shell script this is kept as
-	 * is, then should be changed to RUN_SETUP | NEED_WORK_TREE
-	 */
-	{ "stash", cmd_stash },
+	{ "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 	{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 	{ "stripspace", cmd_stripspace },
 	{ "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 65a3a9e..1a02a12 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -1291,9 +1291,23 @@
 our ($pre_dispatch_hook, $post_dispatch_hook, $pre_listen_hook);
 our $CGI = 'CGI';
 our $cgi;
+our $FCGI_Stream_PRINT_raw = \&FCGI::Stream::PRINT;
 sub configure_as_fcgi {
 	require CGI::Fast;
 	our $CGI = 'CGI::Fast';
+	# FCGI is not Unicode aware hence the UTF-8 encoding must be done manually.
+	# However no encoding must be done within git_blob_plain() and git_snapshot()
+	# which must still output in raw binary mode.
+	no warnings 'redefine';
+	my $enc = Encode::find_encoding('UTF-8');
+	*FCGI::Stream::PRINT = sub {
+		my @OUTPUT = @_;
+		for (my $i = 1; $i < @_; $i++) {
+			$OUTPUT[$i] = $enc->encode($_[$i], Encode::FB_CROAK|Encode::LEAVE_SRC);
+		}
+		@_ = @OUTPUT;
+		goto $FCGI_Stream_PRINT_raw;
+	};
 
 	my $request_number = 0;
 	# let each child service 100 requests
@@ -7079,6 +7093,7 @@
 			($sandbox ? 'attachment' : 'inline')
 			. '; filename="' . $save_as . '"');
 	local $/ = undef;
+	local *FCGI::Stream::PRINT = $FCGI_Stream_PRINT_raw;
 	binmode STDOUT, ':raw';
 	print <$fd>;
 	binmode STDOUT, ':utf8'; # as set at the beginning of gitweb.cgi
@@ -7417,6 +7432,7 @@
 
 	open my $fd, "-|", $cmd
 		or die_error(500, "Execute git-archive failed");
+	local *FCGI::Stream::PRINT = $FCGI_Stream_PRINT_raw;
 	binmode STDOUT, ':raw';
 	print <$fd>;
 	binmode STDOUT, ':utf8'; # as set at the beginning of gitweb.cgi
diff --git a/gpg-interface.c b/gpg-interface.c
index 165274d..2d538bc 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -256,6 +256,55 @@ static void parse_gpg_output(struct signature_check *sigc)
 	FREE_AND_NULL(sigc->key);
 }
 
+static int verify_signed_buffer(const char *payload, size_t payload_size,
+				const char *signature, size_t signature_size,
+				struct strbuf *gpg_output,
+				struct strbuf *gpg_status)
+{
+	struct child_process gpg = CHILD_PROCESS_INIT;
+	struct gpg_format *fmt;
+	struct tempfile *temp;
+	int ret;
+	struct strbuf buf = STRBUF_INIT;
+
+	temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
+	if (!temp)
+		return error_errno(_("could not create temporary file"));
+	if (write_in_full(temp->fd, signature, signature_size) < 0 ||
+	    close_tempfile_gently(temp) < 0) {
+		error_errno(_("failed writing detached signature to '%s'"),
+			    temp->filename.buf);
+		delete_tempfile(&temp);
+		return -1;
+	}
+
+	fmt = get_format_by_sig(signature);
+	if (!fmt)
+		BUG("bad signature '%s'", signature);
+
+	argv_array_push(&gpg.args, fmt->program);
+	argv_array_pushv(&gpg.args, fmt->verify_args);
+	argv_array_pushl(&gpg.args,
+			 "--status-fd=1",
+			 "--verify", temp->filename.buf, "-",
+			 NULL);
+
+	if (!gpg_status)
+		gpg_status = &buf;
+
+	sigchain_push(SIGPIPE, SIG_IGN);
+	ret = pipe_command(&gpg, payload, payload_size,
+			   gpg_status, 0, gpg_output, 0);
+	sigchain_pop(SIGPIPE);
+
+	delete_tempfile(&temp);
+
+	ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
+	strbuf_release(&buf); /* no matter it was used or not */
+
+	return ret;
+}
+
 int check_signature(const char *payload, size_t plen, const char *signature,
 	size_t slen, struct signature_check *sigc)
 {
@@ -418,51 +467,3 @@ int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *sig
 
 	return 0;
 }
-
-int verify_signed_buffer(const char *payload, size_t payload_size,
-			 const char *signature, size_t signature_size,
-			 struct strbuf *gpg_output, struct strbuf *gpg_status)
-{
-	struct child_process gpg = CHILD_PROCESS_INIT;
-	struct gpg_format *fmt;
-	struct tempfile *temp;
-	int ret;
-	struct strbuf buf = STRBUF_INIT;
-
-	temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
-	if (!temp)
-		return error_errno(_("could not create temporary file"));
-	if (write_in_full(temp->fd, signature, signature_size) < 0 ||
-	    close_tempfile_gently(temp) < 0) {
-		error_errno(_("failed writing detached signature to '%s'"),
-			    temp->filename.buf);
-		delete_tempfile(&temp);
-		return -1;
-	}
-
-	fmt = get_format_by_sig(signature);
-	if (!fmt)
-		BUG("bad signature '%s'", signature);
-
-	argv_array_push(&gpg.args, fmt->program);
-	argv_array_pushv(&gpg.args, fmt->verify_args);
-	argv_array_pushl(&gpg.args,
-			 "--status-fd=1",
-			 "--verify", temp->filename.buf, "-",
-			 NULL);
-
-	if (!gpg_status)
-		gpg_status = &buf;
-
-	sigchain_push(SIGPIPE, SIG_IGN);
-	ret = pipe_command(&gpg, payload, payload_size,
-			   gpg_status, 0, gpg_output, 0);
-	sigchain_pop(SIGPIPE);
-
-	delete_tempfile(&temp);
-
-	ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
-	strbuf_release(&buf); /* no matter it was used or not */
-
-	return ret;
-}
diff --git a/gpg-interface.h b/gpg-interface.h
index 796571e..f4e9b4f 100644
--- a/gpg-interface.h
+++ b/gpg-interface.h
@@ -54,15 +54,6 @@ size_t parse_signature(const char *buf, size_t size);
 int sign_buffer(struct strbuf *buffer, struct strbuf *signature,
 		const char *signing_key);
 
-/*
- * Run "gpg" to see if the payload matches the detached signature.
- * gpg_output, when set, receives the diagnostic output from GPG.
- * gpg_status, when set, receives the status output from GPG.
- */
-int verify_signed_buffer(const char *payload, size_t payload_size,
-			 const char *signature, size_t signature_size,
-			 struct strbuf *gpg_output, struct strbuf *gpg_status);
-
 int git_gpg_config(const char *, const char *, void *);
 void set_signing_key(const char *);
 const char *get_signing_key(void);
diff --git a/hash.h b/hash.h
index 52a4f1a..e0f3f16 100644
--- a/hash.h
+++ b/hash.h
@@ -16,6 +16,7 @@
 #endif
 
 #if defined(SHA256_GCRYPT)
+#define SHA256_NEEDS_CLONE_HELPER
 #include "sha256/gcrypt.h"
 #elif defined(SHA256_OPENSSL)
 #include <openssl/sha.h>
@@ -54,12 +55,28 @@
 #define git_SHA256_Update	platform_SHA256_Update
 #define git_SHA256_Final	platform_SHA256_Final
 
+#ifdef platform_SHA256_Clone
+#define git_SHA256_Clone	platform_SHA256_Clone
+#endif
+
 #ifdef SHA1_MAX_BLOCK_SIZE
 #include "compat/sha1-chunked.h"
 #undef git_SHA1_Update
 #define git_SHA1_Update		git_SHA1_Update_Chunked
 #endif
 
+static inline void git_SHA1_Clone(git_SHA_CTX *dst, const git_SHA_CTX *src)
+{
+	memcpy(dst, src, sizeof(*dst));
+}
+
+#ifndef SHA256_NEEDS_CLONE_HELPER
+static inline void git_SHA256_Clone(git_SHA256_CTX *dst, const git_SHA256_CTX *src)
+{
+	memcpy(dst, src, sizeof(*dst));
+}
+#endif
+
 /*
  * Note that these constants are suitable for indexing the hash_algos array and
  * comparing against each other, but are otherwise arbitrary, so they should not
@@ -85,6 +102,7 @@ union git_hash_ctx {
 typedef union git_hash_ctx git_hash_ctx;
 
 typedef void (*git_hash_init_fn)(git_hash_ctx *ctx);
+typedef void (*git_hash_clone_fn)(git_hash_ctx *dst, const git_hash_ctx *src);
 typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len);
 typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx);
 
@@ -110,6 +128,9 @@ struct git_hash_algo {
 	/* The hash initialization function. */
 	git_hash_init_fn init_fn;
 
+	/* The hash context cloning function. */
+	git_hash_clone_fn clone_fn;
+
 	/* The hash update function. */
 	git_hash_update_fn update_fn;
 
diff --git a/hex.c b/hex.c
index fd7f00c..da51e64 100644
--- a/hex.c
+++ b/hex.c
@@ -47,30 +47,71 @@ int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
 	return 0;
 }
 
-int get_sha1_hex(const char *hex, unsigned char *sha1)
+static int get_hash_hex_algop(const char *hex, unsigned char *hash,
+			      const struct git_hash_algo *algop)
 {
 	int i;
-	for (i = 0; i < the_hash_algo->rawsz; i++) {
+	for (i = 0; i < algop->rawsz; i++) {
 		int val = hex2chr(hex);
 		if (val < 0)
 			return -1;
-		*sha1++ = val;
+		*hash++ = val;
 		hex += 2;
 	}
 	return 0;
 }
 
+int get_sha1_hex(const char *hex, unsigned char *sha1)
+{
+	return get_hash_hex_algop(hex, sha1, the_hash_algo);
+}
+
+int get_oid_hex_algop(const char *hex, struct object_id *oid,
+		      const struct git_hash_algo *algop)
+{
+	return get_hash_hex_algop(hex, oid->hash, algop);
+}
+
+/*
+ * NOTE: This function relies on hash algorithms being in order from shortest
+ * length to longest length.
+ */
+int get_oid_hex_any(const char *hex, struct object_id *oid)
+{
+	int i;
+	for (i = GIT_HASH_NALGOS - 1; i > 0; i--) {
+		if (!get_hash_hex_algop(hex, oid->hash, &hash_algos[i]))
+			return i;
+	}
+	return GIT_HASH_UNKNOWN;
+}
+
 int get_oid_hex(const char *hex, struct object_id *oid)
 {
-	return get_sha1_hex(hex, oid->hash);
+	return get_oid_hex_algop(hex, oid, the_hash_algo);
+}
+
+int parse_oid_hex_algop(const char *hex, struct object_id *oid,
+			const char **end,
+			const struct git_hash_algo *algop)
+{
+	int ret = get_hash_hex_algop(hex, oid->hash, algop);
+	if (!ret)
+		*end = hex + algop->hexsz;
+	return ret;
+}
+
+int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end)
+{
+	int ret = get_oid_hex_any(hex, oid);
+	if (ret)
+		*end = hex + hash_algos[ret].hexsz;
+	return ret;
 }
 
 int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
 {
-	int ret = get_oid_hex(hex, oid);
-	if (!ret)
-		*end = hex + the_hash_algo->hexsz;
-	return ret;
+	return parse_oid_hex_algop(hex, oid, end, the_hash_algo);
 }
 
 char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
diff --git a/http.c b/http.c
index 00a0e50..62aa995 100644
--- a/http.c
+++ b/http.c
@@ -86,6 +86,13 @@ static long curl_low_speed_time = -1;
 static int curl_ftp_no_epsv;
 static const char *curl_http_proxy;
 static const char *http_proxy_authmethod;
+
+static const char *http_proxy_ssl_cert;
+static const char *http_proxy_ssl_key;
+static const char *http_proxy_ssl_ca_info;
+static struct credential proxy_cert_auth = CREDENTIAL_INIT;
+static int proxy_ssl_cert_password_required;
+
 static struct {
 	const char *name;
 	long curlauth_param;
@@ -365,6 +372,20 @@ static int http_options(const char *var, const char *value, void *cb)
 	if (!strcmp("http.proxyauthmethod", var))
 		return git_config_string(&http_proxy_authmethod, var, value);
 
+	if (!strcmp("http.proxysslcert", var))
+		return git_config_string(&http_proxy_ssl_cert, var, value);
+
+	if (!strcmp("http.proxysslkey", var))
+		return git_config_string(&http_proxy_ssl_key, var, value);
+
+	if (!strcmp("http.proxysslcainfo", var))
+		return git_config_string(&http_proxy_ssl_ca_info, var, value);
+
+	if (!strcmp("http.proxysslcertpasswordprotected", var)) {
+		proxy_ssl_cert_password_required = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp("http.cookiefile", var))
 		return git_config_pathname(&curl_cookie_file, var, value);
 	if (!strcmp("http.savecookies", var)) {
@@ -558,6 +579,7 @@ static int has_cert_password(void)
 		return 0;
 	if (!cert_auth.password) {
 		cert_auth.protocol = xstrdup("cert");
+		cert_auth.host = xstrdup("");
 		cert_auth.username = xstrdup("");
 		cert_auth.path = xstrdup(ssl_cert);
 		credential_fill(&cert_auth);
@@ -565,6 +587,22 @@ static int has_cert_password(void)
 	return 1;
 }
 
+#if LIBCURL_VERSION_NUM >= 0x073400
+static int has_proxy_cert_password(void)
+{
+	if (http_proxy_ssl_cert == NULL || proxy_ssl_cert_password_required != 1)
+		return 0;
+	if (!proxy_cert_auth.password) {
+		proxy_cert_auth.protocol = xstrdup("cert");
+		proxy_cert_auth.host = xstrdup("");
+		proxy_cert_auth.username = xstrdup("");
+		proxy_cert_auth.path = xstrdup(http_proxy_ssl_cert);
+		credential_fill(&proxy_cert_auth);
+	}
+	return 1;
+}
+#endif
+
 #if LIBCURL_VERSION_NUM >= 0x071900
 static void set_curl_keepalive(CURL *c)
 {
@@ -924,8 +962,14 @@ static CURL *get_curl_handle(void)
 #if LIBCURL_VERSION_NUM >= 0x073400
 		curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, NULL);
 #endif
-	} else if (ssl_cainfo != NULL)
-		curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+	} else if (ssl_cainfo != NULL || http_proxy_ssl_ca_info != NULL) {
+		if (ssl_cainfo != NULL)
+			curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+#if LIBCURL_VERSION_NUM >= 0x073400
+		if (http_proxy_ssl_ca_info != NULL)
+			curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, http_proxy_ssl_ca_info);
+#endif
+	}
 
 	if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 		curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
@@ -1018,9 +1062,18 @@ static CURL *get_curl_handle(void)
 				CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 #endif
 #if LIBCURL_VERSION_NUM >= 0x073400
-		else if (starts_with(curl_http_proxy, "https"))
-			curl_easy_setopt(result,
-				CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
+		else if (starts_with(curl_http_proxy, "https")) {
+			curl_easy_setopt(result, CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
+
+			if (http_proxy_ssl_cert)
+				curl_easy_setopt(result, CURLOPT_PROXY_SSLCERT, http_proxy_ssl_cert);
+
+			if (http_proxy_ssl_key)
+				curl_easy_setopt(result, CURLOPT_PROXY_SSLKEY, http_proxy_ssl_key);
+
+			if (has_proxy_cert_password())
+				curl_easy_setopt(result, CURLOPT_PROXY_KEYPASSWD, proxy_cert_auth.password);
+		}
 #endif
 		if (strstr(curl_http_proxy, "://"))
 			credential_from_url(&proxy_auth, curl_http_proxy);
@@ -1160,6 +1213,13 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 		max_requests = DEFAULT_MAX_REQUESTS;
 #endif
 
+	set_from_env(&http_proxy_ssl_cert, "GIT_PROXY_SSL_CERT");
+	set_from_env(&http_proxy_ssl_key, "GIT_PROXY_SSL_KEY");
+	set_from_env(&http_proxy_ssl_ca_info, "GIT_PROXY_SSL_CAINFO");
+
+	if (getenv("GIT_PROXY_SSL_CERT_PASSWORD_PROTECTED"))
+		proxy_ssl_cert_password_required = 1;
+
 	if (getenv("GIT_CURL_FTP_NO_EPSV"))
 		curl_ftp_no_epsv = 1;
 
@@ -1230,6 +1290,12 @@ void http_cleanup(void)
 	}
 	ssl_cert_password_required = 0;
 
+	if (proxy_cert_auth.password != NULL) {
+		memset(proxy_cert_auth.password, 0, strlen(proxy_cert_auth.password));
+		FREE_AND_NULL(proxy_cert_auth.password);
+	}
+	proxy_ssl_cert_password_required = 0;
+
 	FREE_AND_NULL(cached_accept_language);
 }
 
diff --git a/line-log.c b/line-log.c
index 9010e00..40e1738 100644
--- a/line-log.c
+++ b/line-log.c
@@ -519,7 +519,7 @@ static void fill_line_ends(struct repository *r,
 	unsigned long *ends = NULL;
 	char *data = NULL;
 
-	if (diff_populate_filespec(r, spec, 0))
+	if (diff_populate_filespec(r, spec, NULL))
 		die("Cannot read blob %s", oid_to_hex(&spec->oid));
 
 	ALLOC_ARRAY(ends, size);
@@ -1045,12 +1045,12 @@ static int process_diff_filepair(struct rev_info *rev,
 		return 0;
 
 	assert(pair->two->oid_valid);
-	diff_populate_filespec(rev->diffopt.repo, pair->two, 0);
+	diff_populate_filespec(rev->diffopt.repo, pair->two, NULL);
 	file_target.ptr = pair->two->data;
 	file_target.size = pair->two->size;
 
 	if (pair->one->oid_valid) {
-		diff_populate_filespec(rev->diffopt.repo, pair->one, 0);
+		diff_populate_filespec(rev->diffopt.repo, pair->one, NULL);
 		file_parent.ptr = pair->one->data;
 		file_parent.size = pair->one->size;
 	} else {
diff --git a/ll-merge.c b/ll-merge.c
index d65a897..1ec0b95 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -247,7 +247,7 @@ static int read_merge_config(const char *var, const char *value, void *cb)
 {
 	struct ll_merge_driver *fn;
 	const char *key, *name;
-	int namelen;
+	size_t namelen;
 
 	if (!strcmp(var, "merge.default"))
 		return git_config_string(&default_ll_merge, var, value);
diff --git a/log-tree.c b/log-tree.c
index 5212742..55a68d0 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -81,6 +81,56 @@ const struct name_decoration *get_name_decoration(const struct object *obj)
 	return lookup_decoration(&name_decoration, obj);
 }
 
+static int match_ref_pattern(const char *refname,
+			     const struct string_list_item *item)
+{
+	int matched = 0;
+	if (item->util == NULL) {
+		if (!wildmatch(item->string, refname, 0))
+			matched = 1;
+	} else {
+		const char *rest;
+		if (skip_prefix(refname, item->string, &rest) &&
+		    (!*rest || *rest == '/'))
+			matched = 1;
+	}
+	return matched;
+}
+
+static int ref_filter_match(const char *refname,
+			    const struct decoration_filter *filter)
+{
+	struct string_list_item *item;
+	const struct string_list *exclude_patterns = filter->exclude_ref_pattern;
+	const struct string_list *include_patterns = filter->include_ref_pattern;
+	const struct string_list *exclude_patterns_config =
+				filter->exclude_ref_config_pattern;
+
+	if (exclude_patterns && exclude_patterns->nr) {
+		for_each_string_list_item(item, exclude_patterns) {
+			if (match_ref_pattern(refname, item))
+				return 0;
+		}
+	}
+
+	if (include_patterns && include_patterns->nr) {
+		for_each_string_list_item(item, include_patterns) {
+			if (match_ref_pattern(refname, item))
+				return 1;
+		}
+		return 0;
+	}
+
+	if (exclude_patterns_config && exclude_patterns_config->nr) {
+		for_each_string_list_item(item, exclude_patterns_config) {
+			if (match_ref_pattern(refname, item))
+				return 0;
+		}
+	}
+
+	return 1;
+}
+
 static int add_ref_decoration(const char *refname, const struct object_id *oid,
 			      int flags, void *cb_data)
 {
@@ -88,9 +138,7 @@ static int add_ref_decoration(const char *refname, const struct object_id *oid,
 	enum decoration_type type = DECORATION_NONE;
 	struct decoration_filter *filter = (struct decoration_filter *)cb_data;
 
-	if (filter && !ref_filter_match(refname,
-			      filter->include_ref_pattern,
-			      filter->exclude_ref_pattern))
+	if (filter && !ref_filter_match(refname, filter))
 		return 0;
 
 	if (starts_with(refname, git_replace_ref_base)) {
@@ -155,6 +203,9 @@ void load_ref_decorations(struct decoration_filter *filter, int flags)
 			for_each_string_list_item(item, filter->include_ref_pattern) {
 				normalize_glob_ref(item, NULL, item->string);
 			}
+			for_each_string_list_item(item, filter->exclude_ref_config_pattern) {
+				normalize_glob_ref(item, NULL, item->string);
+			}
 		}
 		decoration_loaded = 1;
 		decoration_flags = flags;
@@ -449,22 +500,21 @@ static void show_signature(struct rev_info *opt, struct commit *commit)
 {
 	struct strbuf payload = STRBUF_INIT;
 	struct strbuf signature = STRBUF_INIT;
-	struct strbuf gpg_output = STRBUF_INIT;
+	struct signature_check sigc = { 0 };
 	int status;
 
 	if (parse_signed_commit(commit, &payload, &signature) <= 0)
 		goto out;
 
-	status = verify_signed_buffer(payload.buf, payload.len,
-				      signature.buf, signature.len,
-				      &gpg_output, NULL);
-	if (status && !gpg_output.len)
-		strbuf_addstr(&gpg_output, "No signature\n");
-
-	show_sig_lines(opt, status, gpg_output.buf);
+	status = check_signature(payload.buf, payload.len, signature.buf,
+				 signature.len, &sigc);
+	if (status && !sigc.gpg_output)
+		show_sig_lines(opt, status, "No signature\n");
+	else
+		show_sig_lines(opt, status, sigc.gpg_output);
+	signature_check_clear(&sigc);
 
  out:
-	strbuf_release(&gpg_output);
 	strbuf_release(&payload);
 	strbuf_release(&signature);
 }
@@ -497,8 +547,9 @@ static int show_one_mergetag(struct commit *commit,
 	struct object_id oid;
 	struct tag *tag;
 	struct strbuf verify_message;
+	struct signature_check sigc = { 0 };
 	int status, nth;
-	size_t payload_size, gpg_message_offset;
+	size_t payload_size;
 
 	hash_object_file(the_hash_algo, extra->value, extra->len,
 			 type_name(OBJ_TAG), &oid);
@@ -520,19 +571,19 @@ static int show_one_mergetag(struct commit *commit,
 	else
 		strbuf_addf(&verify_message,
 			    "parent #%d, tagged '%s'\n", nth + 1, tag->tag);
-	gpg_message_offset = verify_message.len;
 
 	payload_size = parse_signature(extra->value, extra->len);
 	status = -1;
 	if (extra->len > payload_size) {
 		/* could have a good signature */
-		if (!verify_signed_buffer(extra->value, payload_size,
-					  extra->value + payload_size,
-					  extra->len - payload_size,
-					  &verify_message, NULL))
-			status = 0; /* good */
-		else if (verify_message.len <= gpg_message_offset)
+		status = check_signature(extra->value, payload_size,
+					 extra->value + payload_size,
+					 extra->len - payload_size, &sigc);
+		if (sigc.gpg_output)
+			strbuf_addstr(&verify_message, sigc.gpg_output);
+		else
 			strbuf_addstr(&verify_message, "No signature\n");
+		signature_check_clear(&sigc);
 		/* otherwise we couldn't verify, which is shown as bad */
 	}
 
@@ -693,6 +744,7 @@ void show_log(struct rev_info *opt)
 	ctx.abbrev = opt->diffopt.abbrev;
 	ctx.after_subject = extra_headers;
 	ctx.preserve_subject = opt->preserve_subject;
+	ctx.encode_email_headers = opt->encode_email_headers;
 	ctx.reflog_info = opt->reflog_info;
 	ctx.fmt = opt->commit_format;
 	ctx.mailmap = opt->mailmap;
diff --git a/log-tree.h b/log-tree.h
index e668628..8fa7928 100644
--- a/log-tree.h
+++ b/log-tree.h
@@ -8,7 +8,9 @@ struct log_info {
 };
 
 struct decoration_filter {
-	struct string_list *include_ref_pattern, *exclude_ref_pattern;
+	struct string_list *include_ref_pattern;
+	struct string_list *exclude_ref_pattern;
+	struct string_list *exclude_ref_config_pattern;
 };
 
 int parse_decorate_color_config(const char *var, const char *slot_name, const char *value);
diff --git a/ls-refs.c b/ls-refs.c
index 818aef7..50d8686 100644
--- a/ls-refs.c
+++ b/ls-refs.c
@@ -93,7 +93,7 @@ int ls_refs(struct repository *r, struct argv_array *keys,
 
 	git_config(ls_refs_config, NULL);
 
-	while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+	while (packet_reader_read(request) == PACKET_READ_NORMAL) {
 		const char *arg = request->line;
 		const char *out;
 
@@ -105,6 +105,9 @@ int ls_refs(struct repository *r, struct argv_array *keys,
 			argv_array_push(&data.prefixes, out);
 	}
 
+	if (request->status != PACKET_READ_FLUSH)
+		die(_("expected flush after ls-refs arguments"));
+
 	head_ref_namespaced(send_ref, &data);
 	for_each_namespaced_ref(send_ref, &data);
 	packet_flush(1);
diff --git a/mailinfo.c b/mailinfo.c
index 742fa37..5681d91 100644
--- a/mailinfo.c
+++ b/mailinfo.c
@@ -447,19 +447,21 @@ static int convert_to_utf8(struct mailinfo *mi,
 			   struct strbuf *line, const char *charset)
 {
 	char *out;
+	size_t out_len;
 
 	if (!mi->metainfo_charset || !charset || !*charset)
 		return 0;
 
 	if (same_encoding(mi->metainfo_charset, charset))
 		return 0;
-	out = reencode_string(line->buf, mi->metainfo_charset, charset);
+	out = reencode_string_len(line->buf, line->len,
+				  mi->metainfo_charset, charset, &out_len);
 	if (!out) {
 		mi->input_error = -1;
 		return error("cannot convert from %s to %s",
 			     charset, mi->metainfo_charset);
 	}
-	strbuf_attach(line, out, strlen(out), strlen(out));
+	strbuf_attach(line, out, out_len, out_len);
 	return 0;
 }
 
@@ -1136,6 +1138,11 @@ static void handle_info(struct mailinfo *mi)
 		else
 			continue;
 
+		if (memchr(hdr->buf, '\0', hdr->len)) {
+			error("a NUL byte in '%s' is not allowed.", header[i]);
+			mi->input_error = -1;
+		}
+
 		if (!strcmp(header[i], "Subject")) {
 			if (!mi->keep_subject) {
 				cleanup_subject(mi, hdr);
diff --git a/merge-recursive.c b/merge-recursive.c
index 7a4e6f2..d92e2ac 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -958,7 +958,7 @@ static int update_file_flags(struct merge_options *opt,
 		if (S_ISREG(contents->mode)) {
 			struct strbuf strbuf = STRBUF_INIT;
 			if (convert_to_working_tree(opt->repo->index,
-						    path, buf, size, &strbuf)) {
+						    path, buf, size, &strbuf, NULL)) {
 				free(buf);
 				size = strbuf.len;
 				buf = strbuf_detach(&strbuf, NULL);
diff --git a/merge.c b/merge.c
index 7c1d756..aa36de2 100644
--- a/merge.c
+++ b/merge.c
@@ -94,6 +94,7 @@ int checkout_fast_forward(struct repository *r,
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
+	init_checkout_metadata(&opts.meta, NULL, remote, NULL);
 	setup_unpack_trees_porcelain(&opts, "merge");
 
 	if (unpack_trees(nr_trees, t, &opts)) {
diff --git a/midx.c b/midx.c
index 1527e46..a520e26 100644
--- a/midx.c
+++ b/midx.c
@@ -923,6 +923,12 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index *
 	cur_chunk = 0;
 	num_chunks = large_offsets_needed ? 5 : 4;
 
+	if (packs.nr - dropped_packs == 0) {
+		error(_("no pack files to index."));
+		result = 1;
+		goto cleanup;
+	}
+
 	written = write_midx_header(f, num_chunks, packs.nr - dropped_packs);
 
 	chunk_ids[cur_chunk] = MIDX_CHUNKID_PACKNAMES;
@@ -1124,6 +1130,15 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag
 				    i, oid_fanout1, oid_fanout2, i + 1);
 	}
 
+	if (m->num_objects == 0) {
+		midx_report(_("the midx contains no oid"));
+		/*
+		 * Remaining tests assume that we have objects, so we can
+		 * return here.
+		 */
+		return verify_midx_error;
+	}
+
 	if (flags & MIDX_PROGRESS)
 		progress = start_sparse_progress(_("Verifying OID order in multi-pack-index"),
 						 m->num_objects - 1);
diff --git a/object-store.h b/object-store.h
index be72fee..d1e490f 100644
--- a/object-store.h
+++ b/object-store.h
@@ -4,7 +4,7 @@
 #include "cache.h"
 #include "oidmap.h"
 #include "list.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "strbuf.h"
 #include "thread-utils.h"
 
diff --git a/object.h b/object.h
index 2dbabfc..b22328b 100644
--- a/object.h
+++ b/object.h
@@ -59,7 +59,7 @@ struct object_array {
 
 /*
  * object flag allocation:
- * revision.h:               0---------10                              25----28
+ * revision.h:               0---------10         15                   25----28
  * fetch-pack.c:             01
  * negotiator/default.c:       2--5
  * walker.c:                 0-2
diff --git a/sha1-array.c b/oid-array.c
similarity index 93%
rename from sha1-array.c
rename to oid-array.c
index 3eeadfe..8657a5c 100644
--- a/sha1-array.c
+++ b/oid-array.c
@@ -1,5 +1,5 @@
 #include "cache.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "sha1-lookup.h"
 
 void oid_array_append(struct oid_array *array, const struct object_id *oid)
@@ -46,9 +46,9 @@ int oid_array_for_each(struct oid_array *array,
 		       for_each_oid_fn fn,
 		       void *data)
 {
-	int i;
+	size_t i;
 
-	/* No oid_array_sort() here! See sha1-array.h */
+	/* No oid_array_sort() here! See oid-array.h */
 
 	for (i = 0; i < array->nr; i++) {
 		int ret = fn(array->oid + i, data);
@@ -62,7 +62,7 @@ int oid_array_for_each_unique(struct oid_array *array,
 			      for_each_oid_fn fn,
 			      void *data)
 {
-	int i;
+	size_t i;
 
 	if (!array->sorted)
 		oid_array_sort(array);
@@ -82,7 +82,7 @@ void oid_array_filter(struct oid_array *array,
 		      for_each_oid_fn want,
 		      void *cb_data)
 {
-	unsigned nr = array->nr, src, dst;
+	size_t nr = array->nr, src, dst;
 	struct object_id *oids = array->oid;
 
 	for (src = dst = 0; src < nr; src++) {
diff --git a/sha1-array.h b/oid-array.h
similarity index 97%
rename from sha1-array.h
rename to oid-array.h
index dc1bca9..f28d322 100644
--- a/sha1-array.h
+++ b/oid-array.h
@@ -19,7 +19,7 @@
  *
  * void some_func(void)
  * {
- *     struct sha1_array hashes = OID_ARRAY_INIT;
+ *     struct oid_array hashes = OID_ARRAY_INIT;
  *     struct object_id oid;
  *
  *     // Read objects into our set
@@ -49,8 +49,8 @@
  */
 struct oid_array {
 	struct object_id *oid;
-	int nr;
-	int alloc;
+	size_t nr;
+	size_t alloc;
 	int sorted;
 };
 
diff --git a/oidset.h b/oidset.h
index 5346563..3a2d9d1 100644
--- a/oidset.h
+++ b/oidset.h
@@ -1,11 +1,10 @@
 #ifndef OIDSET_H
 #define OIDSET_H
 
-#include "hashmap.h"
 #include "khash.h"
 
 /**
- * This API is similar to sha1-array, in that it maintains a set of object ids
+ * This API is similar to oid-array, in that it maintains a set of object ids
  * in a memory-efficient way. The major differences are:
  *
  *   1. It uses a hash, so we can do online duplicate removal, rather than
diff --git a/parse-options-cb.c b/parse-options-cb.c
index a28b55b..86cd393 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -5,7 +5,7 @@
 #include "color.h"
 #include "string-list.h"
 #include "argv-array.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 
 /*----- some often used options -----*/
 
diff --git a/parse-options.c b/parse-options.c
index 63d6bab..c57618d 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -648,6 +648,7 @@ static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
 		int short_name;
 		const char *long_name;
 		const char *source;
+		struct strbuf help = STRBUF_INIT;
 		int j;
 
 		if (newopt[i].type != OPTION_ALIAS)
@@ -659,6 +660,7 @@ static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
 
 		if (!long_name)
 			BUG("An alias must have long option name");
+		strbuf_addf(&help, _("alias of --%s"), source);
 
 		for (j = 0; j < nr; j++) {
 			const char *name = options[j].long_name;
@@ -669,15 +671,10 @@ static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
 			if (options[j].type == OPTION_ALIAS)
 				BUG("No please. Nested aliases are not supported.");
 
-			/*
-			 * NEEDSWORK: this is a bit inconsistent because
-			 * usage_with_options() on the original options[] will print
-			 * help string as "alias of %s" but "git cmd -h" will
-			 * print the original help string.
-			 */
 			memcpy(newopt + i, options + j, sizeof(*newopt));
 			newopt[i].short_name = short_name;
 			newopt[i].long_name = long_name;
+			newopt[i].help = strbuf_detach(&help, NULL);
 			break;
 		}
 
diff --git a/parse-options.h b/parse-options.h
index fece5ba..46af942 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -336,5 +336,6 @@ int parse_opt_passthru_argv(const struct option *, const char *, int);
 #define OPT_CLEANUP(v) OPT_STRING(0, "cleanup", v, N_("mode"), N_("how to strip spaces and #comments from message"))
 #define OPT_PATHSPEC_FROM_FILE(v) OPT_FILENAME(0, "pathspec-from-file", v, N_("read pathspec from file"))
 #define OPT_PATHSPEC_FILE_NUL(v)  OPT_BOOL(0, "pathspec-file-nul", v, N_("with --pathspec-from-file, pathspec elements are separated with NUL character"))
+#define OPT_AUTOSTASH(v) OPT_BOOL(0, "autostash", v, N_("automatically stash/stash pop before and after"))
 
 #endif
diff --git a/path.c b/path.c
index 88cf593..8b2c753 100644
--- a/path.c
+++ b/path.c
@@ -723,7 +723,7 @@ static struct passwd *getpw_str(const char *username, size_t len)
  * then it is a newly allocated string. Returns NULL on getpw failure or
  * if path is NULL.
  *
- * If real_home is true, real_path($HOME) is used in the expansion.
+ * If real_home is true, strbuf_realpath($HOME) is used in the expansion.
  */
 char *expand_user_path(const char *path, int real_home)
 {
@@ -850,8 +850,8 @@ const char *enter_repo(const char *path, int strict)
 	}
 
 	if (is_git_directory(".")) {
-		set_git_dir(".");
-		check_repository_format();
+		set_git_dir(".", 0);
+		check_repository_format(NULL);
 		return path;
 	}
 
@@ -1535,5 +1535,6 @@ REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG")
 REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR")
 REPO_GIT_PATH_FUNC(merge_mode, "MERGE_MODE")
 REPO_GIT_PATH_FUNC(merge_head, "MERGE_HEAD")
+REPO_GIT_PATH_FUNC(merge_autostash, "MERGE_AUTOSTASH")
 REPO_GIT_PATH_FUNC(fetch_head, "FETCH_HEAD")
 REPO_GIT_PATH_FUNC(shallow, "shallow")
diff --git a/path.h b/path.h
index 14d6dca..1f1bf8f 100644
--- a/path.h
+++ b/path.h
@@ -177,11 +177,12 @@ struct path_cache {
 	const char *merge_rr;
 	const char *merge_mode;
 	const char *merge_head;
+	const char *merge_autostash;
 	const char *fetch_head;
 	const char *shallow;
 };
 
-#define PATH_CACHE_INIT { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
+#define PATH_CACHE_INIT { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
 
 const char *git_path_cherry_pick_head(struct repository *r);
 const char *git_path_revert_head(struct repository *r);
@@ -190,6 +191,7 @@ const char *git_path_merge_msg(struct repository *r);
 const char *git_path_merge_rr(struct repository *r);
 const char *git_path_merge_mode(struct repository *r);
 const char *git_path_merge_head(struct repository *r);
+const char *git_path_merge_autostash(struct repository *r);
 const char *git_path_fetch_head(struct repository *r);
 const char *git_path_shallow(struct repository *r);
 
diff --git a/pretty.c b/pretty.c
index 28afc70..2a3d46b 100644
--- a/pretty.c
+++ b/pretty.c
@@ -474,7 +474,8 @@ void pp_user_info(struct pretty_print_context *pp,
 		}
 
 		strbuf_addstr(sb, "From: ");
-		if (needs_rfc2047_encoding(namebuf, namelen)) {
+		if (pp->encode_email_headers &&
+		    needs_rfc2047_encoding(namebuf, namelen)) {
 			add_rfc2047(sb, namebuf, namelen,
 				    encoding, RFC2047_ADDRESS);
 			max_length = 76; /* per rfc2047 */
@@ -1767,7 +1768,8 @@ void pp_title_line(struct pretty_print_context *pp,
 	if (pp->print_email_subject) {
 		if (pp->rev)
 			fmt_output_email_subject(sb, pp->rev);
-		if (needs_rfc2047_encoding(title.buf, title.len))
+		if (pp->encode_email_headers &&
+		    needs_rfc2047_encoding(title.buf, title.len))
 			add_rfc2047(sb, title.buf, title.len,
 						encoding, RFC2047_SUBJECT);
 		else
diff --git a/pretty.h b/pretty.h
index 4ad1fc3..071f2fb 100644
--- a/pretty.h
+++ b/pretty.h
@@ -43,6 +43,7 @@ struct pretty_print_context {
 	struct string_list *mailmap;
 	int color;
 	struct ident_split *from_ident;
+	unsigned encode_email_headers:1;
 
 	/*
 	 * Fields below here are manipulated internally by pp_* functions and
diff --git a/promisor-remote.c b/promisor-remote.c
index 9f338c9..baaea12 100644
--- a/promisor-remote.c
+++ b/promisor-remote.c
@@ -101,7 +101,7 @@ static void promisor_remote_move_to_tail(struct promisor_remote *r,
 static int promisor_remote_config(const char *var, const char *value, void *data)
 {
 	const char *name;
-	int namelen;
+	size_t namelen;
 	const char *subkey;
 
 	if (!strcmp(var, "core.partialclonefilter"))
@@ -241,6 +241,9 @@ int promisor_remote_get_direct(struct repository *repo,
 	int to_free = 0;
 	int res = -1;
 
+	if (oid_nr == 0)
+		return 0;
+
 	promisor_remote_init();
 
 	for (r = promisors; r; r = r->next) {
diff --git a/promisor-remote.h b/promisor-remote.h
index 737bac3..6343c47 100644
--- a/promisor-remote.h
+++ b/promisor-remote.h
@@ -20,6 +20,14 @@ struct promisor_remote {
 void promisor_remote_reinit(void);
 struct promisor_remote *promisor_remote_find(const char *remote_name);
 int has_promisor_remote(void);
+
+/*
+ * Fetches all requested objects from all promisor remotes, trying them one at
+ * a time until all objects are fetched. Returns 0 upon success, and non-zero
+ * otherwise.
+ *
+ * If oid_nr is 0, this function returns 0 (success) immediately.
+ */
 int promisor_remote_get_direct(struct repository *repo,
 			       const struct object_id *oids,
 			       int oid_nr);
diff --git a/prompt.c b/prompt.c
index 6d5885d..5ded21a 100644
--- a/prompt.c
+++ b/prompt.c
@@ -74,3 +74,15 @@ char *git_prompt(const char *prompt, int flags)
 	}
 	return r;
 }
+
+int git_read_line_interactively(struct strbuf *line)
+{
+	int ret;
+
+	fflush(stdout);
+	ret = strbuf_getline_lf(line, stdin);
+	if (ret != EOF)
+		strbuf_trim_trailing_newline(line);
+
+	return ret;
+}
diff --git a/prompt.h b/prompt.h
index e04cced..e294e93 100644
--- a/prompt.h
+++ b/prompt.h
@@ -6,4 +6,6 @@
 
 char *git_prompt(const char *prompt, int flags);
 
+int git_read_line_interactively(struct strbuf *line);
+
 #endif /* PROMPT_H */
diff --git a/protocol.c b/protocol.c
index 803bef5..d390391 100644
--- a/protocol.c
+++ b/protocol.c
@@ -39,7 +39,7 @@ enum protocol_version get_protocol_version_config(void)
 		return env;
 	}
 
-	return protocol_v2;
+	return protocol_v0;
 }
 
 enum protocol_version determine_protocol_version_server(void)
diff --git a/prune-packed.c b/prune-packed.c
new file mode 100644
index 0000000..261520b
--- /dev/null
+++ b/prune-packed.c
@@ -0,0 +1,43 @@
+#include "object-store.h"
+#include "packfile.h"
+#include "progress.h"
+#include "prune-packed.h"
+
+static struct progress *progress;
+
+static int prune_subdir(unsigned int nr, const char *path, void *data)
+{
+	int *opts = data;
+	display_progress(progress, nr + 1);
+	if (!(*opts & PRUNE_PACKED_DRY_RUN))
+		rmdir(path);
+	return 0;
+}
+
+static int prune_object(const struct object_id *oid, const char *path,
+			 void *data)
+{
+	int *opts = data;
+
+	if (!has_object_pack(oid))
+		return 0;
+
+	if (*opts & PRUNE_PACKED_DRY_RUN)
+		printf("rm -f %s\n", path);
+	else
+		unlink_or_warn(path);
+	return 0;
+}
+
+void prune_packed_objects(int opts)
+{
+	if (opts & PRUNE_PACKED_VERBOSE)
+		progress = start_delayed_progress(_("Removing duplicate objects"), 256);
+
+	for_each_loose_file_in_objdir(get_object_directory(),
+				      prune_object, NULL, prune_subdir, &opts);
+
+	/* Ensure we show 100% before finishing progress */
+	display_progress(progress, 256);
+	stop_progress(&progress);
+}
diff --git a/prune-packed.h b/prune-packed.h
new file mode 100644
index 0000000..936fa9d
--- /dev/null
+++ b/prune-packed.h
@@ -0,0 +1,9 @@
+#ifndef PRUNE_PACKED_H
+#define PRUNE_PACKED_H
+
+#define PRUNE_PACKED_DRY_RUN 01
+#define PRUNE_PACKED_VERBOSE 02
+
+void prune_packed_objects(int);
+
+#endif
diff --git a/range-diff.c b/range-diff.c
index f745567..40af086 100644
--- a/range-diff.c
+++ b/range-diff.c
@@ -63,6 +63,8 @@ static int read_patches(const char *range, struct string_list *list,
 			"--output-indicator-old=<",
 			"--output-indicator-context=#",
 			"--no-abbrev-commit",
+			"--pretty=medium",
+			"--notes",
 			NULL);
 	if (other_arg)
 		argv_array_pushv(&cp.args, other_arg->argv);
@@ -106,20 +108,34 @@ static int read_patches(const char *range, struct string_list *list,
 			continue;
 		}
 
+		if (!util) {
+			error(_("could not parse first line of `log` output: "
+				"did not start with 'commit ': '%s'"),
+			      line);
+			string_list_clear(list, 1);
+			strbuf_release(&buf);
+			strbuf_release(&contents);
+			finish_command(&cp);
+			return -1;
+		}
+
 		if (starts_with(line, "diff --git")) {
 			struct patch patch = { 0 };
 			struct strbuf root = STRBUF_INIT;
 			int linenr = 0;
+			int orig_len;
 
 			in_header = 0;
 			strbuf_addch(&buf, '\n');
 			if (!util->diff_offset)
 				util->diff_offset = buf.len;
 			line[len - 1] = '\n';
+			orig_len = len;
 			len = parse_git_diff_header(&root, &linenr, 0, line,
 						    len, size, &patch);
 			if (len < 0)
-				die(_("could not parse git header '%.*s'"), (int)len, line);
+				die(_("could not parse git header '%.*s'"),
+				    orig_len, line);
 			strbuf_addstr(&buf, " ## ");
 			if (patch.is_new > 0)
 				strbuf_addf(&buf, "%s (new)", patch.new_name);
diff --git a/ref-filter.c b/ref-filter.c
index b1812cb..3577683 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1976,10 +1976,9 @@ static int for_each_fullref_in_pattern(struct ref_filter *filter,
 }
 
 /*
- * Given a ref (sha1, refname), check if the ref belongs to the array
- * of sha1s. If the given ref is a tag, check if the given tag points
- * at one of the sha1s in the given sha1 array.
- * the given sha1_array.
+ * Given a ref (oid, refname), check if the ref belongs to the array
+ * of oids. If the given ref is a tag, check if the given tag points
+ * at one of the oids in the given oid array.
  * NEEDSWORK:
  * 1. Only a single level of inderection is obtained, we might want to
  * change this to account for multiple levels (e.g. annotated tags
diff --git a/ref-filter.h b/ref-filter.h
index f1dcff4..64330e9 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -1,7 +1,7 @@
 #ifndef REF_FILTER_H
 #define REF_FILTER_H
 
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "refs.h"
 #include "commit.h"
 #include "parse-options.h"
diff --git a/refs.c b/refs.c
index 1ab0bb5..224ff66 100644
--- a/refs.c
+++ b/refs.c
@@ -321,50 +321,6 @@ int ref_exists(const char *refname)
 	return refs_ref_exists(get_main_ref_store(the_repository), refname);
 }
 
