Merge branch 'dt/cat-file-batch-ambiguous'

"git cat-file --batch" reported a dangling symbolic link by
mistake, when it wanted to report that a given name is ambiguous.

* dt/cat-file-batch-ambiguous:
  t1512: test ambiguous cat-file --batch and --batch-output
  Do not print 'dangling' for cat-file in case of ambiguity
diff --git a/.gitignore b/.gitignore
index 0d77ea5..6fd61c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+/fuzz-commit-graph
 /fuzz_corpora
 /fuzz-pack-headers
 /fuzz-pack-idx
@@ -124,7 +125,6 @@
 /git-rebase--am
 /git-rebase--common
 /git-rebase--interactive
-/git-rebase--merge
 /git-rebase--preserve-merges
 /git-receive-pack
 /git-reflog
diff --git a/Documentation/Makefile b/Documentation/Makefile
index d5d936e..26a2342 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -36,14 +36,19 @@
 MAN7_TXT += gittutorial.txt
 MAN7_TXT += gitworkflows.txt
 
+ifdef MAN_FILTER
+MAN_TXT = $(filter $(MAN_FILTER),$(MAN1_TXT) $(MAN5_TXT) $(MAN7_TXT))
+else
 MAN_TXT = $(MAN1_TXT) $(MAN5_TXT) $(MAN7_TXT)
+MAN_FILTER = $(MAN_TXT)
+endif
+
 MAN_XML = $(patsubst %.txt,%.xml,$(MAN_TXT))
 MAN_HTML = $(patsubst %.txt,%.html,$(MAN_TXT))
 GIT_MAN_REF = master
 
 OBSOLETE_HTML += everyday.html
 OBSOLETE_HTML += git-remote-helpers.html
-DOC_HTML = $(MAN_HTML) $(OBSOLETE_HTML)
 
 ARTICLES += howto-index
 ARTICLES += git-tools
@@ -89,11 +94,13 @@
 SP_ARTICLES += $(TECH_DOCS)
 SP_ARTICLES += technical/api-index
 
-DOC_HTML += $(patsubst %,%.html,$(ARTICLES) $(SP_ARTICLES))
+ARTICLES_HTML += $(patsubst %,%.html,$(ARTICLES) $(SP_ARTICLES))
+HTML_FILTER ?= $(ARTICLES_HTML) $(OBSOLETE_HTML)
+DOC_HTML = $(MAN_HTML) $(filter $(HTML_FILTER),$(ARTICLES_HTML) $(OBSOLETE_HTML))
 
-DOC_MAN1 = $(patsubst %.txt,%.1,$(MAN1_TXT))
-DOC_MAN5 = $(patsubst %.txt,%.5,$(MAN5_TXT))
-DOC_MAN7 = $(patsubst %.txt,%.7,$(MAN7_TXT))
+DOC_MAN1 = $(patsubst %.txt,%.1,$(filter $(MAN_FILTER),$(MAN1_TXT)))
+DOC_MAN5 = $(patsubst %.txt,%.5,$(filter $(MAN_FILTER),$(MAN5_TXT)))
+DOC_MAN7 = $(patsubst %.txt,%.7,$(filter $(MAN_FILTER),$(MAN7_TXT)))
 
 prefix ?= $(HOME)
 bindir ?= $(prefix)/bin
@@ -457,4 +464,9 @@
 lint-docs::
 	$(QUIET_LINT)$(PERL_PATH) lint-gitlink.perl
 
+ifeq ($(wildcard po/Makefile),po/Makefile)
+doc-l10n install-l10n::
+	$(MAKE) -C po $@
+endif
+
 .PHONY: FORCE
diff --git a/Documentation/RelNotes/2.21.0.txt b/Documentation/RelNotes/2.21.0.txt
index ea78e22..5ad2233 100644
--- a/Documentation/RelNotes/2.21.0.txt
+++ b/Documentation/RelNotes/2.21.0.txt
@@ -51,6 +51,17 @@
    learned to show a few more traits of objects that can be learned by
    the object_info API.
 
+ * "git rebase -i" learned to re-execute a command given with 'exec'
+   to run after it failed the last time.
+
+ * "git diff --color-moved-ws" updates.
+
+ * Custom userformat "log --format" learned %S atom that stands for
+   the tip the traversal reached the commit from, i.e. --source.
+
+ * "git instaweb" learned to drive http.server that comes with
+   "batteries included" Python installation (both Python2 & 3).
+
 
 Performance, Internal Implementation, Development Support etc.
 
