Merge branch 'jk/test-cleanup' Test cleanup. * jk/test-cleanup: t/lib-*.sh: drop executable bit t/lib-credential.sh: drop shebang line

commit: dfe48154b16e35ea01795aa94c7e8686f084e2c3 [log] [tgz]
author: Junio C Hamano <gitster@pobox.com> Wed Apr 22 13:42:44 2020 -0700
committer: Junio C Hamano <gitster@pobox.com> Wed Apr 22 13:42:44 2020 -0700
tree: c88fc577833b0cb582cc4eef77d30f14c3aca66f
parent: d01b722b7a077202c82902f49c48cb8081c696ef [diff]
parent: 12dc0879f18b39e1020bd6afec117bc38110d8c9 [diff]
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/Documentation/Makefile b/Documentation/Makefile
index 8fe829c..59e6ce3 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

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..7a5c7ff
--- /dev/null
+++ b/Documentation/RelNotes/2.27.0.txt

@@ -0,0 +1,94 @@
+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).
+
+
+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.
+
+
+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).
+
+ * 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).

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 08b13ba..2450589 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt

@@ -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/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/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/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/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..00d03ec 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
@@ -164,6 +164,7 @@
 	when the superproject retrieves a commit that updates the submodule's
 	reference to a commit that isn't already in the local submodule
 	clone.
+endif::git-pull[]
 
 -j::
 --jobs=<n>::
@@ -177,9 +178,11 @@
 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 +191,7 @@
 	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

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-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-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-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.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/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/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/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/Makefile b/Makefile
index 9804a07..ef1ff22 100644
--- a/Makefile
+++ b/Makefile

@@ -609,7 +609,6 @@
 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
@@ -695,6 +694,7 @@
 
 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

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/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.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/builtin/cat-file.c b/builtin/cat-file.c
index 272f9fc..6ecc8ee 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c

@@ -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/clone.c b/builtin/clone.c
index 1ad26f4..ae27eef 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c

@@ -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)
@@ -672,8 +676,7 @@ 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 +685,6 @@ 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 +781,11 @@ 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 +800,7 @@ 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 +808,8 @@ 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 +1106,7 @@ 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 +1279,7 @@ 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..d1ab662 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);

diff --git a/builtin/commit.c b/builtin/commit.c
index 7ba33a3..d3e7781 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;

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/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..172dfbd 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c

@@ -494,6 +494,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 		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)
@@ -502,10 +503,12 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 
 		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");
-		}
+		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);

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/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/pack-objects.c b/builtin/pack-objects.c
index 02aa6ee..dc7c58c 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c

@@ -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/pull.c b/builtin/pull.c
index 3e624d1..e42665b 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c

@@ -327,6 +327,22 @@ 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;
 }
 

diff --git a/builtin/rebase.c b/builtin/rebase.c
index bff53d5..27a07d4 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c

@@ -868,6 +868,7 @@ static int reset_head(struct object_id *oid, const char *action,
 	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;
 

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/stash.c b/builtin/stash.c
index 78af6ce..6d586ef 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;
 
@@ -1559,29 +1563,6 @@ 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 +1573,12 @@ 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..cc30d34 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c

@@ -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/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..c77b958 100644
--- a/cache.h
+++ b/cache.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/lib.sh b/ci/lib.sh
index a90d0dc..c3a8cd2 100755
--- a/ci/lib.sh
+++ b/ci/lib.sh

@@ -162,6 +162,9 @@
 	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 +185,9 @@
 	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

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/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.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/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/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/convert.c b/convert.c
index 5ead3ce..5aa87d4 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;
 }
@@ -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..108d9e1 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;
 
@@ -366,8 +391,11 @@ 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, ':');
@@ -392,10 +420,8 @@ 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 +432,19 @@ 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/diff.c b/diff.c
index f2cfbf2..1010d80 100644
--- a/diff.c
+++ b/diff.c

@@ -4062,6 +4062,9 @@ 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 +4074,7 @@ 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;
 	}

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..202dda1 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)
@@ -53,6 +54,7 @@ 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 +133,9 @@ 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;
@@ -222,6 +227,11 @@ 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 +240,29 @@ 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 +291,6 @@ 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 +369,7 @@ 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);
@@ -493,9 +524,8 @@ 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 +546,9 @@ 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 +948,7 @@ 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 +1146,7 @@ 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 +1684,6 @@ 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 +1713,7 @@ 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 +1721,38 @@ 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 +1760,23 @@ 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 +2162,30 @@ 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 +2266,13 @@ 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 +2440,13 @@ 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 +2461,7 @@ 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 +2565,7 @@ 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 +2629,7 @@ 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 +2803,7 @@ 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 +2961,7 @@ 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 +2976,12 @@ 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 +3045,54 @@ 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 +3218,7 @@ 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 +3298,26 @@ 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 +3380,11 @@ 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 +3490,7 @@ 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)

diff --git a/fsck.c b/fsck.c
index 640d813..73f3077 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;
@@ -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.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/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/log-tree.c b/log-tree.c
index 5212742..897a902 100644
--- a/log-tree.c
+++ b/log-tree.c