-static int match_ref_pattern(const char *refname,
-			     const struct string_list_item *item)
-{
-	int matched = 0;
-	if (item->util == NULL) {
-		if (!wildmatch(item->string, refname, 0))
-			matched = 1;
-	} else {
-		const char *rest;
-		if (skip_prefix(refname, item->string, &rest) &&
-		    (!*rest || *rest == '/'))
-			matched = 1;
-	}
-	return matched;
-}
-
-int ref_filter_match(const char *refname,
-		     const struct string_list *include_patterns,
-		     const struct string_list *exclude_patterns)
-{
-	struct string_list_item *item;
-
-	if (exclude_patterns && exclude_patterns->nr) {
-		for_each_string_list_item(item, exclude_patterns) {
-			if (match_ref_pattern(refname, item))
-				return 0;
-		}
-	}
-
-	if (include_patterns && include_patterns->nr) {
-		int found = 0;
-		for_each_string_list_item(item, include_patterns) {
-			if (match_ref_pattern(refname, item)) {
-				found = 1;
-				break;
-			}
-		}
-
-		if (!found)
-			return 0;
-	}
-	return 1;
-}
-
 static int filter_refs(const char *refname, const struct object_id *oid,
 			   int flags, void *data)
 {
@@ -1852,14 +1808,14 @@ static struct ref_store *ref_store_init(const char *gitdir,
 
 struct ref_store *get_main_ref_store(struct repository *r)
 {
-	if (r->refs)
-		return r->refs;
+	if (r->refs_private)
+		return r->refs_private;
 
 	if (!r->gitdir)
 		BUG("attempting to get main_ref_store outside of repository");
 
-	r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
-	return r->refs;
+	r->refs_private = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
+	return r->refs_private;
 }
 
 /*
diff --git a/refs.h b/refs.h
index 545029c..a92d2c7 100644
--- a/refs.h
+++ b/refs.h
@@ -361,18 +361,6 @@ int for_each_rawref(each_ref_fn fn, void *cb_data);
 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
 			const char *pattern);
 
-/*
- * Returns 0 if refname matches any of the exclude_patterns, or if it doesn't
- * match any of the include_patterns. Returns 1 otherwise.
- *
- * If pattern list is NULL or empty, matching against that list is skipped.
- * This has the effect of matching everything by default, unless the user
- * specifies rules otherwise.
- */
-int ref_filter_match(const char *refname,
-		     const struct string_list *include_patterns,
-		     const struct string_list *exclude_patterns);
-
 static inline const char *has_glob_specials(const char *pattern)
 {
 	return strpbrk(pattern, "?*[");
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 561c33a..6516c7b 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2565,17 +2565,19 @@ static void files_transaction_cleanup(struct files_ref_store *refs,
 		}
 	}
 
-	if (backend_data->packed_transaction &&
-	    ref_transaction_abort(backend_data->packed_transaction, &err)) {
-		error("error aborting transaction: %s", err.buf);
-		strbuf_release(&err);
+	if (backend_data) {
+		if (backend_data->packed_transaction &&
+		    ref_transaction_abort(backend_data->packed_transaction, &err)) {
+			error("error aborting transaction: %s", err.buf);
+			strbuf_release(&err);
+		}
+
+		if (backend_data->packed_refs_locked)
+			packed_refs_unlock(refs->packed_ref_store);
+
+		free(backend_data);
 	}
 
-	if (backend_data->packed_refs_locked)
-		packed_refs_unlock(refs->packed_ref_store);
-
-	free(backend_data);
-
 	transaction->state = REF_TRANSACTION_CLOSED;
 }
 
diff --git a/remote-curl.c b/remote-curl.c
index e4cd321..1c9aa3d 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -12,7 +12,7 @@
 #include "sideband.h"
 #include "argv-array.h"
 #include "credential.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "send-pack.h"
 #include "protocol.h"
 #include "quote.h"
diff --git a/remote.c b/remote.c
index c43196e..534c642 100644
--- a/remote.c
+++ b/remote.c
@@ -174,54 +174,43 @@ static void add_merge(struct branch *branch, const char *name)
 	branch->merge_name[branch->merge_nr++] = name;
 }
 
-static struct branch *make_branch(const char *name, int len)
+static struct branch *make_branch(const char *name, size_t len)
 {
 	struct branch *ret;
 	int i;
 
 	for (i = 0; i < branches_nr; i++) {
-		if (len ? (!strncmp(name, branches[i]->name, len) &&
-			   !branches[i]->name[len]) :
-		    !strcmp(name, branches[i]->name))
+		if (!strncmp(name, branches[i]->name, len) &&
+		    !branches[i]->name[len])
 			return branches[i];
 	}
 
 	ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 	ret = xcalloc(1, sizeof(struct branch));
 	branches[branches_nr++] = ret;
-	if (len)
-		ret->name = xstrndup(name, len);
-	else
-		ret->name = xstrdup(name);
+	ret->name = xstrndup(name, len);
 	ret->refname = xstrfmt("refs/heads/%s", ret->name);
 
 	return ret;
 }
 
-static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
+static struct rewrite *make_rewrite(struct rewrites *r,
+				    const char *base, size_t len)
 {
 	struct rewrite *ret;
 	int i;
 
 	for (i = 0; i < r->rewrite_nr; i++) {
-		if (len
-		    ? (len == r->rewrite[i]->baselen &&
-		       !strncmp(base, r->rewrite[i]->base, len))
-		    : !strcmp(base, r->rewrite[i]->base))
+		if (len == r->rewrite[i]->baselen &&
+		    !strncmp(base, r->rewrite[i]->base, len))
 			return r->rewrite[i];
 	}
 
 	ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 	ret = xcalloc(1, sizeof(struct rewrite));
 	r->rewrite[r->rewrite_nr++] = ret;
-	if (len) {
-		ret->base = xstrndup(base, len);
-		ret->baselen = len;
-	}
-	else {
-		ret->base = xstrdup(base);
-		ret->baselen = strlen(base);
-	}
+	ret->base = xstrndup(base, len);
+	ret->baselen = len;
 	return ret;
 }
 
@@ -316,7 +305,7 @@ static void read_branches_file(struct remote *remote)
 static int handle_config(const char *key, const char *value, void *cb)
 {
 	const char *name;
-	int namelen;
+	size_t namelen;
 	const char *subkey;
 	struct remote *remote;
 	struct branch *branch;
@@ -470,7 +459,7 @@ static void read_config(void)
 		const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 		if (head_ref && (flag & REF_ISSYMREF) &&
 		    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
-			current_branch = make_branch(head_ref, 0);
+			current_branch = make_branch(head_ref, strlen(head_ref));
 		}
 	}
 	git_config(handle_config, NULL);
@@ -1584,7 +1573,7 @@ struct branch *branch_get(const char *name)
 	if (!name || !*name || !strcmp(name, "HEAD"))
 		ret = current_branch;
 	else
-		ret = make_branch(name, 0);
+		ret = make_branch(name, strlen(name));
 	set_merge(ret);
 	return ret;
 }
diff --git a/repo-settings.c b/repo-settings.c
index a703e40..dc6817d 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -45,6 +45,8 @@ void prepare_repo_settings(struct repository *r)
 
 	if (!repo_config_get_bool(r, "pack.usesparse", &value))
 		r->settings.pack_use_sparse = value;
+	UPDATE_DEFAULT_BOOL(r->settings.pack_use_sparse, 1);
+
 	if (!repo_config_get_bool(r, "feature.manyfiles", &value) && value) {
 		UPDATE_DEFAULT_BOOL(r->settings.index_version, 4);
 		UPDATE_DEFAULT_BOOL(r->settings.core_untracked_cache, UNTRACKED_CACHE_WRITE);
@@ -52,7 +54,6 @@ void prepare_repo_settings(struct repository *r)
 	if (!repo_config_get_bool(r, "fetch.writecommitgraph", &value))
 		r->settings.fetch_write_commit_graph = value;
 	if (!repo_config_get_bool(r, "feature.experimental", &value) && value) {
-		UPDATE_DEFAULT_BOOL(r->settings.pack_use_sparse, 1);
 		UPDATE_DEFAULT_BOOL(r->settings.fetch_negotiation_algorithm, FETCH_NEGOTIATION_SKIPPING);
 		UPDATE_DEFAULT_BOOL(r->settings.fetch_write_commit_graph, 1);
 	}
diff --git a/repository.c b/repository.c
index a4174dd..6f7f6f0 100644
--- a/repository.c
+++ b/repository.c
@@ -89,6 +89,10 @@ void repo_set_gitdir(struct repository *repo,
 void repo_set_hash_algo(struct repository *repo, int hash_algo)
 {
 	repo->hash_algo = &hash_algos[hash_algo];
+#ifndef ENABLE_SHA256
+	if (hash_algo != GIT_HASH_SHA1)
+		die(_("The hash algorithm %s is not supported in this build."), repo->hash_algo->name);
+#endif
 }
 
 /*
diff --git a/repository.h b/repository.h
index 040057d..6534fbb 100644
--- a/repository.h
+++ b/repository.h
@@ -67,8 +67,12 @@ struct repository {
 	 */
 	struct parsed_object_pool *parsed_objects;
 
-	/* The store in which the refs are held. */
-	struct ref_store *refs;
+	/*
+	 * The store in which the refs are held. This should generally only be
+	 * accessed via get_main_ref_store(), as that will lazily initialize
+	 * the ref object.
+	 */
+	struct ref_store *refs_private;
 
 	/*
 	 * Contains path to often used file names.
diff --git a/reset.c b/reset.c
new file mode 100644
index 0000000..2f4fbd0
--- /dev/null
+++ b/reset.c
@@ -0,0 +1,141 @@
+#include "git-compat-util.h"
+#include "cache-tree.h"
+#include "lockfile.h"
+#include "refs.h"
+#include "reset.h"
+#include "run-command.h"
+#include "tree-walk.h"
+#include "tree.h"
+#include "unpack-trees.h"
+
+int reset_head(struct repository *r, struct object_id *oid, const char *action,
+	       const char *switch_to_branch, unsigned flags,
+	       const char *reflog_orig_head, const char *reflog_head,
+	       const char *default_reflog_action)
+{
+	unsigned detach_head = flags & RESET_HEAD_DETACH;
+	unsigned reset_hard = flags & RESET_HEAD_HARD;
+	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
+	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
+	struct object_id head_oid;
+	struct tree_desc desc[2] = { { NULL }, { NULL } };
+	struct lock_file lock = LOCK_INIT;
+	struct unpack_trees_options unpack_tree_opts;
+	struct tree *tree;
+	const char *reflog_action;
+	struct strbuf msg = STRBUF_INIT;
+	size_t prefix_len;
+	struct object_id *orig = NULL, oid_orig,
+		*old_orig = NULL, oid_old_orig;
+	int ret = 0, nr = 0;
+
+	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
+		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
+
+	if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
+		ret = error(_("could not determine HEAD revision"));
+		goto leave_reset_head;
+	}
+
+	if (!oid)
+		oid = &head_oid;
+
+	if (refs_only)
+		goto reset_head_refs;
+
+	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
+	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
+	unpack_tree_opts.head_idx = 1;
+	unpack_tree_opts.src_index = r->index;
+	unpack_tree_opts.dst_index = r->index;
+	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
+	unpack_tree_opts.update = 1;
+	unpack_tree_opts.merge = 1;
+	init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
+	if (!detach_head)
+		unpack_tree_opts.reset = 1;
+
+	if (repo_read_index_unmerged(r) < 0) {
+		ret = error(_("could not read index"));
+		goto leave_reset_head;
+	}
+
+	if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
+		ret = error(_("failed to find tree of %s"),
+			    oid_to_hex(&head_oid));
+		goto leave_reset_head;
+	}
+
+	if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
+		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
+		goto leave_reset_head;
+	}
+
+	if (unpack_trees(nr, desc, &unpack_tree_opts)) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	tree = parse_tree_indirect(oid);
+	prime_cache_tree(r, r->index, tree);
+
+	if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
+		ret = error(_("could not write index"));
+		goto leave_reset_head;
+	}
+
+reset_head_refs:
+	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
+	prefix_len = msg.len;
+
+	if (update_orig_head) {
+		if (!get_oid("ORIG_HEAD", &oid_old_orig))
+			old_orig = &oid_old_orig;
+		if (!get_oid("HEAD", &oid_orig)) {
+			orig = &oid_orig;
+			if (!reflog_orig_head) {
+				strbuf_addstr(&msg, "updating ORIG_HEAD");
+				reflog_orig_head = msg.buf;
+			}
+			update_ref(reflog_orig_head, "ORIG_HEAD", orig,
+				   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
+		} else if (old_orig)
+			delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
+	}
+
+	if (!reflog_head) {
+		strbuf_setlen(&msg, prefix_len);
+		strbuf_addstr(&msg, "updating HEAD");
+		reflog_head = msg.buf;
+	}
+	if (!switch_to_branch)
+		ret = update_ref(reflog_head, "HEAD", oid, orig,
+				 detach_head ? REF_NO_DEREF : 0,
+				 UPDATE_REFS_MSG_ON_ERR);
+	else {
+		ret = update_ref(reflog_head, switch_to_branch, oid,
+				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+		if (!ret)
+			ret = create_symref("HEAD", switch_to_branch,
+					    reflog_head);
+	}
+	if (run_hook)
+		run_hook_le(NULL, "post-checkout",
+			    oid_to_hex(orig ? orig : &null_oid),
+			    oid_to_hex(oid), "1", NULL);
+
+leave_reset_head:
+	strbuf_release(&msg);
+	rollback_lock_file(&lock);
+	while (nr)
+		free((void *)desc[--nr].buffer);
+	return ret;
+
+}
diff --git a/reset.h b/reset.h
new file mode 100644
index 0000000..12f83c7
--- /dev/null
+++ b/reset.h
@@ -0,0 +1,20 @@
+#ifndef RESET_H
+#define RESET_H
+
+#include "hash.h"
+#include "repository.h"
+
+#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
+
+#define RESET_HEAD_DETACH (1<<0)
+#define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
+#define RESET_HEAD_REFS_ONLY (1<<3)
+#define RESET_ORIG_HEAD (1<<4)
+
+int reset_head(struct repository *r, struct object_id *oid, const char *action,
+	       const char *switch_to_branch, unsigned flags,
+	       const char *reflog_orig_head, const char *reflog_head,
+	       const char *default_reflog_action);
+
+#endif
diff --git a/revision.c b/revision.c
index 8136929..5bc9644 100644
--- a/revision.c
+++ b/revision.c
@@ -870,7 +870,19 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 			}
 			parent->next = NULL;
 			commit->parents = parent;
-			commit->object.flags |= TREESAME;
+
+			/*
+			 * A merge commit is a "diversion" if it is not
+			 * TREESAME to its first parent but is TREESAME
+			 * to a later parent. In the simplified history,
+			 * we "divert" the history walk to the later
+			 * parent. These commits are shown when "show_pulls"
+			 * is enabled, so do not mark the object as
+			 * TREESAME here.
+			 */
+			if (!revs->show_pulls || !nth_parent)
+				commit->object.flags |= TREESAME;
+
 			return;
 
 		case REV_TREE_NEW:
@@ -897,6 +909,10 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 				relevant_change = 1;
 			else
 				irrelevant_change = 1;
+
+			if (!nth_parent)
+				commit->object.flags |= PULL_MERGE;
+
 			continue;
 		}
 		die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
@@ -2241,6 +2257,10 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->topo_order = 1;
 		revs->rewrite_parents = 1;
 		revs->graph = graph_init(revs);
+	} else if (!strcmp(arg, "--encode-email-headers")) {
+		revs->encode_email_headers = 1;
+	} else if (!strcmp(arg, "--no-encode-email-headers")) {
+		revs->encode_email_headers = 0;
 	} else if (!strcmp(arg, "--root")) {
 		revs->show_root_diff = 1;
 	} else if (!strcmp(arg, "--no-commit-id")) {
@@ -2265,6 +2285,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 	} else if (!strcmp(arg, "--full-diff")) {
 		revs->diff = 1;
 		revs->full_diff = 1;
+	} else if (!strcmp(arg, "--show-pulls")) {
+		revs->show_pulls = 1;
 	} else if (!strcmp(arg, "--full-history")) {
 		revs->simplify_history = 0;
 	} else if (!strcmp(arg, "--relative-date")) {
@@ -3019,7 +3041,8 @@ static struct commit_list **simplify_one(struct rev_info *revs, struct commit *c
 	if (!cnt ||
 	    (commit->object.flags & UNINTERESTING) ||
 	    !(commit->object.flags & TREESAME) ||
-	    (parent = one_relevant_parent(revs, commit->parents)) == NULL)
+	    (parent = one_relevant_parent(revs, commit->parents)) == NULL ||
+	    (revs->show_pulls && (commit->object.flags & PULL_MERGE)))
 		st->simplified = commit;
 	else {
 		pst = locate_simplify_state(revs, parent);
@@ -3602,6 +3625,10 @@ enum commit_action get_commit_action(struct rev_info *revs, struct commit *commi
 			/* drop merges unless we want parenthood */
 			if (!want_ancestry(revs))
 				return commit_ignore;
+
+			if (revs->show_pulls && (commit->object.flags & PULL_MERGE))
+				return commit_show;
+
 			/*
 			 * If we want ancestry, then need to keep any merges
 			 * between relevant commits to tie together topology.
diff --git a/revision.h b/revision.h
index 475f048..c1af164 100644
--- a/revision.h
+++ b/revision.h
@@ -34,6 +34,9 @@
 #define SYMMETRIC_LEFT	(1u<<8)
 #define PATCHSAME	(1u<<9)
 #define BOTTOM		(1u<<10)
+
+/* WARNING: This is also used as REACHABLE in commit-graph.c. */
+#define PULL_MERGE	(1u<<15)
 /*
  * Indicates object was reached by traversal. i.e. not given by user on
  * command-line or stdin.
@@ -43,7 +46,7 @@
  */
 #define NOT_USER_GIVEN	(1u<<25)
 #define TRACK_LINEAR	(1u<<26)
-#define ALL_REV_FLAGS	(((1u<<11)-1) | NOT_USER_GIVEN | TRACK_LINEAR)
+#define ALL_REV_FLAGS	(((1u<<11)-1) | NOT_USER_GIVEN | TRACK_LINEAR | PULL_MERGE)
 
 #define TOPO_WALK_EXPLORED	(1u<<27)
 #define TOPO_WALK_INDEGREE	(1u<<28)
@@ -129,6 +132,7 @@ struct rev_info {
 			no_walk:2,
 			remove_empty_trees:1,
 			simplify_history:1,
+			show_pulls:1,
 			topo_order:1,
 			simplify_merges:1,
 			simplify_by_decoration:1,
@@ -203,7 +207,8 @@ struct rev_info {
 			use_terminator:1,
 			missing_newline:1,
 			date_mode_explicit:1,
-			preserve_subject:1;
+			preserve_subject:1,
+			encode_email_headers:1;
 	unsigned int	disable_stdin:1;
 	/* --show-linear-break */
 	unsigned int	track_linear:1,
diff --git a/run-command.c b/run-command.c
index f5e1149..0f41af3 100644
--- a/run-command.c
+++ b/run-command.c
@@ -421,12 +421,12 @@ static int prepare_cmd(struct argv_array *out, const struct child_process *cmd)
 	}
 
 	/*
-	 * If there are no '/' characters in the command then perform a path
-	 * lookup and use the resolved path as the command to exec.  If there
-	 * are '/' characters, we have exec attempt to invoke the command
-	 * directly.
+	 * If there are no dir separator characters in the command then perform
+	 * a path lookup and use the resolved path as the command to exec. If
+	 * there are dir separator characters, we have exec attempt to invoke
+	 * the command directly.
 	 */
-	if (!strchr(out->argv[1], '/')) {
+	if (!has_dir_sep(out->argv[1])) {
 		char *program = locate_in_PATH(out->argv[1]);
 		if (program) {
 			free((char *)out->argv[1]);
diff --git a/send-pack.c b/send-pack.c
index 0407841..d1b7edc 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -12,7 +12,7 @@
 #include "quote.h"
 #include "transport.h"
 #include "version.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "gpg-interface.h"
 #include "cache.h"
 
@@ -190,10 +190,8 @@ static int receive_status(struct packet_reader *reader, struct ref *refs)
 
 		if (reader->line[0] == 'o' && reader->line[1] == 'k')
 			hint->status = REF_STATUS_OK;
-		else {
+		else
 			hint->status = REF_STATUS_REMOTE_REJECT;
-			ret = -1;
-		}
 		hint->remote_status = xstrdup_or_null(msg);
 		/* start our next search from the next ref */
 		hint = hint->next;
@@ -322,29 +320,6 @@ static int generate_push_cert(struct strbuf *req_buf,
 	return update_seen;
 }
 
-
-static int atomic_push_failure(struct send_pack_args *args,
-			       struct ref *remote_refs,
-			       struct ref *failing_ref)
-{
-	struct ref *ref;
-	/* Mark other refs as failed */
-	for (ref = remote_refs; ref; ref = ref->next) {
-		if (!ref->peer_ref && !args->send_mirror)
-			continue;
-
-		switch (ref->status) {
-		case REF_STATUS_EXPECTING_REPORT:
-			ref->status = REF_STATUS_ATOMIC_PUSH_FAILED;
-			continue;
-		default:
-			break; /* do nothing */
-		}
-	}
-	return error("atomic push failed for ref %s. status: %d\n",
-		     failing_ref->name, failing_ref->status);
-}
-
 #define NONCE_LEN_LIMIT 256
 
 static void reject_invalid_nonce(const char *nonce, int len)
@@ -489,7 +464,10 @@ int send_pack(struct send_pack_args *args,
 			if (use_atomic) {
 				strbuf_release(&req_buf);
 				strbuf_release(&cap_buf);
-				return atomic_push_failure(args, remote_refs, ref);
+				reject_atomic_push(remote_refs, args->send_mirror);
+				error("atomic push failed for ref %s. status: %d\n",
+				      ref->name, ref->status);
+				return args->porcelain ? 0 : -1;
 			}
 			/* else fallthrough */
 		default:
diff --git a/sequencer.c b/sequencer.c
index e528225..9d1b3e7 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -32,6 +32,7 @@
 #include "alias.h"
 #include "commit-reach.h"
 #include "rebase-interactive.h"
+#include "reset.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -40,7 +41,7 @@ static const char cherry_picked_prefix[] = "(cherry picked from commit ";
 
 GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
 
-GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
+static GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
 
 static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
 static GIT_PATH_FUNC(git_path_opts_file, "sequencer/opts")
@@ -419,25 +420,15 @@ static int write_message(const void *buf, size_t len, const char *filename,
 	return 0;
 }
 
-/*
- * Reads a file that was presumably written by a shell script, i.e. with an
- * end-of-line marker that needs to be stripped.
- *
- * Note that only the last end-of-line marker is stripped, consistent with the
- * behavior of "$(cat path)" in a shell script.
- *
- * Returns 1 if the file was read, 0 if it could not be read or does not exist.
- */
-static int read_oneliner(struct strbuf *buf,
-	const char *path, int skip_if_empty)
+int read_oneliner(struct strbuf *buf,
+	const char *path, unsigned flags)
 {
 	int orig_len = buf->len;
 
-	if (!file_exists(path))
-		return 0;
-
 	if (strbuf_read_file(buf, path, 0) < 0) {
-		warning_errno(_("could not read '%s'"), path);
+		if ((flags & READ_ONELINER_WARN_MISSING) ||
+		    (errno != ENOENT && errno != ENOTDIR))
+			warning_errno(_("could not read '%s'"), path);
 		return 0;
 	}
 
@@ -447,7 +438,7 @@ static int read_oneliner(struct strbuf *buf,
 		buf->buf[buf->len] = '\0';
 	}
 
-	if (skip_if_empty && buf->len == orig_len)
+	if ((flags & READ_ONELINER_SKIP_IF_EMPTY) && buf->len == orig_len)
 		return 0;
 
 	return 1;
@@ -946,6 +937,8 @@ static int run_git_commit(struct repository *r,
 		argv_array_push(&cmd.args, "--amend");
 	if (opts->gpg_sign)
 		argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
+	else
+		argv_array_push(&cmd.args, "--no-gpg-sign");
 	if (defmsg)
 		argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
 	else if (!(flags & EDIT_MSG))
@@ -1323,7 +1316,7 @@ static int try_to_commit(struct repository *r,
 		return -1;
 
 	if (flags & AMEND_MSG) {
-		const char *exclude_gpgsig[] = { "gpgsig", NULL };
+		const char *exclude_gpgsig[] = { "gpgsig", "gpgsig-sha256", NULL };
 		const char *out_enc = get_commit_output_encoding();
 		const char *message = logmsg_reencode(current_head, NULL,
 						      out_enc);
@@ -1433,9 +1426,19 @@ static int try_to_commit(struct repository *r,
 	return res;
 }
 
+static int write_rebase_head(struct object_id *oid)
+{
+	if (update_ref("rebase", "REBASE_HEAD", oid,
+		       NULL, REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
+		return error(_("could not update %s"), "REBASE_HEAD");
+
+	return 0;
+}
+
 static int do_commit(struct repository *r,
 		     const char *msg_file, const char *author,
-		     struct replay_opts *opts, unsigned int flags)
+		     struct replay_opts *opts, unsigned int flags,
+		     struct object_id *oid)
 {
 	int res = 1;
 
@@ -1460,8 +1463,12 @@ static int do_commit(struct repository *r,
 			return res;
 		}
 	}
-	if (res == 1)
+	if (res == 1) {
+		if (is_rebase_i(opts) && oid)
+			if (write_rebase_head(oid))
+			    return -1;
 		return run_git_commit(r, msg_file, opts, flags);
+	}
 
 	return res;
 }
@@ -1564,7 +1571,7 @@ static const char *command_to_string(const enum todo_command command)
 
 static char command_to_char(const enum todo_command command)
 {
-	if (command < TODO_COMMENT && todo_command_info[command].c)
+	if (command < TODO_COMMENT)
 		return todo_command_info[command].c;
 	return comment_line_char;
 }
@@ -1929,7 +1936,9 @@ static int do_pick_commit(struct repository *r,
 	 * However, if the merge did not even start, then we don't want to
 	 * write it at all.
 	 */
-	if (command == TODO_PICK && !opts->no_commit && (res == 0 || res == 1) &&
+	if ((command == TODO_PICK || command == TODO_REWORD ||
+	     command == TODO_EDIT) && !opts->no_commit &&
+	    (res == 0 || res == 1) &&
 	    update_ref(NULL, "CHERRY_PICK_HEAD", &commit->object.oid, NULL,
 		       REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
 		res = -1;
@@ -1965,7 +1974,8 @@ static int do_pick_commit(struct repository *r,
 	} /* else allow == 0 and there's nothing special to do */
 	if (!opts->no_commit && !drop_commit) {
 		if (author || command == TODO_REVERT || (flags & AMEND_MSG))
-			res = do_commit(r, msg_file, author, opts, flags);
+			res = do_commit(r, msg_file, author, opts, flags,
+					commit? &commit->object.oid : NULL);
 		else
 			res = error(_("unable to parse commit author"));
 		*check_todo = !!(flags & EDIT_MSG);
@@ -2485,8 +2495,10 @@ static int read_populate_opts(struct replay_opts *opts)
 {
 	if (is_rebase_i(opts)) {
 		struct strbuf buf = STRBUF_INIT;
+		int ret = 0;
 
-		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
+		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(),
+				  READ_ONELINER_SKIP_IF_EMPTY)) {
 			if (!starts_with(buf.buf, "-S"))
 				strbuf_reset(&buf);
 			else {
@@ -2496,7 +2508,8 @@ static int read_populate_opts(struct replay_opts *opts)
 			strbuf_reset(&buf);
 		}
 
-		if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1)) {
+		if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(),
+				  READ_ONELINER_SKIP_IF_EMPTY)) {
 			if (!strcmp(buf.buf, "--rerere-autoupdate"))
 				opts->allow_rerere_auto = RERERE_AUTOUPDATE;
 			else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
@@ -2525,10 +2538,11 @@ static int read_populate_opts(struct replay_opts *opts)
 			opts->keep_redundant_commits = 1;
 
 		read_strategy_opts(opts, &buf);
-		strbuf_release(&buf);
+		strbuf_reset(&buf);
 
 		if (read_oneliner(&opts->current_fixups,
-				  rebase_path_current_fixups(), 1)) {
+				  rebase_path_current_fixups(),
+				  READ_ONELINER_SKIP_IF_EMPTY)) {
 			const char *p = opts->current_fixups.buf;
 			opts->current_fixup_count = 1;
 			while ((p = strchr(p, '\n'))) {
@@ -2538,12 +2552,16 @@ static int read_populate_opts(struct replay_opts *opts)
 		}
 
 		if (read_oneliner(&buf, rebase_path_squash_onto(), 0)) {
-			if (get_oid_hex(buf.buf, &opts->squash_onto) < 0)
-				return error(_("unusable squash-onto"));
+			if (get_oid_hex(buf.buf, &opts->squash_onto) < 0) {
+				ret = error(_("unusable squash-onto"));
+				goto done_rebase_i;
+			}
 			opts->have_squash_onto = 1;
 		}
 
-		return 0;
+done_rebase_i:
+		strbuf_release(&buf);
+		return ret;
 	}
 
 	if (!file_exists(git_path_opts_file()))
@@ -3000,9 +3018,7 @@ static int make_patch(struct repository *r,
 	p = short_commit_name(commit);
 	if (write_message(p, strlen(p), rebase_path_stopped_sha(), 1) < 0)
 		return -1;
-	if (update_ref("rebase", "REBASE_HEAD", &commit->object.oid,
-		       NULL, REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
-		res |= error(_("could not update %s"), "REBASE_HEAD");
+	res |= write_rebase_head(&commit->object.oid);
 
 	strbuf_addf(&buf, "%s/patch", get_dir(opts));
 	memset(&log_tree_opt, 0, sizeof(log_tree_opt));
@@ -3113,7 +3129,7 @@ static int do_exec(struct repository *r, const char *command_line)
 	const char *child_argv[] = { NULL, NULL };
 	int dirty, status;
 
-	fprintf(stderr, "Executing: %s\n", command_line);
+	fprintf(stderr, _("Executing: %s\n"), command_line);
 	child_argv[0] = command_line;
 	argv_array_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir()));
 	argv_array_pushf(&child_env, "GIT_WORK_TREE=%s",
@@ -3290,6 +3306,7 @@ static int do_reset(struct repository *r,
 	unpack_tree_opts.fn = oneway_merge;
 	unpack_tree_opts.merge = 1;
 	unpack_tree_opts.update = 1;
+	init_checkout_metadata(&unpack_tree_opts.meta, name, &oid, NULL);
 
 	if (repo_read_index_unmerged(r)) {
 		rollback_lock_file(&lock);
@@ -3659,25 +3676,71 @@ static enum todo_command peek_command(struct todo_list *todo_list, int offset)
 	return -1;
 }
 
-static int apply_autostash(struct replay_opts *opts)
+void create_autostash(struct repository *r, const char *path,
+		      const char *default_reflog_action)
 {
-	struct strbuf stash_sha1 = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct lock_file lock_file = LOCK_INIT;
+	int fd;
+
+	fd = repo_hold_locked_index(r, &lock_file, 0);
+	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
+	if (0 <= fd)
+		repo_update_index_if_able(r, &lock_file);
+	rollback_lock_file(&lock_file);
+
+	if (has_unstaged_changes(r, 1) ||
+	    has_uncommitted_changes(r, 1)) {
+		struct child_process stash = CHILD_PROCESS_INIT;
+		struct object_id oid;
+
+		argv_array_pushl(&stash.args,
+				 "stash", "create", "autostash", NULL);
+		stash.git_cmd = 1;
+		stash.no_stdin = 1;
+		strbuf_reset(&buf);
+		if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
+			die(_("Cannot autostash"));
+		strbuf_trim_trailing_newline(&buf);
+		if (get_oid(buf.buf, &oid))
+			die(_("Unexpected stash response: '%s'"),
+			    buf.buf);
+		strbuf_reset(&buf);
+		strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
+
+		if (safe_create_leading_directories_const(path))
+			die(_("Could not create directory for '%s'"),
+			    path);
+		write_file(path, "%s", oid_to_hex(&oid));
+		printf(_("Created autostash: %s\n"), buf.buf);
+		if (reset_head(r, NULL, "reset --hard",
+			       NULL, RESET_HEAD_HARD, NULL, NULL,
+			       default_reflog_action) < 0)
+			die(_("could not reset --hard"));
+
+		if (discard_index(r->index) < 0 ||
+			repo_read_index(r) < 0)
+			die(_("could not read index"));
+	}
+	strbuf_release(&buf);
+}
+
+static int apply_save_autostash_oid(const char *stash_oid, int attempt_apply)
+{
 	struct child_process child = CHILD_PROCESS_INIT;
 	int ret = 0;
 
-	if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
-		strbuf_release(&stash_sha1);
-		return 0;
+	if (attempt_apply) {
+		child.git_cmd = 1;
+		child.no_stdout = 1;
+		child.no_stderr = 1;
+		argv_array_push(&child.args, "stash");
+		argv_array_push(&child.args, "apply");
+		argv_array_push(&child.args, stash_oid);
+		ret = run_command(&child);
 	}
-	strbuf_trim(&stash_sha1);
 
-	child.git_cmd = 1;
-	child.no_stdout = 1;
-	child.no_stderr = 1;
-	argv_array_push(&child.args, "stash");
-	argv_array_push(&child.args, "apply");
-	argv_array_push(&child.args, stash_sha1.buf);
-	if (!run_command(&child))
+	if (attempt_apply && !ret)
 		fprintf(stderr, _("Applied autostash.\n"));
 	else {
 		struct child_process store = CHILD_PROCESS_INIT;
@@ -3688,30 +3751,67 @@ static int apply_autostash(struct replay_opts *opts)
 		argv_array_push(&store.args, "-m");
 		argv_array_push(&store.args, "autostash");
 		argv_array_push(&store.args, "-q");
-		argv_array_push(&store.args, stash_sha1.buf);
+		argv_array_push(&store.args, stash_oid);
 		if (run_command(&store))
-			ret = error(_("cannot store %s"), stash_sha1.buf);
+			ret = error(_("cannot store %s"), stash_oid);
 		else
 			fprintf(stderr,
-				_("Applying autostash resulted in conflicts.\n"
+				_("%s\n"
 				  "Your changes are safe in the stash.\n"
 				  "You can run \"git stash pop\" or"
-				  " \"git stash drop\" at any time.\n"));
+				  " \"git stash drop\" at any time.\n"),
+				attempt_apply ?
+				_("Applying autostash resulted in conflicts.") :
+				_("Autostash exists; creating a new stash entry."));
 	}
 
-	strbuf_release(&stash_sha1);
 	return ret;
 }
 
+static int apply_save_autostash(const char *path, int attempt_apply)
+{
+	struct strbuf stash_oid = STRBUF_INIT;
+	int ret = 0;
+
+	if (!read_oneliner(&stash_oid, path,
+			   READ_ONELINER_SKIP_IF_EMPTY)) {
+		strbuf_release(&stash_oid);
+		return 0;
+	}
+	strbuf_trim(&stash_oid);
+
+	ret = apply_save_autostash_oid(stash_oid.buf, attempt_apply);
+
+	unlink(path);
+	strbuf_release(&stash_oid);
+	return ret;
+}
+
+int save_autostash(const char *path)
+{
+	return apply_save_autostash(path, 0);
+}
+
+int apply_autostash(const char *path)
+{
+	return apply_save_autostash(path, 1);
+}
+
+int apply_autostash_oid(const char *stash_oid)
+{
+	return apply_save_autostash_oid(stash_oid, 1);
+}
+
 static const char *reflog_message(struct replay_opts *opts,
 	const char *sub_action, const char *fmt, ...)
 {
 	va_list ap;
 	static struct strbuf buf = STRBUF_INIT;
+	char *reflog_action = getenv(GIT_REFLOG_ACTION);
 
 	va_start(ap, fmt);
 	strbuf_reset(&buf);
-	strbuf_addstr(&buf, action_name(opts));
+	strbuf_addstr(&buf, reflog_action ? reflog_action : action_name(opts));
 	if (sub_action)
 		strbuf_addf(&buf, " (%s)", sub_action);
 	if (fmt) {
@@ -3757,7 +3857,7 @@ static int checkout_onto(struct repository *r, struct replay_opts *opts,
 		return error(_("%s: not a valid OID"), orig_head);
 
 	if (run_git_checkout(r, opts, oid_to_hex(onto), action)) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 		return error(_("could not detach HEAD"));
 	}
@@ -3799,8 +3899,11 @@ static int pick_commits(struct repository *r,
 			struct replay_opts *opts)
 {
 	int res = 0, reschedule = 0;
+	char *prev_reflog_action;
 
+	/* Note that 0 for 3rd parameter of setenv means set only if not set */
 	setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
+	prev_reflog_action = xstrdup(getenv(GIT_REFLOG_ACTION));
 	if (opts->allow_ff)
 		assert(!(opts->signoff || opts->no_commit ||
 				opts->record_origin || opts->edit));
@@ -3825,7 +3928,7 @@ static int pick_commits(struct repository *r,
 					fclose(f);
 				}
 				if (!opts->quiet)
-					fprintf(stderr, "Rebasing (%d/%d)%s",
+					fprintf(stderr, _("Rebasing (%d/%d)%s"),
 						todo_list->done_nr,
 						todo_list->total_nr,
 						opts->verbose ? "\n" : "\r");
@@ -3845,12 +3948,14 @@ static int pick_commits(struct repository *r,
 		}
 		if (item->command <= TODO_SQUASH) {
 			if (is_rebase_i(opts))
-				setenv("GIT_REFLOG_ACTION", reflog_message(opts,
+				setenv(GIT_REFLOG_ACTION, reflog_message(opts,
 					command_to_string(item->command), NULL),
 					1);
 			res = do_pick_commit(r, item->command, item->commit,
 					     opts, is_final_fixup(todo_list),
 					     &check_todo);
+			if (is_rebase_i(opts))
+				setenv(GIT_REFLOG_ACTION, prev_reflog_action, 1);
 			if (is_rebase_i(opts) && res < 0) {
 				/* Reschedule */
 				advise(_(rescheduled_advice),
@@ -4071,13 +4176,13 @@ static int pick_commits(struct repository *r,
 				run_command(&hook);
 			}
 		}
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 
 		if (!opts->quiet) {
 			if (!opts->verbose)
 				term_clear_line();
 			fprintf(stderr,
-				"Successfully rebased and updated %s.\n",
+				_("Successfully rebased and updated %s.\n"),
 				head_ref.buf);
 		}
 
@@ -4289,7 +4394,8 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
 		struct strbuf buf = STRBUF_INIT;
 		struct object_id oid;
 
-		if (read_oneliner(&buf, rebase_path_stopped_sha(), 1) &&
+		if (read_oneliner(&buf, rebase_path_stopped_sha(),
+				  READ_ONELINER_SKIP_IF_EMPTY) &&
 		    !get_oid_committish(buf.buf, &oid))
 			record_in_rewritten(&oid, peek_command(&todo_list, 0));
 		strbuf_release(&buf);
@@ -4591,6 +4697,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 				   struct rev_info *revs, struct strbuf *out,
 				   unsigned flags)
 {
+	int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
 	int rebase_cousins = flags & TODO_LIST_REBASE_COUSINS;
 	int root_with_onto = flags & TODO_LIST_ROOT_WITH_ONTO;
 	struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT;
@@ -4645,6 +4752,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 		is_empty = is_original_commit_empty(commit);
 		if (!is_empty && (commit->object.flags & PATCHSAME))
 			continue;
+		if (is_empty && !keep_empty)
+			continue;
 
 		strbuf_reset(&oneline);
 		pretty_print_commit(pp, commit, &oneline);
@@ -4656,6 +4765,9 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 			strbuf_addf(&buf, "%s %s %s", cmd_pick,
 				    oid_to_hex(&commit->object.oid),
 				    oneline.buf);
+			if (is_empty)
+				strbuf_addf(&buf, " %c empty",
+					    comment_line_char);
 
 			FLEX_ALLOC_STR(entry, string, buf.buf);
 			oidcpy(&entry->entry.oid, &commit->object.oid);
@@ -4819,14 +4931,16 @@ int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 	struct pretty_print_context pp = {0};
 	struct rev_info revs;
 	struct commit *commit;
+	int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
 	const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
 	int rebase_merges = flags & TODO_LIST_REBASE_MERGES;
+	int reapply_cherry_picks = flags & TODO_LIST_REAPPLY_CHERRY_PICKS;
 
 	repo_init_revisions(r, &revs, NULL);
 	revs.verbose_header = 1;
 	if (!rebase_merges)
 		revs.max_parents = 1;
-	revs.cherry_mark = 1;
+	revs.cherry_mark = !reapply_cherry_picks;
 	revs.limited = 1;
 	revs.reverse = 1;
 	revs.right_only = 1;
@@ -4858,9 +4972,13 @@ int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 
 		if (!is_empty && (commit->object.flags & PATCHSAME))
 			continue;
+		if (is_empty && !keep_empty)
+			continue;
 		strbuf_addf(out, "%s %s ", insn,
 			    oid_to_hex(&commit->object.oid));
 		pretty_print_commit(&pp, commit, out);
+		if (is_empty)
+			strbuf_addf(out, " %c empty", comment_line_char);
 		strbuf_addch(out, '\n');
 	}
 	return 0;
@@ -4947,6 +5065,8 @@ static void todo_list_to_strbuf(struct repository *r, struct todo_list *todo_lis
 		max = num;
 
 	for (item = todo_list->items, i = 0; i < max; i++, item++) {
+		char cmd;
+
 		/* if the item is not a command write it and continue */
 		if (item->command >= TODO_COMMENT) {
 			strbuf_addf(buf, "%.*s\n", item->arg_len,
@@ -4955,8 +5075,9 @@ static void todo_list_to_strbuf(struct repository *r, struct todo_list *todo_lis
 		}
 
 		/* add command to the buffer */
-		if (flags & TODO_LIST_ABBREVIATE_CMDS)
-			strbuf_addch(buf, command_to_char(item->command));
+		cmd = command_to_char(item->command);
+		if ((flags & TODO_LIST_ABBREVIATE_CMDS) && cmd)
+			strbuf_addch(buf, cmd);
 		else
 			strbuf_addstr(buf, command_to_string(item->command));
 
@@ -5079,7 +5200,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 		todo_list_add_exec_commands(todo_list, commands);
 
 	if (count_commands(todo_list) == 0) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 
 		return error(_("nothing to do"));
@@ -5090,12 +5211,12 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 	if (res == -1)
 		return -1;
 	else if (res == -2) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 
 		return -1;
 	} else if (res == -3) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 		todo_list_release(&new_todo);
 
@@ -5315,3 +5436,24 @@ int todo_list_rearrange_squash(struct todo_list *todo_list)
 
 	return 0;
 }
+
+int sequencer_determine_whence(struct repository *r, enum commit_whence *whence)
+{
+	if (file_exists(git_path_cherry_pick_head(r))) {
+		struct object_id cherry_pick_head, rebase_head;
+
+		if (file_exists(git_path_seq_dir()))
+			*whence = FROM_CHERRY_PICK_MULTI;
+		if (file_exists(rebase_path()) &&
+		    !get_oid("REBASE_HEAD", &rebase_head) &&
+		    !get_oid("CHERRY_PICK_HEAD", &cherry_pick_head) &&
+		    oideq(&rebase_head, &cherry_pick_head))
+			*whence = FROM_REBASE_PICK;
+		else
+			*whence = FROM_CHERRY_PICK_SINGLE;
+
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/sequencer.h b/sequencer.h
index 718a074..d31c41f 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -3,12 +3,12 @@
 
 #include "cache.h"
 #include "strbuf.h"
+#include "wt-status.h"
 
 struct commit;
 struct repository;
 
 const char *git_path_commit_editmsg(void);
-const char *git_path_seq_dir(void);
 const char *rebase_path_todo(void);
 const char *rebase_path_todo_backup(void);
 const char *rebase_path_dropped(void);
@@ -134,7 +134,7 @@ int sequencer_rollback(struct repository *repo, struct replay_opts *opts);
 int sequencer_skip(struct repository *repo, struct replay_opts *opts);
 int sequencer_remove_state(struct replay_opts *opts);
 
-/* #define TODO_LIST_KEEP_EMPTY (1U << 0) */ /* No longer used */
+#define TODO_LIST_KEEP_EMPTY (1U << 0)
 #define TODO_LIST_SHORTEN_IDS (1U << 1)
 #define TODO_LIST_ABBREVIATE_CMDS (1U << 2)
 #define TODO_LIST_REBASE_MERGES (1U << 3)
@@ -150,7 +150,7 @@ int sequencer_remove_state(struct replay_opts *opts);
  * `--onto`, we do not want to re-generate the root commits.
  */
 #define TODO_LIST_ROOT_WITH_ONTO (1U << 6)
-
+#define TODO_LIST_REAPPLY_CHERRY_PICKS (1U << 7)
 
 int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 			  const char **argv, unsigned flags);
@@ -191,6 +191,12 @@ void commit_post_rewrite(struct repository *r,
 			 const struct commit *current_head,
 			 const struct object_id *new_head);
 
+void create_autostash(struct repository *r, const char *path,
+		      const char *default_reflog_action);
+int save_autostash(const char *path);
+int apply_autostash(const char *path);
+int apply_autostash_oid(const char *stash_oid);
+
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)
 #define SUMMARY_SHOW_AUTHOR_DATE (1 << 1)
 void print_commit_summary(struct repository *repo,
@@ -198,6 +204,20 @@ void print_commit_summary(struct repository *repo,
 			  const struct object_id *oid,
 			  unsigned int flags);
 