@@ -77,6 +88,42 @@
    "--stress" option.
    (merge fb7d1e3ac8 sg/stress-test later to maint).
 
+ * Documentation/Makefile is getting prepared for manpage
+   localization.
+
+ * "git fetch-pack" now can talk the version 2 protocol.
+
+ * sha-256 hash has been added and plumbed through the code to allow
+   building Git with the "NewHash".
+
+ * Debugging help for http transport.
+
+ * "git fetch --deepen=<more>" has been corrected to work over v2
+   protocol.
+
+ * The code to walk tree objects has been taught that we may be
+   working with object names that are not computed with SHA-1.
+
+ * The in-core repository instances are passed through more codepaths.
+
+ * Update the protocol message specification to allow only the limited
+   use of scaled quantities.  This is ensure potential compatibility
+   issues will not go out of hand.
+
+ * Micro-optimize the code that prepares commit objects to be walked
+   by "git rev-list" when the commit-graph is available.
+
+ * "git fetch" and "git upload-pack" learned to send all exchange over
+   the sideband channel while talking the v2 protocol.
+
+ * The codepath to write out commit-graph has been optimized by
+   following the usual pattern of visiting objects in in-pack order.
+
+ * The codepath to show progress meter while writing out commit-graph
+   file has been improved.
+
+ * Cocci rules have been updated to encourage use of strbuf_addbuf().
+
 
 Fixes since v2.20
 -----------------
@@ -170,6 +217,98 @@
    corrected.
    (merge 5bdece0d70 js/gc-repack-close-before-remove later to maint).
 