@@ -449,22 +449,21 @@ 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 +496,9 @@ 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 +520,19 @@ 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 */
 	}
 

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/oidset.h b/oidset.h
index 5346563..d8a106b 100644
--- a/oidset.h
+++ b/oidset.h

@@ -1,7 +1,6 @@
 #ifndef OIDSET_H
 #define OIDSET_H
 
-#include "hashmap.h"
 #include "khash.h"
 
 /**

diff --git a/path.c b/path.c
index 88cf593..9bd717c 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;
 	}
 

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/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/sequencer.c b/sequencer.c
index e528225..6fd2674 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -40,7 +40,7 @@ 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")
@@ -1323,7 +1323,7 @@ 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 +1433,19 @@ 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 +1470,12 @@ 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;
 }
@@ -1929,7 +1943,9 @@ 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 +1981,8 @@ 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);
@@ -3000,9 +3017,7 @@ 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));
@@ -3290,6 +3305,7 @@ 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);
@@ -5315,3 +5331,24 @@ 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..0bee850 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);
@@ -206,4 +206,5 @@ 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..6926851 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)

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/submodule.c b/submodule.c
index 31f391d..c3aadf3 100644
--- a/submodule.c
+++ b/submodule.c

@@ -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..d12efcd 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).

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-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-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..5f39597 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 },
@@ -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..4eb5e66 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);

diff --git a/t/lib-credential.sh b/t/lib-credential.sh
index 5ea8bc9..dea2cbe 100644
--- a/t/lib-credential.sh
+++ b/t/lib-credential.sh

@@ -20,7 +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
index 8d28652..9fc5241 100644
--- 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-submodule-update.sh b/t/lib-submodule-update.sh
index 1dd17fc..64fc648 100644
--- 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/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/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/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..5555a15 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 +494,85 @@
 
 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 host 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
+'
+
 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/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/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/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/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/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/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/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/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..5eeb739 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh

@@ -1627,6 +1627,66 @@
 	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 +1708,51 @@
 	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/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 43a7a66..22240fd 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 () {

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/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/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 4f681db..b57209c 100755
--- a/t/t5537-fetch-shallow.sh
+++ b/t/t5537-fetch-shallow.sh

@@ -131,7 +131,7 @@
 	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 &&
 	cat <<EOF >expect.refs &&
 refs/remotes/shallow/no-shallow

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/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/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/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/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/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/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/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/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/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/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/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/test-lib.sh b/t/test-lib.sh
index 0ea1e5a..0bb1105 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='
 '
@@ -882,6 +900,7 @@
 	fi
 }
 
+trace_level_=0
 want_trace () {
 	test "$trace" = t && {
 		test "$verbose" = t || test "$verbose_log" = t
@@ -895,7 +914,7 @@
 test_eval_inner_ () {
 	# Do not add anything extra (including LF) after '$*'
 	eval "
-		want_trace && set -x
+		want_trace && trace_level_=$(($trace_level_+1)) && set -x
 		$*"
 }
 
@@ -926,7 +945,8 @@
 		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 +1105,7 @@
 		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 +1404,20 @@
 	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/unpack-trees.c b/unpack-trees.c
index 1ecdab3..f618a64 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c

@@ -371,6 +371,7 @@ 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);
@@ -1815,9 +1816,6 @@ 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,
@@ -2067,7 +2065,7 @@ 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 +2094,7 @@ 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..ad41b45 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h

@@ -85,6 +85,7 @@ 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,

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/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;
commit	dfe48154b16e35ea01795aa94c7e8686f084e2c3	[log] [tgz]
author	Junio C Hamano <gitster@pobox.com>	Wed Apr 22 13:42:44 2020 -0700
committer	Junio C Hamano <gitster@pobox.com>	Wed Apr 22 13:42:44 2020 -0700
tree	c88fc577833b0cb582cc4eef77d30f14c3aca66f
parent	d01b722b7a077202c82902f49c48cb8081c696ef [diff]
parent	12dc0879f18b39e1020bd6afec117bc38110d8c9 [diff]