+#define READ_ONELINER_SKIP_IF_EMPTY (1 << 0)
+#define READ_ONELINER_WARN_MISSING (1 << 1)
+
+/*
+ * Reads a file that was presumably written by a shell script, i.e. with an
+ * end-of-line marker that needs to be stripped.
+ *
+ * Note that only the last end-of-line marker is stripped, consistent with the
+ * behavior of "$(cat path)" in a shell script.
+ *
+ * Returns 1 if the file was read, 0 if it could not be read or does not exist.
+ */
+int read_oneliner(struct strbuf *buf,
+	const char *path, unsigned flags);
 int read_author_script(const char *path, char **name, char **email, char **date,
 		       int allow_missing);
 void parse_strategy_opts(struct replay_opts *opts, char *raw_opts);
@@ -206,4 +226,5 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 void sequencer_post_commit_cleanup(struct repository *r, int verbose);
 int sequencer_get_last_command(struct repository* r,
 			       enum replay_action *action);
+int sequencer_determine_whence(struct repository *r, enum commit_whence *whence);
 #endif /* SEQUENCER_H */
diff --git a/setup.c b/setup.c
index 5ea9285..65fe5ec 100644
--- a/setup.c
+++ b/setup.c
@@ -32,6 +32,7 @@ static int abspath_part_inside_repo(char *path)
 	char *path0;
 	int off;
 	const char *work_tree = get_git_work_tree();
+	struct strbuf realpath = STRBUF_INIT;
 
 	if (!work_tree)
 		return -1;
@@ -60,8 +61,10 @@ static int abspath_part_inside_repo(char *path)
 		path++;
 		if (*path == '/') {
 			*path = '\0';
-			if (fspathcmp(real_path(path0), work_tree) == 0) {
+			strbuf_realpath(&realpath, path0, 1);
+			if (fspathcmp(realpath.buf, work_tree) == 0) {
 				memmove(path0, path + 1, len - (path - path0));
+				strbuf_release(&realpath);
 				return 0;
 			}
 			*path = '/';
@@ -69,11 +72,14 @@ static int abspath_part_inside_repo(char *path)
 	}
 
 	/* check whole path */
-	if (fspathcmp(real_path(path0), work_tree) == 0) {
+	strbuf_realpath(&realpath, path0, 1);
+	if (fspathcmp(realpath.buf, work_tree) == 0) {
 		*path0 = '\0';
+		strbuf_release(&realpath);
 		return 0;
 	}
 
+	strbuf_release(&realpath);
 	return -1;
 }
 
@@ -623,6 +629,7 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
 	struct stat st;
 	int fd;
 	ssize_t len;
+	static struct strbuf realpath = STRBUF_INIT;
 
 	if (stat(path, &st)) {
 		/* NEEDSWORK: discern between ENOENT vs other errors */
@@ -673,7 +680,9 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
 		error_code = READ_GITFILE_ERR_NOT_A_REPO;
 		goto cleanup_return;
 	}
-	path = real_path(dir);
+
+	strbuf_realpath(&realpath, dir, 1);
+	path = realpath.buf;
 
 cleanup_return:
 	if (return_error_code)
@@ -729,7 +738,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 		}
 
 		/* #18, #26 */
-		set_git_dir(gitdirenv);
+		set_git_dir(gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
@@ -751,7 +760,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 	}
 	else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 		/* #16d */
-		set_git_dir(gitdirenv);
+		set_git_dir(gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
@@ -763,14 +772,14 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 
 	/* both get_git_work_tree() and cwd are already normalized */
 	if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
-		set_git_dir(gitdirenv);
+		set_git_dir(gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
 
 	offset = dir_inside_of(cwd->buf, worktree);
 	if (offset >= 0) {	/* cwd inside worktree? */
-		set_git_dir(real_path(gitdirenv));
+		set_git_dir(gitdirenv, 1);
 		if (chdir(worktree))
 			die_errno(_("cannot chdir to '%s'"), worktree);
 		strbuf_addch(cwd, '/');
@@ -779,7 +788,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 	}
 
 	/* cwd outside worktree */
-	set_git_dir(gitdirenv);
+	set_git_dir(gitdirenv, 0);
 	free(gitfile);
 	return NULL;
 }
@@ -808,7 +817,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 	if (is_bare_repository_cfg > 0) {
-		set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
+		set_git_dir(gitdir, (offset != cwd->len));
 		if (chdir(cwd->buf))
 			die_errno(_("cannot come back to cwd"));
 		return NULL;
@@ -817,7 +826,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 	/* #0, #1, #5, #8, #9, #12, #13 */
 	set_git_work_tree(".");
 	if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
-		set_git_dir(gitdir);
+		set_git_dir(gitdir, 0);
 	inside_git_dir = 0;
 	inside_work_tree = 1;
 	if (offset >= cwd->len)
@@ -860,10 +869,10 @@ static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 			die_errno(_("cannot come back to cwd"));
 		root_len = offset_1st_component(cwd->buf);
 		strbuf_setlen(cwd, offset > root_len ? offset : root_len);
-		set_git_dir(cwd->buf);
+		set_git_dir(cwd->buf, 0);
 	}
 	else
-		set_git_dir(".");
+		set_git_dir(".", 0);
 	return NULL;
 }
 
@@ -881,7 +890,7 @@ static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_
 
 /*
  * A "string_list_each_func_t" function that canonicalizes an entry
- * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
+ * from GIT_CEILING_DIRECTORIES using real_pathdup(), or
  * discards it if unusable.  The presence of an empty entry in
  * GIT_CEILING_DIRECTORIES turns off canonicalization for all
  * subsequent entries.
@@ -1257,10 +1266,12 @@ int git_config_perm(const char *var, const char *value)
 	return -(i & 0666);
 }
 
-void check_repository_format(void)
+void check_repository_format(struct repository_format *fmt)
 {
 	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
-	check_repository_format_gently(get_git_dir(), &repo_fmt, NULL);
+	if (!fmt)
+		fmt = &repo_fmt;
+	check_repository_format_gently(get_git_dir(), fmt, NULL);
 	startup_info->have_repository = 1;
 	clear_repository_format(&repo_fmt);
 }
diff --git a/sha1-file.c b/sha1-file.c
index 6168867..ccd34dd 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -74,6 +74,11 @@ static void git_hash_sha1_init(git_hash_ctx *ctx)
 	git_SHA1_Init(&ctx->sha1);
 }
 
+static void git_hash_sha1_clone(git_hash_ctx *dst, const git_hash_ctx *src)
+{
+	git_SHA1_Clone(&dst->sha1, &src->sha1);
+}
+
 static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
 {
 	git_SHA1_Update(&ctx->sha1, data, len);
@@ -90,6 +95,11 @@ static void git_hash_sha256_init(git_hash_ctx *ctx)
 	git_SHA256_Init(&ctx->sha256);
 }
 
+static void git_hash_sha256_clone(git_hash_ctx *dst, const git_hash_ctx *src)
+{
+	git_SHA256_Clone(&dst->sha256, &src->sha256);
+}
+
 static void git_hash_sha256_update(git_hash_ctx *ctx, const void *data, size_t len)
 {
 	git_SHA256_Update(&ctx->sha256, data, len);
@@ -105,6 +115,11 @@ static void git_hash_unknown_init(git_hash_ctx *ctx)
 	BUG("trying to init unknown hash");
 }
 
+static void git_hash_unknown_clone(git_hash_ctx *dst, const git_hash_ctx *src)
+{
+	BUG("trying to clone unknown hash");
+}
+
 static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
 {
 	BUG("trying to update unknown hash");
@@ -123,6 +138,7 @@ const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 		0,
 		0,
 		git_hash_unknown_init,
+		git_hash_unknown_clone,
 		git_hash_unknown_update,
 		git_hash_unknown_final,
 		NULL,
@@ -136,6 +152,7 @@ const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 		GIT_SHA1_HEXSZ,
 		GIT_SHA1_BLKSZ,
 		git_hash_sha1_init,
+		git_hash_sha1_clone,
 		git_hash_sha1_update,
 		git_hash_sha1_final,
 		&empty_tree_oid,
@@ -149,6 +166,7 @@ const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 		GIT_SHA256_HEXSZ,
 		GIT_SHA256_BLKSZ,
 		git_hash_sha256_init,
+		git_hash_sha256_clone,
 		git_hash_sha256_update,
 		git_hash_sha256_final,
 		&empty_tree_oid_sha256,
@@ -676,20 +694,15 @@ void add_to_alternates_memory(const char *reference)
 char *compute_alternate_path(const char *path, struct strbuf *err)
 {
 	char *ref_git = NULL;
-	const char *repo, *ref_git_s;
+	const char *repo;
 	int seen_error = 0;
 
-	ref_git_s = real_path_if_valid(path);
-	if (!ref_git_s) {
+	ref_git = real_pathdup(path, 0);
+	if (!ref_git) {
 		seen_error = 1;
 		strbuf_addf(err, _("path '%s' does not exist"), path);
 		goto out;
-	} else
-		/*
-		 * Beware: read_gitfile(), real_path() and mkpath()
-		 * return static buffer
-		 */
-		ref_git = xstrdup(ref_git_s);
+	}
 
 	repo = read_gitfile(ref_git);
 	if (!repo)
@@ -868,9 +881,7 @@ void prepare_alt_odb(struct repository *r)
 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
 static int freshen_file(const char *fn)
 {
-	struct utimbuf t;
-	t.actime = t.modtime = time(NULL);
-	return !utime(fn, &t);
+	return !utime(fn, NULL);
 }
 
 /*
diff --git a/sha1-name.c b/sha1-name.c
index 5bb006e..0b8cb52 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -8,7 +8,7 @@
 #include "refs.h"
 #include "remote.h"
 #include "dir.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "packfile.h"
 #include "object-store.h"
 #include "repository.h"
@@ -1815,8 +1815,8 @@ static enum get_oid_result get_oid_with_context_1(struct repository *repo,
 
 			cb.repo = repo;
 			cb.list = &list;
-			refs_for_each_ref(repo->refs, handle_one_ref, &cb);
-			refs_head_ref(repo->refs, handle_one_ref, &cb);
+			refs_for_each_ref(get_main_ref_store(repo), handle_one_ref, &cb);
+			refs_head_ref(get_main_ref_store(repo), handle_one_ref, &cb);
 			commit_list_sort_by_date(&list);
 			return get_oid_oneline(repo, name + 2, oid, list);
 		}
diff --git a/sha256/gcrypt.h b/sha256/gcrypt.h
index 09bd8bb..501da5e 100644
--- a/sha256/gcrypt.h
+++ b/sha256/gcrypt.h
@@ -22,8 +22,14 @@ inline void gcrypt_SHA256_Final(unsigned char *digest, gcrypt_SHA256_CTX *ctx)
 	memcpy(digest, gcry_md_read(*ctx, GCRY_MD_SHA256), SHA256_DIGEST_SIZE);
 }
 
+inline void gcrypt_SHA256_Clone(gcrypt_SHA256_CTX *dst, const gcrypt_SHA256_CTX *src)
+{
+	gcry_md_copy(dst, *src);
+}
+
 #define platform_SHA256_CTX gcrypt_SHA256_CTX
 #define platform_SHA256_Init gcrypt_SHA256_Init
+#define platform_SHA256_Clone gcrypt_SHA256_Clone
 #define platform_SHA256_Update gcrypt_SHA256_Update
 #define platform_SHA256_Final gcrypt_SHA256_Final
 
diff --git a/shallow.c b/shallow.c
index 5010a6c..321a276 100644
--- a/shallow.c
+++ b/shallow.c
@@ -8,7 +8,7 @@
 #include "pkt-line.h"
 #include "remote.h"
 #include "refs.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "diff.h"
 #include "revision.h"
 #include "commit-slab.h"
diff --git a/shell.c b/shell.c
index 54cca74..cef7ffd 100644
--- a/shell.c
+++ b/shell.c
@@ -4,6 +4,7 @@
 #include "strbuf.h"
 #include "run-command.h"
 #include "alias.h"
+#include "prompt.h"
 
 #define COMMAND_DIR "git-shell-commands"
 #define HELP_COMMAND COMMAND_DIR "/help"
@@ -76,12 +77,11 @@ static void run_shell(void)
 		int count;
 
 		fprintf(stderr, "git> ");
-		if (strbuf_getline_lf(&line, stdin) == EOF) {
+		if (git_read_line_interactively(&line) == EOF) {
 			fprintf(stderr, "\n");
 			strbuf_release(&line);
 			break;
 		}
-		strbuf_trim(&line);
 		rawargs = strbuf_detach(&line, NULL);
 		split_args = xstrdup(rawargs);
 		count = split_cmdline(split_args, &argv);
diff --git a/strbuf.c b/strbuf.c
index bb0065c..6e74901 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -690,6 +690,16 @@ int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 }
 #endif
 
+int strbuf_appendwholeline(struct strbuf *sb, FILE *fp, int term)
+{
+	struct strbuf line = STRBUF_INIT;
+	if (strbuf_getwholeline(&line, fp, term))
+		return EOF;
+	strbuf_addbuf(sb, &line);
+	strbuf_release(&line);
+	return 0;
+}
+
 static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)
 {
 	if (strbuf_getwholeline(sb, fp, term))
diff --git a/strbuf.h b/strbuf.h
index ce8e49c..411063c 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -503,6 +503,12 @@ int strbuf_getline(struct strbuf *sb, FILE *file);
 int strbuf_getwholeline(struct strbuf *sb, FILE *file, int term);
 
 /**
+ * Like `strbuf_getwholeline`, but appends the line instead of
+ * resetting the buffer first.
+ */
+int strbuf_appendwholeline(struct strbuf *sb, FILE *file, int term);
+
+/**
  * Like `strbuf_getwholeline`, but operates on a file descriptor.
  * It reads one character at a time, so it is very slow.  Do not
  * use it unless you need the correct position in the file
diff --git a/submodule-config.c b/submodule-config.c
index 4d1c92d..e175dfb 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -225,7 +225,8 @@ static int name_and_item_from_var(const char *var, struct strbuf *name,
 				  struct strbuf *item)
 {
 	const char *subsection, *key;
-	int subsection_len, parse;
+	size_t subsection_len;
+	int parse;
 	parse = parse_config_key(var, "submodule", &subsection,
 			&subsection_len, &key);
 	if (parse < 0 || !subsection)
diff --git a/submodule.c b/submodule.c
index 31f391d..e2ef569 100644
--- a/submodule.c
+++ b/submodule.c
@@ -12,7 +12,7 @@
 #include "diffcore.h"
 #include "refs.h"
 #include "string-list.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "argv-array.h"
 #include "blob.h"
 #include "thread-utils.h"
@@ -2168,13 +2168,13 @@ void absorb_git_dir_into_superproject(const char *path,
 	}
 }
 
-const char *get_superproject_working_tree(void)
+int get_superproject_working_tree(struct strbuf *buf)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct strbuf sb = STRBUF_INIT;
-	const char *one_up = real_path_if_valid("../");
+	struct strbuf one_up = STRBUF_INIT;
 	const char *cwd = xgetcwd();
-	const char *ret = NULL;
+	int ret = 0;
 	const char *subpath;
 	int code;
 	ssize_t len;
@@ -2185,12 +2185,13 @@ const char *get_superproject_working_tree(void)
 		 * We might have a superproject, but it is harder
 		 * to determine.
 		 */
-		return NULL;
+		return 0;
 
-	if (!one_up)
-		return NULL;
+	if (!strbuf_realpath(&one_up, "../", 0))
+		return 0;
 
-	subpath = relative_path(cwd, one_up, &sb);
+	subpath = relative_path(cwd, one_up.buf, &sb);
+	strbuf_release(&one_up);
 
 	prepare_submodule_repo_env(&cp.env_array);
 	argv_array_pop(&cp.env_array);
@@ -2231,7 +2232,8 @@ const char *get_superproject_working_tree(void)
 		super_wt = xstrdup(cwd);
 		super_wt[cwd_len - super_sub_len] = '\0';
 
-		ret = real_path(super_wt);
+		strbuf_realpath(buf, super_wt, 1);
+		ret = 1;
 		free(super_wt);
 	}
 	strbuf_release(&sb);
@@ -2240,10 +2242,10 @@ const char *get_superproject_working_tree(void)
 
 	if (code == 128)
 		/* '../' is not a git repository */
-		return NULL;
+		return 0;
 	if (code == 0 && len == 0)
 		/* There is an unrelated git repository at '../' */
-		return NULL;
+		return 0;
 	if (code)
 		die(_("ls-tree returned unexpected return code %d"), code);
 
diff --git a/submodule.h b/submodule.h
index c81ec1a..4dad649 100644
--- a/submodule.h
+++ b/submodule.h
@@ -152,8 +152,8 @@ void absorb_git_dir_into_superproject(const char *path,
 /*
  * Return the absolute path of the working tree of the superproject, which this
  * project is a submodule of. If this repository is not a submodule of
- * another repository, return NULL.
+ * another repository, return 0.
  */
-const char *get_superproject_working_tree(void);
+int get_superproject_working_tree(struct strbuf *buf);
 
 #endif
diff --git a/t/README b/t/README
index 9afd61e..13747f1 100644
--- a/t/README
+++ b/t/README
@@ -69,7 +69,8 @@
 
 You can pass --verbose (or -v), --debug (or -d), and --immediate
 (or -i) command line argument to the test, or by setting GIT_TEST_OPTS
-appropriately before running "make".
+appropriately before running "make". Short options can be bundled, i.e.
+'-d -v' is the same as '-dv'.
 
 -v::
 --verbose::
@@ -386,17 +387,13 @@
 for the index version specified.  Can be set to any valid version
 (currently 2, 3, or 4).
 
-GIT_TEST_PACK_SPARSE=<boolean> if enabled will default the pack-objects
-builtin to use the sparse object walk. This can still be overridden by
-the --no-sparse command-line argument.
+GIT_TEST_PACK_SPARSE=<boolean> if disabled will default the pack-objects
+builtin to use the non-sparse object walk. This can still be overridden by
+the --sparse command-line argument.
 
 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
 by overriding the minimum number of cache entries required per thread.
 
-GIT_TEST_STASH_USE_BUILTIN=<boolean>, when false, disables the
-built-in version of git-stash. See 'stash.useBuiltin' in
-git-config(1).
-
 GIT_TEST_ADD_I_USE_BUILTIN=<boolean>, when true, enables the
 built-in version of git add -i. See 'add.interactive.useBuiltin' in
 git-config(1).
@@ -550,6 +547,41 @@
    reports "ok" or "not ok" to the end user running the tests. Under
    --verbose, they are shown to help debug the tests.
 
+ - Be careful when you loop
+
+   You may need to verify multiple things in a loop, but the
+   following does not work correctly:
+
+	test_expect_success 'test three things' '
+	    for i in one two three
+	    do
+		test_something "$i"
+	    done &&
+	    test_something_else
+	'
+
+   Because the status of the loop itself is the exit status of the
+   test_something in the last round, the loop does not fail when
+   "test_something" for "one" or "two" fails.  This is not what you
+   want.
+
+   Instead, you can break out of the loop immediately when you see a
+   failure.  Because all test_expect_* snippets are executed inside
+   a function, "return 1" can be used to fail the test immediately
+   upon a failure:
+
+	test_expect_success 'test three things' '
+	    for i in one two three
+	    do
+		test_something "$i" || return 1
+	    done &&
+	    test_something_else
+	'
+
+   Note that we still &&-chain the loop to propagate failures from
+   earlier commands.
+
+
 And here are the "don'ts:"
 
  - Don't exit() within a <script> part.
diff --git a/t/helper/test-advise.c b/t/helper/test-advise.c
new file mode 100644
index 0000000..38cdc28
--- /dev/null
+++ b/t/helper/test-advise.c
@@ -0,0 +1,22 @@
+#include "test-tool.h"
+#include "cache.h"
+#include "advice.h"
+#include "config.h"
+
+int cmd__advise_if_enabled(int argc, const char **argv)
+{
+	if (!argv[1])
+	die("usage: %s <advice>", argv[0]);
+
+	setup_git_directory();
+	git_config(git_default_config, NULL);
+
+	/*
+	 * Any advice type can be used for testing, but NESTED_TAG was
+	 * selected here and in t0018 where this command is being
+	 * executed.
+	 */
+	advise_if_enabled(ADVICE_NESTED_TAG, argv[1]);
+
+	return 0;
+}
diff --git a/t/helper/test-dump-split-index.c b/t/helper/test-dump-split-index.c
index 63c689d..a209880 100644
--- a/t/helper/test-dump-split-index.c
+++ b/t/helper/test-dump-split-index.c
@@ -13,6 +13,8 @@ int cmd__dump_split_index(int ac, const char **av)
 	struct split_index *si;
 	int i;
 
+	setup_git_directory();
+
 	do_read_index(&the_index, av[1], 1);
 	printf("own %s\n", oid_to_hex(&the_index.oid));
 	si = the_index.split_index;
diff --git a/t/helper/test-sha1-array.c b/t/helper/test-oid-array.c
similarity index 83%
rename from t/helper/test-sha1-array.c
rename to t/helper/test-oid-array.c
index ad5e69f..ce9fd5f 100644
--- a/t/helper/test-sha1-array.c
+++ b/t/helper/test-oid-array.c
@@ -1,6 +1,6 @@
 #include "test-tool.h"
 #include "cache.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 
 static int print_oid(const struct object_id *oid, void *data)
 {
@@ -8,7 +8,7 @@ static int print_oid(const struct object_id *oid, void *data)
 	return 0;
 }
 
-int cmd__sha1_array(int argc, const char **argv)
+int cmd__oid_array(int argc, const char **argv)
 {
 	struct oid_array array = OID_ARRAY_INIT;
 	struct strbuf line = STRBUF_INIT;
@@ -19,11 +19,11 @@ int cmd__sha1_array(int argc, const char **argv)
 
 		if (skip_prefix(line.buf, "append ", &arg)) {
 			if (get_oid_hex(arg, &oid))
-				die("not a hexadecimal SHA1: %s", arg);
+				die("not a hexadecimal oid: %s", arg);
 			oid_array_append(&array, &oid);
 		} else if (skip_prefix(line.buf, "lookup ", &arg)) {
 			if (get_oid_hex(arg, &oid))
-				die("not a hexadecimal SHA1: %s", arg);
+				die("not a hexadecimal oid: %s", arg);
 			printf("%d\n", oid_array_lookup(&array, &oid));
 		} else if (!strcmp(line.buf, "clear"))
 			oid_array_clear(&array);
diff --git a/t/helper/test-path-utils.c b/t/helper/test-path-utils.c
index 409034c..313a153 100644
--- a/t/helper/test-path-utils.c
+++ b/t/helper/test-path-utils.c
@@ -290,11 +290,14 @@ int cmd__path_utils(int argc, const char **argv)
 	}
 
 	if (argc >= 2 && !strcmp(argv[1], "real_path")) {
+		struct strbuf realpath = STRBUF_INIT;
 		while (argc > 2) {
-			puts(real_path(argv[2]));
+			strbuf_realpath(&realpath, argv[2], 1);
+			puts(realpath.buf);
 			argc--;
 			argv++;
 		}
+		strbuf_release(&realpath);
 		return 0;
 	}
 
diff --git a/t/helper/test-pkt-line.c b/t/helper/test-pkt-line.c
index 282d536..12ca698 100644
--- a/t/helper/test-pkt-line.c
+++ b/t/helper/test-pkt-line.c
@@ -67,7 +67,7 @@ static void unpack_sideband(void)
 		case PACKET_READ_NORMAL:
 			band = reader.line[0] & 0xff;
 			if (band < 1 || band > 2)
-				die("unexpected side band %d", band);
+				continue; /* skip non-sideband packets */
 			fd = band;
 
 			write_or_die(fd, reader.line + 1, reader.pktlen - 1);
diff --git a/t/helper/test-repository.c b/t/helper/test-repository.c
index f7f8618..56f0e3c 100644
--- a/t/helper/test-repository.c
+++ b/t/helper/test-repository.c
@@ -19,12 +19,11 @@ static void test_parse_commit_in_graph(const char *gitdir, const char *worktree,
 
 	memset(the_repository, 0, sizeof(*the_repository));
 
-	/* TODO: Needed for temporary hack in hashcmp, see 183a638b7da. */
-	repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
-
 	if (repo_init(&r, gitdir, worktree))
 		die("Couldn't init repo");
 
+	repo_set_hash_algo(the_repository, hash_algo_by_ptr(r.hash_algo));
+
 	c = lookup_commit(&r, commit_oid);
 
 	if (!parse_commit_in_graph(&r, c))
@@ -50,12 +49,11 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
 
 	memset(the_repository, 0, sizeof(*the_repository));
 
-	/* TODO: Needed for temporary hack in hashcmp, see 183a638b7da. */
-	repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
-
 	if (repo_init(&r, gitdir, worktree))
 		die("Couldn't init repo");
 
+	repo_set_hash_algo(the_repository, hash_algo_by_ptr(r.hash_algo));
+
 	c = lookup_commit(&r, commit_oid);
 
 	/*
@@ -75,6 +73,10 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
 
 int cmd__repository(int argc, const char **argv)
 {
+	int nongit_ok = 0;
+
+	setup_git_directory_gently(&nongit_ok);
+
 	if (argc < 2)
 		die("must have at least 2 arguments");
 	if (!strcmp(argv[1], "parse_commit_in_graph")) {
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index c9a232d..2ece4d1 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -14,6 +14,7 @@ struct test_cmd {
 };
 
 static struct test_cmd cmds[] = {
+	{ "advise", cmd__advise_if_enabled },
 	{ "chmtime", cmd__chmtime },
 	{ "config", cmd__config },
 	{ "ctype", cmd__ctype },
@@ -36,6 +37,7 @@ static struct test_cmd cmds[] = {
 	{ "match-trees", cmd__match_trees },
 	{ "mergesort", cmd__mergesort },
 	{ "mktemp", cmd__mktemp },
+	{ "oid-array", cmd__oid_array },
 	{ "oidmap", cmd__oidmap },
 	{ "online-cpus", cmd__online_cpus },
 	{ "parse-options", cmd__parse_options },
@@ -56,7 +58,6 @@ static struct test_cmd cmds[] = {
 	{ "scrap-cache-tree", cmd__scrap_cache_tree },
 	{ "serve-v2", cmd__serve_v2 },
 	{ "sha1", cmd__sha1 },
-	{ "sha1-array", cmd__sha1_array },
 	{ "sha256", cmd__sha256 },
 	{ "sigchain", cmd__sigchain },
 	{ "strcmp-offset", cmd__strcmp_offset },
@@ -111,6 +112,7 @@ int cmd_main(int argc, const char **argv)
 			argc--;
 			trace2_cmd_name(cmds[i].name);
 			trace2_cmd_list_config();
+			trace2_cmd_list_env_vars();
 			return cmds[i].fn(argc, argv);
 		}
 	}
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index c8549fd..1cbaec0 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -4,6 +4,7 @@
 #define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "git-compat-util.h"
 
+int cmd__advise_if_enabled(int argc, const char **argv);
 int cmd__chmtime(int argc, const char **argv);
 int cmd__config(int argc, const char **argv);
 int cmd__ctype(int argc, const char **argv);
@@ -46,7 +47,7 @@ int cmd__run_command(int argc, const char **argv);
 int cmd__scrap_cache_tree(int argc, const char **argv);
 int cmd__serve_v2(int argc, const char **argv);
 int cmd__sha1(int argc, const char **argv);
-int cmd__sha1_array(int argc, const char **argv);
+int cmd__oid_array(int argc, const char **argv);
 int cmd__sha256(int argc, const char **argv);
 int cmd__sigchain(int argc, const char **argv);
 int cmd__strcmp_offset(int argc, const char **argv);
diff --git a/t/lib-credential.sh b/t/lib-credential.sh
old mode 100755
new mode 100644
index 937b831..dea2cbe
--- a/t/lib-credential.sh
+++ b/t/lib-credential.sh
@@ -1,4 +1,5 @@
-#!/bin/sh
+# Shell library for testing credential handling including helpers. See t0302
+# for an example of testing a specific helper.
 
 # Try a set of credential helpers; the expected stdin,
 # stdout and stderr should be provided on stdin,
@@ -19,7 +20,7 @@
 		false
 	fi &&
 	test_cmp expect-stdout stdout &&
-	test_cmp expect-stderr stderr
+	test_i18ncmp expect-stderr stderr
 }
 
 read_chunk() {
diff --git a/t/lib-gpg.sh b/t/lib-gpg.sh
old mode 100755
new mode 100644
index 8d28652..9fc5241
--- a/t/lib-gpg.sh
+++ b/t/lib-gpg.sh
@@ -1,14 +1,25 @@
-#!/bin/sh
+# We always set GNUPGHOME, even if no usable GPG was found, as
+#
+# - It does not hurt, and
+#
+# - we cannot set global environment variables in lazy prereqs because they are
+#   executed in an eval'ed subshell that changes the working directory to a
+#   temporary one.
 
-gpg_version=$(gpg --version 2>&1)
-if test $? != 127
-then
+GNUPGHOME="$PWD/gpghome"
+export GNUPGHOME
+
+test_lazy_prereq GPG '
+	gpg_version=$(gpg --version 2>&1)
+	test $? != 127 || exit 1
+
 	# As said here: http://www.gnupg.org/documentation/faqs.html#q6.19
-	# the gpg version 1.0.6 didn't parse trust packets correctly, so for
+	# the gpg version 1.0.6 did not parse trust packets correctly, so for
 	# that version, creation of signed tags using the generated key fails.
 	case "$gpg_version" in
-	'gpg (GnuPG) 1.0.6'*)
+	"gpg (GnuPG) 1.0.6"*)
 		say "Your version of gpg (1.0.6) is too buggy for testing"
+		exit 1
 		;;
 	*)
 		# Available key info:
@@ -27,55 +38,54 @@
 		# To export ownertrust:
 		#	gpg --homedir /tmp/gpghome --export-ownertrust \
 		#		> lib-gpg/ownertrust
-		mkdir ./gpghome &&
-		chmod 0700 ./gpghome &&
-		GNUPGHOME="$(pwd)/gpghome" &&
-		export GNUPGHOME &&
-		(gpgconf --kill gpg-agent >/dev/null 2>&1 || : ) &&
-		gpg --homedir "${GNUPGHOME}" 2>/dev/null --import \
+		mkdir "$GNUPGHOME" &&
+		chmod 0700 "$GNUPGHOME" &&
+		(gpgconf --kill gpg-agent || : ) &&
+		gpg --homedir "${GNUPGHOME}" --import \
 			"$TEST_DIRECTORY"/lib-gpg/keyring.gpg &&
-		gpg --homedir "${GNUPGHOME}" 2>/dev/null --import-ownertrust \
+		gpg --homedir "${GNUPGHOME}" --import-ownertrust \
 			"$TEST_DIRECTORY"/lib-gpg/ownertrust &&
-		gpg --homedir "${GNUPGHOME}" </dev/null >/dev/null 2>&1 \
-			--sign -u committer@example.com &&
-		test_set_prereq GPG &&
-		# Available key info:
-		# * see t/lib-gpg/gpgsm-gen-key.in
-		# To generate new certificate:
-		#  * no passphrase
-		#	gpgsm --homedir /tmp/gpghome/ \
-		#		-o /tmp/gpgsm.crt.user \
-		#		--generate-key \
-		#		--batch t/lib-gpg/gpgsm-gen-key.in
-		# To import certificate:
-		#	gpgsm --homedir /tmp/gpghome/ \
-		#		--import /tmp/gpgsm.crt.user
-		# To export into a .p12 we can later import:
-		#	gpgsm --homedir /tmp/gpghome/ \
-		#		-o t/lib-gpg/gpgsm_cert.p12 \
-		#		--export-secret-key-p12 "committer@example.com"
-		echo | gpgsm --homedir "${GNUPGHOME}" 2>/dev/null \
-			--passphrase-fd 0 --pinentry-mode loopback \
-			--import "$TEST_DIRECTORY"/lib-gpg/gpgsm_cert.p12 &&
-
-		gpgsm --homedir "${GNUPGHOME}" 2>/dev/null -K |
-		grep fingerprint: |
-		cut -d" " -f4 |
-		tr -d '\n' >"${GNUPGHOME}/trustlist.txt" &&
-
-		echo " S relax" >>"${GNUPGHOME}/trustlist.txt" &&
-		echo hello | gpgsm --homedir "${GNUPGHOME}" >/dev/null \
-			-u committer@example.com -o /dev/null --sign - 2>&1 &&
-		test_set_prereq GPGSM
+		gpg --homedir "${GNUPGHOME}" </dev/null >/dev/null \
+			--sign -u committer@example.com
 		;;
 	esac
-fi
+'
 
-if test_have_prereq GPG &&
-    echo | gpg --homedir "${GNUPGHOME}" -b --rfc1991 >/dev/null 2>&1
-then
-	test_set_prereq RFC1991
-fi
+test_lazy_prereq GPGSM '
+	test_have_prereq GPG &&
+	# Available key info:
+	# * see t/lib-gpg/gpgsm-gen-key.in
+	# To generate new certificate:
+	#  * no passphrase
+	#	gpgsm --homedir /tmp/gpghome/ \
+	#		-o /tmp/gpgsm.crt.user \
+	#		--generate-key \
+	#		--batch t/lib-gpg/gpgsm-gen-key.in
+	# To import certificate:
+	#	gpgsm --homedir /tmp/gpghome/ \
+	#		--import /tmp/gpgsm.crt.user
+	# To export into a .p12 we can later import:
+	#	gpgsm --homedir /tmp/gpghome/ \
+	#		-o t/lib-gpg/gpgsm_cert.p12 \
+	#		--export-secret-key-p12 "committer@example.com"
+	echo | gpgsm --homedir "${GNUPGHOME}" \
+		--passphrase-fd 0 --pinentry-mode loopback \
+		--import "$TEST_DIRECTORY"/lib-gpg/gpgsm_cert.p12 &&
+
+	gpgsm --homedir "${GNUPGHOME}" -K |
+	grep fingerprint: |
+	cut -d" " -f4 |
+	tr -d "\\n" >"${GNUPGHOME}/trustlist.txt" &&
+
+	echo " S relax" >>"${GNUPGHOME}/trustlist.txt" &&
+	echo hello | gpgsm --homedir "${GNUPGHOME}" >/dev/null \
+	       -u committer@example.com -o /dev/null --sign -
+'
+
+test_lazy_prereq RFC1991 '
+	test_have_prereq GPG &&
+	echo | gpg --homedir "${GNUPGHOME}" -b --rfc1991 >/dev/null
+'
 
 sanitize_pgp() {
 	perl -ne '
diff --git a/t/lib-log-graph.sh b/t/lib-log-graph.sh
old mode 100755
new mode 100644
diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
old mode 100755
new mode 100644
index 1dd17fc..64fc648
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -297,7 +297,7 @@
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # The default is that submodule contents aren't changed until "git submodule
 # update" is run. And even then that command doesn't delete the work tree of
@@ -621,11 +621,13 @@
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # New test cases
 # - Removing a submodule with a git directory absorbs the submodules
 #   git directory first into the superproject.
+# - Switching from no submodule to nested submodules
+# - Switching from nested submodules to no submodule
 
 # Internal function; use test_submodule_switch_recursing_with_args() or
 # test_submodule_forced_switch_recursing_with_args() instead.
@@ -658,22 +660,6 @@
 			test_submodule_content sub1 origin/add_sub1
 		)
 	'
-	test_expect_success "$command: submodule branch is not changed, detach HEAD instead" '
-		prolog &&
-		reset_work_tree_to_interested add_sub1 &&
-		(
-			cd submodule_update &&
-			git -C sub1 checkout -b keep_branch &&
-			git -C sub1 rev-parse HEAD >expect &&
-			git branch -t modify_sub1 origin/modify_sub1 &&
-			$command modify_sub1 &&
-			test_superproject_content origin/modify_sub1 &&
-			test_submodule_content sub1 origin/modify_sub1 &&
-			git -C sub1 rev-parse keep_branch >actual &&
-			test_cmp expect actual &&
-			test_must_fail git -C sub1 symbolic-ref HEAD
-		)
-	'
 
 	# Replacing a tracked file with a submodule produces a checked out submodule
 	test_expect_success "$command: replace tracked file with submodule checks out submodule" '
@@ -699,6 +685,19 @@
 			test_submodule_content sub1 origin/replace_directory_with_sub1
 		)
 	'
+	# Switching to a commit with nested submodules recursively checks them out
+	test_expect_success "$command: nested submodules are checked out" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t modify_sub1_recursively origin/modify_sub1_recursively &&
+			$command modify_sub1_recursively &&
+			test_superproject_content origin/modify_sub1_recursively &&
+			test_submodule_content sub1 origin/modify_sub1_recursively &&
+			test_submodule_content -C sub1 sub2 origin/modify_sub1_recursively
+		)
+	'
 
 	######################## Disappearing submodule #######################
 	# Removing a submodule removes its work tree ...
@@ -762,6 +761,21 @@
 		)
 	'
 
+	# Switching to a commit without nested submodules removes their worktrees
+	test_expect_success "$command: worktrees of nested submodules are removed" '
+		prolog &&
+		reset_work_tree_to_interested add_nested_sub &&
+		(
+			cd submodule_update &&
+			git branch -t no_submodule origin/no_submodule &&
+			$command no_submodule &&
+			test_superproject_content origin/no_submodule &&
+			! test_path_is_dir sub1 &&
+			test_must_fail git config -f .git/modules/sub1/config core.worktree &&
+			test_must_fail git config -f .git/modules/sub1/modules/sub2/config core.worktree
+		)
+	'
+
 	########################## Modified submodule #########################
 	# Updating a submodule sha1 updates the submodule's work tree
 	test_expect_success "$command: modified submodule updates submodule work tree" '
@@ -789,6 +803,23 @@
 			test_submodule_content sub1 origin/add_sub1
 		)
 	'
+	# Updating a submodule does not touch the currently checked out branch in the submodule
+	test_expect_success "$command: submodule branch is not changed, detach HEAD instead" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git -C sub1 checkout -b keep_branch &&
+			git -C sub1 rev-parse HEAD >expect &&
+			git branch -t modify_sub1 origin/modify_sub1 &&
+			$command modify_sub1 &&
+			test_superproject_content origin/modify_sub1 &&
+			test_submodule_content sub1 origin/modify_sub1 &&
+			git -C sub1 rev-parse keep_branch >actual &&
+			test_cmp expect actual &&
+			test_must_fail git -C sub1 symbolic-ref HEAD
+		)
+	'
 }
 
 # Declares and invokes several tests that, in various situations, checks that
@@ -908,7 +939,6 @@
 		)
 	'
 
-	# recursing deeper than one level doesn't work yet.
 	test_expect_success "$command: modified submodule updates submodule recursively" '
 		prolog &&
 		reset_work_tree_to_interested add_nested_sub &&
diff --git a/t/perf/p5310-pack-bitmaps.sh b/t/perf/p5310-pack-bitmaps.sh
index 7743f4f..80c53ed 100755
--- a/t/perf/p5310-pack-bitmaps.sh
+++ b/t/perf/p5310-pack-bitmaps.sh
@@ -31,10 +31,6 @@
 	} | git pack-objects --revs --stdout >/dev/null
 '
 
-test_perf 'pack to file' '
-	git pack-objects --all pack1 </dev/null >/dev/null
-'
-
 test_perf 'pack to file (bitmap)' '
 	git pack-objects --use-bitmap-index --all pack1b </dev/null >/dev/null
 '
diff --git a/t/perf/p9300-fast-import-export.sh b/t/perf/p9300-fast-import-export.sh
new file mode 100755
index 0000000..586161e
--- /dev/null
+++ b/t/perf/p9300-fast-import-export.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+test_description='test fast-import and fast-export performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+# Use --no-data here to produce a vastly smaller export file.
+# This is much cheaper to work with but should still exercise
+# fast-import pretty well (we'll still process all commits and
+# trees, which account for 60% or more of objects in most repos).
+#
+# Use --reencode to avoid the default of aborting on non-utf8 commits,
+# which lets this test run against a wider variety of sample repos.
+test_perf 'export (no-blobs)' '
+	git fast-export --reencode=yes --no-data HEAD >export
+'
+
+test_perf 'import (no-blobs)' '
+	git fast-import --force <export
+'
+
+test_done
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 3e440c0..b859721 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -833,6 +833,19 @@
 	exit 1
 fi
 
+test_expect_success 'lazy prereqs do not turn off tracing' "
+	run_sub_test_lib_test lazy-prereq-and-tracing \
+		'lazy prereqs and -x' -v -x <<-\\EOF &&
+	test_lazy_prereq LAZY true
+
+	test_expect_success lazy 'test_have_prereq LAZY && echo trace'
+
+	test_done
+	EOF
+
+	grep 'echo trace' lazy-prereq-and-tracing/err
+"
+
 test_expect_success 'tests clean up even on failures' "
 	run_sub_test_lib_test_err \
 		failing-cleanup 'Failing tests with cleanup commands' <<-\\EOF &&
diff --git a/t/t0001-init.sh b/t/t0001-init.sh
index 26f8206..1edd5ae 100755
--- a/t/t0001-init.sh
+++ b/t/t0001-init.sh
@@ -392,13 +392,6 @@
 	test_path_is_dir realgitdir/refs
 '
 
-# Tests for the hidden file attribute on windows
-is_hidden () {
-	# Use the output of `attrib`, ignore the absolute path
-	case "$(attrib "$1")" in *H*?:*) return 0;; esac
-	return 1
-}
-
 test_expect_success MINGW '.git hidden' '
 	rm -rf newdir &&
 	(
@@ -406,7 +399,7 @@
 		mkdir newdir &&
 		cd newdir &&
 		git init &&
-		is_hidden .git
+		test_path_is_hidden .git
 	) &&
 	check_config newdir/.git false unset
 '
diff --git a/t/t0007-git-var.sh b/t/t0007-git-var.sh
index 1f600e2..88b9ae8 100755
--- a/t/t0007-git-var.sh
+++ b/t/t0007-git-var.sh
@@ -17,7 +17,7 @@
 	test_cmp expect actual
 '
 
-test_expect_success !FAIL_PREREQS,!AUTOIDENT 'requested identites are strict' '
+test_expect_success !FAIL_PREREQS,!AUTOIDENT 'requested identities are strict' '
 	(
 		sane_unset GIT_COMMITTER_NAME &&
 		sane_unset GIT_COMMITTER_EMAIL &&
diff --git a/t/t0018-advice.sh b/t/t0018-advice.sh
new file mode 100755
index 0000000..e03554d
--- /dev/null
+++ b/t/t0018-advice.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+test_description='Test advise_if_enabled functionality'
+
+. ./test-lib.sh
+
+test_expect_success 'advice should be printed when config variable is unset' '
+	cat >expect <<-\EOF &&
+	hint: This is a piece of advice
+	hint: Disable this message with "git config advice.nestedTag false"
+	EOF
+	test-tool advise "This is a piece of advice" 2>actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success 'advice should be printed when config variable is set to true' '
+	cat >expect <<-\EOF &&
+	hint: This is a piece of advice
+	hint: Disable this message with "git config advice.nestedTag false"
+	EOF
+	test_config advice.nestedTag true &&
+	test-tool advise "This is a piece of advice" 2>actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success 'advice should not be printed when config variable is set to false' '
+	test_config advice.nestedTag false &&
+	test-tool advise "This is a piece of advice" 2>actual &&
+	test_must_be_empty actual
+'
+
+test_done
diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index dc664da..4bfffa9 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -364,6 +364,10 @@
 		S=$(file_size test.r) &&
 		S2=$(file_size test2.r) &&
 		S3=$(file_size "testsubdir/test3 '\''sq'\'',\$x=.r") &&
+		M=$(git hash-object test.r) &&
+		M2=$(git hash-object test2.r) &&
+		M3=$(git hash-object "testsubdir/test3 '\''sq'\'',\$x=.r") &&
+		EMPTY=$(git hash-object /dev/null) &&
 
 		filter_git add . &&
 		cat >expected.log <<-EOF &&
@@ -378,14 +382,16 @@
 		test_cmp_count expected.log debug.log &&
 
 		git commit -m "test commit 2" &&
+		MASTER=$(git rev-parse --verify master) &&
+		META="ref=refs/heads/master treeish=$MASTER" &&
 		rm -f test2.r "testsubdir/test3 '\''sq'\'',\$x=.r" &&
 
 		filter_git checkout --quiet --no-progress . &&
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
-			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $S3 [OK] -- OUT: $S3 . [OK]
+			IN: smudge test2.r blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&
@@ -406,10 +412,10 @@
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
-			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
-			IN: smudge test4-empty.r 0 [OK] -- OUT: 0  [OK]
-			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $S3 [OK] -- OUT: $S3 . [OK]
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&
@@ -420,6 +426,117 @@
 	)
 '
 
+test_expect_success PERL 'required process filter should filter data for various subcommands' '
+	test_config_global filter.protocol.process "rot13-filter.pl debug.log clean smudge" &&
+	test_config_global filter.protocol.required true &&
+	(
+		cd repo &&
+
+		S=$(file_size test.r) &&
+		S2=$(file_size test2.r) &&
+		S3=$(file_size "testsubdir/test3 '\''sq'\'',\$x=.r") &&
+		M=$(git hash-object test.r) &&
+		M2=$(git hash-object test2.r) &&
+		M3=$(git hash-object "testsubdir/test3 '\''sq'\'',\$x=.r") &&
+		EMPTY=$(git hash-object /dev/null) &&
+
+		MASTER=$(git rev-parse --verify master) &&
+
+		cp "$TEST_ROOT/test.o" test5.r &&
+		git add test5.r &&
+		git commit -m "test commit 3" &&
+		git checkout empty-branch &&
+		filter_git rebase --onto empty-branch master^^ master &&
+		MASTER2=$(git rev-parse --verify master) &&
+		META="ref=refs/heads/master treeish=$MASTER2" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		git reset --hard empty-branch &&
+		filter_git reset --hard $MASTER &&
+		META="treeish=$MASTER" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		git branch old-master $MASTER &&
+		git reset --hard empty-branch &&
+		filter_git reset --hard old-master &&
+		META="ref=refs/heads/old-master treeish=$MASTER" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		git checkout -b merge empty-branch &&
+		git branch -f master $MASTER2 &&
+		filter_git merge master &&
+		META="treeish=$MASTER2" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		filter_git archive master >/dev/null &&
+		META="ref=refs/heads/master treeish=$MASTER2" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		TREE="$(git rev-parse $MASTER2^{tree})" &&
+		filter_git archive $TREE >/dev/null &&
+		META="treeish=$TREE" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log
+	)
+'
+
 test_expect_success PERL 'required process filter takes precedence' '
 	test_config_global filter.protocol.clean false &&
 	test_config_global filter.protocol.process "rot13-filter.pl debug.log clean" &&
@@ -519,17 +636,22 @@
 		EOF
 		test_cmp_count expected.log debug.log &&
 