+ * The code to drive GIT_EXTERNAL_DIFF command relied on the string
+   returned from getenv() to be non-volatile, which is not true, that
+   has been corrected.
+   (merge 6776a84dae kg/external-diff-save-env later to maint).
+
+ * There were many places the code relied on the string returned from
+   getenv() to be non-volatile, which is not true, that have been
+   corrected.
+   (merge 0da0e9268b jk/save-getenv-result later to maint).
+
+ * The v2 upload-pack protocol implementation failed to honor
+   hidden-ref configuration, which has been corrected.
+   (merge e20b4192a3 jk/proto-v2-hidden-refs-fix later to maint).
+
+ * "git fetch --recurse-submodules" may not fetch the necessary commit
+   that is bound to the superproject, which is getting corrected.
+   (merge be76c21282 sb/submodule-recursive-fetch-gets-the-tip later to maint).
+
+ * "git rebase" internally runs "checkout" to switch between branches,
+   and the command used to call the post-checkout hook, but the
+   reimplementation stopped doing so, which is getting fixed.
+
+ * "git add -e" got confused when the change it wants to let the user
+   edit is smaller than the previous change that was left over in a
+   temporary file.
+   (merge fa6f225e01 js/add-e-clear-patch-before-stating later to maint).
+
+ * "git p4" failed to update a shelved change when there were moved
+   files, which has been corrected.
+   (merge 7a10946ab9 ld/git-p4-shelve-update-fix later to maint).
+
+ * The codepath to read from the commit-graph file attempted to read
+   past the end of it when the file's table-of-contents was corrupt.
+
+ * The compat/obstack code had casts that -Wcast-function-type
+   compilation option found questionable.
+   (merge 764473d257 sg/obstack-cast-function-type-fix later to maint).
+
+ * An obvious typo in an assertion error message has been fixed.
+   (merge 3c27e2e059 cc/test-ref-store-typofix later to maint).
+
+ * In Git for Windows, "git clone \\server\share\path" etc. that uses
+   UNC paths from command line had bad interaction with its shell
+   emulation.
+
+ * "git add --ignore-errors" did not work as advertised and instead
+   worked as an unintended synonym for "git add --renormalize", which
+   has been fixed.
+   (merge 9e5da3d055 jk/add-ignore-errors-bit-assignment-fix later to maint).
+
+ * On a case-insensitive filesystem, we failed to compare the part of
+   the path that is above the worktree directory in an absolute
+   pathname, which has been corrected.
+
+ * Asking "git check-attr" about a macro (e.g. "binary") on a specific
+   path did not work correctly, even though "git check-attr -a" listed
+   such a macro correctly.  This has been corrected.
+   (merge 7b95849be4 jk/attr-macro-fix later to maint).
+
+ * "git pack-objects" incorrectly used uninitialized mutex, which has
+   been corrected.
+   (merge edb673cf10 ph/pack-objects-mutex-fix later to maint).
+
+ * "git checkout -b <new> [HEAD]" to create a new branch from the
+   current commit and check it out ought to be a no-op in the index
+   and the working tree in normal cases, but there are corner cases
+   that do require updates to the index and the working tree.  Running
+   it immediately after "git clone --no-checkout" is one of these
+   cases that an earlier optimization kicked in incorrectly, which has
+   been fixed.
+   (merge 8424bfd45b bp/checkout-new-branch-optim later to maint).
+
+ * "git diff --color-moved --cc --stat -p" did not work well due to
+   funny interaction between a bug in color-moved and the rest, which
+   has been fixed.
+   (merge dac03b5518 jk/diff-cc-stat-fixes later to maint).
+
+ * When GIT_SEQUENCE_EDITOR is set, the command was incorrectly
+   started when modes of "git rebase" that implicitly uses the
+   machinery for the interactive rebase are run, which has been
+   corrected.
+   (merge 891d4a0313 pw/no-editor-in-rebase-i-implicit later to maint).
+
+ * The commit-graph facility did not work when in-core objects that
+   are promoted from unknown type to commit (e.g. a commit that is
+   accessed via a tag that refers to it) were involved, which has been
+   corrected.
+   (merge 4468d4435c sg/object-as-type-commit-graph-fix later to maint).
+
+ * "git fetch" output cleanup.
+   (merge dc40b24df4 nd/fetch-compact-update later to maint).
+
  * Code cleanup, docfix, build fix, etc.
    (merge 89ba9a79ae hb/t0061-dot-in-path-fix later to maint).
    (merge d173e799ea sb/diff-color-moved-config-option-fixup later to maint).
@@ -186,3 +325,8 @@
    (merge 0650614982 cy/completion-typofix later to maint).
    (merge 6881925ef5 rs/sha1-file-close-mapped-file-on-error later to maint).
    (merge bd8d6f0def en/show-ref-doc-fix later to maint).
+   (merge 1747125e2c cc/parial-clone-doc-typofix later to maint).
+   (merge e01378753d cc/fetch-error-message-fix later to maint).
+   (merge 54e8c11215 jk/remote-insteadof-cleanup later to maint).
+   (merge d609615f48 js/test-git-installed later to maint).
+   (merge ba170517be ja/doc-style-fix later to maint).
diff --git a/Documentation/config/rebase.txt b/Documentation/config/rebase.txt
index f079bf6..331d250 100644
--- a/Documentation/config/rebase.txt
+++ b/Documentation/config/rebase.txt
@@ -64,3 +64,8 @@
 -------------------------------------------
 +
 Defaults to false.
+
+rebase.rescheduleFailedExec::
+	Automatically reschedule `exec` commands that failed. This only makes
+	sense in interactive mode (or when an `--exec` option was provided).
+	This is the same as specifying the `--reschedule-failed-exec` option.
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index b94d332..554a340 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -293,8 +293,12 @@
 	`dimmed_zebra` is a deprecated synonym.
 --
 
+--no-color-moved::
+	Turn off move detection. This can be used to override configuration
+	settings. It is the same as `--color-moved=no`.
+
 --color-moved-ws=<modes>::
-	This configures how white spaces are ignored when performing the
+	This configures how whitespace is ignored when performing the
 	move detection for `--color-moved`.
 ifdef::git-diff[]
 	It can be set by the `diff.colorMovedWS` configuration setting.
@@ -302,6 +306,8 @@
 	These modes can be given as a comma separated list:
 +
 --
+no::
+	Do not ignore whitespace when performing move detection.
 ignore-space-at-eol::
 	Ignore changes in whitespace at EOL.
 ignore-space-change::
@@ -312,12 +318,17 @@
 	Ignore whitespace when comparing lines. This ignores differences
 	even if one line has whitespace where the other line has none.
 allow-indentation-change::
-	Initially ignore any white spaces in the move detection, then
+	Initially ignore any whitespace in the move detection, then
 	group the moved code blocks only into a block if the change in
 	whitespace is the same per line. This is incompatible with the
 	other modes.
 --
 