-		rm -f *.file &&
+		M1="blob=$(git hash-object 1pkt_1__.file)" &&
+		M2="blob=$(git hash-object 2pkt_1+1.file)" &&
+		M3="blob=$(git hash-object 2pkt_2-1.file)" &&
+		M4="blob=$(git hash-object 2pkt_2__.file)" &&
+		M5="blob=$(git hash-object 3pkt_2+1.file)" &&
+		rm -f *.file debug.log &&
 
 		filter_git checkout --quiet --no-progress -- *.file &&
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge 1pkt_1__.file $(($S    )) [OK] -- OUT: $(($S    )) . [OK]
-			IN: smudge 2pkt_1+1.file $(($S  +1)) [OK] -- OUT: $(($S  +1)) .. [OK]
-			IN: smudge 2pkt_2-1.file $(($S*2-1)) [OK] -- OUT: $(($S*2-1)) .. [OK]
-			IN: smudge 2pkt_2__.file $(($S*2  )) [OK] -- OUT: $(($S*2  )) .. [OK]
-			IN: smudge 3pkt_2+1.file $(($S*2+1)) [OK] -- OUT: $(($S*2+1)) ... [OK]
+			IN: smudge 1pkt_1__.file $M1 $(($S    )) [OK] -- OUT: $(($S    )) . [OK]
+			IN: smudge 2pkt_1+1.file $M2 $(($S  +1)) [OK] -- OUT: $(($S  +1)) .. [OK]
+			IN: smudge 2pkt_2-1.file $M3 $(($S*2-1)) [OK] -- OUT: $(($S*2-1)) .. [OK]
+			IN: smudge 2pkt_2__.file $M4 $(($S*2  )) [OK] -- OUT: $(($S*2  )) .. [OK]
+			IN: smudge 3pkt_2+1.file $M5 $(($S*2+1)) [OK] -- OUT: $(($S*2+1)) ... [OK]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&
@@ -578,6 +700,10 @@
 		S=$(file_size test.r) &&
 		S2=$(file_size test2.r) &&
 		SF=$(file_size smudge-write-fail.r) &&
+		M=$(git hash-object test.r) &&
+		M2=$(git hash-object test2.r) &&
+		MF=$(git hash-object smudge-write-fail.r) &&
+		rm -f debug.log &&
 
 		git add . &&
 		rm -f *.r &&
@@ -591,11 +717,11 @@
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge smudge-write-fail.r $SF [OK] -- [WRITE FAIL]
+			IN: smudge smudge-write-fail.r blob=$MF $SF [OK] -- [WRITE FAIL]
 			START
 			init handshake complete
-			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
-			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test.r blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&
@@ -629,6 +755,10 @@
 		S=$(file_size test.r) &&
 		S2=$(file_size test2.r) &&
 		SE=$(file_size error.r) &&
+		M=$(git hash-object test.r) &&
+		M2=$(git hash-object test2.r) &&
+		ME=$(git hash-object error.r) &&
+		rm -f debug.log &&
 
 		git add . &&
 		rm -f *.r &&
@@ -637,9 +767,9 @@
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge error.r $SE [OK] -- [ERROR]
-			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
-			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge error.r blob=$ME $SE [OK] -- [ERROR]
+			IN: smudge test.r blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&
@@ -665,18 +795,21 @@
 		echo "error this blob and all future blobs" >abort.o &&
 		cp abort.o abort.r &&
 
+		M="blob=$(git hash-object abort.r)" &&
+		rm -f debug.log &&
 		SA=$(file_size abort.r) &&
 
 		git add . &&
 		rm -f *.r &&
 
+
 		# Note: This test assumes that Git filters files in alphabetical
 		# order ("abort.r" before "test.r").
 		filter_git checkout --quiet --no-progress . &&
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge abort.r $SA [OK] -- [ABORT]
+			IN: smudge abort.r $M $SA [OK] -- [ABORT]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&
@@ -727,27 +860,29 @@
 	) &&
 
 	S=$(file_size "$TEST_ROOT/test.o") &&
+	PM="ref=refs/heads/master treeish=$(git -C repo rev-parse --verify master) " &&
+	M="${PM}blob=$(git -C repo rev-parse --verify master:test.a)" &&
 	cat >a.exp <<-EOF &&
 		START
 		init handshake complete
-		IN: smudge test.a $S [OK] -- OUT: $S . [OK]
-		IN: smudge test-delay10.a $S [OK] -- [DELAYED]
-		IN: smudge test-delay11.a $S [OK] -- [DELAYED]
-		IN: smudge test-delay20.a $S [OK] -- [DELAYED]
+		IN: smudge test.a $M $S [OK] -- OUT: $S . [OK]
+		IN: smudge test-delay10.a $M $S [OK] -- [DELAYED]
+		IN: smudge test-delay11.a $M $S [OK] -- [DELAYED]
+		IN: smudge test-delay20.a $M $S [OK] -- [DELAYED]
 		IN: list_available_blobs test-delay10.a test-delay11.a [OK]
-		IN: smudge test-delay10.a 0 [OK] -- OUT: $S . [OK]
-		IN: smudge test-delay11.a 0 [OK] -- OUT: $S . [OK]
+		IN: smudge test-delay10.a $M 0 [OK] -- OUT: $S . [OK]
+		IN: smudge test-delay11.a $M 0 [OK] -- OUT: $S . [OK]
 		IN: list_available_blobs test-delay20.a [OK]
-		IN: smudge test-delay20.a 0 [OK] -- OUT: $S . [OK]
+		IN: smudge test-delay20.a $M 0 [OK] -- OUT: $S . [OK]
 		IN: list_available_blobs [OK]
 		STOP
 	EOF
 	cat >b.exp <<-EOF &&
 		START
 		init handshake complete
-		IN: smudge test-delay10.b $S [OK] -- [DELAYED]
+		IN: smudge test-delay10.b $M $S [OK] -- [DELAYED]
 		IN: list_available_blobs test-delay10.b [OK]
-		IN: smudge test-delay10.b 0 [OK] -- OUT: $S . [OK]
+		IN: smudge test-delay10.b $M 0 [OK] -- OUT: $S . [OK]
 		IN: list_available_blobs [OK]
 		STOP
 	EOF
@@ -767,8 +902,11 @@
 
 		rm *.a *.b &&
 		filter_git checkout . &&
-		test_cmp_count ../a.exp a.log &&
-		test_cmp_count ../b.exp b.log &&
+		# We are not checking out a ref here, so filter out ref metadata.
+		sed -e "s!$PM!!" ../a.exp >a.exp.filtered &&
+		sed -e "s!$PM!!" ../b.exp >b.exp.filtered &&
+		test_cmp_count a.exp.filtered a.log &&
+		test_cmp_count b.exp.filtered b.log &&
 
 		test_cmp_committed_rot13 "$TEST_ROOT/test.o" test.a &&
 		test_cmp_committed_rot13 "$TEST_ROOT/test.o" test-delay10.a &&
diff --git a/t/t0021/rot13-filter.pl b/t/t0021/rot13-filter.pl
index 4701072..cd32a82 100644
--- a/t/t0021/rot13-filter.pl
+++ b/t/t0021/rot13-filter.pl
@@ -135,7 +135,13 @@
 				if ( exists $DELAY{$pathname} and $DELAY{$pathname}{"requested"} == 0 ) {
 					$DELAY{$pathname}{"requested"} = 1;
 				}
+			} elsif ($buffer =~ /^(ref|treeish|blob)=/) {
+				print $debug " $buffer";
 			} else {
+				# In general, filters need to be graceful about
+				# new metadata, since it's documented that we
+				# can pass any key-value pairs, but for tests,
+				# let's be a little stricter.
 				die "Unknown message '$buffer'";
 			}
 
diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
index 3483b72..f8178ee 100755
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@@ -54,7 +54,7 @@
     -A, --alias-source <string>
                           get a string
     -Z, --alias-target <string>
-                          get a string
+                          alias of --alias-source
 
 EOF
 
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index 2ea2d00..56db5c8 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -476,6 +476,7 @@
 		C:\\git \
 		comm \
 		conout.c \
+		com0.c \
 		lptN \
 		\
 		--not \
@@ -488,6 +489,7 @@
 		"AUX.c" \
 		"abc/conOut\$  .xyz/test" \
 		lpt8 \
+		com9.c \
 		"lpt*" \
 		Nul \
 		"PRN./abc"
diff --git a/t/t0064-sha1-array.sh b/t/t0064-sha1-array.sh
index 5dda570..45685af 100755
--- a/t/t0064-sha1-array.sh
+++ b/t/t0064-sha1-array.sh
@@ -18,7 +18,7 @@
 	{
 		echoid append 88 44 aa 55 &&
 		echo for_each_unique
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	test_cmp expect actual
 '
 
@@ -28,7 +28,7 @@
 		echoid append 88 44 aa 55 &&
 		echoid append 88 44 aa 55 &&
 		echo for_each_unique
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	test_cmp expect actual
 '
 
@@ -36,7 +36,7 @@
 	{
 		echoid append 88 44 aa 55 &&
 		echoid lookup 55
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	n=$(cat actual) &&
 	test "$n" -eq 1
 '
@@ -45,7 +45,7 @@
 	{
 		echoid append 88 44 aa 55 &&
 		echoid lookup 33
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	n=$(cat actual) &&
 	test "$n" -lt 0
 '
@@ -55,7 +55,7 @@
 		echoid append 88 44 aa 55 &&
 		echoid append 88 44 aa 55 &&
 		echoid lookup 55
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	n=$(cat actual) &&
 	test "$n" -ge 2 &&
 	test "$n" -le 3
@@ -66,7 +66,7 @@
 		echoid append 88 44 aa 55 &&
 		echoid append 88 44 aa 55 &&
 		echoid lookup 66
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	n=$(cat actual) &&
 	test "$n" -lt 0
 '
@@ -81,7 +81,7 @@
 		echo "append $id1" &&
 		echo "append $id2" &&
 		echoid lookup 55
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	n=$(cat actual) &&
 	test "$n" -eq 0
 '
@@ -90,7 +90,7 @@
 	{
 		echoid append 55 55 &&
 		echoid lookup 55
-	} | test-tool sha1-array >actual &&
+	} | test-tool oid-array >actual &&
 	n=$(cat actual) &&
 	test "$n" -ge 0 &&
 	test "$n" -le 1
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 7065a1b..1529155 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -199,6 +199,43 @@
 	test_cmp expect actual
 '
 
+# Test listing of all "interesting" environment variables.
+
+test_expect_success JSON_PP 'event stream, list env vars' '
+	test_when_finished "rm trace.event actual expect" &&
+	GIT_TRACE2_EVENT="$(pwd)/trace.event" \
+		GIT_TRACE2_ENV_VARS="A_VAR,OTHER_VAR,MISSING" \
+		A_VAR=1 OTHER_VAR="hello world" test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
+	sed -e "s/^|//" >expect <<-EOF &&
+	|VAR1 = {
+	|  "_SID0_":{
+	|    "argv":[
+	|      "_EXE_",
+	|      "trace2",
+	|      "001return",
+	|      "0"
+	|    ],
+	|    "exit_code":0,
+	|    "hierarchy":"trace2",
+	|    "name":"trace2",
+	|    "params":[
+	|      {
+	|        "param":"A_VAR",
+	|        "value":"1"
+	|      },
+	|      {
+	|        "param":"OTHER_VAR",
+	|        "value":"hello world"
+	|      }
+	|    ],
+	|    "version":"$V"
+	|  }
+	|};
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success JSON_PP 'basic trace2_data' '
 	test_when_finished "rm trace.event actual expect" &&
 	GIT_TRACE2_EVENT="$(pwd)/trace.event" test-tool trace2 006data test_category k1 v1 test_category k2 v2 &&
diff --git a/t/t0300-credentials.sh b/t/t0300-credentials.sh
index 39f097e..48484cb 100755
--- a/t/t0300-credentials.sh
+++ b/t/t0300-credentials.sh
@@ -22,6 +22,11 @@
 	exit 0
 	EOF
 
+	write_script git-credential-quit <<-\EOF &&
+	. ./dump
+	echo quit=1
+	EOF
+
 	write_script git-credential-verbatim <<-\EOF &&
 	user=$1; shift
 	pass=$1; shift
@@ -35,43 +40,71 @@
 
 test_expect_success 'credential_fill invokes helper' '
 	check fill "verbatim foo bar" <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=foo
 	password=bar
 	--
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	EOF
 '
 
 test_expect_success 'credential_fill invokes multiple helpers' '
 	check fill useless "verbatim foo bar" <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=foo
 	password=bar
 	--
 	useless: get
+	useless: protocol=http
+	useless: host=example.com
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	EOF
 '
 
 test_expect_success 'credential_fill stops when we get a full response' '
 	check fill "verbatim one two" "verbatim three four" <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=one
 	password=two
 	--
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	EOF
 '
 
 test_expect_success 'credential_fill continues through partial response' '
 	check fill "verbatim one \"\"" "verbatim two three" <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=two
 	password=three
 	--
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	verbatim: username=one
 	EOF
 '
@@ -97,14 +130,20 @@
 
 test_expect_success 'credential_approve calls all helpers' '
 	check approve useless "verbatim one two" <<-\EOF
+	protocol=http
+	host=example.com
 	username=foo
 	password=bar
 	--
 	--
 	useless: store
+	useless: protocol=http
+	useless: host=example.com
 	useless: username=foo
 	useless: password=bar
 	verbatim: store
+	verbatim: protocol=http
+	verbatim: host=example.com
 	verbatim: username=foo
 	verbatim: password=bar
 	EOF
@@ -112,6 +151,8 @@
 
 test_expect_success 'do not bother storing password-less credential' '
 	check approve useless <<-\EOF
+	protocol=http
+	host=example.com
 	username=foo
 	--
 	--
@@ -121,14 +162,20 @@
 
 test_expect_success 'credential_reject calls all helpers' '
 	check reject useless "verbatim one two" <<-\EOF
+	protocol=http
+	host=example.com
 	username=foo
 	password=bar
 	--
 	--
 	useless: erase
+	useless: protocol=http
+	useless: host=example.com
 	useless: username=foo
 	useless: password=bar
 	verbatim: erase
+	verbatim: protocol=http
+	verbatim: host=example.com
 	verbatim: username=foo
 	verbatim: password=bar
 	EOF
@@ -136,33 +183,49 @@
 
 test_expect_success 'usernames can be preserved' '
 	check fill "verbatim \"\" three" <<-\EOF
+	protocol=http
+	host=example.com
 	username=one
 	--
+	protocol=http
+	host=example.com
 	username=one
 	password=three
 	--
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	verbatim: username=one
 	EOF
 '
 
 test_expect_success 'usernames can be overridden' '
 	check fill "verbatim two three" <<-\EOF
+	protocol=http
+	host=example.com
 	username=one
 	--
+	protocol=http
+	host=example.com
 	username=two
 	password=three
 	--
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	verbatim: username=one
 	EOF
 '
 
 test_expect_success 'do not bother completing already-full credential' '
 	check fill "verbatim three four" <<-\EOF
+	protocol=http
+	host=example.com
 	username=one
 	password=two
 	--
+	protocol=http
+	host=example.com
 	username=one
 	password=two
 	--
@@ -174,23 +237,31 @@
 # askpass helper is run, we know the internal getpass is working.
 test_expect_success 'empty helper list falls back to internal getpass' '
 	check fill <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=askpass-username
 	password=askpass-password
 	--
-	askpass: Username:
-	askpass: Password:
+	askpass: Username for '\''http://example.com'\'':
+	askpass: Password for '\''http://askpass-username@example.com'\'':
 	EOF
 '
 
 test_expect_success 'internal getpass does not ask for known username' '
 	check fill <<-\EOF
+	protocol=http
+	host=example.com
 	username=foo
 	--
+	protocol=http
+	host=example.com
 	username=foo
 	password=askpass-password
 	--
-	askpass: Password:
+	askpass: Password for '\''http://foo@example.com'\'':
 	EOF
 '
 
@@ -202,7 +273,11 @@
 test_expect_success 'respect configured credentials' '
 	test_config credential.helper "$HELPER" &&
 	check fill <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=foo
 	password=bar
 	--
@@ -419,21 +494,119 @@
 
 test_expect_success 'helpers can abort the process' '
 	test_must_fail git \
-		-c credential.helper="!f() { echo quit=1; }; f" \
+		-c credential.helper=quit \
 		-c credential.helper="verbatim foo bar" \
-		credential fill >stdout &&
-	test_must_be_empty stdout
+		credential fill >stdout 2>stderr <<-\EOF &&
+	protocol=http
+	host=example.com
+	EOF
+	test_must_be_empty stdout &&
+	cat >expect <<-\EOF &&
+	quit: get
+	quit: protocol=http
+	quit: host=example.com
+	fatal: credential helper '\''quit'\'' told us to quit
+	EOF
+	test_i18ncmp expect stderr
 '
 
 test_expect_success 'empty helper spec resets helper list' '
 	test_config credential.helper "verbatim file file" &&
 	check fill "" "verbatim cmdline cmdline" <<-\EOF
+	protocol=http
+	host=example.com
 	--
+	protocol=http
+	host=example.com
 	username=cmdline
 	password=cmdline
 	--
 	verbatim: get
+	verbatim: protocol=http
+	verbatim: host=example.com
 	EOF
 '
 
+test_expect_success 'url parser rejects embedded newlines' '
+	test_must_fail git credential fill 2>stderr <<-\EOF &&
+	url=https://one.example.com?%0ahost=two.example.com/
+	EOF
+	cat >expect <<-\EOF &&
+	warning: url contains a newline in its path component: https://one.example.com?%0ahost=two.example.com/
+	fatal: credential url cannot be parsed: https://one.example.com?%0ahost=two.example.com/
+	EOF
+	test_i18ncmp expect stderr
+'
+
+test_expect_success 'host-less URLs are parsed as empty host' '
+	check fill "verbatim foo bar" <<-\EOF
+	url=cert:///path/to/cert.pem
+	--
+	protocol=cert
+	host=
+	path=path/to/cert.pem
+	username=foo
+	password=bar
+	--
+	verbatim: get
+	verbatim: protocol=cert
+	verbatim: host=
+	verbatim: path=path/to/cert.pem
+	EOF
+'
+
+test_expect_success 'credential system refuses to work with missing host' '
+	test_must_fail git credential fill 2>stderr <<-\EOF &&
+	protocol=http
+	EOF
+	cat >expect <<-\EOF &&
+	fatal: refusing to work with credential missing host field
+	EOF
+	test_i18ncmp expect stderr
+'
+
+test_expect_success 'credential system refuses to work with missing protocol' '
+	test_must_fail git credential fill 2>stderr <<-\EOF &&
+	host=example.com
+	EOF
+	cat >expect <<-\EOF &&
+	fatal: refusing to work with credential missing protocol field
+	EOF
+	test_i18ncmp expect stderr
+'
+
+# usage: check_host_and_path <url> <expected-host> <expected-path>
+check_host_and_path () {
+	# we always parse the path component, but we need this to make sure it
+	# is passed to the helper
+	test_config credential.useHTTPPath true &&
+	check fill "verbatim user pass" <<-EOF
+	url=$1
+	--
+	protocol=https
+	host=$2
+	path=$3
+	username=user
+	password=pass
+	--
+	verbatim: get
+	verbatim: protocol=https
+	verbatim: host=$2
+	verbatim: path=$3
+	EOF
+}
+
+test_expect_success 'url parser handles bare query marker' '
+	check_host_and_path https://example.com?foo.git example.com ?foo.git
+'
+
+test_expect_success 'url parser handles bare fragment marker' '
+	check_host_and_path https://example.com#foo.git example.com "#foo.git"
+'
+
+test_expect_success 'url parser not confused by encoded markers' '
+	check_host_and_path https://example.com%23%3f%2f/foo.git \
+		"example.com#?/" foo.git
+'
+
 test_done
diff --git a/t/t1011-read-tree-sparse-checkout.sh b/t/t1011-read-tree-sparse-checkout.sh
index eb44baf..63223e1 100755
--- a/t/t1011-read-tree-sparse-checkout.sh
+++ b/t/t1011-read-tree-sparse-checkout.sh
@@ -233,18 +233,19 @@
 	test_must_be_empty result
 '
 
-test_expect_success 'print errors when failed to update worktree' '
+test_expect_success 'print warnings when some worktree updates disabled' '
 	echo sub >.git/info/sparse-checkout &&
 	git checkout -f init &&
 	mkdir sub &&
 	touch sub/added sub/addedtoo &&
-	test_must_fail git checkout top 2>actual &&
+	# Use -q to suppress "Previous HEAD position" and "Head is now at" msgs
+	git checkout -q top 2>actual &&
 	cat >expected <<\EOF &&
-error: The following untracked working tree files would be overwritten by checkout:
+warning: The following paths were already present and thus not updated despite sparse patterns:
 	sub/added
 	sub/addedtoo
-Please move or remove them before you switch branches.
-Aborting
+
+After fixing the above paths, you may want to run `git sparse-checkout reapply`.
 EOF
 	test_i18ncmp expected actual
 '
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 44a9120..dee99ee 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -277,15 +277,23 @@
 	check_files repo a deep folder1
 '
 
-test_expect_success 'revert to old sparse-checkout on bad update' '
+test_expect_success 'not-up-to-date does not block rest of sparsification' '
+	test_when_finished git -C repo sparse-checkout disable &&
 	test_when_finished git -C repo reset --hard &&
 	git -C repo sparse-checkout set deep &&
+
 	echo update >repo/deep/deeper2/a &&
 	cp repo/.git/info/sparse-checkout expect &&
-	test_must_fail git -C repo sparse-checkout set deep/deeper1 2>err &&
-	test_i18ngrep "cannot set sparse-checkout patterns" err &&
-	test_cmp repo/.git/info/sparse-checkout expect &&
-	check_files repo/deep a deeper1 deeper2
+	test_write_lines "!/deep/*/" "/deep/deeper1/" >>expect &&
+
+	git -C repo sparse-checkout set deep/deeper1 2>err &&
+
+	test_i18ngrep "The following paths are not up to date" err &&
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	check_files repo/deep a deeper1 deeper2 &&
+	check_files repo/deep/deeper1 a deepest &&
+	check_files repo/deep/deeper1/deepest a &&
+	check_files repo/deep/deeper2 a
 '
 
 test_expect_success 'revert to old sparse-checkout on empty update' '
@@ -315,19 +323,96 @@
 	test_i18ngrep ! "disabling cone patterns" err
 '
 
-test_expect_success 'sparse-checkout (init|set|disable) fails with dirty status' '
+test_expect_success 'sparse-checkout (init|set|disable) warns with dirty status' '
 	git clone repo dirty &&
 	echo dirty >dirty/folder1/a &&
-	test_must_fail git -C dirty sparse-checkout init &&
-	test_must_fail git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* &&
-	test_must_fail git -C dirty sparse-checkout disable &&
+
+	git -C dirty sparse-checkout init 2>err &&
+	test_i18ngrep "warning.*The following paths are not up to date" err &&
+
+	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* 2>err &&
+	test_i18ngrep "warning.*The following paths are not up to date" err &&
+	test_path_is_file dirty/folder1/a &&
+
+	git -C dirty sparse-checkout disable 2>err &&
+	test_must_be_empty err &&
+
 	git -C dirty reset --hard &&
 	git -C dirty sparse-checkout init &&
 	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* &&
-	git -C dirty sparse-checkout disable
+	test_path_is_missing dirty/folder1/a &&
+	git -C dirty sparse-checkout disable &&
+	test_path_is_file dirty/folder1/a
+'
+
+test_expect_success 'sparse-checkout (init|set|disable) warns with unmerged status' '
+	git clone repo unmerged &&
+
+	cat >input <<-EOF &&
+	0 0000000000000000000000000000000000000000	folder1/a
+	100644 $(git -C unmerged rev-parse HEAD:folder1/a) 1	folder1/a
+	EOF
+	git -C unmerged update-index --index-info <input &&
+
+	git -C unmerged sparse-checkout init 2>err &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+
+	git -C unmerged sparse-checkout set /folder2/* /deep/deeper1/* 2>err &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+	test_path_is_file dirty/folder1/a &&
+
+	git -C unmerged sparse-checkout disable 2>err &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+
+	git -C unmerged reset --hard &&
+	git -C unmerged sparse-checkout init &&
+	git -C unmerged sparse-checkout set /folder2/* /deep/deeper1/* &&
+	git -C unmerged sparse-checkout disable
+'
+
+test_expect_success 'sparse-checkout reapply' '
+	git clone repo tweak &&
+
+	echo dirty >tweak/deep/deeper2/a &&
+
+	cat >input <<-EOF &&
+	0 0000000000000000000000000000000000000000	folder1/a
+	100644 $(git -C tweak rev-parse HEAD:folder1/a) 1	folder1/a
+	EOF
+	git -C tweak update-index --index-info <input &&
+
+	git -C tweak sparse-checkout init --cone 2>err &&
+	test_i18ngrep "warning.*The following paths are not up to date" err &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+
+	git -C tweak sparse-checkout set folder2 deep/deeper1 2>err &&
+	test_i18ngrep "warning.*The following paths are not up to date" err &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+
+	git -C tweak sparse-checkout reapply 2>err &&
+	test_i18ngrep "warning.*The following paths are not up to date" err &&
+	test_path_is_file tweak/deep/deeper2/a &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+	test_path_is_file tweak/folder1/a &&
+
+	git -C tweak checkout HEAD deep/deeper2/a &&
+	git -C tweak sparse-checkout reapply 2>err &&
+	test_i18ngrep ! "warning.*The following paths are not up to date" err &&
+	test_path_is_missing tweak/deep/deeper2/a &&
+	test_i18ngrep "warning.*The following paths are unmerged" err &&
+	test_path_is_file tweak/folder1/a &&
+
+	git -C tweak add folder1/a &&
+	git -C tweak sparse-checkout reapply 2>err &&
+	test_must_be_empty err &&
+	test_path_is_missing tweak/deep/deeper2/a &&
+	test_path_is_missing tweak/folder1/a &&
+
+	git -C tweak sparse-checkout disable
 '
 
 test_expect_success 'cone mode: set with core.ignoreCase=true' '
+	rm repo/.git/info/sparse-checkout &&
 	git -C repo sparse-checkout init --cone &&
 	git -C repo -c core.ignoreCase=true sparse-checkout set folder1 &&
 	cat >expect <<-\EOF &&
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index a6224ef..48d0d42 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -1404,4 +1404,135 @@
 	! test_cmp main-head worktree-head
 '
 
+test_expect_success 'transaction handles empty commit' '
+	cat >stdin <<-EOF &&
+	start
+	prepare
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start prepare commit >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles empty commit with missing prepare' '
+	cat >stdin <<-EOF &&
+	start
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start commit >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles sole commit' '
+	cat >stdin <<-EOF &&
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" commit >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles empty abort' '
+	cat >stdin <<-EOF &&
+	start
+	prepare
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start prepare abort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction exits on multiple aborts' '
+	cat >stdin <<-EOF &&
+	abort
+	abort
+	EOF
+	test_must_fail git update-ref --stdin <stdin >actual 2>err &&
+	printf "%s: ok\n" abort >expect &&
+	test_cmp expect actual &&
+	grep "fatal: transaction is closed" err
+'
+
+test_expect_success 'transaction exits on start after prepare' '
+	cat >stdin <<-EOF &&
+	prepare
+	start
+	EOF
+	test_must_fail git update-ref --stdin <stdin 2>err >actual &&
+	printf "%s: ok\n" prepare >expect &&
+	test_cmp expect actual &&
+	grep "fatal: prepared transactions can only be closed" err
+'
+
+test_expect_success 'transaction handles empty abort with missing prepare' '
+	cat >stdin <<-EOF &&
+	start
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start abort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles sole abort' '
+	cat >stdin <<-EOF &&
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" abort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction can handle commit' '
+	cat >stdin <<-EOF &&
+	start
+	create $a HEAD
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start commit >expect &&
+	test_cmp expect actual &&
+	git rev-parse HEAD >expect &&
+	git rev-parse $a >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction can handle abort' '
+	cat >stdin <<-EOF &&
+	start
+	create $b HEAD
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start abort >expect &&
+	test_cmp expect actual &&
+	test_path_is_missing .git/$b
+'
+
+test_expect_success 'transaction aborts by default' '
+	cat >stdin <<-EOF &&
+	start
+	create $b HEAD
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start >expect &&
+	test_cmp expect actual &&
+	test_path_is_missing .git/$b
+'
+
+test_expect_success 'transaction with prepare aborts by default' '
+	cat >stdin <<-EOF &&
+	start
+	create $b HEAD
+	prepare
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start prepare >expect &&
+	test_cmp expect actual &&
+	test_path_is_missing .git/$b
+'
+
 test_done
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index d09eff5..449ebc5 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -133,6 +133,30 @@
 	test_i18ngrep "worktrees/other/HEAD points to something strange" out
 '
 
+test_expect_success 'commit with multiple signatures is okay' '
+	git cat-file commit HEAD >basis &&
+	cat >sigs <<-EOF &&
+	gpgsig -----BEGIN PGP SIGNATURE-----
+	  VGhpcyBpcyBub3QgcmVhbGx5IGEgc2lnbmF0dXJlLg==
+	  -----END PGP SIGNATURE-----
+	gpgsig-sha256 -----BEGIN PGP SIGNATURE-----
+	  VGhpcyBpcyBub3QgcmVhbGx5IGEgc2lnbmF0dXJlLg==
+	  -----END PGP SIGNATURE-----
+	EOF
+	sed -e "/^committer/q" basis >okay &&
+	cat sigs >>okay &&
+	echo >>okay &&
+	sed -e "1,/^$/d" basis >>okay &&
+	cat okay &&
+	new=$(git hash-object -t commit -w --stdin <okay) &&
+	test_when_finished "remove_object $new" &&
+	git update-ref refs/heads/bogus "$new" &&
+	test_when_finished "git update-ref -d refs/heads/bogus" &&
+	git fsck 2>out &&
+	cat out &&
+	! grep "commit $new" out
+'
+
 test_expect_success 'email without @ is okay' '
 	git cat-file commit HEAD >basis &&
 	sed "s/@/AT/" basis >okay &&
diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
index bbca7ef..2158315 100755
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -238,4 +238,26 @@
 	test_path_is_file dest/a.t
 '
 
+test_expect_success 'checkout -b to a new branch preserves mergeable changes despite sparse-checkout' '
+	test_when_finished "
+		git reset --hard &&
+		git checkout branch1-scratch &&
+		test_might_fail git branch -D branch3 &&
+		git config core.sparseCheckout false &&
+		rm .git/info/sparse-checkout" &&
+
+	test_commit file2 &&
+
+	echo stuff >>file1 &&
+	echo file2 >.git/info/sparse-checkout &&
+	git config core.sparseCheckout true &&
+
+	CURHEAD=$(git rev-parse HEAD) &&
+	do_checkout branch3 $CURHEAD &&
+
+	echo file1 >expect &&
+	git diff --name-only >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t2402-worktree-list.sh b/t/t2402-worktree-list.sh
index 69ffe86..52585ec 100755
--- a/t/t2402-worktree-list.sh
+++ b/t/t2402-worktree-list.sh
@@ -152,7 +152,7 @@
 '
 
 test_expect_success 'worktree path when called in .git directory' '
-	git worktree list >list1&&
+	git worktree list >list1 &&
 	git -C .git worktree list >list2 &&
 	test_cmp list1 list2
 '
diff --git a/t/t3000-ls-files-others.sh b/t/t3000-ls-files-others.sh
index 0aefada..ffdfb16 100755
--- a/t/t3000-ls-files-others.sh
+++ b/t/t3000-ls-files-others.sh
@@ -91,4 +91,125 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'setup nested pathspec search' '
+	test_create_repo nested &&
+	(
+		cd nested &&
+
+		mkdir -p partially_tracked/untracked_dir &&
+		> partially_tracked/content &&
+		> partially_tracked/untracked_dir/file &&
+
+		mkdir -p untracked/deep &&
+		> untracked/deep/path &&
+		> untracked/deep/foo.c &&
+
+		git add partially_tracked/content
+	)
+'
+
+test_expect_success 'ls-files -o --directory with single deep dir pathspec' '
+	(
+		cd nested &&
+
+		git ls-files -o --directory untracked/deep/ >actual &&
+
+		cat <<-EOF >expect &&
+		untracked/deep/
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'ls-files -o --directory with multiple dir pathspecs' '
+	(
+		cd nested &&
+
+		git ls-files -o --directory partially_tracked/ untracked/ >actual &&
+
+		cat <<-EOF >expect &&
+		partially_tracked/untracked_dir/
+		untracked/
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'ls-files -o --directory with mix dir/file pathspecs' '
+	(
+		cd nested &&
+
+		git ls-files -o --directory partially_tracked/ untracked/deep/path >actual &&
+
+		cat <<-EOF >expect &&
+		partially_tracked/untracked_dir/
+		untracked/deep/path
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'ls-files --o --directory with glob filetype match' '
+	(
+		cd nested &&
+
+		# globs kinda defeat --directory, but only for that pathspec
+		git ls-files --others --directory partially_tracked "untracked/*.c" >actual &&
+
+		cat <<-EOF >expect &&
+		partially_tracked/untracked_dir/
+		untracked/deep/foo.c
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'ls-files --o --directory with mix of tracked states' '
+	(
+		cd nested &&
+
+		# globs kinda defeat --directory, but only for that pathspec
+		git ls-files --others --directory partially_tracked/ "untracked/?*" >actual &&
+
+		cat <<-EOF >expect &&
+		partially_tracked/untracked_dir/
+		untracked/deep/
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'ls-files --o --directory with glob filetype match only' '
+	(
+		cd nested &&
+
+		git ls-files --others --directory "untracked/*.c" >actual &&
+
+		cat <<-EOF >expect &&
+		untracked/deep/foo.c
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'ls-files --o --directory to get immediate paths under one dir only' '
+	(
+		cd nested &&
+
+		git ls-files --others --directory "untracked/?*" >actual &&
+
+		cat <<-EOF >expect &&
+		untracked/deep/
+		EOF
+
+		test_cmp expect actual
+	)
+'
+
 test_done
diff --git a/t/t3033-merge-toplevel.sh b/t/t3033-merge-toplevel.sh
index d314599..e29c284 100755
--- a/t/t3033-merge-toplevel.sh
+++ b/t/t3033-merge-toplevel.sh
@@ -142,6 +142,17 @@
 	test_must_fail git merge five
 '
 
+test_expect_success 'refuse two-project merge by default, quit before --autostash happens' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff >expect &&
+	test_must_fail git merge --autostash five 2>err &&
+	test_i18ngrep ! "stash" err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'two-project merge with --allow-unrelated-histories' '
 	t3033_reset &&
 	git reset --hard four &&
@@ -149,4 +160,15 @@
 	git diff --exit-code five
 '
 
+test_expect_success 'two-project merge with --allow-unrelated-histories with --autostash' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff one.t >expect &&
+	git merge --allow-unrelated-histories --autostash five 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff one.t >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
index bd808f8..e024cff 100755
--- a/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@ -513,6 +513,16 @@
 	git -c diff.noprefix=true range-diff HEAD^...
 '
 
+test_expect_success 'basic with modified format.pretty with suffix' '
+	git -c format.pretty="format:commit %H%d%n" range-diff \
+		master..topic master..unmodified
+'
+
+test_expect_success 'basic with modified format.pretty without "commit "' '
+	git -c format.pretty="format:%H%n" range-diff \
+		master..topic master..unmodified
+'
+
 test_expect_success 'range-diff compares notes by default' '
 	git notes add -m "topic note" topic &&
 	git notes add -m "unmodified note" unmodified &&
diff --git a/t/t3402-rebase-merge.sh b/t/t3402-rebase-merge.sh
index a1ec501..6e03271 100755
--- a/t/t3402-rebase-merge.sh
+++ b/t/t3402-rebase-merge.sh
@@ -162,4 +162,81 @@
 	git rebase --skip
 '
 
+test_expect_success '--reapply-cherry-picks' '
+	git init repo &&
+
+	# O(1-10) -- O(1-11) -- O(0-10) master
+	#        \
+	#         -- O(1-11) -- O(1-12) otherbranch
+
+	printf "Line %d\n" $(test_seq 1 10) >repo/file.txt &&
+	git -C repo add file.txt &&
+	git -C repo commit -m "base commit" &&
+
+	printf "Line %d\n" $(test_seq 1 11) >repo/file.txt &&
+	git -C repo commit -a -m "add 11" &&
+
+	printf "Line %d\n" $(test_seq 0 10) >repo/file.txt &&
+	git -C repo commit -a -m "add 0 delete 11" &&
+
+	git -C repo checkout -b otherbranch HEAD^^ &&
+	printf "Line %d\n" $(test_seq 1 11) >repo/file.txt &&
+	git -C repo commit -a -m "add 11 in another branch" &&
+
+	printf "Line %d\n" $(test_seq 1 12) >repo/file.txt &&
+	git -C repo commit -a -m "add 12 in another branch" &&
+
+	# Regular rebase fails, because the 1-11 commit is deduplicated
+	test_must_fail git -C repo rebase --merge master 2> err &&
+	test_i18ngrep "error: could not apply.*add 12 in another branch" err &&
+	git -C repo rebase --abort &&
+
+	# With --reapply-cherry-picks, it works
+	git -C repo rebase --merge --reapply-cherry-picks master
+'
+
+test_expect_success '--reapply-cherry-picks refrains from reading unneeded blobs' '
+	git init server &&
+
+	# O(1-10) -- O(1-11) -- O(1-12) master
+	#        \
+	#         -- O(0-10) otherbranch
+
+	printf "Line %d\n" $(test_seq 1 10) >server/file.txt &&
+	git -C server add file.txt &&
+	git -C server commit -m "merge base" &&
+
+	printf "Line %d\n" $(test_seq 1 11) >server/file.txt &&
+	git -C server commit -a -m "add 11" &&
+
+	printf "Line %d\n" $(test_seq 1 12) >server/file.txt &&
+	git -C server commit -a -m "add 12" &&
+
+	git -C server checkout -b otherbranch HEAD^^ &&
+	printf "Line %d\n" $(test_seq 0 10) >server/file.txt &&
+	git -C server commit -a -m "add 0" &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+
+	git clone --filter=blob:none "file://$(pwd)/server" client &&
+	git -C client checkout origin/master &&
+	git -C client checkout origin/otherbranch &&
+
+	# Sanity check to ensure that the blobs from the merge base and "add
+	# 11" are missing
+	git -C client rev-list --objects --all --missing=print >missing_list &&
+	MERGE_BASE_BLOB=$(git -C server rev-parse master^^:file.txt) &&
+	ADD_11_BLOB=$(git -C server rev-parse master^:file.txt) &&
+	grep "[?]$MERGE_BASE_BLOB" missing_list &&
+	grep "[?]$ADD_11_BLOB" missing_list &&
+
+	git -C client rebase --merge --reapply-cherry-picks origin/master &&
+
+	# The blob from the merge base had to be fetched, but not "add 11"
+	git -C client rev-list --objects --all --missing=print >missing_list &&
+	! grep "[?]$MERGE_BASE_BLOB" missing_list &&
+	grep "[?]$ADD_11_BLOB" missing_list
+'
+
 test_done
diff --git a/t/t3403-rebase-skip.sh b/t/t3403-rebase-skip.sh
index ee8a8db..a927774 100755
--- a/t/t3403-rebase-skip.sh
+++ b/t/t3403-rebase-skip.sh
@@ -29,6 +29,13 @@
 	test_tick &&
 	git commit -m reverted-goodbye &&
 	git tag reverted-goodbye &&
+	git checkout goodbye &&
+	test_tick &&
+	GIT_AUTHOR_NAME="Another Author" \
+		GIT_AUTHOR_EMAIL="another.author@example.com" \
+		git commit --amend --no-edit -m amended-goodbye &&
+	test_tick &&
+	git tag amended-goodbye &&
 
 	git checkout -f skip-reference &&
 	echo moo > hello &&
@@ -85,6 +92,78 @@
 
 test_debug 'gitk --all & sleep 1'
 
+test_expect_success 'correct advice upon picking empty commit' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -i --onto goodbye \
+		amended-goodbye^ amended-goodbye 2>err &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct authorship when committing empty pick' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -i --onto goodbye \
+		amended-goodbye^ amended-goodbye &&
+	git commit --allow-empty &&
+	git log --pretty=format:"%an <%ae>%n%ad%B" -1 amended-goodbye >expect &&
+	git log --pretty=format:"%an <%ae>%n%ad%B" -1 HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'correct advice upon rewording empty commit' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="reword 1" git rebase -i \
+			--onto goodbye amended-goodbye^ amended-goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct advice upon editing empty commit' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="edit 1" git rebase -i \
+			--onto goodbye amended-goodbye^ amended-goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct advice upon cherry-picking an empty commit during a rebase' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="1 exec_git_cherry-pick_amended-goodbye" \
+			git rebase -i goodbye^ goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
+	test_must_fail git commit 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err
+'
+
+test_expect_success 'correct advice upon multi cherry-pick picking an empty commit during a rebase' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="1 exec_git_cherry-pick_goodbye_amended-goodbye" \
+			git rebase -i goodbye^^ goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
+	test_must_fail git commit 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err
+'
+
 test_expect_success 'fixup that empties commit fails' '
 	test_when_finished "git rebase --abort" &&
 	(
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index c5ce3ab..4a7d21f 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -187,7 +187,7 @@
 	git checkout branch2 &&
 	git rebase -i F &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch2" &&
-	test $(git rev-parse I) = $(git rev-parse HEAD)
+	test_cmp_rev I HEAD
 '
 
 test_expect_success 'test the [branch] option' '
@@ -196,16 +196,16 @@
 	git commit -m "stop here" &&
 	git rebase -i F branch2 &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch2" &&
-	test $(git rev-parse I) = $(git rev-parse branch2) &&
-	test $(git rev-parse I) = $(git rev-parse HEAD)
+	test_cmp_rev I branch2 &&
+	test_cmp_rev I HEAD
 '
 
 test_expect_success 'test --onto <branch>' '
 	git checkout -b test-onto branch2 &&
 	git rebase -i --onto branch1 F &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/test-onto" &&
-	test $(git rev-parse HEAD^) = $(git rev-parse branch1) &&
-	test $(git rev-parse I) = $(git rev-parse branch2)
+	test_cmp_rev HEAD^ branch1 &&
+	test_cmp_rev I branch2
 '
 
 test_expect_success 'rebase on top of a non-conflicting commit' '
@@ -214,12 +214,12 @@
 	git rebase -i branch2 &&
 	test file6 = $(git diff --name-only original-branch1) &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch1" &&
-	test $(git rev-parse I) = $(git rev-parse branch2) &&
-	test $(git rev-parse I) = $(git rev-parse HEAD~2)
+	test_cmp_rev I branch2 &&
+	test_cmp_rev I HEAD~2
 '
 
 test_expect_success 'reflog for the branch shows state before rebase' '
-	test $(git rev-parse branch1@{1}) = $(git rev-parse original-branch1)
+	test_cmp_rev branch1@{1} original-branch1
 '
 
 test_expect_success 'reflog for the branch shows correct finish message' '
@@ -279,7 +279,7 @@
 
 test_expect_success 'abort' '
 	git rebase --abort &&
-	test $(git rev-parse new-branch1) = $(git rev-parse HEAD) &&
+	test_cmp_rev new-branch1 HEAD &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch1" &&
 	test_path_is_missing .git/rebase-merge
 '
@@ -322,7 +322,7 @@
 	echo resolved >conflict &&
 	git add conflict &&
 	git rebase --continue &&
-	test $(git rev-parse conflict-a^0) = $(git rev-parse HEAD^) &&
+	test_cmp_rev conflict-a^0 HEAD^ &&
 	git show >out &&
 	grep AttributeMe out
 '
@@ -339,7 +339,7 @@
 			git rebase -i --onto master HEAD~2
 	) &&
 	test B = $(cat file7) &&
-	test $(git rev-parse HEAD^) = $(git rev-parse master)
+	test_cmp_rev HEAD^ master
 '
 
 test_expect_success 'retain authorship when squashing' '
@@ -398,9 +398,9 @@
 	git update-index --refresh &&
 	git diff-files --quiet &&
 	git diff-index --quiet --cached HEAD -- &&
-	test $(git rev-parse HEAD~6) = $(git rev-parse branch1) &&
-	test $(git rev-parse HEAD~4^2) = $(git rev-parse to-be-preserved) &&
-	test $(git rev-parse HEAD^^2^) = $(git rev-parse HEAD^^^) &&
+	test_cmp_rev HEAD~6 branch1 &&
+	test_cmp_rev HEAD~4^2 to-be-preserved &&
+	test_cmp_rev HEAD^^2^ HEAD^^^ &&
 	test $(git show HEAD~5:file1) = B &&
 	test $(git show HEAD~3:file1) = C &&
 	test $(git show HEAD:file1) = E &&
@@ -432,7 +432,7 @@
 		git add file1 &&
 		FAKE_COMMIT_MESSAGE="chouette!" git rebase --continue
 	) &&
-	test $(git rev-parse HEAD^) = $(git rev-parse new-branch1) &&
+	test_cmp_rev HEAD^ new-branch1 &&
 	git show HEAD | grep chouette
 '
 
@@ -739,7 +739,7 @@
 		--author="Somebody else <somebody@else.com>" &&
 	test $(git rev-parse branch3) != $(git rev-parse branch4) &&
 	git rebase -i branch3 &&
-	test $(git rev-parse branch3) = $(git rev-parse branch4)
+	test_cmp_rev branch3 branch4
 
 '
 
@@ -798,7 +798,7 @@
 	test_must_fail git rebase -i submodule-base &&
 	git reset &&
 	git rebase --continue &&
-	test $(git rev-parse submodule-base) = $(git rev-parse HEAD)
+	test_cmp_rev submodule-base HEAD
 '
 
 test_expect_success 'avoid unnecessary reset' '
@@ -821,7 +821,7 @@
 			git rebase -i A &&
 		git show HEAD | grep "E changed" &&
 		test $(git rev-parse master) != $(git rev-parse HEAD) &&
-		test $(git rev-parse master^) = $(git rev-parse HEAD^) &&
+		test_cmp_rev master^ HEAD^ &&
 		FAKE_LINES="1 2 reword 3 4" FAKE_COMMIT_MESSAGE="D changed" \
 			git rebase -i A &&
 		git show HEAD^ | grep "D changed" &&
@@ -885,7 +885,7 @@
 		git diff HEAD~$p original-no-ff-branch~$p > out &&
 		test_must_be_empty out
 	done &&
-	test $(git rev-parse HEAD~3) = $(git rev-parse original-no-ff-branch~3) &&
+	test_cmp_rev HEAD~3 original-no-ff-branch~3 &&
 	git diff HEAD~3 original-no-ff-branch~3 > out &&
 	test_must_be_empty out
 '
@@ -1734,6 +1734,32 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'correct error message for partial commit after empty pick' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="2 1 1" &&
+		export FAKE_LINES &&
+		test_must_fail git rebase -i A D
+	) &&
+	echo x >file1 &&
+	test_must_fail git commit file1 2>err &&
+	test_i18ngrep "cannot do a partial commit during a rebase." err
+'
+
+test_expect_success 'correct error message for commit --amend after empty pick' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="1 1" &&
+		export FAKE_LINES &&
+		test_must_fail git rebase -i A D
+	) &&
+	echo x>file1 &&
+	test_must_fail git commit -a --amend 2>err &&
+	test_i18ngrep "middle of a rebase -- cannot amend." err
+'
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index 61b76f3..927a4f4 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -89,22 +89,22 @@
 	git checkout -b reflog-topic start &&
 	test_commit reflog-to-rebase &&
 
-	git rebase --apply reflog-onto &&
+	git rebase reflog-onto &&
 	git log -g --format=%gs -3 >actual &&
 	cat >expect <<-\EOF &&
-	rebase finished: returning to refs/heads/reflog-topic
-	rebase: reflog-to-rebase
-	rebase: checkout reflog-onto
+	rebase (finish): returning to refs/heads/reflog-topic
+	rebase (pick): reflog-to-rebase
+	rebase (start): checkout reflog-onto
 	EOF
 	test_cmp expect actual &&
 
 	git checkout -b reflog-prefix reflog-to-rebase &&
-	GIT_REFLOG_ACTION=change-the-reflog git rebase --apply reflog-onto &&
+	GIT_REFLOG_ACTION=change-the-reflog git rebase reflog-onto &&
 	git log -g --format=%gs -3 >actual &&
 	cat >expect <<-\EOF &&
-	rebase finished: returning to refs/heads/reflog-prefix
-	change-the-reflog: reflog-to-rebase
-	change-the-reflog: checkout reflog-onto
+	change-the-reflog (finish): returning to refs/heads/reflog-prefix
+	change-the-reflog (pick): reflog-to-rebase
+	change-the-reflog (start): checkout reflog-onto
 	EOF
 	test_cmp expect actual
 '
diff --git a/t/t3417-rebase-whitespace-fix.sh b/t/t3417-rebase-whitespace-fix.sh
index e85cdc7..946e92f 100755
--- a/t/t3417-rebase-whitespace-fix.sh
+++ b/t/t3417-rebase-whitespace-fix.sh
@@ -52,7 +52,7 @@
 	git commit --allow-empty -m "Initial empty commit" &&
 	git add file && git commit -m first &&
 	mv second file &&
-	git add file &&	git commit -m second &&
+	git add file && git commit -m second &&
 	git rebase --whitespace=fix HEAD^^ &&
 	git diff --exit-code HEAD^:file expect-first &&
 	test_cmp expect-second file
@@ -118,7 +118,7 @@
 	for i in 1 2 3 4 5; do
 		echo $i
 	done >> file &&
-	git commit -m more file	&&
+	git commit -m more file &&
 	git rebase --whitespace=fix HEAD^^ &&
 	test_cmp expect-beginning file
 '
diff --git a/t/t3419-rebase-patch-id.sh b/t/t3419-rebase-patch-id.sh
index d934583..1f32faa 100755
--- a/t/t3419-rebase-patch-id.sh
+++ b/t/t3419-rebase-patch-id.sh
@@ -4,15 +4,6 @@
 
 . ./test-lib.sh
 
-count () {
-	i=0
-	while test $i -lt $1
-	do
-		echo "$i"
-		i=$(($i+1))
-	done
-}
-
 scramble () {
 	i=0
 	while read x
@@ -26,76 +17,55 @@
 	mv -f "$1.new" "$1"
 }
 
-run () {
-	echo \$ "$@"
-	/usr/bin/time "$@" >/dev/null
-}
-
 test_expect_success 'setup' '
 	git commit --allow-empty -m initial &&
 	git tag root
 '
 
-do_tests () {
-	nlines=$1 pr=${2-}
+test_expect_success 'setup: 500 lines' '
+	rm -f .gitattributes &&
+	git checkout -q -f master &&
+	git reset --hard root &&
+	test_seq 500 >file &&
+	git add file &&
+	git commit -q -m initial &&
+	git branch -f other &&
 
-	test_expect_success $pr "setup: $nlines lines" "
-		rm -f .gitattributes &&
-		git checkout -q -f master &&
-		git reset --hard root &&
-		count $nlines >file &&
-		git add file &&
-		git commit -q -m initial &&
-		git branch -f other &&
+	scramble file &&
+	git add file &&
+	git commit -q -m "change big file" &&
 
-		scramble file &&
-		git add file &&
-		git commit -q -m 'change big file' &&
+	git checkout -q other &&
+	: >newfile &&
+	git add newfile &&
+	git commit -q -m "add small file" &&
 
-		git checkout -q other &&
-		: >newfile &&
-		git add newfile &&
-		git commit -q -m 'add small file' &&
+	git cherry-pick master >/dev/null 2>&1
+'
 
-		git cherry-pick master >/dev/null 2>&1
-	"
+test_expect_success 'setup attributes' '
+	echo "file binary" >.gitattributes
+'
 
-	test_debug "
-		run git diff master^\!
-	"
+test_expect_success 'detect upstream patch' '
+	git checkout -q master &&
+	scramble file &&
+	git add file &&
+	git commit -q -m "change big file again" &&
+	git checkout -q other^{} &&
+	git rebase master &&
+	git rev-list master...HEAD~ >revs &&
+	test_must_be_empty revs
+'
 
-	test_expect_success $pr 'setup attributes' "
-		echo 'file binary' >.gitattributes
-	"
-
-	test_debug "
-		run git format-patch --stdout master &&
-		run git format-patch --stdout --ignore-if-in-upstream master
-	"
-
-	test_expect_success $pr 'detect upstream patch' '
-		git checkout -q master &&
-		scramble file &&
-		git add file &&
-		git commit -q -m "change big file again" &&
-		git checkout -q other^{} &&
-		git rebase master &&
-		git rev-list master...HEAD~ >revs &&
-		test_must_be_empty revs
-	'
-
-	test_expect_success $pr 'do not drop patch' '
-		git branch -f squashed master &&
-		git checkout -q -f squashed &&
-		git reset -q --soft HEAD~2 &&
-		git commit -q -m squashed &&
-		git checkout -q other^{} &&
-		test_must_fail git rebase squashed &&
-		git rebase --quit
-	'
-}
-
-do_tests 500
-do_tests 50000 EXPENSIVE
+test_expect_success 'do not drop patch' '
+	git branch -f squashed master &&
+	git checkout -q -f squashed &&
+	git reset -q --soft HEAD~2 &&
+	git commit -q -m squashed &&
+	git checkout -q other^{} &&
+	test_must_fail git rebase squashed &&
+	git rebase --quit
+'
 
 test_done
diff --git a/t/t3420-rebase-autostash.sh b/t/t3420-rebase-autostash.sh
index b97ea62..ca33173 100755
--- a/t/t3420-rebase-autostash.sh
+++ b/t/t3420-rebase-autostash.sh
@@ -184,6 +184,26 @@
 		git checkout feature-branch
 	'
 
+	test_expect_success "rebase$type: --quit" '
+		test_config rebase.autostash true &&
+		git reset --hard &&
+		git checkout -b rebased-feature-branch feature-branch &&
+		test_when_finished git branch -D rebased-feature-branch &&
+		echo dirty >>file3 &&
+		git diff >expect &&
+		test_must_fail git rebase$type related-onto-branch &&
+		test_path_is_file $dotest/autostash &&
+		test_path_is_missing file3 &&
+		git rebase --quit &&
+		test_when_finished git stash drop &&
+		test_path_is_missing $dotest/autostash &&
+		! grep dirty file3 &&
+		git stash show -p >actual &&
+		test_cmp expect actual &&
+		git reset --hard &&
+		git checkout feature-branch
+	'
+
 	test_expect_success "rebase$type: non-conflicting rebase, conflicting stash" '
 		test_config rebase.autostash true &&
 		git reset --hard &&
diff --git a/t/t3421-rebase-topology-linear.sh b/t/t3421-rebase-topology-linear.sh
index cf8dfd6..4a9204b 100755
--- a/t/t3421-rebase-topology-linear.sh
+++ b/t/t3421-rebase-topology-linear.sh
@@ -220,14 +220,13 @@
 test_run_rebase () {
 	result=$1
 	shift
-	test_expect_$result "rebase $* --keep-empty" "
+	test_expect_$result "rebase $* --no-keep-empty drops begin-empty commits" "
 		reset_rebase &&
-		git rebase $* --keep-empty c l &&
-		test_cmp_rev c HEAD~3 &&
-		test_linear_range 'd k l' c..
+		git rebase $* --no-keep-empty c l &&
+		test_cmp_rev c HEAD~2 &&
+		test_linear_range 'd l' c..
 	"
 }
-test_run_rebase success --apply
 test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
@@ -242,7 +241,6 @@
 		test_linear_range 'd k l' j..
 	"
 }
-test_run_rebase success --apply
 test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
diff --git a/t/t3424-rebase-empty.sh b/t/t3424-rebase-empty.sh
index e1e3051..5e1045a 100755
--- a/t/t3424-rebase-empty.sh
+++ b/t/t3424-rebase-empty.sh
@@ -123,6 +123,42 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'rebase --merge --empty=drop --keep-empty' '
+	git checkout -B testing localmods &&
+	git rebase --merge --empty=drop --keep-empty upstream &&
+
+	test_write_lines D C B A >expect &&
+	git log --format=%s >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rebase --merge --empty=drop --no-keep-empty' '
+	git checkout -B testing localmods &&
+	git rebase --merge --empty=drop --no-keep-empty upstream &&
+
+	test_write_lines C B A >expect &&
+	git log --format=%s >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rebase --merge --empty=keep --keep-empty' '
+	git checkout -B testing localmods &&
+	git rebase --merge --empty=keep --keep-empty upstream &&
+
+	test_write_lines D C2 C B A >expect &&
+	git log --format=%s >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rebase --merge --empty=keep --no-keep-empty' '
+	git checkout -B testing localmods &&
+	git rebase --merge --empty=keep --no-keep-empty upstream &&
+
+	test_write_lines C2 C B A >expect &&
+	git log --format=%s >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'rebase --merge does not leave state laying around' '
 	git checkout -B testing localmods~2 &&
 	git rebase --merge upstream &&
diff --git a/t/t3431-rebase-fork-point.sh b/t/t3431-rebase-fork-point.sh
index 78851b9..1725627 100755
--- a/t/t3431-rebase-fork-point.sh
+++ b/t/t3431-rebase-fork-point.sh
@@ -47,11 +47,31 @@
 test_rebase 'G F C E D B A' --no-fork-point
 test_rebase 'G F C D B A' --no-fork-point --onto D
 test_rebase 'G F C B A' --no-fork-point --keep-base
+
 test_rebase 'G F E D B A' --fork-point refs/heads/master
+test_rebase 'G F E D B A' --fork-point master
+
 test_rebase 'G F D B A' --fork-point --onto D refs/heads/master
+test_rebase 'G F D B A' --fork-point --onto D master
+
 test_rebase 'G F B A' --fork-point --keep-base refs/heads/master
+test_rebase 'G F B A' --fork-point --keep-base master
+
 test_rebase 'G F C E D B A' refs/heads/master
+test_rebase 'G F C E D B A' master
+
 test_rebase 'G F C D B A' --onto D refs/heads/master
+test_rebase 'G F C D B A' --onto D master
+
 test_rebase 'G F C B A' --keep-base refs/heads/master
+test_rebase 'G F C B A' --keep-base master
+
+test_expect_success 'git rebase --fork-point with ambigous refname' '
+	git checkout master &&
+	git checkout -b one &&
+	git checkout side &&
+	git tag one &&
+	test_must_fail git rebase --fork-point --onto D one
+'
 
 test_done
diff --git a/t/t3432-rebase-fast-forward.sh b/t/t3432-rebase-fast-forward.sh
index 6c9d4a1..6f0452c 100755
--- a/t/t3432-rebase-fast-forward.sh
+++ b/t/t3432-rebase-fast-forward.sh
@@ -28,10 +28,12 @@
 	shift &&
 	cmp_f="$1" &&
 	shift &&
-	test_rebase_same_head_ $status_n $what_n $cmp_n " --apply" "$*" &&
-	test_rebase_same_head_ $status_f $what_f $cmp_f " --apply --no-ff" "$*"
-	test_rebase_same_head_ $status_n $what_n $cmp_n " --merge" "$*" &&
-	test_rebase_same_head_ $status_f $what_f $cmp_f " --merge --no-ff" "$*"
+	test_rebase_same_head_ $status_n $what_n $cmp_n 0 " --apply" "$*" &&
+	test_rebase_same_head_ $status_f $what_f $cmp_f 0 " --apply --no-ff" "$*"
+	test_rebase_same_head_ $status_n $what_n $cmp_n 0 " --merge" "$*" &&
+	test_rebase_same_head_ $status_f $what_f $cmp_f 0 " --merge --no-ff" "$*"
+	test_rebase_same_head_ $status_n $what_n $cmp_n 1 " --merge" "$*" &&
+	test_rebase_same_head_ $status_f $what_f $cmp_f 1 " --merge --no-ff" "$*"
 }
 
 test_rebase_same_head_ () {
@@ -41,9 +43,21 @@
 	shift &&
 	cmp="$1" &&
 	shift &&
+	abbreviate="$1" &&
+	shift &&
 	flag="$1"
 	shift &&
-	test_expect_$status "git rebase$flag $* with $changes is $what with $cmp HEAD" "
+	if test $abbreviate -eq 1
+	then
+		msg="git rebase$flag $* (rebase.abbreviateCommands = true) with $changes is $what with $cmp HEAD"
+	else
+		msg="git rebase$flag $* with $changes is $what with $cmp HEAD"
+	fi &&
+	test_expect_$status "$msg" "
+		if test $abbreviate -eq 1
+		then
+			test_config rebase.abbreviateCommands true
+		fi &&
 		oldhead=\$(git rev-parse HEAD) &&
 		test_when_finished 'git reset --hard \$oldhead' &&
 		cp .git/logs/HEAD expect &&
diff --git a/t/t3435-rebase-gpg-sign.sh b/t/t3435-rebase-gpg-sign.sh
new file mode 100755
index 0000000..b47c59c
--- /dev/null
+++ b/t/t3435-rebase-gpg-sign.sh
@@ -0,0 +1,71 @@
+#!/bin/sh
+#
+# Copyright (c) 2020 Doan Tran Cong Danh
+#
+
+test_description='test rebase --[no-]gpg-sign'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-rebase.sh"
+. "$TEST_DIRECTORY/lib-gpg.sh"
+
+if ! test_have_prereq GPG
+then
+	skip_all='skip all test rebase --[no-]gpg-sign, gpg not available'
+	test_done
+fi
+
+test_rebase_gpg_sign () {
+	local must_fail= will=will fake_editor=
+	if test "x$1" = "x!"
+	then
+		must_fail=test_must_fail
+		will="won't"
+		shift
+	fi
+	conf=$1
+	shift
+	test_expect_success "rebase $* with commit.gpgsign=$conf $will sign commit" "
+		git reset two &&
+		git config commit.gpgsign $conf &&
+		set_fake_editor &&
+		FAKE_LINES='r 1 p 2' git rebase --force-rebase --root $* &&
+		$must_fail git verify-commit HEAD^ &&
+		$must_fail git verify-commit HEAD
+	"
+}
+
+test_expect_success 'setup' '
+	test_commit one &&
+	test_commit two &&
+	test_must_fail git verify-commit HEAD &&
+	test_must_fail git verify-commit HEAD^
+'
+
+test_expect_success 'setup: merge commit' '
+	test_commit fork-point &&
+	git switch -c side &&
+	test_commit three &&
+	git switch master &&
+	git merge --no-ff side &&
+	git tag merged
+'
+
+test_rebase_gpg_sign ! false
+test_rebase_gpg_sign   true
+test_rebase_gpg_sign ! true  --no-gpg-sign
+test_rebase_gpg_sign ! true  --gpg-sign --no-gpg-sign
+test_rebase_gpg_sign   false --no-gpg-sign --gpg-sign
+test_rebase_gpg_sign   true  -i
+test_rebase_gpg_sign ! true  -i --no-gpg-sign
+test_rebase_gpg_sign ! true  -i --gpg-sign --no-gpg-sign
+test_rebase_gpg_sign   false -i --no-gpg-sign --gpg-sign
+
+test_expect_failure 'rebase -p --no-gpg-sign override commit.gpgsign' '
+	git reset --hard merged &&
+	git config commit.gpgsign true &&
+	git rebase -p --no-gpg-sign --onto=one fork-point master &&
+	test_must_fail git verify-commit HEAD
+'
+
+test_done
diff --git a/t/t3507-cherry-pick-conflict.sh b/t/t3507-cherry-pick-conflict.sh
index 9bd482c..752bc43 100755
--- a/t/t3507-cherry-pick-conflict.sh
+++ b/t/t3507-cherry-pick-conflict.sh
@@ -161,6 +161,29 @@
 
 	test_must_fail git rev-parse --verify CHERRY_PICK_HEAD
 '
+
+test_expect_success 'partial commit of cherry-pick fails' '
+	pristine_detach initial &&
+
+	test_must_fail git cherry-pick picked &&
+	echo resolved >foo &&
+	git add foo &&
+	test_must_fail git commit foo 2>err &&
+
+	test_i18ngrep "cannot do a partial commit during a cherry-pick." err
+'
+
+test_expect_success 'commit --amend of cherry-pick fails' '
+	pristine_detach initial &&
+
+	test_must_fail git cherry-pick picked &&
+	echo resolved >foo &&
+	git add foo &&
+	test_must_fail git commit --amend 2>err &&
+
+	test_i18ngrep "in the middle of a cherry-pick -- cannot amend." err
+'
+
 test_expect_success 'successful final commit clears cherry-pick state' '
 	pristine_detach initial &&
 
diff --git a/t/t3510-cherry-pick-sequence.sh b/t/t3510-cherry-pick-sequence.sh
index 793bcc7..5b94fda 100755
--- a/t/t3510-cherry-pick-sequence.sh
+++ b/t/t3510-cherry-pick-sequence.sh
@@ -123,7 +123,8 @@
 test_expect_success 'skip "empty" commit' '
 	pristine_detach picked &&
 	test_commit dummy foo d &&
-	test_must_fail git cherry-pick anotherpick &&
+	test_must_fail git cherry-pick anotherpick 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
 	git cherry-pick --skip &&
 	test_cmp_rev dummy HEAD
 '
diff --git a/t/t3514-cherry-pick-revert-gpg.sh b/t/t3514-cherry-pick-revert-gpg.sh
new file mode 100755
index 0000000..5b2e250
--- /dev/null
+++ b/t/t3514-cherry-pick-revert-gpg.sh
@@ -0,0 +1,86 @@
+#!/bin/sh
+#
+# Copyright (c) 2020 Doan Tran Cong Danh
+#
+
+test_description='test {cherry-pick,revert} --[no-]gpg-sign'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-gpg.sh"
+
+if ! test_have_prereq GPG
+then
+	skip_all='skip all test {cherry-pick,revert} --[no-]gpg-sign, gpg not available'
+	test_done
+fi
+
+test_gpg_sign () {
+	local must_fail= will=will fake_editor=
+	if test "x$1" = "x!"
+	then
+		must_fail=test_must_fail
+		will="won't"
+		shift
+	fi
+	conf=$1
+	cmd=$2
+	cmit=$3
+	shift 3
+	test_expect_success "$cmd $* $cmit with commit.gpgsign=$conf $will sign commit" "
+		git reset --hard tip &&
+		git config commit.gpgsign $conf &&
+		git $cmd $* $cmit &&
+		git rev-list tip.. >rev-list &&
+		$must_fail git verify-commit \$(cat rev-list)
+	"
+}
+
+test_expect_success 'setup' '
+	test_commit one &&
+	git switch -c side &&
+	test_commit side1 &&
+	test_commit side2 &&
+	git switch - &&
+	test_commit two &&
+	test_commit three &&
+	test_commit tip
+'
+
+test_gpg_sign ! false cherry-pick   side
+test_gpg_sign ! false cherry-pick ..side
+test_gpg_sign   true  cherry-pick   side
+test_gpg_sign   true  cherry-pick ..side
+test_gpg_sign ! true  cherry-pick   side --no-gpg-sign
+test_gpg_sign ! true  cherry-pick ..side --no-gpg-sign
+test_gpg_sign ! true  cherry-pick   side --gpg-sign --no-gpg-sign
+test_gpg_sign ! true  cherry-pick ..side --gpg-sign --no-gpg-sign
+test_gpg_sign   false cherry-pick   side --no-gpg-sign --gpg-sign
+test_gpg_sign   false cherry-pick ..side --no-gpg-sign --gpg-sign
+test_gpg_sign   true  cherry-pick   side --edit
+test_gpg_sign   true  cherry-pick ..side --edit
+test_gpg_sign ! true  cherry-pick   side --edit --no-gpg-sign
+test_gpg_sign ! true  cherry-pick ..side --edit --no-gpg-sign
+test_gpg_sign ! true  cherry-pick   side --edit --gpg-sign --no-gpg-sign
+test_gpg_sign ! true  cherry-pick ..side --edit --gpg-sign --no-gpg-sign
+test_gpg_sign   false cherry-pick   side --edit --no-gpg-sign --gpg-sign
+test_gpg_sign   false cherry-pick ..side --edit --no-gpg-sign --gpg-sign
+
+test_gpg_sign ! false revert HEAD  --edit
+test_gpg_sign ! false revert two.. --edit
+test_gpg_sign   true  revert HEAD  --edit
+test_gpg_sign   true  revert two.. --edit
+test_gpg_sign ! true  revert HEAD  --edit --no-gpg-sign
+test_gpg_sign ! true  revert two.. --edit --no-gpg-sign
+test_gpg_sign ! true  revert HEAD  --edit --gpg-sign --no-gpg-sign
+test_gpg_sign ! true  revert two.. --edit --gpg-sign --no-gpg-sign
+test_gpg_sign   false revert HEAD  --edit --no-gpg-sign --gpg-sign
+test_gpg_sign   false revert two.. --edit --no-gpg-sign --gpg-sign
+test_gpg_sign   true  revert HEAD  --no-edit
+test_gpg_sign   true  revert two.. --no-edit
+test_gpg_sign ! true  revert HEAD  --no-edit --no-gpg-sign
+test_gpg_sign ! true  revert two.. --no-edit --no-gpg-sign
+test_gpg_sign ! true  revert HEAD  --no-edit --gpg-sign --no-gpg-sign
+test_gpg_sign ! true  revert two.. --no-edit --gpg-sign --no-gpg-sign
+test_gpg_sign   false revert HEAD  --no-edit --no-gpg-sign --gpg-sign
+
+test_done
diff --git a/t/t3700-add.sh b/t/t3700-add.sh
index 88bc7998..b7d4ba6 100755
--- a/t/t3700-add.sh
+++ b/t/t3700-add.sh
@@ -192,7 +192,7 @@
 	test_must_be_empty actual &&
 
 	git diff-files --name-only >actual &&
-	! grep bar actual&&
+	! grep bar actual &&
 	grep baz actual
 '
 
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 5bae6e5..b3d8bb7 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -780,7 +780,7 @@
 test_expect_success 'checkout -p works with pathological context lines' '
 	test_write_lines a a a a a a >a &&
 	git add a &&
-	test_write_lines a b a b a b a b a b a > a&&
+	test_write_lines a b a b a b a b a b a >a &&
 	test_write_lines s n n y q | git checkout -p &&
 	test_write_lines a b a b a a b a b a >expect &&
 	test_cmp expect a
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 3ad23e2..9f7ca98 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -1290,4 +1290,18 @@
 	git rev-parse --verify refs/stash:A.t
 '
 
+test_expect_success 'stash -c stash.useBuiltin=false warning ' '
+	expected="stash.useBuiltin support has been removed" &&
+
+	git -c stash.useBuiltin=false stash 2>err &&
+	test_i18ngrep "$expected" err &&
+	env GIT_TEST_STASH_USE_BUILTIN=false git stash 2>err &&
+	test_i18ngrep "$expected" err &&
+
+	git -c stash.useBuiltin=true stash 2>err &&
+	test_must_be_empty err &&
+	env GIT_TEST_STASH_USE_BUILTIN=true git stash 2>err &&
+	test_must_be_empty err
+'
+
 test_done
diff --git a/t/t3904-stash-patch.sh b/t/t3904-stash-patch.sh
index 9546b6f..accfe38 100755
--- a/t/t3904-stash-patch.sh
+++ b/t/t3904-stash-patch.sh
@@ -89,7 +89,7 @@
 	verify_saved_head
 '
 
-test_expect_failure 'stash -p with split hunk' '
+test_expect_success 'stash -p with split hunk' '
 	git reset --hard &&
 	cat >test <<-\EOF &&
 	aaa
@@ -106,8 +106,8 @@
 	ccc
 	EOF
 	printf "%s\n" s n y q |
-	test_might_fail git stash -p 2>error &&
-	! test_must_be_empty error &&
+	git stash -p 2>error &&
+	test_must_be_empty error &&
 	grep "added line 1" test &&
 	! grep "added line 2" test
 '
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index dde3f11..3f60f7d 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -95,6 +95,15 @@
 	git commit -m "update mode" &&
 	git checkout -f master &&
 
+	GIT_AUTHOR_DATE="2006-06-26 00:06:00 +0000" &&
+	GIT_COMMITTER_DATE="2006-06-26 00:06:00 +0000" &&
+	export GIT_AUTHOR_DATE GIT_COMMITTER_DATE &&
+	git checkout -b note initial &&
+	git update-index --chmod=+x file2 &&
+	git commit -m "update mode (file2)" &&
+	git notes add -m "note" &&
+	git checkout -f master &&
+
 	# Same merge as master, but with parents reversed. Hide it in a
 	# pseudo-ref to avoid impacting tests with --all.
 	commit=$(echo reverse |
@@ -398,6 +407,9 @@
 
 diff-tree --pretty --root --stat --compact-summary initial
 diff-tree --pretty -R --root --stat --compact-summary initial
+diff-tree --pretty note
+diff-tree --pretty --notes note
+diff-tree --format=%N note
 diff-tree --stat --compact-summary initial mode
 diff-tree -R --stat --compact-summary initial mode
 EOF
diff --git a/t/t4013/diff.diff-tree_--format=%N_note b/t/t4013/diff.diff-tree_--format=%N_note
new file mode 100644
index 0000000..93042ed
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--format=%N_note
@@ -0,0 +1,6 @@
+$ git diff-tree --format=%N note
+note
+
+
+:100644 100755 01e79c32a8c99c557f0757da7cb6d65b3414466d 01e79c32a8c99c557f0757da7cb6d65b3414466d M	file2
+$
diff --git a/t/t4013/diff.diff-tree_--pretty_--notes_note b/t/t4013/diff.diff-tree_--pretty_--notes_note
new file mode 100644
index 0000000..4d0bde6
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--pretty_--notes_note
@@ -0,0 +1,12 @@
+$ git diff-tree --pretty --notes note
+commit a6f364368ca320bc5a92e18912e16fa6b3dff598
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    update mode (file2)
+
+Notes:
+    note
+
+:100644 100755 01e79c32a8c99c557f0757da7cb6d65b3414466d 01e79c32a8c99c557f0757da7cb6d65b3414466d M	file2
+$
diff --git a/t/t4013/diff.diff-tree_--pretty_note b/t/t4013/diff.diff-tree_--pretty_note
new file mode 100644
index 0000000..1fa5967
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--pretty_note
@@ -0,0 +1,9 @@
+$ git diff-tree --pretty note
+commit a6f364368ca320bc5a92e18912e16fa6b3dff598
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    update mode (file2)
+
+:100644 100755 01e79c32a8c99c557f0757da7cb6d65b3414466d 01e79c32a8c99c557f0757da7cb6d65b3414466d M	file2
+$
diff --git a/t/t4013/diff.log_--decorate=full_--all b/t/t4013/diff.log_--decorate=full_--all
index 2afe91f..3f9b872 100644
--- a/t/t4013/diff.log_--decorate=full_--all
+++ b/t/t4013/diff.log_--decorate=full_--all
@@ -5,12 +5,27 @@
 
     update mode
 
+commit a6f364368ca320bc5a92e18912e16fa6b3dff598 (refs/heads/note)
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    update mode (file2)
+
+Notes:
+    note
+
 commit cd4e72fd96faed3f0ba949dc42967430374e2290 (refs/heads/rearrange)
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:06:00 2006 +0000
 
     Rearranged lines in dir/sub
 
+commit cbacedd14cb8b89255a2c02b59e77a2e9a8021a0 (refs/notes/commits)
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    Notes added by 'git notes add'
+
 commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (HEAD -> refs/heads/master)
 Merge: 9a6d494 c7a2ab9
 Author: A U Thor <author@example.com>
diff --git a/t/t4013/diff.log_--decorate_--all b/t/t4013/diff.log_--decorate_--all
index d0f308a..f5e20e1 100644
--- a/t/t4013/diff.log_--decorate_--all
+++ b/t/t4013/diff.log_--decorate_--all
@@ -5,12 +5,27 @@
 
     update mode
 
+commit a6f364368ca320bc5a92e18912e16fa6b3dff598 (note)
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    update mode (file2)
+
+Notes:
+    note
+
 commit cd4e72fd96faed3f0ba949dc42967430374e2290 (rearrange)
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:06:00 2006 +0000
 
     Rearranged lines in dir/sub
 
+commit cbacedd14cb8b89255a2c02b59e77a2e9a8021a0 (refs/notes/commits)
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    Notes added by 'git notes add'
+
 commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (HEAD -> master)
 Merge: 9a6d494 c7a2ab9
 Author: A U Thor <author@example.com>
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index b653dd7..db7e733 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -1161,6 +1161,59 @@
 '
 
 cat >expect <<'EOF'
+From: Foö Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar
+ Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo
+ Bar Foo Bar Foo Bar Foo Bar <author@example.com>
+EOF
+test_expect_success 'format-patch wraps extremely long from-header (non-ASCII without Q-encoding)' '
+	echo content >>file &&
+	git add file &&
+	GIT_AUTHOR_NAME="Foö Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar" \
+	git commit -m author-check &&
+	git format-patch --no-encode-email-headers --stdout -1 >patch &&
+	sed -n "/^From: /p; /^ /p; /^$/q" patch >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+Subject: [PATCH] Foö
+EOF
+test_expect_success 'subject lines are unencoded with --no-encode-email-headers' '
+	echo content >>file &&
+	git add file &&
+	git commit -m "Foö" &&
+	git format-patch --no-encode-email-headers -1 --stdout >patch &&
+	grep ^Subject: patch >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+Subject: [PATCH] Foö
+EOF
+test_expect_success 'subject lines are unencoded with format.encodeEmailHeaders=false' '
+	echo content >>file &&
+	git add file &&
+	git commit -m "Foö" &&
+	git config format.encodeEmailHeaders false &&
+	git format-patch -1 --stdout >patch &&
+	grep ^Subject: patch >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+Subject: [PATCH] =?UTF-8?q?Fo=C3=B6?=
+EOF
+test_expect_success '--encode-email-headers overrides format.encodeEmailHeaders' '
+	echo content >>file &&
+	git add file &&
+	git commit -m "Foö" &&
+	git config format.encodeEmailHeaders false &&
+	git format-patch --encode-email-headers -1 --stdout >patch &&
+	grep ^Subject: patch >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
 Subject: header with . in it
 EOF
 test_expect_success 'subject lines do not have 822 atom-quoting' '
diff --git a/t/t4057-diff-combined-paths.sh b/t/t4057-diff-combined-paths.sh
index 4f4b541..0b78573 100755
--- a/t/t4057-diff-combined-paths.sh
+++ b/t/t4057-diff-combined-paths.sh
@@ -14,7 +14,7 @@
 test_expect_success 'trivial merge - combine-diff empty' '
 	for i in $(test_seq 1 9)
 	do
-		echo $i >$i.txt	&&
+		echo $i >$i.txt &&
 		git add $i.txt
 	done &&
 	git commit -m "init" &&
diff --git a/t/t4061-diff-indent.sh b/t/t4061-diff-indent.sh
index 2affd7a..0f7a6d9 100755
--- a/t/t4061-diff-indent.sh
+++ b/t/t4061-diff-indent.sh
@@ -17,7 +17,7 @@
 # Compare blame output using the expectation for a diff as reference.
 # Only look for the lines coming from non-boundary commits.
 compare_blame () {
-	sed -n -e "1,4d" -e "s/^\+//p" <"$1" >.tmp-1
+	sed -n -e "1,4d" -e "s/^+//p" <"$1" >.tmp-1
 	sed -ne "s/^[^^][^)]*) *//p" <"$2" >.tmp-2
 	test_cmp .tmp-1 .tmp-2 && rm -f .tmp-1 .tmp-2
 }
diff --git a/t/t4067-diff-partial-clone.sh b/t/t4067-diff-partial-clone.sh
index 4831ad3..c1ed1c2 100755
--- a/t/t4067-diff-partial-clone.sh
+++ b/t/t4067-diff-partial-clone.sh
@@ -131,4 +131,52 @@
 	test_line_count = 1 done_lines
 '
 
+test_expect_success 'diff does not fetch anything if inexact rename detection is not needed' '
+	test_when_finished "rm -rf server client trace" &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	printf "b\nb\nb\nb\nb\n" >server/b &&
+	git -C server add a b &&
+	git -C server commit -m x &&
+	mv server/b server/c &&
+	git -C server add c &&
+	git -C server commit -a -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+	git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client &&
+
+	# Ensure no fetches.
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD &&
+	! test_path_exists trace
+'
+
+test_expect_success 'diff --break-rewrites fetches only if necessary, and batches blobs if it does' '
+	test_when_finished "rm -rf server client trace" &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	printf "b\nb\nb\nb\nb\n" >server/b &&
+	git -C server add a b &&
+	git -C server commit -m x &&
+	printf "c\nc\nc\nc\nc\n" >server/b &&
+	git -C server commit -a -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+	git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client &&
+
+	# Ensure no fetches.
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD &&
+	! test_path_exists trace &&
+
+	# But with --break-rewrites, ensure that there is exactly 1 negotiation
+	# by checking that there is only 1 "done" line sent. ("done" marks the
+	# end of negotiation.)
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --break-rewrites --raw -M HEAD^ HEAD &&
+	grep "git> done" trace >done_lines &&
+	test_line_count = 1 done_lines
+'
+
 test_done
diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
index 971a5a7..0ca2982 100755
--- a/t/t4124-apply-ws-rule.sh
+++ b/t/t4124-apply-ws-rule.sh
@@ -52,6 +52,13 @@
 
 	# find touched lines
 	$DIFF file target | sed -n -e "s/^> //p" >fixed
+	# busybox's diff(1) doesn't output normal format
+	if ! test -s fixed
+	then
+		$DIFF -u file target |
+		grep -v '^+++ target' |
+		sed -ne "/^+/s/+//p" >fixed
+	fi
 
 	# the changed lines are all expected to change
 	fixed_cnt=$(wc -l <fixed)
diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index cb45271..bda4586 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -166,7 +166,7 @@
 	test_tick &&
 	git commit -m third &&
 
-	git format-patch --stdout first >patch2	&&
+	git format-patch --stdout first >patch2 &&
 
 	git checkout -b lorem &&
 	sed -n -e "11,\$p" msg >file &&
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 0f766ba..f1ea7d9 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -742,8 +742,24 @@
 	octopus-a (octopus-a)
 	reach
 	EOF
+	cat >expect.no-decorate <<-\EOF &&
+	Merge-tag-reach
+	Merge-tags-octopus-a-and-octopus-b
+	seventh
+	octopus-b
+	octopus-a
+	reach
+	EOF
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs="heads/octopus*" >actual &&
+	test_cmp expect.decorate actual &&
+	git log -n6 --decorate=short --pretty="tformat:%f%d" \
+		--decorate-refs-exclude="heads/octopus*" \
+		--decorate-refs="heads/octopus*" >actual &&
+	test_cmp expect.no-decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" \
+		--decorate-refs="heads/octopus*" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -787,6 +803,9 @@
 	EOF
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="heads/octopus*" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -801,6 +820,9 @@
 	EOF
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="tags/reach" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="tags/reach" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -816,11 +838,19 @@
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="heads/octopus*" \
 		--decorate-refs-exclude="tags/reach" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" \
+		-c log.excludeDecoration="tags/reach" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" log \
+		--decorate-refs-exclude="tags/reach" \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
 test_expect_success 'decorate-refs and decorate-refs-exclude' '
-	cat >expect.decorate <<-\EOF &&
+	cat >expect.no-decorate <<-\EOF &&
 	Merge-tag-reach (master)
 	Merge-tags-octopus-a-and-octopus-b
 	seventh
@@ -831,6 +861,21 @@
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs="heads/*" \
 		--decorate-refs-exclude="heads/oc*" >actual &&
+	test_cmp expect.no-decorate actual
+'
+
+test_expect_success 'deocrate-refs and log.excludeDecoration' '
+	cat >expect.decorate <<-\EOF &&
+	Merge-tag-reach (master)
+	Merge-tags-octopus-a-and-octopus-b
+	seventh
+	octopus-b (octopus-b)
+	octopus-a (octopus-a)
+	reach (reach)
+	EOF
+	git -c log.excludeDecoration="heads/oc*" log \
+		--decorate-refs="heads/*" \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -846,6 +891,10 @@
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="*octopus*" \
 		--simplify-by-decoration >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="*octopus*" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" \
+		--simplify-by-decoration >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -1627,6 +1676,66 @@
 	grep "tag signed_tag_shallow names a non-parent $hash" actual
 '
 
+test_expect_success GPG 'log --graph --show-signature for merged tag with missing key' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	git checkout -b plain-nokey master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-nokey master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_nokey &&
+	git checkout plain-nokey &&
+	git merge --no-ff -m msg signed_tag_nokey &&
+	GNUPGHOME=. git log --graph --show-signature -n1 plain-nokey >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpg: Signature made" actual &&
+	grep "^| | gpg: Can'"'"'t check signature: \(public key not found\|No public key\)" actual
+'
+
+test_expect_success GPG 'log --graph --show-signature for merged tag with bad signature' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	git checkout -b plain-bad master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-bad master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_bad &&
+	git cat-file tag signed_tag_bad >raw &&
+	sed -e "s/signed_tag_msg/forged/" raw >forged &&
+	git hash-object -w -t tag forged >forged.tag &&
+	git checkout plain-bad &&
+	git merge --no-ff -m msg "$(cat forged.tag)" &&
+	git log --graph --show-signature -n1 plain-bad >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpg: Signature made" actual &&
+	grep "^| | gpg: BAD signature from" actual
+'
+
+test_expect_success GPG 'log --show-signature for merged tag with GPG failure' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	git checkout -b plain-fail master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-fail master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_fail &&
+	git checkout plain-fail &&
+	git merge --no-ff -m msg signed_tag_fail &&
+	TMPDIR="$(pwd)/bogus" git log --show-signature -n1 plain-fail >actual &&
+	grep "^merged tag" actual &&
+	grep "^No signature" actual &&
+	! grep "^gpg: Signature made" actual
+'
+
 test_expect_success GPGSM 'log --graph --show-signature for merged tag x509' '
 	test_when_finished "git reset --hard && git checkout master" &&
 	test_config gpg.format x509 &&
@@ -1648,6 +1757,51 @@
 	grep "^| | gpgsm: Good signature" actual
 '
 
+test_expect_success GPGSM 'log --graph --show-signature for merged tag x509 missing key' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	test_config gpg.format x509 &&
+	test_config user.signingkey $GIT_COMMITTER_EMAIL &&
+	git checkout -b plain-x509-nokey master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-x509-nokey master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_x509_nokey &&
+	git checkout plain-x509-nokey &&
+	git merge --no-ff -m msg signed_tag_x509_nokey &&
+	GNUPGHOME=. git log --graph --show-signature -n1 plain-x509-nokey >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpgsm: certificate not found" actual
+'
+
+test_expect_success GPGSM 'log --graph --show-signature for merged tag x509 bad signature' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	test_config gpg.format x509 &&
+	test_config user.signingkey $GIT_COMMITTER_EMAIL &&
+	git checkout -b plain-x509-bad master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-x509-bad master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_x509_bad &&
+	git cat-file tag signed_tag_x509_bad >raw &&
+	sed -e "s/signed_tag_msg/forged/" raw >forged &&
+	git hash-object -w -t tag forged >forged.tag &&
+	git checkout plain-x509-bad &&
+	git merge --no-ff -m msg "$(cat forged.tag)" &&
+	git log --graph --show-signature -n1 plain-x509-bad >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpgsm: Signature made" actual &&
+	grep "^| | gpgsm: invalid signature" actual
+'
+
+
 test_expect_success GPG '--no-show-signature overrides --show-signature' '
 	git log -1 --show-signature --no-show-signature signed >actual &&
 	! grep "^gpg:" actual
diff --git a/t/t4208-log-magic-pathspec.sh b/t/t4208-log-magic-pathspec.sh
index 4c8f3b8..6cdbe47 100755
--- a/t/t4208-log-magic-pathspec.sh
+++ b/t/t4208-log-magic-pathspec.sh
@@ -55,6 +55,10 @@
 	git log -- :/a
 '
 
+test_expect_success '"git log :/any/path/" should not segfault' '
+	test_must_fail git log :/any/path/
+'
+
 # This differs from the ":/a" check above in that :/in looks like a pathspec,
 # but doesn't match an actual file.
 test_expect_success '"git log :/in" should not be ambiguous' '
diff --git a/t/t4254-am-corrupt.sh b/t/t4254-am-corrupt.sh
index fd3bdbf..daf01c3 100755
--- a/t/t4254-am-corrupt.sh
+++ b/t/t4254-am-corrupt.sh
@@ -3,6 +3,37 @@
 test_description='git am with corrupt input'
 . ./test-lib.sh
 
+make_mbox_with_nul () {
+	space=' '
+	q_nul_in_subject=
+	q_nul_in_body=
+	while test $# -ne 0
+	do
+		case "$1" in
+		subject) q_nul_in_subject='=00' ;;
+		body)    q_nul_in_body='=00' ;;
+		esac &&
+		shift
+	done &&
+	cat <<-EOF
+	From ec7364544f690c560304f5a5de9428ea3b978b26 Mon Sep 17 00:00:00 2001
+	From: A U Thor <author@example.com>
+	Date: Sun, 19 Apr 2020 13:42:07 +0700
+	Subject: [PATCH] =?ISO-8859-1?q?=C4=CB${q_nul_in_subject}=D1=CF=D6?=
+	MIME-Version: 1.0
+	Content-Type: text/plain; charset=ISO-8859-1
+	Content-Transfer-Encoding: quoted-printable
+
+	abc${q_nul_in_body}def
+	---
+	diff --git a/afile b/afile
+	new file mode 100644
+	index 0000000000..e69de29bb2
+	--$space
+	2.26.1
+	EOF
+}
+
 test_expect_success setup '
 	# Note the missing "+++" line:
 	cat >bad-patch.diff <<-\EOF &&
@@ -25,13 +56,27 @@
 #   fatal: unable to write file '(null)' mode 100644: Bad address
 # Also, it had the unwanted side-effect of deleting f.
 test_expect_success 'try to apply corrupted patch' '
-	test_must_fail git -c advice.amWorkDir=false am bad-patch.diff 2>actual
-'
-
-test_expect_success 'compare diagnostic; ensure file is still here' '
+	test_when_finished "git am --abort" &&
+	test_must_fail git -c advice.amWorkDir=false am bad-patch.diff 2>actual &&
 	echo "error: git diff header lacks filename information (line 4)" >expected &&
 	test_path_is_file f &&
 	test_i18ncmp expected actual
 '
 
+test_expect_success "NUL in commit message's body" '
+	test_when_finished "git am --abort" &&
+	make_mbox_with_nul body >body.patch &&
+	test_must_fail git am body.patch 2>err &&
+	grep "a NUL byte in commit log message not allowed" err
+'
+
+test_expect_success "NUL in commit message's header" "
+	test_when_finished 'git am --abort' &&
+	make_mbox_with_nul subject >subject.patch &&
+	test_must_fail git mailinfo msg patch <subject.patch 2>err &&
+	grep \"a NUL byte in 'Subject' is not allowed\" err &&
+	test_must_fail git am subject.patch 2>err &&
+	grep \"a NUL byte in 'Subject' is not allowed\" err
+"
+
 test_done
diff --git a/t/t5003-archive-zip.sh b/t/t5003-archive-zip.sh
index 106eddb..3b76d2e 100755
--- a/t/t5003-archive-zip.sh
+++ b/t/t5003-archive-zip.sh
@@ -7,12 +7,12 @@
 SUBSTFORMAT=%H%n
 
 test_lazy_prereq UNZIP_SYMLINKS '
-	(
-		mkdir unzip-symlinks &&
-		cd unzip-symlinks &&
-		"$GIT_UNZIP" "$TEST_DIRECTORY"/t5003/infozip-symlinks.zip &&
-		test -h symlink
-	)
+	"$GIT_UNZIP" "$TEST_DIRECTORY"/t5003/infozip-symlinks.zip &&
+	test -h symlink
+'
+
+test_lazy_prereq UNZIP_CONVERT '
+	"$GIT_UNZIP" -a "$TEST_DIRECTORY"/t5003/infozip-symlinks.zip
 '
 
 check_zip() {
@@ -39,33 +39,33 @@
 	extracted=${dir_with_prefix}a
 	original=a
 
-	test_expect_success UNZIP " extract ZIP archive with EOL conversion" '
+	test_expect_success UNZIP_CONVERT " extract ZIP archive with EOL conversion" '
 		(mkdir $dir && cd $dir && "$GIT_UNZIP" -a ../$zipfile)
 	'
 