+--no-color-moved-ws::
+	Do not ignore whitespace when performing move detection. This can be
+	used to override configuration settings. It is the same as
+	`--color-moved-ws=no`.
+
 --word-diff[=<mode>]::
 	Show a word diff, using the <mode> to delimit changed words.
 	By default, words are delimited by whitespace; see
diff --git a/Documentation/git-add.txt b/Documentation/git-add.txt
index 45652fe..37bcab9 100644
--- a/Documentation/git-add.txt
+++ b/Documentation/git-add.txt
@@ -58,9 +58,9 @@
 	specifying `dir` will record not just a file `dir/file1`
 	modified in the working tree, a file `dir/file2` added to
 	the working tree, but also a file `dir/file3` removed from
-	the working tree.  Note that older versions of Git used
+	the working tree). Note that older versions of Git used
 	to ignore removed files; use `--no-all` option if you want
-	to add modified or new files but ignore removed	ones.
+	to add modified or new files but ignore removed ones.
 +
 For more details about the <pathspec> syntax, see the 'pathspec' entry
 in linkgit:gitglossary[7].
@@ -124,7 +124,7 @@
 --no-ignore-removal::
 	Update the index not only where the working tree has a file
 	matching <pathspec> but also where the index already has an
-	entry.	This adds, modifies, and removes index entries to
+	entry. This adds, modifies, and removes index entries to
 	match the working tree.
 +
 If no <pathspec> is given when `-A` option is used, all
@@ -206,7 +206,7 @@
 --------
 
 * Adds content from all `*.txt` files under `Documentation` directory
-and its subdirectories:
+  and its subdirectories:
 +
 ------------
 $ git add Documentation/\*.txt
diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index bf5316f..3bd83a7 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -297,7 +297,7 @@
 ------------
 +
 <1> This step and the next one could be combined into a single step with
-"checkout -b my2.6.14 v2.6.14".
+    "checkout -b my2.6.14 v2.6.14".
 
 Delete an unneeded branch::
 +
@@ -309,10 +309,10 @@
 ------------
 +
 <1> Delete the remote-tracking branches "todo", "html" and "man". The next
-'fetch' or 'pull' will create them again unless you configure them not to.
-See linkgit:git-fetch[1].
+    'fetch' or 'pull' will create them again unless you configure them not to.
+    See linkgit:git-fetch[1].
 <2> Delete the "test" branch even if the "master" branch (or whichever branch
-is currently checked out) does not have all commits from the test branch.
+    is currently checked out) does not have all commits from the test branch.
 
 
 NOTES
diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
index e27a940..8eca671 100644
--- a/Documentation/git-cat-file.txt
+++ b/Documentation/git-cat-file.txt
@@ -23,8 +23,8 @@
 stdin, and the SHA-1, type, and size of each object is printed on stdout. The
 output format can be overridden using the optional `<format>` argument. If
 either `--textconv` or `--filters` was specified, the input is expected to
-list the object names followed by the path name, separated by a single white
-space, so that the appropriate drivers can be determined.
+list the object names followed by the path name, separated by a single
+whitespace, so that the appropriate drivers can be determined.
 
 OPTIONS
 -------
@@ -79,7 +79,7 @@
 	Print object information and contents for each object provided
 	on stdin.  May not be combined with any other options or arguments
 	except `--textconv` or `--filters`, in which case the input lines
-	also need to specify the path, separated by white space.  See the
+	also need to specify the path, separated by whitespace.  See the
 	section `BATCH OUTPUT` below for details.
 
 --batch-check::
@@ -87,7 +87,7 @@
 	Print object information for each object provided on stdin.  May
 	not be combined with any other options or arguments except
 	`--textconv` or `--filters`, in which case the input lines also
-	need to specify the path, separated by white space.  See the
+	need to specify the path, separated by whitespace.  See the
 	section `BATCH OUTPUT` below for details.
 
 --batch-all-objects::
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 6acc3d9..9a39649 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -424,14 +424,14 @@
 ------------
 
 <1> creates a new branch 'foo', which refers to commit 'f', and then
-updates HEAD to refer to branch 'foo'. In other words, we'll no longer
-be in detached HEAD state after this command.
+    updates HEAD to refer to branch 'foo'. In other words, we'll no longer
+    be in detached HEAD state after this command.
 
 <2> similarly creates a new branch 'foo', which refers to commit 'f',
-but leaves HEAD detached.
+    but leaves HEAD detached.
 
 <3> creates a new tag 'foo', which refers to commit 'f',
-leaving HEAD detached.
+    leaving HEAD detached.
 