-	test_expect_success UNZIP " validate that text files are converted" "
+	test_expect_success UNZIP_CONVERT " validate that text files are converted" "
 		test_cmp_bin $extracted/text.cr $extracted/text.crlf &&
 		test_cmp_bin $extracted/text.cr $extracted/text.lf
 	"
 
-	test_expect_success UNZIP " validate that binary files are unchanged" "
+	test_expect_success UNZIP_CONVERT " validate that binary files are unchanged" "
 		test_cmp_bin $original/binary.cr   $extracted/binary.cr &&
 		test_cmp_bin $original/binary.crlf $extracted/binary.crlf &&
 		test_cmp_bin $original/binary.lf   $extracted/binary.lf
 	"
 
-	test_expect_success UNZIP " validate that diff files are converted" "
+	test_expect_success UNZIP_CONVERT " validate that diff files are converted" "
 		test_cmp_bin $extracted/diff.cr $extracted/diff.crlf &&
 		test_cmp_bin $extracted/diff.cr $extracted/diff.lf
 	"
 
-	test_expect_success UNZIP " validate that -diff files are unchanged" "
+	test_expect_success UNZIP_CONVERT " validate that -diff files are unchanged" "
 		test_cmp_bin $original/nodiff.cr   $extracted/nodiff.cr &&
 		test_cmp_bin $original/nodiff.crlf $extracted/nodiff.crlf &&
 		test_cmp_bin $original/nodiff.lf   $extracted/nodiff.lf
 	"
 
-	test_expect_success UNZIP " validate that custom diff is unchanged " "
+	test_expect_success UNZIP_CONVERT " validate that custom diff is unchanged " "
 		test_cmp_bin $original/custom.cr   $extracted/custom.cr &&
 		test_cmp_bin $original/custom.crlf $extracted/custom.crlf &&
 		test_cmp_bin $original/custom.lf   $extracted/custom.lf
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 43a7a66..030a722 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -42,10 +42,15 @@
 	EOF
 '
 
-test_expect_success 'write midx with no packs' '
-	test_when_finished rm -f pack/multi-pack-index &&
-	git multi-pack-index --object-dir=. write &&
-	midx_read_expect 0 0 4 .
+test_expect_success "don't write midx with no packs" '
+	test_must_fail git multi-pack-index --object-dir=. write &&
+	test_path_is_missing pack/multi-pack-index
+'
+
+test_expect_success "Warn if a midx contains no oid" '
+	cp "$TEST_DIRECTORY"/t5319/no-objects.midx $objdir/pack/multi-pack-index &&
+	test_must_fail git multi-pack-index verify &&
+	rm $objdir/pack/multi-pack-index
 '
 
 generate_objects () {
@@ -521,10 +526,10 @@
 		cd dup &&
 		rm -rf .git/objects/pack &&
 		mv .git/objects/pack-backup .git/objects/pack &&
-		touch -m -t 201901010000 .git/objects/pack/pack-D* &&
-		touch -m -t 201901010001 .git/objects/pack/pack-C* &&
-		touch -m -t 201901010002 .git/objects/pack/pack-B* &&
-		touch -m -t 201901010003 .git/objects/pack/pack-A* &&
+		test-tool chmtime =-5 .git/objects/pack/pack-D* &&
+		test-tool chmtime =-4 .git/objects/pack/pack-C* &&
+		test-tool chmtime =-3 .git/objects/pack/pack-B* &&
+		test-tool chmtime =-2 .git/objects/pack/pack-A* &&
 		ls .git/objects/pack >expect &&
 		MINSIZE=$(test-tool path-utils file-size .git/objects/pack/*pack | sort -n | head -n 1) &&
 		git multi-pack-index repack --batch-size=$MINSIZE &&
diff --git a/t/t5319/no-objects.midx b/t/t5319/no-objects.midx
new file mode 100644
index 0000000..e466b8e
--- /dev/null
+++ b/t/t5319/no-objects.midx
Binary files differ
diff --git a/t/t5322-pack-objects-sparse.sh b/t/t5322-pack-objects-sparse.sh
index 7124b55..a581eaf 100755
--- a/t/t5322-pack-objects-sparse.sh
+++ b/t/t5322-pack-objects-sparse.sh
@@ -105,14 +105,16 @@
 	test_cmp required_objects.txt nonsparse_required_objects.txt
 '
 
+# --sparse is enabled by default by pack.useSparse
 test_expect_success 'sparse pack-objects' '
+	GIT_TEST_PACK_SPARSE=-1 &&
 	git rev-parse			\
 		topic1			\
 		topic1^{tree}		\
 		topic1:f3		\
 		topic1:f3/f4		\
 		topic1:f3/f4/data.txt | sort >expect_sparse_objects.txt &&
-	git pack-objects --stdout --revs --sparse <packinput.txt >sparse.pack &&
+	git pack-objects --stdout --revs <packinput.txt >sparse.pack &&
 	git index-pack -o sparse.idx sparse.pack &&
 	git show-index <sparse.idx | awk "{print \$2}" >sparse_objects.txt &&
 	test_cmp expect_sparse_objects.txt sparse_objects.txt
diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh
index 53b2e6b..b8b208f 100755
--- a/t/t5324-split-commit-graph.sh
+++ b/t/t5324-split-commit-graph.sh
@@ -210,8 +210,14 @@
 		git config core.commitGraph true &&
 		test_line_count = 2 $graphdir/commit-graph-chain &&
 		test_commit 15 &&
-		git commit-graph write --reachable --split --size-multiple=10 --expire-time=1980-01-01 &&
+		touch $graphdir/to-delete.graph $graphdir/to-keep.graph &&
+		test-tool chmtime =1546362000 $graphdir/to-delete.graph &&
+		test-tool chmtime =1546362001 $graphdir/to-keep.graph &&
+		git commit-graph write --reachable --split --size-multiple=10 \
+			--expire-time="2019-01-01 12:00 -05:00" &&
 		test_line_count = 1 $graphdir/commit-graph-chain &&
+		test_path_is_missing $graphdir/to-delete.graph &&
+		test_path_is_file $graphdir/to-keep.graph &&
 		ls $graphdir/graph-*.graph >graph-files &&
 		test_line_count = 3 graph-files
 	) &&
diff --git a/t/t5504-fetch-receive-strict.sh b/t/t5504-fetch-receive-strict.sh
index 645b4c7..a32efe2 100755
--- a/t/t5504-fetch-receive-strict.sh
+++ b/t/t5504-fetch-receive-strict.sh
@@ -65,6 +65,7 @@
 cat >exp <<EOF
 To dst
 !	refs/heads/master:refs/heads/test	[remote rejected] (missing necessary objects)
+Done
 EOF
 
 test_expect_success 'push without strict' '
diff --git a/t/t5512-ls-remote.sh b/t/t5512-ls-remote.sh
index 04b3540..e98c3a0 100755
--- a/t/t5512-ls-remote.sh
+++ b/t/t5512-ls-remote.sh
@@ -4,6 +4,14 @@
 
 . ./test-lib.sh
 
+generate_references () {
+	for ref
+	do
+		oid=$(git rev-parse "$ref") &&
+		printf '%s\t%s\n' "$oid" "$ref" || return 1
+	done
+}
+
 test_expect_success setup '
 	>file &&
 	git add file &&
@@ -13,11 +21,11 @@
 	git tag mark1.1 &&
 	git tag mark1.2 &&
 	git tag mark1.10 &&
-	git show-ref --tags -d | sed -e "s/ /	/" >expected.tag &&
-	(
-		echo "$(git rev-parse HEAD)	HEAD" &&
-		git show-ref -d	| sed -e "s/ /	/"
-	) >expected.all &&
+	git show-ref --tags -d >expected.tag.raw &&
+	sed -e "s/ /	/" expected.tag.raw >expected.tag &&
+	generate_references HEAD >expected.all &&
+	git show-ref -d	>refs &&
+	sed -e "s/ /	/" refs >>expected.all &&
 
 	git remote add self "$(pwd)/.git"
 '
@@ -43,34 +51,31 @@
 '
 
 test_expect_success 'ls-remote --sort="version:refname" --tags self' '
-	cat >expect <<-EOF &&
-	$(git rev-parse mark)	refs/tags/mark
-	$(git rev-parse mark1.1)	refs/tags/mark1.1
-	$(git rev-parse mark1.2)	refs/tags/mark1.2
-	$(git rev-parse mark1.10)	refs/tags/mark1.10
-	EOF
+	generate_references \
+		refs/tags/mark \
+		refs/tags/mark1.1 \
+		refs/tags/mark1.2 \
+		refs/tags/mark1.10 >expect &&
 	git ls-remote --sort="version:refname" --tags self >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'ls-remote --sort="-version:refname" --tags self' '
-	cat >expect <<-EOF &&
-	$(git rev-parse mark1.10)	refs/tags/mark1.10
-	$(git rev-parse mark1.2)	refs/tags/mark1.2
-	$(git rev-parse mark1.1)	refs/tags/mark1.1
-	$(git rev-parse mark)	refs/tags/mark
-	EOF
+	generate_references \
+		refs/tags/mark1.10 \
+		refs/tags/mark1.2 \
+		refs/tags/mark1.1 \
+		refs/tags/mark >expect &&
 	git ls-remote --sort="-version:refname" --tags self >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'ls-remote --sort="-refname" --tags self' '
-	cat >expect <<-EOF &&
-	$(git rev-parse mark1.2)	refs/tags/mark1.2
-	$(git rev-parse mark1.10)	refs/tags/mark1.10
-	$(git rev-parse mark1.1)	refs/tags/mark1.1
-	$(git rev-parse mark)	refs/tags/mark
-	EOF
+	generate_references \
+		refs/tags/mark1.2 \
+		refs/tags/mark1.10 \
+		refs/tags/mark1.1 \
+		refs/tags/mark >expect &&
 	git ls-remote --sort="-refname" --tags self >actual &&
 	test_cmp expect actual
 '
@@ -92,7 +97,7 @@
 
 test_expect_success 'suppress "From <url>" with -q' '
 	git ls-remote -q 2>actual_err &&
-	test_must_fail test_cmp exp_err actual_err
+	! test_cmp exp_err actual_err
 '
 
 test_expect_success 'use branch.<name>.remote if possible' '
@@ -180,8 +185,8 @@
 		test_config $configsection.hiderefs refs/tags &&
 		git ls-remote . >actual &&
 		test_unconfig $configsection.hiderefs &&
-		git ls-remote . |
-		sed -e "/	refs\/tags\//d" >expect &&
+		git ls-remote . >expect.raw &&
+		sed -e "/	refs\/tags\//d" expect.raw >expect &&
 		test_cmp expect actual
 	'
 
@@ -212,17 +217,18 @@
 
 test_expect_success 'ls-remote --symref' '
 	git fetch origin &&
-	cat >expect <<-EOF &&
-	ref: refs/heads/master	HEAD
-	$(git rev-parse HEAD)	HEAD
-	$(git rev-parse refs/heads/master)	refs/heads/master
-	$(git rev-parse HEAD)	refs/remotes/origin/HEAD
-	$(git rev-parse refs/remotes/origin/master)	refs/remotes/origin/master
-	$(git rev-parse refs/tags/mark)	refs/tags/mark
-	$(git rev-parse refs/tags/mark1.1)	refs/tags/mark1.1
-	$(git rev-parse refs/tags/mark1.10)	refs/tags/mark1.10
-	$(git rev-parse refs/tags/mark1.2)	refs/tags/mark1.2
-	EOF
+	echo "ref: refs/heads/master	HEAD" >expect &&
+	generate_references \
+		HEAD \
+		refs/heads/master >>expect &&
+	oid=$(git rev-parse HEAD) &&
+	echo "$oid	refs/remotes/origin/HEAD" >>expect &&
+	generate_references \
+		refs/remotes/origin/master \
+		refs/tags/mark \
+		refs/tags/mark1.1 \
+		refs/tags/mark1.10 \
+		refs/tags/mark1.2 >>expect &&
 	# Protocol v2 supports sending symrefs for refs other than HEAD, so use
 	# protocol v0 here.
 	GIT_TEST_PROTOCOL_VERSION=0 git ls-remote --symref >actual &&
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 9ff041a..9c6218f 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1066,6 +1066,7 @@
 
 	echo >.git/foo  "To testrepo"  &&
 	echo >>.git/foo "!	refs/heads/master:refs/heads/master	[remote rejected] (branch is currently checked out)" &&
+	echo >>.git/foo "Done" &&
 
 	test_must_fail git push >.git/bar --porcelain  testrepo refs/heads/master:refs/heads/master &&
 	test_cmp .git/foo .git/bar
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 2f86fca..37535d6 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -10,11 +10,13 @@
 }
 
 test_pull_autostash () {
+	expect_parent_num="$1" &&
+	shift &&
 	git reset --hard before-rebase &&
 	echo dirty >new_file &&
 	git add new_file &&
 	git pull "$@" . copy &&
-	test_cmp_rev HEAD^ copy &&
+	test_cmp_rev HEAD^"$expect_parent_num" copy &&
 	echo dirty >expect &&
 	test_cmp expect new_file &&
 	echo "modified again" >expect &&
@@ -26,7 +28,7 @@
 	echo dirty >new_file &&
 	git add new_file &&
 	test_must_fail git pull "$@" . copy 2>err &&
-	test_i18ngrep "uncommitted changes." err
+	test_i18ngrep "\(uncommitted changes.\)\|\(overwritten by merge:\)" err
 }
 
 test_expect_success setup '
@@ -369,22 +371,22 @@
 
 test_expect_success 'pull --rebase succeeds with dirty working directory and rebase.autostash set' '
 	test_config rebase.autostash true &&
-	test_pull_autostash --rebase
+	test_pull_autostash 1 --rebase
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash=true' '
 	test_config rebase.autostash true &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash=false' '
 	test_config rebase.autostash false &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash unset' '
 	test_unconfig rebase.autostash &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --no-autostash & rebase.autostash=true' '
@@ -402,13 +404,40 @@
 	test_pull_autostash_fail --rebase --no-autostash
 '
 
-for i in --autostash --no-autostash
-do
-	test_expect_success "pull $i (without --rebase) is illegal" '
-		test_must_fail git pull $i . copy 2>err &&
-		test_i18ngrep "only valid with --rebase" err
-	'
-done
+test_expect_success 'pull succeeds with dirty working directory and merge.autostash set' '
+	test_config merge.autostash true &&
+	test_pull_autostash 2
+'
+
+test_expect_success 'pull --autostash & merge.autostash=true' '
+	test_config merge.autostash true &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --autostash & merge.autostash=false' '
+	test_config merge.autostash false &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --autostash & merge.autostash unset' '
+	test_unconfig merge.autostash &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash=true' '
+	test_config merge.autostash true &&
+	test_pull_autostash_fail --no-autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash=false' '
+	test_config merge.autostash false &&
+	test_pull_autostash_fail --no-autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash unset' '
+	test_unconfig merge.autostash &&
+	test_pull_autostash_fail --no-autostash
+'
 
 test_expect_success 'pull.rebase' '
 	git reset --hard before-rebase &&
@@ -422,7 +451,7 @@
 
 test_expect_success 'pull --autostash & pull.rebase=true' '
 	test_config pull.rebase true &&
-	test_pull_autostash --autostash
+	test_pull_autostash 1 --autostash
 '
 
 test_expect_success 'pull --no-autostash & pull.rebase=true' '
diff --git a/t/t5521-pull-options.sh b/t/t5521-pull-options.sh
index ccde8ba..159afa7 100755
--- a/t/t5521-pull-options.sh
+++ b/t/t5521-pull-options.sh
@@ -11,10 +11,10 @@
 	 git commit -m one)
 '
 
-test_expect_success 'git pull -q' '
+test_expect_success 'git pull -q --no-rebase' '
 	mkdir clonedq &&
 	(cd clonedq && git init &&
-	git pull -q "../parent" >out 2>err &&
+	git pull -q --no-rebase "../parent" >out 2>err &&
 	test_must_be_empty err &&
 	test_must_be_empty out)
 '
@@ -30,10 +30,10 @@
 	test_must_be_empty out)
 '
 
-test_expect_success 'git pull' '
+test_expect_success 'git pull --no-rebase' '
 	mkdir cloned &&
 	(cd cloned && git init &&
-	git pull "../parent" >out 2>err &&
+	git pull --no-rebase "../parent" >out 2>err &&
 	test -s err &&
 	test_must_be_empty out)
 '
@@ -46,10 +46,10 @@
 	test_must_be_empty out)
 '
 
-test_expect_success 'git pull -v' '
+test_expect_success 'git pull -v --no-rebase' '
 	mkdir clonedv &&
 	(cd clonedv && git init &&
-	git pull -v "../parent" >out 2>err &&
+	git pull -v --no-rebase "../parent" >out 2>err &&
 	test -s err &&
 	test_must_be_empty out)
 '
@@ -62,25 +62,25 @@
 	test_must_be_empty out)
 '
 
-test_expect_success 'git pull -v -q' '
+test_expect_success 'git pull -v -q --no-rebase' '
 	mkdir clonedvq &&
 	(cd clonedvq && git init &&
-	git pull -v -q "../parent" >out 2>err &&
+	git pull -v -q --no-rebase "../parent" >out 2>err &&
 	test_must_be_empty out &&
 	test_must_be_empty err)
 '
 
-test_expect_success 'git pull -q -v' '
+test_expect_success 'git pull -q -v --no-rebase' '
 	mkdir clonedqv &&
 	(cd clonedqv && git init &&
-	git pull -q -v "../parent" >out 2>err &&
+	git pull -q -v --no-rebase "../parent" >out 2>err &&
 	test_must_be_empty out &&
 	test -s err)
 '
 test_expect_success 'git pull --cleanup errors early on invalid argument' '
 	mkdir clonedcleanup &&
 	(cd clonedcleanup && git init &&
-	test_must_fail git pull --cleanup invalid "../parent" >out 2>err &&
+	test_must_fail git pull --no-rebase --cleanup invalid "../parent" >out 2>err &&
 	test_must_be_empty out &&
 	test -s err)
 '
diff --git a/t/t5537-fetch-shallow.sh b/t/t5537-fetch-shallow.sh
index 1266548..d427a2d 100755
--- a/t/t5537-fetch-shallow.sh
+++ b/t/t5537-fetch-shallow.sh
@@ -108,7 +108,7 @@
 	git init notshallow &&
 	(
 	cd notshallow &&
-	git fetch ../shallow/.git refs/heads/*:refs/remotes/shallow/*&&
+	git fetch ../shallow/.git refs/heads/*:refs/remotes/shallow/* &&
 	git for-each-ref --format="%(refname)" >actual.refs &&
 	echo refs/remotes/shallow/no-shallow >expect.refs &&
 	test_cmp expect.refs actual.refs &&
diff --git a/t/t5541-http-push-smart.sh b/t/t5541-http-push-smart.sh
index 23be8ce..afc680d 100755
--- a/t/t5541-http-push-smart.sh
+++ b/t/t5541-http-push-smart.sh
@@ -177,6 +177,9 @@
 	 test $HEAD = $(git rev-parse --verify HEAD))
 '
 
+## References of remote: atomic1(1)            master(2) collateral(2) other(2)
+## References of local :            atomic2(2) master(1) collateral(3) other(2) collateral1(3) atomic(1)
+## Atomic push         :                       master(1) collateral(3)                         atomic(1)
 test_expect_success 'push --atomic also prevents branch creation, reports collateral' '
 	# Setup upstream repo - empty for now
 	d=$HTTPD_DOCUMENT_ROOT_PATH/atomic-branches.git &&
@@ -189,7 +192,8 @@
 	test_commit atomic2 &&
 	git branch collateral &&
 	git branch other &&
-	git push "$up" master collateral other &&
+	git push "$up" atomic1 master collateral other &&
+	git tag -d atomic1 &&
 
 	# collateral is a valid push, but should be failed by atomic push
 	git checkout collateral &&
@@ -224,7 +228,11 @@
 
 	# the collateral failure refs should be indicated to the user
 	grep "^ ! .*rejected.* atomic -> atomic .*atomic push failed" output &&
-	grep "^ ! .*rejected.* collateral -> collateral .*atomic push failed" output
+	grep "^ ! .*rejected.* collateral -> collateral .*atomic push failed" output &&
+
+	# never report what we do not push
+	! grep "^ ! .*rejected.* atomic1 " output &&
+	! grep "^ ! .*rejected.* other " output
 '
 
 test_expect_success 'push --atomic fails on server-side errors' '
diff --git a/t/t5543-atomic-push.sh b/t/t5543-atomic-push.sh
index 7079bcf..620c30d 100755
--- a/t/t5543-atomic-push.sh
+++ b/t/t5543-atomic-push.sh
@@ -27,6 +27,12 @@
 	test_cmp expect actual
 }
 
+fmt_status_report () {
+	sed -n \
+		-e "/^To / { s/   */ /g; p; }" \
+		-e "/^ ! / { s/   */ /g; p; }"
+}
+
 test_expect_success 'atomic push works for a single branch' '
 	mk_repo_pair &&
 	(
@@ -191,4 +197,87 @@
 	test_refs master HEAD@{1}
 '
 
+# References in upstream : master(1) one(1) foo(1)
+# References in workbench: master(2)        foo(1) two(2) bar(2)
+# Atomic push            : master(2)               two(2) bar(2)
+test_expect_success 'atomic push reports (reject by update hook)' '
+	mk_repo_pair &&
+	(
+		cd workbench &&
+		test_commit one &&
+		git branch foo &&
+		git push up master one foo &&
+		git tag -d one
+	) &&
+	(
+		mkdir -p upstream/.git/hooks &&
+		cat >upstream/.git/hooks/update <<-EOF &&
+		#!/bin/sh
+
+		if test "\$1" = "refs/heads/bar"
+		then
+			echo >&2 "Pusing to branch bar is prohibited"
+			exit 1
+		fi
+		EOF
+		chmod a+x upstream/.git/hooks/update
+	) &&
+	(
+		cd workbench &&
+		test_commit two &&
+		git branch bar
+	) &&
+	test_must_fail git -C workbench \
+		push --atomic up master two bar >out 2>&1 &&
+	fmt_status_report <out >actual &&
+	cat >expect <<-EOF &&
+	To ../upstream
+	 ! [remote rejected] master -> master (atomic push failure)
+	 ! [remote rejected] two -> two (atomic push failure)
+	 ! [remote rejected] bar -> bar (hook declined)
+	EOF
+	test_cmp expect actual
+'
+
+# References in upstream : master(1) one(1) foo(1)
+# References in workbench: master(2)        foo(1) two(2) bar(2)
+test_expect_success 'atomic push reports (mirror, but reject by update hook)' '
+	(
+		cd workbench &&
+		git remote remove up &&
+		git remote add up ../upstream
+	) &&
+	test_must_fail git -C workbench \
+		push --atomic --mirror up >out 2>&1 &&
+	fmt_status_report <out >actual &&
+	cat >expect <<-EOF &&
+	To ../upstream
+	 ! [remote rejected] master -> master (atomic push failure)
+	 ! [remote rejected] one (atomic push failure)
+	 ! [remote rejected] bar -> bar (hook declined)
+	 ! [remote rejected] two -> two (atomic push failure)
+	EOF
+	test_cmp expect actual
+'
+
+# References in upstream : master(2) one(1) foo(1)
+# References in workbench: master(1)        foo(1) two(2) bar(2)
+test_expect_success 'atomic push reports (reject by non-ff)' '
+	rm upstream/.git/hooks/update &&
+	(
+		cd workbench &&
+		git push up master &&
+		git reset --hard HEAD^
+	) &&
+	test_must_fail git -C workbench \
+		push --atomic up master foo bar >out 2>&1 &&
+	fmt_status_report <out >actual &&
+	cat >expect <<-EOF &&
+	To ../upstream
+	 ! [rejected] master -> master (non-fast-forward)
+	 ! [rejected] bar -> bar (atomic push failed)
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t5548-push-porcelain.sh b/t/t5548-push-porcelain.sh
new file mode 100755
index 0000000..1b19b3e
--- /dev/null
+++ b/t/t5548-push-porcelain.sh
@@ -0,0 +1,279 @@
+#!/bin/sh
+#
+# Copyright (c) 2020 Jiang Xin
+#
+test_description='Test git push porcelain output'
+
+. ./test-lib.sh
+
+# Create commits in <repo> and assign each commit's oid to shell variables
+# given in the arguments (A, B, and C). E.g.:
+#
+#     create_commits_in <repo> A B C
+#
+# NOTE: Never calling this function from a subshell since variable
+# assignments will disappear when subshell exits.
+create_commits_in () {
+	repo="$1" &&
+	if ! parent=$(git -C "$repo" rev-parse HEAD^{} --)
+	then
+		parent=
+	fi &&
+	T=$(git -C "$repo" write-tree) &&
+	shift &&
+	while test $# -gt 0
+	do
+		name=$1 &&
+		test_tick &&
+		if test -z "$parent"
+		then
+			oid=$(echo $name | git -C "$repo" commit-tree $T)
+		else
+			oid=$(echo $name | git -C "$repo" commit-tree -p $parent $T)
+		fi &&
+		eval $name=$oid &&
+		parent=$oid &&
+		shift ||
+		return 1
+	done &&
+	git -C "$repo" update-ref refs/heads/master $oid
+}
+
+# Format the output of git-push, git-show-ref and other commands to make a
+# user-friendly and stable text.  We can easily prepare the expect text
+# without having to worry about future changes of the commit ID and spaces
+# of the output.
+make_user_friendly_and_stable_output () {
+	sed \
+		-e "s/  *\$//" \
+		-e "s/   */ /g" \
+		-e "s/	/    /g" \
+		-e "s/$A/<COMMIT-A>/g" \
+		-e "s/$B/<COMMIT-B>/g" \
+		-e "s/$ZERO_OID/<ZERO-OID>/g" \
+		-e "s/$(echo $A | cut -c1-7)[0-9a-f]*/<OID-A>/g" \
+		-e "s/$(echo $B | cut -c1-7)[0-9a-f]*/<OID-B>/g" \
+		-e "s#To $URL_PREFIX/upstream.git#To <URL/of/upstream.git>#"
+}
+
+setup_upstream_and_workbench () {
+	# Upstream  after setup : master(B)  foo(A)  bar(A)  baz(A)
+	# Workbench after setup : master(A)
+	test_expect_success "setup upstream repository and workbench" '
+		rm -rf upstream.git workbench &&
+		git init --bare upstream.git &&
+		git init workbench &&
+		create_commits_in workbench A B &&
+		(
+			cd workbench &&
+			# Try to make a stable fixed width for abbreviated commit ID,
+			# this fixed-width oid will be replaced with "<OID>".
+			git config core.abbrev 7 &&
+			git remote add origin ../upstream.git &&
+			git update-ref refs/heads/master $A &&
+			git push origin \
+				$B:refs/heads/master \
+				$A:refs/heads/foo \
+				$A:refs/heads/bar \
+				$A:refs/heads/baz
+		) &&
+		git -C "workbench" config advice.pushUpdateRejected false &&
+		upstream=upstream.git
+	'
+}
+
+run_git_push_porcelain_output_test() {
+	case $1 in
+	http)
+		PROTOCOL="HTTP protocol"
+		URL_PREFIX="http://.*"
+		;;
+	file)
+		PROTOCOL="builtin protocol"
+		URL_PREFIX="\.\."
+		;;
+	esac
+
+	# Refs of upstream : master(B)  foo(A)  bar(A)  baz(A)
+	# Refs of workbench: master(A)                  baz(A)  next(A)
+	# git-push         : master(A)  NULL    (B)     baz(A)  next(A)
+	test_expect_success "porcelain output of successful git-push ($PROTOCOL)" '
+		(
+			cd workbench &&
+			git update-ref refs/heads/master $A &&
+			git update-ref refs/heads/baz $A &&
+			git update-ref refs/heads/next $A &&
+			git push --porcelain --force origin \
+				master \
+				:refs/heads/foo \
+				$B:bar \
+				baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/baz:refs/heads/baz    [up to date]
+		     <COMMIT-B>:refs/heads/bar    <OID-A>..<OID-B>
+		-    :refs/heads/foo    [deleted]
+		+    refs/heads/master:refs/heads/master    <OID-B>...<OID-A> (forced update)
+		*    refs/heads/next:refs/heads/next    [new branch]
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$upstream" show-ref >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		<COMMIT-B> refs/heads/bar
+		<COMMIT-A> refs/heads/baz
+		<COMMIT-A> refs/heads/master
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+
+	# Refs of upstream : master(A)  bar(B)  baz(A)  next(A)
+	# Refs of workbench: master(B)  bar(A)  baz(A)  next(A)
+	# git-push         : master(B)  bar(A)  NULL    next(A)
+	test_expect_success "atomic push failed ($PROTOCOL)" '
+		(
+			cd workbench &&
+			git update-ref refs/heads/master $B &&
+			git update-ref refs/heads/bar $A &&
+			test_must_fail git push --atomic --porcelain origin \
+				master \
+				bar \
+				:baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/next:refs/heads/next    [up to date]
+		!    refs/heads/bar:refs/heads/bar    [rejected] (non-fast-forward)
+		!    (delete):refs/heads/baz    [rejected] (atomic push failed)
+		!    refs/heads/master:refs/heads/master    [rejected] (atomic push failed)
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$upstream" show-ref >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		<COMMIT-B> refs/heads/bar
+		<COMMIT-A> refs/heads/baz
+		<COMMIT-A> refs/heads/master
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+	test_expect_success "prepare pre-receive hook ($PROTOCOL)" '
+		write_script "$upstream/hooks/pre-receive" <<-EOF
+		exit 1
+		EOF
+	'
+
+	# Refs of upstream : master(A)  bar(B)  baz(A)  next(A)
+	# Refs of workbench: master(B)  bar(A)  baz(A)  next(A)
+	# git-push         : master(B)  bar(A)  NULL    next(A)
+	test_expect_success "pre-receive hook declined ($PROTOCOL)" '
+		(
+			cd workbench &&
+			git update-ref refs/heads/master $B &&
+			git update-ref refs/heads/bar $A &&
+			test_must_fail git push --porcelain --force origin \
+				master \
+				bar \
+				:baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/next:refs/heads/next    [up to date]
+		!    refs/heads/bar:refs/heads/bar    [remote rejected] (pre-receive hook declined)
+		!    :refs/heads/baz    [remote rejected] (pre-receive hook declined)
+		!    refs/heads/master:refs/heads/master    [remote rejected] (pre-receive hook declined)
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$upstream" show-ref >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		<COMMIT-B> refs/heads/bar
+		<COMMIT-A> refs/heads/baz
+		<COMMIT-A> refs/heads/master
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+
+	test_expect_success "remove pre-receive hook ($PROTOCOL)" '
+		rm "$upstream/hooks/pre-receive"
+	'
+
+	# Refs of upstream : master(A)  bar(B)  baz(A)  next(A)
+	# Refs of workbench: master(B)  bar(A)  baz(A)  next(A)
+	# git-push         : master(B)  bar(A)  NULL    next(A)
+	test_expect_success "non-fastforward push ($PROTOCOL)" '
+		(
+			cd workbench &&
+			test_must_fail git push --porcelain origin \
+				master \
+				bar \
+				:baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/next:refs/heads/next    [up to date]
+		-    :refs/heads/baz    [deleted]
+		     refs/heads/master:refs/heads/master    <OID-A>..<OID-B>
+		!    refs/heads/bar:refs/heads/bar    [rejected] (non-fast-forward)
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$upstream" show-ref >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		<COMMIT-B> refs/heads/bar
+		<COMMIT-B> refs/heads/master
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+}
+
+# Initialize the upstream repository and local workbench.
+setup_upstream_and_workbench
+
+# Run git-push porcelain test on builtin protocol
+run_git_push_porcelain_output_test file
+
+ROOT_PATH="$PWD"
+. "$TEST_DIRECTORY"/lib-gpg.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+. "$TEST_DIRECTORY"/lib-terminal.sh
+start_httpd
+
+# Re-initialize the upstream repository and local workbench.
+setup_upstream_and_workbench
+
+test_expect_success "setup for http" '
+	git -C upstream.git config http.receivepack true &&
+	upstream="$HTTPD_DOCUMENT_ROOT_PATH/upstream.git" &&
+	mv upstream.git "$upstream" &&
+
+	git -C workbench remote set-url origin $HTTPD_URL/smart/upstream.git
+'
+
+setup_askpass_helper
+
+# Run git-push porcelain test on HTTP protocol
+run_git_push_porcelain_output_test http
+
+test_done
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index b811d89..5048530 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -248,9 +248,7 @@
 '
 
 test_expect_success 'did not use upload-pack service' '
-	test_might_fail grep '/git-upload-pack' <"$HTTPD_ROOT_PATH"/access.log >act &&
-	: >exp &&
-	test_cmp exp act
+	! grep "/git-upload-pack" "$HTTPD_ROOT_PATH/access.log"
 '
 
 test_expect_success 'git client shows text/plain errors' '
@@ -321,11 +319,17 @@
 '
 
 test_expect_success 'remote-http complains cleanly about malformed urls' '
-	# do not actually issue "list" or other commands, as we do not
-	# want to rely on what curl would actually do with such a broken
-	# URL. This is just about making sure we do not segfault during
-	# initialization.
-	test_must_fail git remote-http http::/example.com/repo.git
+	test_must_fail git remote-http http::/example.com/repo.git 2>stderr &&
+	test_i18ngrep "url has no scheme" stderr
+'
+
+# NEEDSWORK: Writing commands to git-remote-curl can race against the latter
+# erroring out, producing SIGPIPE. Remove "ok=sigpipe" once transport-helper has
+# learned to handle early remote helper failures more cleanly.
+test_expect_success 'remote-http complains cleanly about empty scheme' '
+	test_must_fail ok=sigpipe git ls-remote \
+		http::${HTTPD_URL#http}/dumb/repo.git 2>stderr &&
+	test_i18ngrep "url has no scheme" stderr
 '
 
 test_expect_success 'redirects can be forbidden/allowed' '
diff --git a/t/t5562-http-backend-content-length.sh b/t/t5562-http-backend-content-length.sh
index 4a110b3..3f4ac71 100755
--- a/t/t5562-http-backend-content-length.sh
+++ b/t/t5562-http-backend-content-length.sh
@@ -53,15 +53,20 @@
 	test_commit c1 &&
 	hash_head=$(git rev-parse HEAD) &&
 	hash_prev=$(git rev-parse HEAD~1) &&
-	printf "want %s" "$hash_head" | packetize >fetch_body &&
-	printf 0000 >>fetch_body &&
-	printf "have %s" "$hash_prev" | packetize >>fetch_body &&
-	printf done | packetize >>fetch_body &&
+	{
+		packetize "want $hash_head" &&
+		printf 0000 &&
+		packetize "have $hash_prev" &&
+		packetize "done"
+	} >fetch_body &&
 	test_copy_bytes 10 <fetch_body >fetch_body.trunc &&
 	hash_next=$(git commit-tree -p HEAD -m next HEAD^{tree}) &&
-	printf "%s %s refs/heads/newbranch\\0report-status\\n" "$ZERO_OID" "$hash_next" | packetize >push_body &&
-	printf 0000 >>push_body &&
-	echo "$hash_next" | git pack-objects --stdout >>push_body &&
+	{
+		printf "%s %s refs/heads/newbranch\\0report-status\\n" \
+			"$ZERO_OID" "$hash_next" | packetize &&
+		printf 0000 &&
+		echo "$hash_next" | git pack-objects --stdout
+	} >push_body &&
 	test_copy_bytes 10 <push_body >push_body.trunc &&
 	: >empty_body
 '
diff --git a/t/t5604-clone-reference.sh b/t/t5604-clone-reference.sh
index 0c74b4e..2f7be23 100755
--- a/t/t5604-clone-reference.sh
+++ b/t/t5604-clone-reference.sh
@@ -175,7 +175,7 @@
 test_expect_success 'clone and dissociate from reference' '
 	git init P &&
 	(
-		cd P &&	test_commit one
+		cd P && test_commit one
 	) &&
 	git clone P Q &&
 	(
diff --git a/t/t5607-clone-bundle.sh b/t/t5607-clone-bundle.sh
index 9108ff6..6d5a977 100755
--- a/t/t5607-clone-bundle.sh
+++ b/t/t5607-clone-bundle.sh
@@ -16,7 +16,7 @@
 
 test_expect_success '"verify" needs a worktree' '
 	git bundle create tip.bundle -1 master &&
-	test_must_fail nongit git bundle verify ../tip.bundle 2>err &&
+	nongit test_must_fail git bundle verify ../tip.bundle 2>err &&
 	test_i18ngrep "need a repository" err
 '
 
diff --git a/t/t5611-clone-config.sh b/t/t5611-clone-config.sh
index 60c1ba9..8e0fd39 100755
--- a/t/t5611-clone-config.sh
+++ b/t/t5611-clone-config.sh
@@ -92,24 +92,17 @@
 	test_cmp expect actual
 '
 
-# Tests for the hidden file attribute on windows
-is_hidden () {
-	# Use the output of `attrib`, ignore the absolute path
-	case "$(attrib "$1")" in *H*?:*) return 0;; esac
-	return 1
-}
-
 test_expect_success MINGW 'clone -c core.hideDotFiles' '
 	test_commit attributes .gitattributes "" &&
 	rm -rf child &&
 	git clone -c core.hideDotFiles=false . child &&
-	! is_hidden child/.gitattributes &&
+	! test_path_is_hidden child/.gitattributes &&
 	rm -rf child &&
 	git clone -c core.hideDotFiles=dotGitOnly . child &&
-	! is_hidden child/.gitattributes &&
+	! test_path_is_hidden child/.gitattributes &&
 	rm -rf child &&
 	git clone -c core.hideDotFiles=true . child &&
-	is_hidden child/.gitattributes
+	test_path_is_hidden child/.gitattributes
 '
 
 test_done
diff --git a/t/t5612-clone-refspec.sh b/t/t5612-clone-refspec.sh
index e36ac01..e3b436d 100755
--- a/t/t5612-clone-refspec.sh
+++ b/t/t5612-clone-refspec.sh
@@ -71,9 +71,9 @@
 	(
 		cd dir_all &&
 		git fetch &&
-		git for-each-ref refs/remotes/origin |
+		git for-each-ref refs/remotes/origin >refs &&
 		sed -e "/HEAD$/d" \
-		    -e "s|/remotes/origin/|/heads/|" >../actual
+		    -e "s|/remotes/origin/|/heads/|" refs >../actual
 	) &&
 	# follow both master and side
 	git for-each-ref refs/heads >expect &&
@@ -87,7 +87,7 @@
 		git for-each-ref refs/tags >../actual
 	) &&
 	git for-each-ref refs/tags >expect &&
-	test_must_fail test_cmp expect actual &&
+	! test_cmp expect actual &&
 	test_line_count = 2 actual
 '
 
@@ -104,9 +104,9 @@
 	(
 		cd dir_master &&
 		git fetch --force &&
-		git for-each-ref refs/remotes/origin |
+		git for-each-ref refs/remotes/origin >refs &&
 		sed -e "/HEAD$/d" \
-		    -e "s|/remotes/origin/|/heads/|" >../actual
+		    -e "s|/remotes/origin/|/heads/|" refs >../actual
 	) &&
 	# only follow master
 	git for-each-ref refs/heads/master >expect &&
@@ -126,9 +126,9 @@
 	(
 		cd dir_master_no_tags &&
 		git fetch &&
-		git for-each-ref refs/remotes/origin |
+		git for-each-ref refs/remotes/origin >refs &&
 		sed -e "/HEAD$/d" \
-		    -e "s|/remotes/origin/|/heads/|" >../actual
+		    -e "s|/remotes/origin/|/heads/|" refs >../actual
 	) &&
 	# only follow master
 	git for-each-ref refs/heads/master >expect &&
@@ -156,9 +156,9 @@
 	(
 		cd dir_side &&
 		git fetch &&
-		git for-each-ref refs/remotes/origin |
+		git for-each-ref refs/remotes/origin >refs &&
 		sed -e "/HEAD$/d" \
-		    -e "s|/remotes/origin/|/heads/|" >../actual
+		    -e "s|/remotes/origin/|/heads/|" refs >../actual
 	) &&
 	# only follow side
 	git for-each-ref refs/heads/side >expect &&
@@ -169,9 +169,9 @@
 	(
 		cd dir_side2 &&
 		git fetch &&
-		git for-each-ref refs/remotes/origin |
+		git for-each-ref refs/remotes/origin >refs &&
 		sed -e "/HEAD$/d" \
-		    -e "s|/remotes/origin/|/heads/|" >../actual
+		    -e "s|/remotes/origin/|/heads/|" refs >../actual
 	) &&
 	# only follow side
 	git for-each-ref refs/heads/side >expect &&
@@ -223,9 +223,9 @@
 	(
 		cd dir_detached &&
 		git fetch &&
-		git for-each-ref refs/remotes/origin |
+		git for-each-ref refs/remotes/origin >refs &&
 		sed -e "/HEAD$/d" \
-		    -e "s|/remotes/origin/|/heads/|" >../actual
+		    -e "s|/remotes/origin/|/heads/|" refs >../actual
 	) &&
 	# nothing
 	test_must_be_empty actual
diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh
index 77bb91e..88002b2 100755
--- a/t/t5616-partial-clone.sh
+++ b/t/t5616-partial-clone.sh
@@ -49,7 +49,7 @@
 test_expect_success 'verify that .promisor file contains refs fetched' '
 	ls pc1/.git/objects/pack/pack-*.promisor >promisorlist &&
 	test_line_count = 1 promisorlist &&
-	git -C srv.bare rev-list HEAD >headhash &&
+	git -C srv.bare rev-parse --verify HEAD >headhash &&
 	grep "$(cat headhash) HEAD" $(cat promisorlist) &&
 	grep "$(cat headhash) refs/heads/master" $(cat promisorlist)
 '
@@ -415,6 +415,14 @@
 	test_line_count = 3 pack-list
 '
 
+test_expect_success 'single-branch tag following respects partial clone' '
+	git clone --single-branch -b B --filter=blob:none \
+		"file://$(pwd)/srv.bare" single &&
+	git -C single rev-parse --verify refs/tags/B &&
+	git -C single rev-parse --verify refs/tags/A &&
+	test_must_fail git -C single rev-parse --verify refs/tags/C
+'
+
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/t/t5703-upload-pack-ref-in-want.sh b/t/t5703-upload-pack-ref-in-want.sh
index 7fba306..a34460f 100755
--- a/t/t5703-upload-pack-ref-in-want.sh
+++ b/t/t5703-upload-pack-ref-in-want.sh
@@ -13,10 +13,7 @@
 }
 
 get_actual_commits () {
-	sed -n -e '/packfile/,/0000/{
-		/packfile/d
-		p
-		}' <out | test-tool pkt-line unpack-sideband >o.pack &&
+	test-tool pkt-line unpack-sideband <out >o.pack &&
 	git index-pack o.pack &&
 	git verify-pack -v o.idx >objs &&
 	grep commit objs | cut -d" " -f1 | sort >actual_commits
diff --git a/t/t5704-protocol-violations.sh b/t/t5704-protocol-violations.sh
new file mode 100755
index 0000000..950cfb2
--- /dev/null
+++ b/t/t5704-protocol-violations.sh
@@ -0,0 +1,33 @@
+#!/bin/sh
+
+test_description='Test responses to violations of the network protocol. In most
+of these cases it will generally be acceptable for one side to break off
+communications if the other side says something unexpected. We are mostly
+making sure that we do not segfault or otherwise behave badly.'
+. ./test-lib.sh
+
+test_expect_success 'extra delim packet in v2 ls-refs args' '
+	{
+		packetize command=ls-refs &&
+		printf 0001 &&
+		# protocol expects 0000 flush here
+		printf 0001
+	} >input &&
+	test_must_fail env GIT_PROTOCOL=version=2 \
+		git upload-pack . <input 2>err &&
+	test_i18ngrep "expected flush after ls-refs arguments" err
+'
+
+test_expect_success 'extra delim packet in v2 fetch args' '
+	{
+		packetize command=fetch &&
+		printf 0001 &&
+		# protocol expects 0000 flush here
+		printf 0001
+	} >input &&
+	test_must_fail env GIT_PROTOCOL=version=2 \
+		git upload-pack . <input 2>err &&
+	test_i18ngrep "expected flush after fetch arguments" err
+'
+
+test_done
diff --git a/t/t5801-remote-helpers.sh b/t/t5801-remote-helpers.sh
index 121e5c6..0f04b6c 100755
--- a/t/t5801-remote-helpers.sh
+++ b/t/t5801-remote-helpers.sh
@@ -11,9 +11,15 @@
 PATH="$TEST_DIRECTORY/t5801:$PATH"
 
 compare_refs() {
+	fail= &&
+	if test "x$1" = 'x!'
+	then
+		fail='!' &&
+		shift
+	fi &&
 	git --git-dir="$1/.git" rev-parse --verify $2 >expect &&
 	git --git-dir="$3/.git" rev-parse --verify $4 >actual &&
-	test_cmp expect actual
+	eval $fail test_cmp expect actual
 }
 
 test_expect_success 'setup repository' '
@@ -189,7 +195,7 @@
 	git push origin signed-tag
 	) &&
 	compare_refs local signed-tag^{} server signed-tag^{} &&
-	test_must_fail compare_refs local signed-tag server signed-tag
+	compare_refs ! local signed-tag server signed-tag
 '
 
 test_expect_success GPG 'push signed tag with signed-tags capability' '
diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
index a10f0df..b6fa43a 100755
--- a/t/t6012-rev-list-simplify.sh
+++ b/t/t6012-rev-list-simplify.sh
@@ -154,4 +154,124 @@
 	test_cmp expected actual
 '
 
+#
+# Create a new history to demonstrate the value of --show-pulls
+# with respect to the subtleties of simplified history, --full-history,
+# and --simplify-merges.
+#
+#   .-A---M-----C--N---O---P
+#  /     / \  \  \/   /   /
+# I     B   \  R-'`-Z'   /
+#  \   /     \/         /
+#   \ /      /\        /
+#    `---X--'  `---Y--'
+#
+# This example is explained in Documentation/rev-list-options.txt
+
+test_expect_success 'rebuild repo' '
+	rm -rf .git * &&
+	git init &&
+	git switch -c main &&
+
+	echo base >file &&
+	git add file &&
+	test_commit I &&
+
+	echo A >file &&
+	git add file &&
+	test_commit A &&
+
+	git switch -c branchB I &&
+	echo B >file &&
+	git add file &&
+	test_commit B &&
+
+	git switch main &&
+	test_must_fail git merge -m "M" B &&
+	echo A >file &&
+	echo B >>file &&
+	git add file &&
+	git merge --continue &&
+	note M &&
+
+	echo C >other &&
+	git add other &&
+	test_commit C &&
+
+	git switch -c branchX I &&
+	echo X >file &&
+	git add file &&
+	test_commit X &&
+
+	git switch -c branchR M &&
+	git merge -m R -Xtheirs X &&
+	note R &&
+
+	git switch main &&
+	git merge -m N R &&
+	note N &&
+
+	git switch -c branchY M &&
+	echo Y >y &&
+	git add y &&
+	test_commit Y &&
+
+	git switch -c branchZ C &&
+	echo Z >z &&
+	git add z &&
+	test_commit Z &&
+
+	git switch main &&
+	git merge -m O Z &&
+	note O &&
+
+	git merge -m P Y &&
+	note P
+'
+
+check_result 'X I' -- file
+check_result 'N R X I' --show-pulls -- file
+
+check_result 'P O N R X M B A I' --full-history --topo-order -- file
+check_result 'N R X M B A I' --simplify-merges --topo-order --show-pulls -- file
+check_result 'R X M B A I' --simplify-merges --topo-order -- file
+check_result 'N M A I' --first-parent -- file
+check_result 'N M A I' --first-parent --show-pulls -- file
+
+# --ancestry-path implies --full-history
+check_result 'P O N R M' --topo-order \
+	--ancestry-path A..HEAD -- file
+check_result 'P O N R M' --topo-order \
+	--show-pulls \
+	--ancestry-path A..HEAD -- file
+check_result 'P O N R M' --topo-order \
+	--full-history \
+	--ancestry-path A..HEAD -- file
+check_result 'R M' --topo-order \
+	--simplify-merges \
+	--ancestry-path A..HEAD -- file
+check_result 'N R M' --topo-order \
+	--simplify-merges --show-pulls \
+	--ancestry-path A..HEAD -- file
+
+test_expect_success 'log --graph --simplify-merges --show-pulls' '
+	cat >expect <<-\EOF &&
+	* N
+	*   R
+	|\  
+	| * X
+	* |   M
+	|\ \  
+	| * | B
+	| |/  
+	* / A
+	|/  
+	* I
+	EOF
+	git log --graph --pretty="%s" \
+		--simplify-merges --show-pulls \
+		-- file >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index 821a0c8..1313142 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -148,7 +148,7 @@
 	test_must_fail git bisect start $HASH4 foo -- &&
 	git branch > branch.output &&
 	grep "* other" branch.output > /dev/null &&
-	test_must_fail test -e .git/BISECT_START
+	test_path_is_missing .git/BISECT_START
 '
 
 test_expect_success 'bisect start: existing ".git/BISECT_START" not modified if junk rev' '
@@ -166,7 +166,7 @@
 	test_must_fail git bisect start $HASH1 $HASH4 -- &&
 	git branch > branch.output &&
 	grep "* other" branch.output > /dev/null &&
-	test_must_fail test -e .git/BISECT_START
+	test_path_is_missing .git/BISECT_START
 '
 
 test_expect_success 'bisect start: no ".git/BISECT_START" if checkout error' '
@@ -175,7 +175,7 @@
 	git branch &&
 	git branch > branch.output &&
 	grep "* other" branch.output > /dev/null &&
-	test_must_fail test -e .git/BISECT_START &&
+	test_path_is_missing .git/BISECT_START &&
 	test -z "$(git for-each-ref "refs/bisect/*")" &&
 	git checkout HEAD hello
 '
@@ -485,7 +485,7 @@
 	git bisect bad &&
 	git bisect good "$A_HASH" > my_bisect_log4.txt &&
 	test_i18ngrep "merge base must be tested" my_bisect_log4.txt &&
-	test_must_fail test -f ".git/BISECT_ANCESTORS_OK"
+	test_path_is_missing ".git/BISECT_ANCESTORS_OK"
 '
 
 # This creates another side branch called "parallel" with some files
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 34502e3..f822d5d 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -129,12 +129,30 @@
 	mv .git/refs/tags/A .git/refs/tags/Q
 '
 cat - >err.expect <<EOF
-warning: tag 'A' is really 'Q' here
+warning: tag 'Q' is externally known as 'A'
 EOF
 check_describe A-* HEAD
 test_expect_success 'warning was displayed for Q' '
 	test_i18ncmp err.expect err.actual
 '
+test_expect_success 'misnamed annotated tag forces long output' '
+	description=$(git describe --no-long Q^0) &&
+	expr "$description" : "A-0-g[0-9a-f]*$" &&
+	git rev-parse --verify "$description" >actual &&
+	git rev-parse --verify Q^0 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'abbrev=0 will not break misplaced tag (1)' '
+	description=$(git describe --abbrev=0 Q^0) &&
+	expr "$description" : "A-0-g[0-9a-f]*$"
+'
+
+test_expect_success 'abbrev=0 will not break misplaced tag (2)' '
+	description=$(git describe --abbrev=0 c^0) &&
+	expr "$description" : "A-1-g[0-9a-f]*$"
+'
+
 test_expect_success 'rename tag Q back to A' '
 	mv .git/refs/tags/Q .git/refs/tags/A
 '
diff --git a/t/t6200-fmt-merge-msg.sh b/t/t6200-fmt-merge-msg.sh
index 8a72b4c..b15582a 100755
--- a/t/t6200-fmt-merge-msg.sh
+++ b/t/t6200-fmt-merge-msg.sh
@@ -6,6 +6,7 @@
 test_description='fmt-merge-msg test'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success setup '
 	echo one >one &&
@@ -73,6 +74,10 @@
 	apos="'\''"
 '
 
+test_expect_success GPG 'set up a signed tag' '
+	git tag -s -m signed-tag-msg signed-good-tag left
+'
+
 test_expect_success 'message for merging local branch' '
 	echo "Merge branch ${apos}left${apos}" >expected &&
 
@@ -83,6 +88,24 @@
 	test_cmp expected actual
 '
 
+test_expect_success GPG 'message for merging local tag signed by good key' '
+	git checkout master &&
+	git fetch . signed-good-tag &&
+	git fmt-merge-msg <.git/FETCH_HEAD >actual 2>&1 &&
+	grep "^Merge tag ${apos}signed-good-tag${apos}" actual &&
+	grep "^# gpg: Signature made" actual &&
+	grep "^# gpg: Good signature from" actual
+'
+
+test_expect_success GPG 'message for merging local tag signed by unknown key' '
+	git checkout master &&
+	git fetch . signed-good-tag &&
+	GNUPGHOME=. git fmt-merge-msg <.git/FETCH_HEAD >actual 2>&1 &&
+	grep "^Merge tag ${apos}signed-good-tag${apos}" actual &&
+	grep "^# gpg: Signature made" actual &&
+	grep "^# gpg: Can${apos}t check signature: \(public key not found\|No public key\)" actual
+'
+
 test_expect_success 'message for merging external branch' '
 	echo "Merge branch ${apos}left${apos} of $(pwd)" >expected &&
 
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 9c910ce..b3c1092 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -20,6 +20,10 @@
 }
 
 test_expect_success setup '
+	test_oid_cache <<-EOF &&
+	disklen sha1:138
+	disklen sha256:154
+	EOF
 	setdate_and_increment &&
 	echo "Using $datestamp" > one &&
 	git add one &&
@@ -50,6 +54,9 @@
 	"
 }
 
+hexlen=$(test_oid hexsz)
+disklen=$(test_oid disklen)
+
 test_atom head refname refs/heads/master
 test_atom head refname: refs/heads/master
 test_atom head refname:short master
@@ -82,9 +89,9 @@
 test_atom head push:strip=1 remotes/myfork/master
 test_atom head push:strip=-1 master
 test_atom head objecttype commit
-test_atom head objectsize 171
-test_atom head objectsize:disk 138
-test_atom head deltabase 0000000000000000000000000000000000000000
+test_atom head objectsize $((131 + hexlen))
+test_atom head objectsize:disk $disklen
+test_atom head deltabase $ZERO_OID
 test_atom head objectname $(git rev-parse refs/heads/master)
 test_atom head objectname:short $(git rev-parse --short refs/heads/master)
 test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
@@ -125,11 +132,11 @@
 test_atom tag upstream ''
 test_atom tag push ''
 test_atom tag objecttype tag
-test_atom tag objectsize 154
-test_atom tag objectsize:disk 138
-test_atom tag '*objectsize:disk' 138
-test_atom tag deltabase 0000000000000000000000000000000000000000
-test_atom tag '*deltabase' 0000000000000000000000000000000000000000
+test_atom tag objectsize $((114 + hexlen))
+test_atom tag objectsize:disk $disklen
+test_atom tag '*objectsize:disk' $disklen
+test_atom tag deltabase $ZERO_OID
+test_atom tag '*deltabase' $ZERO_OID
 test_atom tag objectname $(git rev-parse refs/tags/testtag)
 test_atom tag objectname:short $(git rev-parse --short refs/tags/testtag)
 test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
@@ -139,7 +146,7 @@
 test_atom tag numparent ''
 test_atom tag object $(git rev-parse refs/tags/testtag^0)
 test_atom tag type 'commit'
-test_atom tag '*objectname' 'ea122842f48be4afb2d1fc6a4b96c05885ab7463'
+test_atom tag '*objectname' $(git rev-parse refs/tags/testtag^{})
 test_atom tag '*objecttype' 'commit'
 test_atom tag author ''
 test_atom tag authorname ''
@@ -643,7 +650,7 @@
 body contents
 $sig"
 
-cat >expected <<EOF
+sort >expected <<EOF
 $(git rev-parse refs/tags/bogo) <committer@example.com> refs/tags/bogo
 $(git rev-parse refs/tags/master) <committer@example.com> refs/tags/master
 EOF
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 6db92bd..74b637d 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1726,6 +1726,7 @@
 	hint: already a tag. If you meant to tag the object that it points to, use:
 	hint: |
 	hint: 	git tag -f nested annotated-v4.0^{}
+	hint: Disable this message with "git config advice.nestedTag false"
 	EOF
 	git tag -m nested nested annotated-v4.0 2>actual &&
 	test_i18ncmp expect actual
diff --git a/t/t7063-status-untracked-cache.sh b/t/t7063-status-untracked-cache.sh
index 190ae14..428cff9 100755
--- a/t/t7063-status-untracked-cache.sh
+++ b/t/t7063-status-untracked-cache.sh
@@ -18,7 +18,7 @@
 export GIT_FORCE_UNTRACKED_CACHE
 
 sync_mtime () {
-	find . -type d -ls >/dev/null
+	find . -type d -exec ls -ld {} + >/dev/null
 }
 
 avoid_racy() {
@@ -30,6 +30,30 @@
 	test_must_be_empty ../status.actual
 }
 
+# Ignore_Untracked_Cache, abbreviated to 3 letters because then people can
+# compare commands side-by-side, e.g.
+#    iuc status --porcelain >expect &&
+#    git status --porcelain >actual &&
+#    test_cmp expect actual
+iuc () {
+	git ls-files -s >../current-index-entries
+	git ls-files -t | sed -ne s/^S.//p >../current-sparse-entries
+
+	GIT_INDEX_FILE=.git/tmp_index
+	export GIT_INDEX_FILE
+	git update-index --index-info <../current-index-entries
+	git update-index --skip-worktree $(cat ../current-sparse-entries)
+
+	git -c core.untrackedCache=false "$@"
+	ret=$?
+
+	rm ../current-index-entries
+	rm $GIT_INDEX_FILE
+	unset GIT_INDEX_FILE
+
+	return $ret
+}
+
 test_lazy_prereq UNTRACKED_CACHE '
 	{ git update-index --test-untracked-cache; ret=$?; } &&
 	test $ret -ne 1
@@ -95,6 +119,8 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 3
@@ -115,6 +141,8 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -136,6 +164,7 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
 A  done/one
 A  one
@@ -145,6 +174,7 @@
 ?? four
 ?? three
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -183,6 +213,7 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
 A  done/one
 A  one
@@ -192,6 +223,7 @@
 ?? dtwo/
 ?? three
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -230,6 +262,7 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
 A  done/one
 A  one
@@ -237,6 +270,7 @@
 ?? .gitignore
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -286,6 +320,7 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
 A  done/one
 A  one
@@ -293,6 +328,7 @@
 ?? dtwo/
 ?? two
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -343,6 +379,7 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
 A  done/one
 A  one
@@ -350,6 +387,7 @@
 ?? .gitignore
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -390,10 +428,12 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
 ?? .gitignore
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -447,12 +487,14 @@
 	avoid_racy &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
  M done/two
 ?? .gitignore
 ?? done/five
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../status.actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -487,12 +529,14 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
  M done/two
 ?? .gitignore
 ?? done/five
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../status.actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -514,6 +558,7 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
  M done/two
 ?? .gitignore
@@ -521,6 +566,7 @@
 ?? done/sub/
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../status.actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 2
@@ -560,6 +606,8 @@
 	: >../trace &&
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
+	iuc status --porcelain >../status.iuc &&
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../status.actual &&
 	cat >../trace.expect <<EOF &&
 node creation: 0
@@ -573,6 +621,7 @@
 test_expect_success 'move entry in subdir from untracked to cached' '
 	git add dtwo/two &&
 	git status --porcelain >../status.actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
  M done/two
 A  dtwo/two
@@ -580,12 +629,14 @@
 ?? done/five
 ?? done/sub/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../status.actual
 '
 
 test_expect_success 'move entry in subdir from cached to untracked' '
 	git rm --cached dtwo/two &&
 	git status --porcelain >../status.actual &&
+	iuc status --porcelain >../status.iuc &&
 	cat >../status.expect <<EOF &&
  M done/two
 ?? .gitignore
@@ -593,6 +644,7 @@
 ?? done/sub/
 ?? dtwo/
 EOF
+	test_cmp ../status.expect ../status.iuc &&
 	test_cmp ../status.expect ../status.actual
 '
 
diff --git a/t/t7112-reset-submodule.sh b/t/t7112-reset-submodule.sh
index a1cb9ff..6734642 100755
--- a/t/t7112-reset-submodule.sh
+++ b/t/t7112-reset-submodule.sh
@@ -5,7 +5,6 @@
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
-KNOWN_FAILURE_SUBMODULE_RECURSIVE_NESTED=1
 KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS=1
 KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED=1
 
diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index e3e2aab..956e17a 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -938,7 +938,7 @@
 		echo "repo" >expect &&
 		test_must_fail git config -f .gitmodules submodule.repo.path &&
 		git config -f .gitmodules submodule.repo_new.path >actual &&
-		test_cmp expect actual&&
+		test_cmp expect actual &&
 		echo "$submodurl/repo" >expect &&
 		test_must_fail git config -f .gitmodules submodule.repo.url &&
 		echo "$submodurl/bare.git" >expect &&
@@ -1010,7 +1010,7 @@
 		test -d repo &&
 		echo "repo" >expect &&
 		git config -f .gitmodules submodule.repo_new.path >actual &&
-		test_cmp expect actual&&
+		test_cmp expect actual &&
 		echo "$submodurl/repo.git" >expect &&
 		git config -f .gitmodules submodule.repo_new.url >actual &&
 		test_cmp expect actual &&
diff --git a/t/t7408-submodule-reference.sh b/t/t7408-submodule-reference.sh
index 34ac28c..a3892f4 100755
--- a/t/t7408-submodule-reference.sh
+++ b/t/t7408-submodule-reference.sh
@@ -122,8 +122,8 @@
 		# update of the submodule succeeds
 		test_must_fail git submodule update --init &&
 		# and we have no alternates:
-		test_must_fail test_alternate_is_used .git/modules/sub/objects/info/alternates sub &&
-		test_must_fail test_path_is_file sub/file1
+		test_path_is_missing .git/modules/sub/objects/info/alternates &&
+		test_path_is_missing sub/file1
 	)
 '
 
@@ -137,7 +137,7 @@
 		# update of the submodule succeeds
 		git submodule update --init &&
 		# and we have no alternates:
-		test_must_fail test_alternate_is_used .git/modules/sub/objects/info/alternates sub &&
+		test_path_is_missing .git/modules/sub/objects/info/alternates &&
 		test_path_is_file sub/file1
 	)
 '
@@ -182,7 +182,7 @@
 	# immediate submodule has alternate:
 	test_alternate_is_used .git/modules/subwithsub/objects/info/alternates subwithsub &&
 	# but nested submodule has no alternate:
-	test_must_fail test_alternate_is_used .git/modules/subwithsub/modules/sub/objects/info/alternates subwithsub/sub
+	test_path_is_missing .git/modules/subwithsub/modules/sub/objects/info/alternates
 }
 
 
diff --git a/t/t7416-submodule-dash-url.sh b/t/t7416-submodule-dash-url.sh
index 5ba041f..eec96e0 100755
--- a/t/t7416-submodule-dash-url.sh
+++ b/t/t7416-submodule-dash-url.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='check handling of .gitmodule url with dash'
+test_description='check handling of disallowed .gitmodule urls'
 . ./test-lib.sh
 
 test_expect_success 'create submodule with protected dash in url' '
@@ -60,4 +60,145 @@
 	test_i18ngrep ! "unknown option" err
 '
 
+test_expect_success 'fsck rejects missing URL scheme' '
+	git checkout --orphan missing-scheme &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = http::one.example.com/foo.git
+	EOF
+	git add .gitmodules &&
+	test_tick &&
+	git commit -m "gitmodules with missing URL scheme" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck rejects relative URL resolving to missing scheme' '
+	git checkout --orphan relative-missing-scheme &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = "..\\../.\\../:one.example.com/foo.git"
+	EOF
+	git add .gitmodules &&
+	test_tick &&
+	git commit -m "gitmodules with relative URL that strips off scheme" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck rejects empty URL scheme' '
+	git checkout --orphan empty-scheme &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = http::://one.example.com/foo.git
+	EOF
+	git add .gitmodules &&
+	test_tick &&
+	git commit -m "gitmodules with empty URL scheme" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck rejects relative URL resolving to empty scheme' '
+	git checkout --orphan relative-empty-scheme &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = ../../../:://one.example.com/foo.git
+	EOF
+	git add .gitmodules &&
+	test_tick &&
+	git commit -m "relative gitmodules URL resolving to empty scheme" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck rejects empty hostname' '
+	git checkout --orphan empty-host &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = http:///one.example.com/foo.git
+	EOF
+	git add .gitmodules &&
+	test_tick &&
+	git commit -m "gitmodules with extra slashes" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck rejects relative url that produced empty hostname' '
+	git checkout --orphan messy-relative &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = ../../..//one.example.com/foo.git
+	EOF
+	git add .gitmodules &&
+	test_tick &&
+	git commit -m "gitmodules abusing relative_path" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck permits embedded newline with unrecognized scheme' '
+	git checkout --orphan newscheme &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = "data://acjbkd%0akajfdickajkd"
+	EOF
+	git add .gitmodules &&
+	git commit -m "gitmodules with unrecognized scheme" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	git push dst HEAD
+'
+
+test_expect_success 'fsck rejects embedded newline in url' '
+	# create an orphan branch to avoid existing .gitmodules objects
+	git checkout --orphan newline &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+	url = "https://one.example.com?%0ahost=two.example.com/foo.git"
+	EOF
+	git add .gitmodules &&
+	git commit -m "gitmodules with newline" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_expect_success 'fsck rejects embedded newline in relative url' '
+	git checkout --orphan relative-newline &&
+	cat >.gitmodules <<-\EOF &&
+	[submodule "foo"]
+		url = "./%0ahost=two.example.com/foo.git"
+	EOF
+	git add .gitmodules &&
+	git commit -m "relative url with newline" &&
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
 test_done
diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index 482ce35..8e969f3 100755
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -1471,7 +1471,7 @@
 test_expect_success '"status.branch=true" different from "--no-branch"' '
 	git status -s --no-branch  >expected_nobranch &&
 	git -c status.branch=true status -s >actual &&
-	test_must_fail test_cmp expected_nobranch actual
+	! test_cmp expected_nobranch actual
 '
 
 test_expect_success '"status.branch=true" weaker than "--no-branch"' '
diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index 0c06d22..6baaa1a 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh
@@ -6,6 +6,11 @@
 . "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success GPG 'create signed commits' '
+	test_oid_cache <<-\EOF &&
+	header sha1:gpgsig
+	header sha256:gpgsig-sha256
+	EOF
+
 	test_when_finished "test_unconfig commit.gpgsign" &&
 
 	echo 1 >file && git add file &&
@@ -155,6 +160,11 @@
 	)
 '
 
+test_expect_success GPG 'proper header is used for hash algorithm' '
+	git cat-file commit fourth-signed >output &&
+	grep "^$(test_oid header) -----BEGIN PGP SIGNATURE-----" output
+'
+
 test_expect_success GPG 'show signed commit with signature' '
 	git show -s initial >commit &&
 	git show -s --show-signature initial >show &&
@@ -162,7 +172,7 @@
 	git cat-file commit initial >cat &&
 	grep -v -e "gpg: " -e "Warning: " show >show.commit &&
 	grep -e "gpg: " -e "Warning: " show >show.gpg &&
-	grep -v "^ " cat | grep -v "^gpgsig " >cat.commit &&
+	grep -v "^ " cat | grep -v "^$(test_oid header) " >cat.commit &&
 	test_cmp show.commit commit &&
 	test_cmp show.gpg verify.2 &&
 	test_cmp cat.commit verify.1
@@ -299,10 +309,10 @@
 test_expect_success GPG 'detect fudged commit with double signature' '
 	sed -e "/gpgsig/,/END PGP/d" forged1 >double-base &&
 	sed -n -e "/gpgsig/,/END PGP/p" forged1 | \
-		sed -e "s/^gpgsig//;s/^ //" | gpg --dearmor >double-sig1.sig &&
+		sed -e "s/^$(test_oid header)//;s/^ //" | gpg --dearmor >double-sig1.sig &&
 	gpg -o double-sig2.sig -u 29472784 --detach-sign double-base &&
 	cat double-sig1.sig double-sig2.sig | gpg --enarmor >double-combined.asc &&
-	sed -e "s/^\(-.*\)ARMORED FILE/\1SIGNATURE/;1s/^/gpgsig /;2,\$s/^/ /" \
+	sed -e "s/^\(-.*\)ARMORED FILE/\1SIGNATURE/;1s/^/$(test_oid header) /;2,\$s/^/ /" \
 		double-combined.asc > double-gpgsig &&
 	sed -e "/committer/r double-gpgsig" double-base >double-commit &&
 	git hash-object -w -t commit double-commit >double-commit.commit &&
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 1326088..5883a6a 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -29,15 +29,19 @@
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-gpg.sh
 
-printf '%s\n' 1 2 3 4 5 6 7 8 9 >file
-printf '%s\n' '1 X' 2 3 4 5 6 7 8 9 >file.1
-printf '%s\n' 1 2 3 4 '5 X' 6 7 8 9 >file.5
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 X' >file.9
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 Y' >file.9y
-printf '%s\n' '1 X' 2 3 4 5 6 7 8 9 >result.1
-printf '%s\n' '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
-printf '%s\n' '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 Z' >result.9z
+test_write_lines 1 2 3 4 5 6 7 8 9 >file
+cp file file.orig
+test_write_lines '1 X' 2 3 4 5 6 7 8 9 >file.1
+test_write_lines 1 2 '3 X' 4 5 6 7 8 9 >file.3
+test_write_lines 1 2 3 4 '5 X' 6 7 8 9 >file.5
+test_write_lines 1 2 3 4 5 6 7 8 '9 X' >file.9
+test_write_lines 1 2 3 4 5 6 7 8 '9 Y' >file.9y
+test_write_lines '1 X' 2 3 4 5 6 7 8 9 >result.1
+test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
+test_write_lines '1 X' 2 3 4 5 6 7 8 '9 X' >result.1-9
+test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
+test_write_lines '1 X' 2 '3 X' 4 '5 X' 6 7 8 '9 X' >result.1-3-5-9
+test_write_lines 1 2 3 4 5 6 7 8 '9 Z' >result.9z
 
 create_merge_msgs () {
 	echo "Merge tag 'c2'" >msg.1-5 &&
@@ -81,7 +85,7 @@
 }
 
 verify_parents () {
-	printf '%s\n' "$@" >parents.expected &&
+	test_write_lines "$@" >parents.expected &&
 	>parents.actual &&
 	i=1 &&
 	while test $i -le $#
@@ -95,7 +99,7 @@
 }
 
 verify_mergeheads () {
-	printf '%s\n' "$@" >mergehead.expected &&
+	test_write_lines "$@" >mergehead.expected &&
 	while read sha1 rest
 	do
 		git rev-parse $sha1
@@ -675,6 +679,134 @@
 	git merge c3
 '
 
+test_expect_success 'merge with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git merge --autostash c2 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'merge with merge.autoStash' '
+	test_config merge.autoStash true &&
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git merge c2 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'fast-forward merge with --autostash' '
+	git reset --hard c0 &&
+	git merge-file file file.orig file.5 &&
+	git merge --autostash c1 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp result.1-5 file
+'
+
+test_expect_success 'octopus merge with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.3 &&
+	git merge --autostash c2 c3 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5-9 merge-result &&
+	test_cmp result.1-3-5-9 file
+'
+
+test_expect_success 'conflicted merge with --autostash, --abort restores stash' '
+	git reset --hard c3 &&
+	cp file.1 file &&
+	test_must_fail git merge --autostash c7 &&
+	git merge --abort 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp file.1 file
+'
+
+test_expect_success 'completed merge (git commit) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git commit 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'completed merge (git merge --continue) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git merge --continue 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'aborted merge (merge --abort) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git merge --abort 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'aborted merge (reset --hard) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git reset --hard 2>err &&
+	test_i18ngrep "Autostash exists; creating a new stash entry." err &&
+	git diff --exit-code
+'
+
+test_expect_success 'quit merge with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git diff HEAD >expect &&
+	git merge --quit 2>err &&
+	test_i18ngrep "Autostash exists; creating a new stash entry." err &&
+	git diff HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge with conflicted --autostash changes' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9y &&
+	git diff >expect &&
+	test_when_finished "test_might_fail git stash drop" &&
+	git merge --autostash c3 2>err &&
+	test_i18ngrep "Applying autostash resulted in conflicts." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-9 merge-result &&
+	git stash show -p >actual &&
+	test_cmp expect actual
+'
+
 cat >expected.branch <<\EOF
 Merge branch 'c5-branch' (early part)
 EOF
diff --git a/t/t7601-merge-pull-config.sh b/t/t7601-merge-pull-config.sh
index c6c44ec..0f97828 100755
--- a/t/t7601-merge-pull-config.sh
+++ b/t/t7601-merge-pull-config.sh
@@ -27,6 +27,44 @@
 	git tag c3
 '
 
+test_expect_success 'pull.rebase not set' '
+	git reset --hard c0 &&
+	git pull . c1 2>err &&
+	test_i18ngrep "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and pull.ff=false' '
+	git reset --hard c0 &&
+	test_config pull.ff false &&
+	git pull . c1 2>err &&
+	test_i18ngrep "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and pull.ff=only' '
+	git reset --hard c0 &&
+	test_config pull.ff only &&
+	git pull . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and --rebase given' '
+	git reset --hard c0 &&
+	git pull --rebase . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and --no-rebase given' '
+	git reset --hard c0 &&
+	git pull --no-rebase . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
+test_expect_success 'pull.rebase not set and --ff-only given' '
+	git reset --hard c0 &&
+	git pull --ff-only . c1 2>err &&
+	test_i18ngrep ! "Pulling without specifying how to reconcile" err
+'
+
 test_expect_success 'merge c1 with c2' '
 	git reset --hard c1 &&
 	test -f c0.c &&
diff --git a/t/t7609-merge-co-error-msgs.sh b/t/t7609-merge-co-error-msgs.sh
index e904132..5c8894d 100755
--- a/t/t7609-merge-co-error-msgs.sh
+++ b/t/t7609-merge-co-error-msgs.sh
@@ -126,7 +126,7 @@
 	git rm rep2 -r &&
 	>rep &&
 	>rep2 &&
-	git add rep rep2&&
+	git add rep rep2 &&
 	git commit -m "added test as a file" &&
 	git checkout master &&
 	>rep/untracked-file &&
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 7d7b396..991d5bd 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -72,6 +72,11 @@
 	# Still a no-op.
 	function dummy() {}
 	EOF
+	if test_have_prereq FUNNYNAMES
+	then
+		echo unusual >"\"unusual\" pathname" &&
+		echo unusual >"t/nested \"unusual\" pathname"
+	fi &&
 	git add . &&
 	test_tick &&
 	git commit -m initial
@@ -481,6 +486,48 @@
 		git grep --count -h -e b $H -- ab >actual &&
 		test_cmp expected actual
 	'
+
+	test_expect_success FUNNYNAMES "grep $L should quote unusual pathnames" '
+		cat >expected <<-EOF &&
+		${HC}"\"unusual\" pathname":unusual
+		${HC}"t/nested \"unusual\" pathname":unusual
+		EOF
+		git grep unusual $H >actual &&
+		test_cmp expected actual
+	'
+
+	test_expect_success FUNNYNAMES "grep $L in subdir should quote unusual relative pathnames" '
+		cat >expected <<-EOF &&
+		${HC}"nested \"unusual\" pathname":unusual
+		EOF
+		(
+			cd t &&
+			git grep unusual $H
+		) >actual &&
+		test_cmp expected actual
+	'
+
+	test_expect_success FUNNYNAMES "grep -z $L with unusual pathnames" '
+		cat >expected <<-EOF &&
+		${HC}"unusual" pathname:unusual
+		${HC}t/nested "unusual" pathname:unusual
+		EOF
+		git grep -z unusual $H >actual &&
+		tr "\0" ":" <actual >actual-replace-null &&
+		test_cmp expected actual-replace-null
+	'
+
+	test_expect_success FUNNYNAMES "grep -z $L in subdir with unusual relative pathnames" '
+		cat >expected <<-EOF &&
+		${HC}nested "unusual" pathname:unusual
+		EOF
+		(
+			cd t &&
+			git grep -z unusual $H
+		) >actual &&
+		tr "\0" ":" <actual >actual-replace-null &&
+		test_cmp expected actual-replace-null
+	'
 done
 
 cat >expected <<EOF
diff --git a/t/t9010-svn-fe.sh b/t/t9010-svn-fe.sh
index c90fdc5..83f8f5c 100755
--- a/t/t9010-svn-fe.sh
+++ b/t/t9010-svn-fe.sh
@@ -486,7 +486,7 @@
 	{
 		properties \
 			unimportant "something with a NUL (Q)" \
-			svn:log "commit message"&&
+			svn:log "commit message" &&
 		echo PROPS-END
 	} |
 	q_to_nul >props &&
diff --git a/t/t9141-git-svn-multiple-branches.sh b/t/t9141-git-svn-multiple-branches.sh
index 8e7f7d6..bf168a3 100755
--- a/t/t9141-git-svn-multiple-branches.sh
+++ b/t/t9141-git-svn-multiple-branches.sh
@@ -90,10 +90,10 @@
 	) &&
 	( cd svn_project &&
 		svn_cmd up &&
-		test_must_fail test -d b_one/Nope &&
-		test_must_fail test -d b_two/Nope &&
-		test_must_fail test -d tags_A/Tagless &&
-		test_must_fail test -d tags_B/Tagless
+		test_path_is_missing b_one/Nope &&
+		test_path_is_missing b_two/Nope &&
+		test_path_is_missing tags_A/Tagless &&
+		test_path_is_missing tags_B/Tagless
 	)
 '
 
diff --git a/t/t9160-git-svn-preserve-empty-dirs.sh b/t/t9160-git-svn-preserve-empty-dirs.sh
index 0ede3cf..36c6b1a 100755
--- a/t/t9160-git-svn-preserve-empty-dirs.sh
+++ b/t/t9160-git-svn-preserve-empty-dirs.sh
@@ -86,8 +86,8 @@
 		cd "$GIT_REPO" &&
 		git checkout HEAD~2
 	) &&
-	test_must_fail test -f "$GIT_REPO"/2/.gitignore &&
-	test_must_fail test -f "$GIT_REPO"/3/.gitignore
+	test_path_is_missing "$GIT_REPO"/2/.gitignore &&
+	test_path_is_missing "$GIT_REPO"/3/.gitignore
 '
 
 # After re-cloning the repository with --placeholder-file specified, there
diff --git a/t/t9164-git-svn-dcommit-concurrent.sh b/t/t9164-git-svn-dcommit-concurrent.sh
index 90346ff..8466269 100755
--- a/t/t9164-git-svn-dcommit-concurrent.sh
+++ b/t/t9164-git-svn-dcommit-concurrent.sh
@@ -92,7 +92,7 @@
 		echo 1 >> file &&
 		svn_cmd commit -m "changing file" &&
 		svn_cmd up &&
-		test_must_fail test_cmp auto_updated_file au_file_saved
+		! test_cmp auto_updated_file au_file_saved
 	)
 '
 
@@ -103,7 +103,7 @@
 		echo 2 >> file &&
 		svn_cmd commit -m "changing file once again" &&
 		echo 3 >> file &&
-		test_must_fail svn_cmd commit -m "this commit should fail" &&
+		! svn_cmd commit -m "this commit should fail" &&
 		svn_cmd revert file
 	)
 '
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 3e41c58..768257b 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -3381,4 +3381,113 @@
 	git log -1 --format=%B encoding | grep $(printf "\317\200")
 '
 
+###
+### series Y (submodules and hash algorithms)
+###
+
+cat >Y-sub-input <<\Y_INPUT_END
+blob
+mark :1
+data 4
+foo
+
+reset refs/heads/master
+commit refs/heads/master
+mark :2
+author Full Name <user@company.tld> 1000000000 +0100
+committer Full Name <user@company.tld> 1000000000 +0100
+data 24
+Test submodule commit 1
+M 100644 :1 file
+
+blob
+mark :3
+data 8
+foo
+bar
+
+commit refs/heads/master
+mark :4
+author Full Name <user@company.tld> 1000000001 +0100
+committer Full Name <user@company.tld> 1000000001 +0100
+data 24
+Test submodule commit 2
+from :2
+M 100644 :3 file
+Y_INPUT_END
+
+# Note that the submodule object IDs are intentionally not translated.
+cat >Y-main-input <<\Y_INPUT_END
+blob
+mark :1
+data 4
+foo
+
+reset refs/heads/master
+commit refs/heads/master
+mark :2
+author Full Name <user@company.tld> 2000000000 +0100
+committer Full Name <user@company.tld> 2000000000 +0100
+data 14
+Test commit 1
+M 100644 :1 file
+
+blob
+mark :3
+data 73
+[submodule "sub1"]
+	path = sub1
+	url = https://void.example.com/main.git
+
+commit refs/heads/master
+mark :4
+author Full Name <user@company.tld> 2000000001 +0100
+committer Full Name <user@company.tld> 2000000001 +0100
+data 14
+Test commit 2
+from :2
+M 100644 :3 .gitmodules
+M 160000 0712c5be7cf681388e355ef47525aaf23aee1a6d sub1
+
+blob
+mark :5
+data 8
+foo
+bar
+
+commit refs/heads/master
+mark :6
+author Full Name <user@company.tld> 2000000002 +0100
+committer Full Name <user@company.tld> 2000000002 +0100
+data 14
+Test commit 3
+from :4
+M 100644 :5 file
+M 160000 ff729f5e62f72c0c3978207d9a80e5f3a65f14d7 sub1
+Y_INPUT_END
+
+cat >Y-marks <<\Y_INPUT_END
+:2 0712c5be7cf681388e355ef47525aaf23aee1a6d
+:4 ff729f5e62f72c0c3978207d9a80e5f3a65f14d7
+Y_INPUT_END
+
+test_expect_success 'Y: setup' '
+	test_oid_cache <<-EOF
+	Ymaster sha1:9afed2f9161ddf416c0a1863b8b0725b00070504
+	Ymaster sha256:c0a1010da1df187b2e287654793df01b464bd6f8e3f17fc1481a7dadf84caee3
+	EOF
+'
+
+test_expect_success 'Y: rewrite submodules' '
+	git init main1 &&
+	(
+		cd main1 &&
+		git init sub2 &&
+		git -C sub2 fast-import --export-marks=../sub2-marks <../Y-sub-input &&
+		git fast-import --rewrite-submodules-from=sub:../Y-marks \
+			--rewrite-submodules-to=sub:sub2-marks <../Y-main-input &&
+		test "$(git rev-parse master)" = "$(test_oid Ymaster)"
+	)
+'
+
 test_done
diff --git a/t/t9500-gitweb-standalone-no-errors.sh b/t/t9500-gitweb-standalone-no-errors.sh
index cc8d463..267ddc9 100755
--- a/t/t9500-gitweb-standalone-no-errors.sh
+++ b/t/t9500-gitweb-standalone-no-errors.sh
@@ -53,7 +53,7 @@
 
 test_expect_success \
 	'Make initial commit' \
-	'echo "Not an empty file." > file &&
+	'echo "Not an empty file." >file &&
 	 git add file &&
 	 git commit -a -m "Initial commit." &&
 	 git branch b'
@@ -139,7 +139,7 @@
 
 test_expect_success \
 	'commitdiff(0): file added' \
-	'echo "New file" > new_file &&
+	'echo "New file" >new_file &&
 	 git add new_file &&
 	 git commit -a -m "File added." &&
 	 gitweb_run "p=.git;a=commitdiff"'
@@ -179,7 +179,7 @@
 
 test_expect_success \
 	'commitdiff(0): mode change and modified' \
-	'echo "New line" >> file2 &&
+	'echo "New line" >>file2 &&
 	 test_chmod +x file2 &&
 	 git commit -a -m "Mode change and modification." &&
 	 gitweb_run "p=.git;a=commitdiff"'
@@ -197,14 +197,14 @@
 EOF
 	 git commit -a -m "File added." &&
 	 git mv file2 file3 &&
-	 echo "Propter nomen suum." >> file3 &&
+	 echo "Propter nomen suum." >>file3 &&
 	 git commit -a -m "File rename and modification." &&
 	 gitweb_run "p=.git;a=commitdiff"'
 
 test_expect_success \
 	'commitdiff(0): renamed, mode change and modified' \
 	'git mv file3 file2 &&
-	 echo "Propter nomen suum." >> file2 &&
+	 echo "Propter nomen suum." >>file2 &&
 	 test_chmod +x file2 &&
 	 git commit -a -m "File rename, mode change and modification." &&
 	 gitweb_run "p=.git;a=commitdiff"'
@@ -213,8 +213,8 @@
 # commitdiff testing (taken from t4114-apply-typechange.sh)
 
 test_expect_success 'setup typechange commits' '
-	echo "hello world" > foo &&
-	echo "hi planet" > bar &&
+	echo "hello world" >foo &&
+	echo "hi planet" >bar &&
 	git update-index --add foo bar &&
 	git commit -m initial &&
 	git branch initial &&
@@ -223,18 +223,18 @@
 	git commit -m "foo symlinked to bar" &&
 	git branch foo-symlinked-to-bar &&
 	rm -f foo &&
-	echo "how far is the sun?" > foo &&
+	echo "how far is the sun?" >foo &&
 	git update-index foo &&
 	git commit -m "foo back to file" &&
 	git branch foo-back-to-file &&
 	rm -f foo &&
 	git update-index --remove foo &&
 	mkdir foo &&
-	echo "if only I knew" > foo/baz &&
+	echo "if only I knew" >foo/baz &&
 	git update-index --add foo/baz &&
 	git commit -m "foo becomes a directory" &&
 	git branch "foo-becomes-a-directory" &&
-	echo "hello world" > foo/baz &&
+	echo "hello world" >foo/baz &&
 	git update-index foo/baz &&
 	git commit -m "foo/baz is the original foo" &&
 	git branch foo-baz-renamed-from-foo
@@ -324,7 +324,7 @@
 test_expect_success \
 	'Create a merge' \
 	'git checkout b &&
-	 echo "Branch" >> b &&
+	 echo "Branch" >>b &&
 	 git add b &&
 	 git commit -a -m "On branch" &&
 	 git checkout master &&
@@ -342,26 +342,26 @@
 test_expect_success \
 	'Prepare large commit' \
 	'git checkout b &&
-	 echo "To be changed" > 01-change &&
-	 echo "To be renamed" > 02-pure-rename-from &&
-	 echo "To be deleted" > 03-delete &&
-	 echo "To be renamed and changed" > 04-rename-from &&
-	 echo "To have mode changed" > 05-mode-change &&
-	 echo "File to symlink" > 06-file-or-symlink &&
-	 echo "To be changed and have mode changed" > 07-change-mode-change	&&
+	 echo "To be changed" >01-change &&
+	 echo "To be renamed" >02-pure-rename-from &&
+	 echo "To be deleted" >03-delete &&
+	 echo "To be renamed and changed" >04-rename-from &&
+	 echo "To have mode changed" >05-mode-change &&
+	 echo "File to symlink" >06-file-or-symlink &&
+	 echo "To be changed and have mode changed" >07-change-mode-change &&
 	 git add 0* &&
 	 git commit -a -m "Prepare large commit" &&
-	 echo "Changed" > 01-change &&
+	 echo "Changed" >01-change &&
 	 git mv 02-pure-rename-from 02-pure-rename-to &&
 	 git rm 03-delete && rm -f 03-delete &&
-	 echo "A new file" > 03-new &&
+	 echo "A new file" >03-new &&
 	 git add 03-new &&
 	 git mv 04-rename-from 04-rename-to &&
-	 echo "Changed" >> 04-rename-to &&
+	 echo "Changed" >>04-rename-to &&
 	 test_chmod +x 05-mode-change &&
 	 rm -f 06-file-or-symlink &&
 	 test_ln_s_add 01-change 06-file-or-symlink &&
-	 echo "Changed and have mode changed" > 07-change-mode-change	&&
+	 echo "Changed and have mode changed" >07-change-mode-change &&
 	 test_chmod +x 07-change-mode-change &&
 	 git commit -a -m "Large commit" &&
 	 git checkout master'
@@ -444,7 +444,7 @@
 test_expect_success \
 	'logs: history (implicit HEAD, deleted file)' \
 	'git checkout master &&
-	 echo "to be deleted" > deleted_file &&
+	 echo "to be deleted" >deleted_file &&
 	 git add deleted_file &&
 	 git commit -m "Add file to be deleted" &&
 	 git rm deleted_file &&
@@ -522,7 +522,7 @@
 	'. "$TEST_DIRECTORY"/t3901/utf8.txt &&
 	 test_when_finished "GIT_AUTHOR_NAME=\"A U Thor\"" &&
 	 test_when_finished "GIT_COMMITTER_NAME=\"C O Mitter\"" &&
-	 echo "UTF-8" >> file &&
+	 echo "UTF-8" >>file &&
 	 git add file &&
 	 git commit -F "$TEST_DIRECTORY"/t3900/1-UTF-8.txt &&
 	 gitweb_run "p=.git;a=commit"'
@@ -532,7 +532,7 @@
 	'. "$TEST_DIRECTORY"/t3901/8859-1.txt &&
 	 test_when_finished "GIT_AUTHOR_NAME=\"A U Thor\"" &&
 	 test_when_finished "GIT_COMMITTER_NAME=\"C O Mitter\"" &&
-	 echo "ISO-8859-1" >> file &&
+	 echo "ISO-8859-1" >>file &&
 	 git add file &&
 	 test_config i18n.commitencoding ISO-8859-1 &&
 	 git commit -F "$TEST_DIRECTORY"/t3900/ISO8859-1.txt &&
@@ -675,8 +675,8 @@
 
 test_expect_success \
 	'README.html with non-ASCII characters (utf-8)' \
-	'echo "<b>UTF-8 example:</b><br />" > .git/README.html &&
-	 cat "$TEST_DIRECTORY"/t3900/1-UTF-8.txt >> .git/README.html &&
+	'echo "<b>UTF-8 example:</b><br />" >.git/README.html &&
+	 cat "$TEST_DIRECTORY"/t3900/1-UTF-8.txt >>.git/README.html &&
 	 gitweb_run "p=.git;a=summary"'
 
 # ----------------------------------------------------------------------
@@ -704,7 +704,7 @@
 test_expect_success HIGHLIGHT \
 	'syntax highlighting (highlighted, shell script)' \
 	'git config gitweb.highlight yes &&
-	 echo "#!/usr/bin/sh" > test.sh &&
+	 echo "#!/usr/bin/sh" >test.sh &&
 	 git add test.sh &&
 	 git commit -m "Add test.sh" &&
 	 gitweb_run "p=.git;a=blob;f=test.sh"'
@@ -712,7 +712,7 @@
 test_expect_success HIGHLIGHT \
 	'syntax highlighting (highlighter language autodetection)' \
 	'git config gitweb.highlight yes &&
-	 echo "#!/usr/bin/perl" > test &&
+	 echo "#!/usr/bin/perl" >test &&
 	 git add test &&
 	 git commit -m "Add test" &&
 	 gitweb_run "p=.git;a=blob;f=test"'
@@ -729,11 +729,11 @@
 	'git init --bare foo.git &&
 	 git --git-dir=foo.git --work-tree=. add file &&
 	 git --git-dir=foo.git --work-tree=. commit -m "Initial commit" &&
-	 echo "foo" > foo.git/description &&
+	 echo "foo" >foo.git/description &&
 	 mkdir -p foo &&
 	 (cd foo &&
 	  git clone --shared --bare ../foo.git foo-forked.git &&
-	  echo "fork of foo" > foo-forked.git/description)'
+	  echo "fork of foo" >foo-forked.git/description)'
 
 test_expect_success \
 	'forks: projects list' \
@@ -754,8 +754,8 @@
 test_expect_success \
 	'ctags: tag cloud in projects list' \
 	'mkdir .git/ctags &&
-	 echo "2" > .git/ctags/foo &&
-	 echo "1" > .git/ctags/bar &&
+	 echo "2" >.git/ctags/foo &&
+	 echo "1" >.git/ctags/bar &&
 	gitweb_run'
 
 test_expect_success \
@@ -769,8 +769,8 @@
 test_expect_success \
 	'ctags: malformed tag weights' \
 	'mkdir -p .git/ctags &&
-	 echo "not-a-number" > .git/ctags/nan &&
-	 echo "not-a-number-2" > .git/ctags/nan2 &&
+	 echo "not-a-number" >.git/ctags/nan &&
+	 echo "not-a-number-2" >.git/ctags/nan2 &&
 	 echo "0.1" >.git/ctags/floating-point &&
 	 gitweb_run'
 
diff --git a/t/t9819-git-p4-case-folding.sh b/t/t9819-git-p4-case-folding.sh
index 600ce1e..b4d93f0 100755
--- a/t/t9819-git-p4-case-folding.sh
+++ b/t/t9819-git-p4-case-folding.sh
@@ -30,7 +30,7 @@
 		cd "$cli" &&
 		>lc/FILE.TXT &&
 		p4 add lc/FILE.TXT &&
-		test_must_fail p4 submit -d "Cannot add file differing only in case" lc/FILE.TXT
+		! p4 submit -d "Cannot add file differing only in case" lc/FILE.TXT
 	)
 '
 
diff --git a/t/t9831-git-p4-triggers.sh b/t/t9831-git-p4-triggers.sh
index d743ca3..ff6c035 100755
--- a/t/t9831-git-p4-triggers.sh
+++ b/t/t9831-git-p4-triggers.sh
@@ -58,7 +58,7 @@
 	(
 		cd "$git" &&
 		git p4 sync
-	)&&
+	) &&
 	(
 		p4 triggers -i <<-EOF
 		Triggers:
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 5505e5a..3c44af6 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1638,6 +1638,11 @@
 	echo modify > modified &&
 	test_completion "git add " "modified" &&
 
+	mkdir -p some/deep &&
+	touch some/deep/path &&
+	test_completion "git add some/" "some/deep" &&
+	git clean -f some &&
+
 	touch untracked &&
 
 	: TODO .gitignore should not be here &&
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 352c213..3103be8 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -905,7 +905,7 @@
 # - not all diff versions understand "-u"
 
 test_cmp() {
-	$GIT_TEST_CMP "$@"
+	eval "$GIT_TEST_CMP" '"$@"'
 }
 
 # Check that the given config key has the expected value.
@@ -1362,14 +1362,22 @@
 	)
 } 7>&2 2>&4
 
-# convert stdin to pktline representation; note that empty input becomes an
-# empty packet, not a flush packet (for that you can just print 0000 yourself).
+# convert function arguments or stdin (if not arguments given) to pktline
+# representation. If multiple arguments are given, they are separated by
+# whitespace and put in a single packet. Note that data containing NULs must be
+# given on stdin, and that empty input becomes an empty packet, not a flush
+# packet (for that you can just print 0000 yourself).
 packetize() {
-	cat >packetize.tmp &&
-	len=$(wc -c <packetize.tmp) &&
-	printf '%04x%s' "$(($len + 4))" &&
-	cat packetize.tmp &&
-	rm -f packetize.tmp
+	if test $# -gt 0
+	then
+		packet="$*"
+		printf '%04x%s' "$((4 + ${#packet}))" "$packet"
+	else
+		perl -e '
+			my $packet = do { local $/; <STDIN> };
+			printf "%04x%s", 4 + length($packet), $packet;
+		'
+	fi
 }
 
 # Parse the input as a series of pktlines, writing the result to stdout.
@@ -1543,3 +1551,13 @@
 	test_cmp "$1.normalized" "$2.normalized" &&
 	rm -f "$1.normalized" "$2.normalized"
 }
+
+# Tests for the hidden file attribute on Windows
+test_path_is_hidden () {
+	test_have_prereq MINGW ||
+	BUG "test_path_is_hidden can only be used on Windows"
+
+	# Use the output of `attrib`, ignore the absolute path
+	case "$("$SYSTEMROOT"/system32/attrib "$1")" in *H*?:*) return 0;; esac
+	return 1
+}
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 0ea1e5a..13ba00d 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -78,20 +78,23 @@
 	exit 1
 fi
 
-# Parse options while taking care to leave $@ intact, so we will still
-# have all the original command line options when executing the test
-# script again for '--tee' and '--verbose-log' below.
 store_arg_to=
-prev_opt=
-for opt
-do
-	if test -n "$store_arg_to"
+opt_required_arg=
+# $1: option string
+# $2: name of the var where the arg will be stored
+mark_option_requires_arg () {
+	if test -n "$opt_required_arg"
 	then
-		eval $store_arg_to=\$opt
-		store_arg_to=
-		prev_opt=
-		continue
+		echo "error: options that require args cannot be bundled" \
+			"together: '$opt_required_arg' and '$1'" >&2
+		exit 1
 	fi
+	opt_required_arg=$1
+	store_arg_to=$2
+}
+
+parse_option () {
+	local opt="$1"
 
 	case "$opt" in
 	-d|--d|--de|--deb|--debu|--debug)
@@ -101,7 +104,7 @@
 	-l|--l|--lo|--lon|--long|--long-|--long-t|--long-te|--long-tes|--long-test|--long-tests)
 		GIT_TEST_LONG=t; export GIT_TEST_LONG ;;
 	-r)
-		store_arg_to=run_list
+		mark_option_requires_arg "$opt" run_list
 		;;
 	--run=*)
 		run_list=${opt#--*=} ;;
@@ -185,12 +188,42 @@
 	*)
 		echo "error: unknown test option '$opt'" >&2; exit 1 ;;
 	esac
+}
 
-	prev_opt=$opt
+# Parse options while taking care to leave $@ intact, so we will still
+# have all the original command line options when executing the test
+# script again for '--tee' and '--verbose-log' later.
+for opt
+do
+	if test -n "$store_arg_to"
+	then
+		eval $store_arg_to=\$opt
+		store_arg_to=
+		opt_required_arg=
+		continue
+	fi
+
+	case "$opt" in
+	--*|-?)
+		parse_option "$opt" ;;
+	-?*)
+		# bundled short options must be fed separately to parse_option
+		opt=${opt#-}
+		while test -n "$opt"
+		do
+			extra=${opt#?}
+			this=${opt%$extra}
+			opt=$extra
+			parse_option "-$this"
+		done
+		;;
+	*)
+		echo "error: unknown test option '$opt'" >&2; exit 1 ;;
+	esac
 done
 if test -n "$store_arg_to"
 then
-	echo "error: $prev_opt requires an argument" >&2
+	echo "error: $opt_required_arg requires an argument" >&2
 	exit 1
 fi
 
@@ -494,21 +527,6 @@
 	;;
 esac
 
-# Convenience
-#
-# A regexp to match 5, 35 and 40 hexdigits
-_x05='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
-_x35="$_x05$_x05$_x05$_x05$_x05$_x05$_x05"
-_x40="$_x35$_x05"
-
-# Zero SHA-1
-_z40=0000000000000000000000000000000000000000
-
-OID_REGEX="$_x40"
-ZERO_OID=$_z40
-EMPTY_TREE=4b825dc642cb6eb9a060e54bf8d69288fbee4904
-EMPTY_BLOB=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
-
 # Line feed
 LF='
 '
@@ -657,6 +675,18 @@
 	fi
 }
 
+file_lineno () {
+	test -z "$GIT_TEST_FRAMEWORK_SELFTEST" && test -n "$BASH" || return 0
+	local i
+	for i in ${!BASH_SOURCE[*]}
+	do
+		case $i,"${BASH_SOURCE[$i]##*/}" in
+		0,t[0-9]*.sh) echo "t/${BASH_SOURCE[$i]}:$LINENO: ${1+$1: }"; return;;
+		*,t[0-9]*.sh) echo "t/${BASH_SOURCE[$i]}:${BASH_LINENO[$(($i-1))]}: ${1+$1: }"; return;;
+		esac
+	done
+}
+
 GIT_EXIT_OK=
 trap 'die' EXIT
 # Disable '-x' tracing, because with some shells, notably dash, it
@@ -702,7 +732,7 @@
 		write_junit_xml_testcase "$1" "      $junit_insert"
 	fi
 	test_failure=$(($test_failure + 1))
-	say_color error "not ok $test_count - $1"
+	say_color error "$(file_lineno error)not ok $test_count - $1"
 	shift
 	printf '%s\n' "$*" | sed -e 's/^/#	/'
 	test "$immediate" = "" || { finalize_junit_xml; GIT_EXIT_OK=t; exit 1; }
@@ -882,6 +912,7 @@
 	fi
 }
 
+trace_level_=0
 want_trace () {
 	test "$trace" = t && {
 		test "$verbose" = t || test "$verbose_log" = t
@@ -895,7 +926,7 @@
 test_eval_inner_ () {
 	# Do not add anything extra (including LF) after '$*'
 	eval "
-		want_trace && set -x
+		want_trace && trace_level_=$(($trace_level_+1)) && set -x
 		$*"
 }
 
@@ -926,7 +957,8 @@
 		test_eval_ret_=$?
 		if want_trace
 		then
-			set +x
+			test 1 = $trace_level_ && set +x
+			trace_level_=$(($trace_level_-1))
 		fi
 	} 2>/dev/null 4>&2
 
@@ -1085,6 +1117,7 @@
 		junit_time=$(test-tool date getnanos $junit_suite_start)
 		sed -e "s/\(<testsuite.*\) time=\"[^\"]*\"/\1/" \
 			-e "s/<testsuite [^>]*/& time=\"$junit_time\"/" \
+			-e '/^ *<\/testsuite/d' \
 			<"$junit_xml_path" >"$junit_xml_path.new"
 		mv "$junit_xml_path.new" "$junit_xml_path"
 
@@ -1383,6 +1416,20 @@
 	fi
 fi
 
+# Convenience
+# A regexp to match 5, 35 and 40 hexdigits
+_x05='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
+_x35="$_x05$_x05$_x05$_x05$_x05$_x05$_x05"
+_x40="$_x35$_x05"
+
+test_oid_init
+
+ZERO_OID=$(test_oid zero)
+OID_REGEX=$(echo $ZERO_OID | sed -e 's/0/[0-9a-f]/g')
+EMPTY_TREE=$(test_oid empty_tree)
+EMPTY_BLOB=$(test_oid empty_blob)
+_z40=$ZERO_OID
+
 # Provide an implementation of the 'yes' utility; the upper bound
 # limit is there to help Windows that cannot stop this loop from
 # wasting cycles when the downstream stops reading, so do not be
diff --git a/trace2.c b/trace2.c
index c7b4f14..2c6b570 100644
--- a/trace2.c
+++ b/trace2.c
@@ -121,6 +121,7 @@ static void tr2main_atexit_handler(void)
 	tr2_sid_release();
 	tr2_cmd_name_release();
 	tr2_cfg_free_patterns();
+	tr2_cfg_free_env_vars();
 	tr2_sysenv_release();
 
 	trace2_enabled = 0;
@@ -311,6 +312,14 @@ void trace2_cmd_list_config_fl(const char *file, int line)
 	tr2_cfg_list_config_fl(file, line);
 }
 
+void trace2_cmd_list_env_vars_fl(const char *file, int line)
+{
+	if (!trace2_enabled)
+		return;
+
+	tr2_list_env_vars_fl(file, line);
+}
+
 void trace2_cmd_set_config_fl(const char *file, int line, const char *key,
 			      const char *value)
 {
diff --git a/trace2.h b/trace2.h
index e5e81c0..b18bc55 100644
--- a/trace2.h
+++ b/trace2.h
@@ -183,6 +183,19 @@ void trace2_cmd_list_config_fl(const char *file, int line);
 #define trace2_cmd_list_config() trace2_cmd_list_config_fl(__FILE__, __LINE__)
 
 /*
+ * Emit one or more 'def_param' events for "important" environment variables.
+ *
+ * Use the TR2_SYSENV_ENV_VARS setting to register a comma-separated list of
+ * environment variables considered important.  For example:
+ *     git config --system trace2.envVars 'GIT_HTTP_USER_AGENT,GIT_CONFIG'
+ * or:
+ *     GIT_TRACE2_ENV_VARS="GIT_HTTP_USER_AGENT,GIT_CONFIG"
+ */
+void trace2_cmd_list_env_vars_fl(const char *file, int line);
+
+#define trace2_cmd_list_env_vars() trace2_cmd_list_env_vars_fl(__FILE__, __LINE__)
+
+/*
  * Emit a "def_param" event for the given config key/value pair IF
  * we consider the key to be "important".
  *
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index caa7f06..ec9ac1a 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -7,6 +7,10 @@ static struct strbuf **tr2_cfg_patterns;
 static int tr2_cfg_count_patterns;
 static int tr2_cfg_loaded;
 
+static struct strbuf **tr2_cfg_env_vars;
+static int tr2_cfg_env_vars_count;
+static int tr2_cfg_env_vars_loaded;
+
 /*
  * Parse a string containing a comma-delimited list of config keys
  * or wildcard patterns into a list of strbufs.
@@ -46,6 +50,45 @@ void tr2_cfg_free_patterns(void)
 	tr2_cfg_loaded = 0;
 }
 
+/*
+ * Parse a string containing a comma-delimited list of environment variable
+ * names into a list of strbufs.
+ */
+static int tr2_load_env_vars(void)
+{
+	struct strbuf **s;
+	const char *varlist;
+
+	if (tr2_cfg_env_vars_loaded)
+		return tr2_cfg_env_vars_count;
+	tr2_cfg_env_vars_loaded = 1;
+
+	varlist = tr2_sysenv_get(TR2_SYSENV_ENV_VARS);
+	if (!varlist || !*varlist)
+		return tr2_cfg_env_vars_count;
+
+	tr2_cfg_env_vars = strbuf_split_buf(varlist, strlen(varlist), ',', -1);
+	for (s = tr2_cfg_env_vars; *s; s++) {
+		struct strbuf *buf = *s;
+
+		if (buf->len && buf->buf[buf->len - 1] == ',')
+			strbuf_setlen(buf, buf->len - 1);
+		strbuf_trim_trailing_newline(*s);
+		strbuf_trim(*s);
+	}
+
+	tr2_cfg_env_vars_count = s - tr2_cfg_env_vars;
+	return tr2_cfg_env_vars_count;
+}
+
+void tr2_cfg_free_env_vars(void)
+{
+	if (tr2_cfg_env_vars)
+		strbuf_list_free(tr2_cfg_env_vars);
+	tr2_cfg_env_vars_count = 0;
+	tr2_cfg_env_vars_loaded = 0;
+}
+
 struct tr2_cfg_data {
 	const char *file;
 	int line;
@@ -79,6 +122,21 @@ void tr2_cfg_list_config_fl(const char *file, int line)
 		read_early_config(tr2_cfg_cb, &data);
 }
 
+void tr2_list_env_vars_fl(const char *file, int line)
+{
+	struct strbuf **s;
+
+	if (tr2_load_env_vars() <= 0)
+		return;
+
+	for (s = tr2_cfg_env_vars; *s; s++) {
+		struct strbuf *buf = *s;
+		const char *val = getenv(buf->buf);
+		if (val && *val)
+			trace2_def_param_fl(file, line, buf->buf, val);
+	}
+}
+
 void tr2_cfg_set_fl(const char *file, int line, const char *key,
 		    const char *value)
 {
diff --git a/trace2/tr2_cfg.h b/trace2/tr2_cfg.h
index d9c98f6..a11d71f 100644
--- a/trace2/tr2_cfg.h
+++ b/trace2/tr2_cfg.h
@@ -8,6 +8,12 @@
 void tr2_cfg_list_config_fl(const char *file, int line);
 
 /*
+ * Iterate over all "interesting" environment variables and emit 'def_param'
+ * events for them to TRACE2.
+ */
+void tr2_list_env_vars_fl(const char *file, int line);
+
+/*
  * Emit a "def_param" event for the given key/value pair IF we consider
  * the key to be "interesting".
  */
@@ -16,4 +22,6 @@ void tr2_cfg_set_fl(const char *file, int line, const char *key,
 
 void tr2_cfg_free_patterns(void);
 
+void tr2_cfg_free_env_vars(void);
+
 #endif /* TR2_CFG_H */
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
index 3c3792e..a380dcf 100644
--- a/trace2/tr2_sysenv.c
+++ b/trace2/tr2_sysenv.c
@@ -29,6 +29,8 @@ struct tr2_sysenv_entry {
 static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
 	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TRACE2_CONFIG_PARAMS",
 				       "trace2.configparams" },
+	[TR2_SYSENV_ENV_VARS]      = { "GIT_TRACE2_ENV_VARS",
+				       "trace2.envvars" },
 
 	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TRACE2_DST_DEBUG",
 				       "trace2.destinationdebug" },
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
index d4364a7..3292ee1 100644
--- a/trace2/tr2_sysenv.h
+++ b/trace2/tr2_sysenv.h
@@ -11,6 +11,7 @@
  */
 enum tr2_sysenv_variable {
 	TR2_SYSENV_CFG_PARAM = 0,
+	TR2_SYSENV_ENV_VARS,
 
 	TR2_SYSENV_DST_DEBUG,
 
diff --git a/transport-helper.c b/transport-helper.c
index 20a7185..a46afcb 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -894,6 +894,7 @@ static int push_refs_with_push(struct transport *transport,
 		case REF_STATUS_REJECT_STALE:
 		case REF_STATUS_REJECT_ALREADY_EXISTS:
 			if (atomic) {
+				reject_atomic_push(remote_refs, mirror);
 				string_list_clear(&cas_options, 0);
 				return 0;
 			} else
@@ -1488,3 +1489,25 @@ int bidirectional_transfer_loop(int input, int output)
 
 	return tloop_spawnwait_tasks(&state);
 }
+
+void reject_atomic_push(struct ref *remote_refs, int mirror_mode)
+{
+	struct ref *ref;
+
+	/* Mark other refs as failed */
+	for (ref = remote_refs; ref; ref = ref->next) {
+		if (!ref->peer_ref && !mirror_mode)
+			continue;
+
+		switch (ref->status) {
+		case REF_STATUS_NONE:
+		case REF_STATUS_OK:
+		case REF_STATUS_EXPECTING_REPORT:
+			ref->status = REF_STATUS_ATOMIC_PUSH_FAILED;
+			continue;
+		default:
+			break; /* do nothing */
+		}
+	}
+	return;
+}
diff --git a/transport.c b/transport.c
index 1fdc7da..15f5ba4 100644
--- a/transport.c
+++ b/transport.c
@@ -16,7 +16,7 @@
 #include "url.h"
 #include "submodule.h"
 #include "string-list.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "sigchain.h"
 #include "transport-internal.h"
 #include "protocol.h"
@@ -715,7 +715,15 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 
 	close(data->fd[1]);
 	close(data->fd[0]);
-	ret |= finish_connect(data->conn);
+	/*
+	 * Atomic push may abort the connection early and close the pipe,
+	 * which may cause an error for `finish_connect()`. Ignore this error
+	 * for atomic git-push.
+	 */
+	if (ret || args.atomic)
+		finish_connect(data->conn);
+	else
+		ret = finish_connect(data->conn);
 	data->conn = NULL;
 	data->got_remote_heads = 0;
 
@@ -1240,20 +1248,6 @@ int transport_push(struct repository *r,
 		err = push_had_errors(remote_refs);
 		ret = push_ret | err;
 
-		if ((flags & TRANSPORT_PUSH_ATOMIC) && err) {
-			struct ref *it;
-			for (it = remote_refs; it; it = it->next)
-				switch (it->status) {
-				case REF_STATUS_NONE:
-				case REF_STATUS_UPTODATE:
-				case REF_STATUS_OK:
-					it->status = REF_STATUS_ATOMIC_PUSH_FAILED;
-					break;
-				default:
-					break;
-				}
-		}
-
 		if (!quiet || err)
 			transport_print_push_status(transport->url, remote_refs,
 					verbose | porcelain, porcelain,
diff --git a/transport.h b/transport.h
index e0131da..4298c85 100644
--- a/transport.h
+++ b/transport.h
@@ -265,4 +265,7 @@ int transport_refs_pushed(struct ref *ref);
 void transport_print_push_status(const char *dest, struct ref *refs,
 		  int verbose, int porcelain, unsigned int *reject_reasons);
 
+/* common method used by transport-helper.c and send-pack.c */
+void reject_atomic_push(struct ref *refs, int mirror_mode);
+
 #endif
diff --git a/unpack-trees.c b/unpack-trees.c
index 1ecdab3..6bbf58d 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -24,7 +24,7 @@
  * situation better.  See how "git checkout" and "git merge" replaces
  * them using setup_unpack_trees_porcelain(), for example.
  */
-static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
+static const char *unpack_plumbing_errors[NB_UNPACK_TREES_WARNING_TYPES] = {
 	/* ERROR_WOULD_OVERWRITE */
 	"Entry '%s' would be overwritten by merge. Cannot merge.",
 
@@ -43,17 +43,20 @@ static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* ERROR_BIND_OVERLAP */
 	"Entry '%s' overlaps with '%s'.  Cannot bind.",
 
-	/* ERROR_SPARSE_NOT_UPTODATE_FILE */
-	"Entry '%s' not uptodate. Cannot update sparse checkout.",
-
-	/* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
-	"Working tree file '%s' would be overwritten by sparse checkout update.",
-
-	/* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
-	"Working tree file '%s' would be removed by sparse checkout update.",
-
 	/* ERROR_WOULD_LOSE_SUBMODULE */
 	"Submodule '%s' cannot checkout new HEAD.",
+
+	/* NB_UNPACK_TREES_ERROR_TYPES; just a meta value */
+	"",
+
+	/* WARNING_SPARSE_NOT_UPTODATE_FILE */
+	"Path '%s' not uptodate; will not remove from working tree.",
+
+	/* WARNING_SPARSE_UNMERGED_FILE */
+	"Path '%s' unmerged; will not remove from working tree.",
+
+	/* WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN */
+	"Path '%s' already present; will not overwrite with sparse update.",
 };
 
 #define ERRORMSG(o,type) \
@@ -168,15 +171,16 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
 	 */
 	msgs[ERROR_BIND_OVERLAP] = _("Entry '%s' overlaps with '%s'.  Cannot bind.");
 
-	msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
-		_("Cannot update sparse checkout: the following entries are not up to date:\n%s");
-	msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
-		_("The following working tree files would be overwritten by sparse checkout update:\n%s");
-	msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
-		_("The following working tree files would be removed by sparse checkout update:\n%s");
 	msgs[ERROR_WOULD_LOSE_SUBMODULE] =
 		_("Cannot update submodule:\n%s");
 
+	msgs[WARNING_SPARSE_NOT_UPTODATE_FILE] =
+		_("The following paths are not up to date and were left despite sparse patterns:\n%s");
+	msgs[WARNING_SPARSE_UNMERGED_FILE] =
+		_("The following paths are unmerged and were left despite sparse patterns:\n%s");
+	msgs[WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN] =
+		_("The following paths were already present and thus not updated despite sparse patterns:\n%s");
+
 	opts->show_all_errors = 1;
 	/* rejected paths may not have a static buffer */
 	for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
@@ -226,7 +230,7 @@ static int add_rejected_path(struct unpack_trees_options *o,
 
 	/*
 	 * Otherwise, insert in a list for future display by
-	 * display_error_msgs()
+	 * display_(error|warning)_msgs()
 	 */
 	string_list_append(&o->unpack_rejects[e], path);
 	return -1;
@@ -237,13 +241,16 @@ static int add_rejected_path(struct unpack_trees_options *o,
  */
 static void display_error_msgs(struct unpack_trees_options *o)
 {
-	int e, i;
-	int something_displayed = 0;
+	int e;
+	unsigned error_displayed = 0;
 	for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
 		struct string_list *rejects = &o->unpack_rejects[e];
+
 		if (rejects->nr > 0) {
+			int i;
 			struct strbuf path = STRBUF_INIT;
-			something_displayed = 1;
+
+			error_displayed = 1;
 			for (i = 0; i < rejects->nr; i++)
 				strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
 			error(ERRORMSG(o, e), super_prefixed(path.buf));
@@ -251,10 +258,36 @@ static void display_error_msgs(struct unpack_trees_options *o)
 		}
 		string_list_clear(rejects, 0);
 	}
-	if (something_displayed)
+	if (error_displayed)
 		fprintf(stderr, _("Aborting\n"));
 }
 
+/*
+ * display all the warning messages stored in a nice way
+ */
+static void display_warning_msgs(struct unpack_trees_options *o)
+{
+	int e;
+	unsigned warning_displayed = 0;
+	for (e = NB_UNPACK_TREES_ERROR_TYPES + 1;
+	     e < NB_UNPACK_TREES_WARNING_TYPES; e++) {
+		struct string_list *rejects = &o->unpack_rejects[e];
+
+		if (rejects->nr > 0) {
+			int i;
+			struct strbuf path = STRBUF_INIT;
+
+			warning_displayed = 1;
+			for (i = 0; i < rejects->nr; i++)
+				strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
+			warning(ERRORMSG(o, e), super_prefixed(path.buf));
+			strbuf_release(&path);
+		}
+		string_list_clear(rejects, 0);
+	}
+	if (warning_displayed)
+		fprintf(stderr, _("After fixing the above paths, you may want to run `git sparse-checkout reapply`.\n"));
+}
 static int check_submodule_move_head(const struct cache_entry *ce,
 				     const char *old_id,
 				     const char *new_id,
@@ -357,12 +390,12 @@ static void report_collided_checkout(struct index_state *index)
 	string_list_clear(&list, 0);
 }
 
-static int check_updates(struct unpack_trees_options *o)
+static int check_updates(struct unpack_trees_options *o,
+			 struct index_state *index)
 {
 	unsigned cnt = 0;
 	int errs = 0;
 	struct progress *progress;
-	struct index_state *index = &o->result;
 	struct checkout state = CHECKOUT_INIT;
 	int i;
 
@@ -371,6 +404,7 @@ static int check_updates(struct unpack_trees_options *o)
 	state.quiet = 1;
 	state.refresh_cache = 1;
 	state.istate = index;
+	clone_checkout_metadata(&state.meta, &o->meta, NULL);
 
 	if (!o->update || o->dry_run) {
 		remove_marked_cache_entries(index, 0);
@@ -422,9 +456,8 @@ static int check_updates(struct unpack_trees_options *o)
 				continue;
 			oid_array_append(&to_fetch, &ce->oid);
 		}
-		if (to_fetch.nr)
-			promisor_remote_get_direct(the_repository,
-						   to_fetch.oid, to_fetch.nr);
+		promisor_remote_get_direct(the_repository,
+					   to_fetch.oid, to_fetch.nr);
 		oid_array_clear(&to_fetch);
 	}
 	for (i = 0; i < index->cache_nr; i++) {
@@ -504,19 +537,39 @@ static int apply_sparse_checkout(struct index_state *istate,
 		 * also stat info may have lost after merged_entry() so calling
 		 * verify_uptodate() again may fail
 		 */
-		if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
+		if (!(ce->ce_flags & CE_UPDATE) &&
+		    verify_uptodate_sparse(ce, o)) {
+			ce->ce_flags &= ~CE_SKIP_WORKTREE;
 			return -1;
+		}
 		ce->ce_flags |= CE_WT_REMOVE;
 		ce->ce_flags &= ~CE_UPDATE;
 	}
 	if (was_skip_worktree && !ce_skip_worktree(ce)) {
-		if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
+		if (verify_absent_sparse(ce, WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN, o))
 			return -1;
 		ce->ce_flags |= CE_UPDATE;
 	}
 	return 0;
 }
 
+static int warn_conflicted_path(struct index_state *istate,
+				int i,
+				struct unpack_trees_options *o)
+{
+	char *conflicting_path = istate->cache[i]->name;
+	int count = 0;
+
+	add_rejected_path(o, WARNING_SPARSE_UNMERGED_FILE, conflicting_path);
+
+	/* Find out how many higher stage entries at same path */
+	while (++count < istate->cache_nr &&
+	       !strcmp(conflicting_path,
+		       istate->cache[i+count]->name))
+		/* do nothing */;
+	return count;
+}
+
 static inline int call_unpack_fn(const struct cache_entry * const *src,
 				 struct unpack_trees_options *o)
 {
@@ -1493,6 +1546,20 @@ static void mark_new_skip_worktree(struct pattern_list *pl,
 	clear_ce_flags(istate, select_flag, skip_wt_flag, pl, show_progress);
 }
 
+static void populate_from_existing_patterns(struct unpack_trees_options *o,
+					    struct pattern_list *pl)
+{
+	char *sparse = git_pathdup("info/sparse-checkout");
+
+	pl->use_cone_patterns = core_sparse_checkout_cone;
+	if (add_patterns_from_file_to_list(sparse, "", 0, pl, NULL) < 0)
+		o->skip_sparse_checkout = 1;
+	else
+		o->pl = pl;
+	free(sparse);
+}
+
+
 static int verify_absent(const struct cache_entry *,
 			 enum unpack_trees_error_types,
 			 struct unpack_trees_options *);
@@ -1507,22 +1574,18 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	int i, ret;
 	static struct cache_entry *dfc;
 	struct pattern_list pl;
+	int free_pattern_list = 0;
 
 	if (len > MAX_UNPACK_TREES)
 		die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
 
 	trace_performance_enter();
-	memset(&pl, 0, sizeof(pl));
 	if (!core_apply_sparse_checkout || !o->update)
 		o->skip_sparse_checkout = 1;
 	if (!o->skip_sparse_checkout && !o->pl) {
-		char *sparse = git_pathdup("info/sparse-checkout");
-		pl.use_cone_patterns = core_sparse_checkout_cone;
-		if (add_patterns_from_file_to_list(sparse, "", 0, &pl, NULL) < 0)
-			o->skip_sparse_checkout = 1;
-		else
-			o->pl = &pl;
-		free(sparse);
+		memset(&pl, 0, sizeof(pl));
+		free_pattern_list = 1;
+		populate_from_existing_patterns(o, &pl);
 	}
 
 	memset(&o->result, 0, sizeof(o->result));
@@ -1618,7 +1681,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
 		/*
 		 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
-		 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
+		 * If they will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
 		 * so apply_sparse_checkout() won't attempt to remove it from worktree
 		 */
 		mark_new_skip_worktree(o->pl, &o->result,
@@ -1638,23 +1701,15 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 			 * correct CE_NEW_SKIP_WORKTREE
 			 */
 			if (ce->ce_flags & CE_ADDED &&
-			    verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
-				if (!o->show_all_errors)
-					goto return_failed;
-				ret = -1;
-			}
+			    verify_absent(ce, WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN, o))
+				ret = 1;
 
-			if (apply_sparse_checkout(&o->result, ce, o)) {
-				if (!o->show_all_errors)
-					goto return_failed;
-				ret = -1;
-			}
+			if (apply_sparse_checkout(&o->result, ce, o))
+				ret = 1;
+
 			if (!ce_skip_worktree(ce))
 				empty_worktree = 0;
-
 		}
-		if (ret < 0)
-			goto return_failed;
 		/*
 		 * Sparse checkout is meant to narrow down checkout area
 		 * but it does not make sense to narrow down to empty working
@@ -1665,9 +1720,18 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 			ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
 			goto done;
 		}
+		if (ret == 1) {
+			/*
+			 * Inability to sparsify or de-sparsify individual
+			 * paths is not an error, but just a warning.
+			 */
+			if (o->show_all_errors)
+				display_warning_msgs(o);
+			ret = 0;
+		}
 	}
 
-	ret = check_updates(o) ? (-2) : 0;
+	ret = check_updates(o, &o->result) ? (-2) : 0;
 	if (o->dst_index) {
 		move_index_extensions(&o->result, o->src_index);
 		if (!ret) {
@@ -1690,9 +1754,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	o->src_index = NULL;
 
 done:
-	trace_performance_leave("unpack_trees");
-	if (!o->keep_pattern_list)
+	if (free_pattern_list)
 		clear_pattern_list(&pl);
+	trace_performance_leave("unpack_trees");
 	return ret;
 
 return_failed:
@@ -1705,6 +1769,91 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	goto done;
 }
 
+/*
+ * Update SKIP_WORKTREE bits according to sparsity patterns, and update
+ * working directory to match.
+ *
+ * CE_NEW_SKIP_WORKTREE is used internally.
+ */
+enum update_sparsity_result update_sparsity(struct unpack_trees_options *o)
+{
+	enum update_sparsity_result ret = UPDATE_SPARSITY_SUCCESS;
+	struct pattern_list pl;
+	int i, empty_worktree;
+	unsigned old_show_all_errors;
+	int free_pattern_list = 0;
+
+	old_show_all_errors = o->show_all_errors;
+	o->show_all_errors = 1;
+
+	/* Sanity checks */
+	if (!o->update || o->index_only || o->skip_sparse_checkout)
+		BUG("update_sparsity() is for reflecting sparsity patterns in working directory");
+	if (o->src_index != o->dst_index || o->fn)
+		BUG("update_sparsity() called wrong");
+
+	trace_performance_enter();
+
+	/* If we weren't given patterns, use the recorded ones */
+	if (!o->pl) {
+		memset(&pl, 0, sizeof(pl));
+		free_pattern_list = 1;
+		populate_from_existing_patterns(o, &pl);
+		if (o->skip_sparse_checkout)
+			goto skip_sparse_checkout;
+	}
+
+	/* Set NEW_SKIP_WORKTREE on existing entries. */
+	mark_all_ce_unused(o->src_index);
+	mark_new_skip_worktree(o->pl, o->src_index, 0,
+			       CE_NEW_SKIP_WORKTREE, o->verbose_update);
+
+	/* Then loop over entries and update/remove as needed */
+	ret = UPDATE_SPARSITY_SUCCESS;
+	empty_worktree = 1;
+	for (i = 0; i < o->src_index->cache_nr; i++) {
+		struct cache_entry *ce = o->src_index->cache[i];
+
+
+		if (ce_stage(ce)) {
+			/* -1 because for loop will increment by 1 */
+			i += warn_conflicted_path(o->src_index, i, o) - 1;
+			ret = UPDATE_SPARSITY_WARNINGS;
+			continue;
+		}
+
+		if (apply_sparse_checkout(o->src_index, ce, o))
+			ret = UPDATE_SPARSITY_WARNINGS;
+
+		if (!ce_skip_worktree(ce))
+			empty_worktree = 0;
+	}
+
+	/*
+	 * Sparse checkout is meant to narrow down checkout area
+	 * but it does not make sense to narrow down to empty working
+	 * tree. This is usually a mistake in sparse checkout rules.
+	 * Do not allow users to do that.
+	 */
+	if (o->src_index->cache_nr && empty_worktree) {
+		unpack_failed(o, "Sparse checkout leaves no entry on working directory");
+		ret = UPDATE_SPARSITY_INDEX_UPDATE_FAILURES;
+		goto done;
+	}
+
+skip_sparse_checkout:
+	if (check_updates(o, o->src_index))
+		ret = UPDATE_SPARSITY_WORKTREE_UPDATE_FAILURES;
+
+done:
+	display_warning_msgs(o);
+	o->show_all_errors = old_show_all_errors;
+	if (free_pattern_list)
+		clear_pattern_list(&pl);
+	trace_performance_leave("update_sparsity");
+	return ret;
+}
+
 /* Here come the merge functions */
 
 static int reject_merge(const struct cache_entry *ce,
@@ -1789,7 +1938,7 @@ int verify_uptodate(const struct cache_entry *ce,
 static int verify_uptodate_sparse(const struct cache_entry *ce,
 				  struct unpack_trees_options *o)
 {
-	return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
+	return verify_uptodate_1(ce, o, WARNING_SPARSE_NOT_UPTODATE_FILE);
 }
 
 /*
@@ -1815,9 +1964,6 @@ static void invalidate_ce_path(const struct cache_entry *ce,
 /*
  * Check that checking out ce->sha1 in subdir ce->name is not
  * going to overwrite any working files.
- *
- * Currently, git does not checkout subprojects during a superproject
- * checkout, so it is not going to overwrite anything.
  */
 static int verify_clean_submodule(const char *old_sha1,
 				  const struct cache_entry *ce,
@@ -2030,11 +2176,7 @@ static int verify_absent_sparse(const struct cache_entry *ce,
 				enum unpack_trees_error_types error_type,
 				struct unpack_trees_options *o)
 {
-	enum unpack_trees_error_types orphaned_error = error_type;
-	if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
-		orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
-
-	return verify_absent_1(ce, orphaned_error, o);
+	return verify_absent_1(ce, error_type, o);
 }
 
 static int merged_entry(const struct cache_entry *ce,
@@ -2067,7 +2209,7 @@ static int merged_entry(const struct cache_entry *ce,
 		}
 		invalidate_ce_path(merge, o);
 
-		if (submodule_from_ce(ce)) {
+		if (submodule_from_ce(ce) && file_exists(ce->name)) {
 			int ret = check_submodule_move_head(ce, NULL,
 							    oid_to_hex(&ce->oid),
 							    o);
@@ -2096,7 +2238,7 @@ static int merged_entry(const struct cache_entry *ce,
 			invalidate_ce_path(old, o);
 		}
 
-		if (submodule_from_ce(ce)) {
+		if (submodule_from_ce(ce) && file_exists(ce->name)) {
 			int ret = check_submodule_move_head(ce, oid_to_hex(&old->oid),
 							    oid_to_hex(&ce->oid),
 							    o);
diff --git a/unpack-trees.h b/unpack-trees.h
index ae1557f..9c2f082 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -22,11 +22,15 @@ enum unpack_trees_error_types {
 	ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN,
 	ERROR_WOULD_LOSE_UNTRACKED_REMOVED,
 	ERROR_BIND_OVERLAP,
-	ERROR_SPARSE_NOT_UPTODATE_FILE,
-	ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN,
-	ERROR_WOULD_LOSE_ORPHANED_REMOVED,
 	ERROR_WOULD_LOSE_SUBMODULE,
-	NB_UNPACK_TREES_ERROR_TYPES
+
+	NB_UNPACK_TREES_ERROR_TYPES,
+
+	WARNING_SPARSE_NOT_UPTODATE_FILE,
+	WARNING_SPARSE_UNMERGED_FILE,
+	WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN,
+
+	NB_UNPACK_TREES_WARNING_TYPES,
 };
 
 /*
@@ -59,20 +63,19 @@ struct unpack_trees_options {
 		     quiet,
 		     exiting_early,
 		     show_all_errors,
-		     dry_run,
-		     keep_pattern_list;
+		     dry_run;
 	const char *prefix;
 	int cache_bottom;
 	struct dir_struct *dir;
 	struct pathspec *pathspec;
 	merge_fn_t fn;
-	const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
+	const char *msgs[NB_UNPACK_TREES_WARNING_TYPES];
 	struct argv_array msgs_to_free;
 	/*
 	 * Store error messages in an array, each case
 	 * corresponding to a error message type
 	 */
-	struct string_list unpack_rejects[NB_UNPACK_TREES_ERROR_TYPES];
+	struct string_list unpack_rejects[NB_UNPACK_TREES_WARNING_TYPES];
 
 	int head_idx;
 	int merge_size;
@@ -85,11 +88,21 @@ struct unpack_trees_options {
 	struct index_state result;
 
 	struct pattern_list *pl; /* for internal use */
+	struct checkout_metadata meta;
 };
 
 int unpack_trees(unsigned n, struct tree_desc *t,
 		 struct unpack_trees_options *options);
 
+enum update_sparsity_result {
+	UPDATE_SPARSITY_SUCCESS = 0,
+	UPDATE_SPARSITY_WARNINGS = 1,
+	UPDATE_SPARSITY_INDEX_UPDATE_FAILURES = -1,
+	UPDATE_SPARSITY_WORKTREE_UPDATE_FAILURES = -2
+};
+
+enum update_sparsity_result update_sparsity(struct unpack_trees_options *options);
+
 int verify_uptodate(const struct cache_entry *ce,
 		    struct unpack_trees_options *o);
 
diff --git a/upload-pack.c b/upload-pack.c
index c53249c..902d0ad 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1252,7 +1252,7 @@ static void process_args(struct packet_reader *request,
 			 struct upload_pack_data *data,
 			 struct object_array *want_obj)
 {
-	while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+	while (packet_reader_read(request) == PACKET_READ_NORMAL) {
 		const char *arg = request->line;
 		const char *p;
 
@@ -1321,6 +1321,9 @@ static void process_args(struct packet_reader *request,
 		/* ignore unknown lines maybe? */
 		die("unexpected line: '%s'", arg);
 	}
+
+	if (request->status != PACKET_READ_FLUSH)
+		die(_("expected flush after fetch arguments"));
 }
 
 static int process_haves(struct oid_array *haves, struct oid_array *common,
diff --git a/userdiff.c b/userdiff.c
index efbe05e..30ab42d 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -222,7 +222,7 @@ static struct userdiff_driver driver_false = {
 	{ NULL, 0 }
 };
 
-static struct userdiff_driver *userdiff_find_by_namelen(const char *k, int len)
+static struct userdiff_driver *userdiff_find_by_namelen(const char *k, size_t len)
 {
 	int i;
 	for (i = 0; i < ndrivers; i++) {
@@ -266,7 +266,7 @@ int userdiff_config(const char *k, const char *v)
 {
 	struct userdiff_driver *drv;
 	const char *name, *type;
-	int namelen;
+	size_t namelen;
 
 	if (parse_config_key(k, "diff", &name, &namelen, &type) || !name)
 		return 0;
diff --git a/worktree.c b/worktree.c
index eba4fd3..ee82235 100644
--- a/worktree.c
+++ b/worktree.c
@@ -226,17 +226,20 @@ struct worktree *find_worktree(struct worktree **list,
 
 struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
 {
+	struct strbuf wt_path = STRBUF_INIT;
 	char *path = real_pathdup(p, 0);
 
 	if (!path)
 		return NULL;
 	for (; *list; list++) {
-		const char *wt_path = real_path_if_valid((*list)->path);
+		if (!strbuf_realpath(&wt_path, (*list)->path, 0))
+			continue;
 
-		if (wt_path && !fspathcmp(path, wt_path))
+		if (!fspathcmp(path, wt_path.buf))
 			break;
 	}
 	free(path);
+	strbuf_release(&wt_path);
 	return *list;
 }
 
@@ -285,6 +288,7 @@ int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 		      unsigned flags)
 {
 	struct strbuf wt_path = STRBUF_INIT;
+	struct strbuf realpath = STRBUF_INIT;
 	char *path = NULL;
 	int err, ret = -1;
 
@@ -336,7 +340,8 @@ int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 		goto done;
 	}
 
-	ret = fspathcmp(path, real_path(git_common_path("worktrees/%s", wt->id)));
+	strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
+	ret = fspathcmp(path, realpath.buf);
 
 	if (ret)
 		strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
@@ -344,6 +349,7 @@ int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 done:
 	free(path);
 	strbuf_release(&wt_path);
+	strbuf_release(&realpath);
 	return ret;
 }
 
@@ -450,7 +456,7 @@ const struct worktree *find_shared_symref(const char *symref,
 int submodule_uses_worktrees(const char *path)
 {
 	char *submodule_gitdir;
-	struct strbuf sb = STRBUF_INIT;
+	struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
 	DIR *dir;
 	struct dirent *d;
 	int ret = 0;
@@ -464,18 +470,16 @@ int submodule_uses_worktrees(const char *path)
 	get_common_dir_noenv(&sb, submodule_gitdir);
 	free(submodule_gitdir);
 
-	/*
-	 * The check below is only known to be good for repository format
-	 * version 0 at the time of writing this code.
-	 */
 	strbuf_addstr(&sb, "/config");
 	read_repository_format(&format, sb.buf);
-	if (format.version != 0) {
+	if (verify_repository_format(&format, &err)) {
+		strbuf_release(&err);
 		strbuf_release(&sb);
 		clear_repository_format(&format);
 		return 1;
 	}
 	clear_repository_format(&format);
+	strbuf_release(&err);
 
 	/* Replace config by worktrees. */
 	strbuf_setlen(&sb, sb.len - strlen("config"));
diff --git a/wrapper.c b/wrapper.c
index e1eaef2..3a1c0e0 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -218,7 +218,7 @@ ssize_t xread(int fd, void *buf, size_t len)
 {
 	ssize_t nr;
 	if (len > MAX_IO_SIZE)
-	    len = MAX_IO_SIZE;
+		len = MAX_IO_SIZE;
 	while (1) {
 		nr = read(fd, buf, len);
 		if (nr < 0) {
@@ -240,7 +240,7 @@ ssize_t xwrite(int fd, const void *buf, size_t len)
 {
 	ssize_t nr;
 	if (len > MAX_IO_SIZE)
-	    len = MAX_IO_SIZE;
+		len = MAX_IO_SIZE;
 	while (1) {
 		nr = write(fd, buf, len);
 		if (nr < 0) {
diff --git a/wt-status.c b/wt-status.c
index cc6f945..98dfa6f 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -722,16 +722,14 @@ static void wt_status_collect_untracked(struct wt_status *s)
 
 	for (i = 0; i < dir.nr; i++) {
 		struct dir_entry *ent = dir.entries[i];
-		if (index_name_is_other(istate, ent->name, ent->len) &&
-		    dir_path_match(istate, ent, &s->pathspec, 0, NULL))
+		if (index_name_is_other(istate, ent->name, ent->len))
 			string_list_insert(&s->untracked, ent->name);
 		free(ent);
 	}
 
 	for (i = 0; i < dir.ignored_nr; i++) {
 		struct dir_entry *ent = dir.ignored[i];
-		if (index_name_is_other(istate, ent->name, ent->len) &&
-		    dir_path_match(istate, ent, &s->pathspec, 0, NULL))
+		if (index_name_is_other(istate, ent->name, ent->len))
 			string_list_insert(&s->ignored, ent->name);
 		free(ent);
 	}
diff --git a/wt-status.h b/wt-status.h
index 71c3f25..73ab5d4 100644
--- a/wt-status.h
+++ b/wt-status.h
@@ -38,9 +38,22 @@ enum show_ignored_type {
 enum commit_whence {
 	FROM_COMMIT,     /* normal */
 	FROM_MERGE,      /* commit came from merge */
-	FROM_CHERRY_PICK /* commit came from cherry-pick */
+	FROM_CHERRY_PICK_SINGLE, /* commit came from cherry-pick */
+	FROM_CHERRY_PICK_MULTI, /* commit came from a sequence of cherry-picks */
+	FROM_REBASE_PICK /* commit came from a pick/reword/edit */
 };
 
+static inline int is_from_cherry_pick(enum commit_whence whence)
+{
+	return whence == FROM_CHERRY_PICK_SINGLE ||
+		whence == FROM_CHERRY_PICK_MULTI;
+}
+
+static inline int is_from_rebase(enum commit_whence whence)
+{
+	return whence == FROM_REBASE_PICK;
+}
+
 struct wt_status_change_data {
 	int worktree_status;
 	int index_status;