 If we have moved away from commit 'f', then we must first recover its object
 name (typically by using git reflog), and then we can create a reference to
@@ -459,8 +459,8 @@
 --------
 
 . The following sequence checks out the `master` branch, reverts
-the `Makefile` to two revisions back, deletes hello.c by
-mistake, and gets it back from the index.
+  the `Makefile` to two revisions back, deletes hello.c by
+  mistake, and gets it back from the index.
 +
 ------------
 $ git checkout master             <1>
@@ -494,7 +494,7 @@
 ------------
 
 . After working in the wrong branch, switching to the correct
-branch would be done using:
+  branch would be done using:
 +
 ------------
 $ git checkout mytopic
@@ -522,7 +522,7 @@
 changes you made since the tip of the new branch.
 
 . When a merge conflict happens during switching branches with
-the `-m` option, you would see something like this:
+  the `-m` option, you would see something like this:
 +
 ------------
 $ git checkout -m mytopic
diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index d35d771..b8cfeec 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -213,16 +213,16 @@
 $ git cherry-pick -Xpatience topic^  <4>
 ------------
 <1> apply the change that would be shown by `git show topic^`.
-In this example, the patch does not apply cleanly, so
-information about the conflict is written to the index and
-working tree and no new commit results.
+    In this example, the patch does not apply cleanly, so
+    information about the conflict is written to the index and
+    working tree and no new commit results.
 <2> summarize changes to be reconciled
 <3> cancel the cherry-pick.  In other words, return to the
-pre-cherry-pick state, preserving any local modifications you had in
-the working tree.
+    pre-cherry-pick state, preserving any local modifications
+    you had in the working tree.
 <4> try to apply the change introduced by `topic^` again,
-spending extra time to avoid mistakes based on incorrectly matching
-context lines.
+    spending extra time to avoid mistakes based on incorrectly
+    matching context lines.
 
 SEE ALSO
 --------
diff --git a/Documentation/git-diff.txt b/Documentation/git-diff.txt
index 030f162..72179d9 100644
--- a/Documentation/git-diff.txt
+++ b/Documentation/git-diff.txt
@@ -132,9 +132,9 @@
 +
 <1> Changes in the working tree not yet staged for the next commit.
 <2> Changes between the index and your last commit; what you
-would be committing if you run "git commit" without "-a" option.
+    would be committing if you run "git commit" without "-a" option.
 <3> Changes in the working tree since your last commit; what you
-would be committing if you run "git commit -a"
+    would be committing if you run "git commit -a"
 
 Comparing with arbitrary commits::
 +
@@ -145,10 +145,10 @@
 ------------
 +
 <1> Instead of using the tip of the current branch, compare with the
-tip of "test" branch.
+    tip of "test" branch.
 <2> Instead of comparing with the tip of "test" branch, compare with
-the tip of the current branch, but limit the comparison to the
-file "test".
+    the tip of the current branch, but limit the comparison to the
+    file "test".
 <3> Compare the version before the last commit and the last commit.
 
 Comparing branches::
@@ -162,7 +162,7 @@
 <1> Changes between the tips of the topic and the master branches.
 <2> Same as above.
 <3> Changes that occurred on the master branch since when the topic
-branch was started off it.
+    branch was started off it.
 
 Limiting the diff output::
 +
@@ -173,9 +173,9 @@
 ------------
 +
 <1> Show only modification, rename, and copy, but not addition
-or deletion.
+    or deletion.
 <2> Show only names and the nature of change, but not actual
-diff output.
+    diff output.
 <3> Limit diff output to named subtrees.
 
 Munging the diff output::
@@ -186,7 +186,7 @@
 ------------
 +
 <1> Spend extra cycles to find renames, copies and complete
-rewrites (very expensive).
+    rewrites (very expensive).
 <2> Output diff in reverse.
 
 SEE ALSO
diff --git a/Documentation/git-fetch.txt b/Documentation/git-fetch.txt
index e319935..266d63c 100644
--- a/Documentation/git-fetch.txt
+++ b/Documentation/git-fetch.txt
@@ -266,7 +266,7 @@
 because it is prefixed with a plus sign; `tmp` will not be.
 
 * Peek at a remote's branch, without configuring the remote in your local
-repository:
+  repository:
 +
 ------------------------------------------------
 $ git fetch git://git.kernel.org/pub/scm/git/git.git maint
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 2730442..1af85d4 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -504,9 +504,9 @@
 "mailnews.wraplength" and set the value to 0.
 
 3. Disable the use of format=flowed:
-Edit..Preferences..Advanced..Config Editor.  Search for
-"mailnews.send_plaintext_flowed".
-Toggle it to make sure it is set to `false`.
+   Edit..Preferences..Advanced..Config Editor.  Search for
+   "mailnews.send_plaintext_flowed".
+   Toggle it to make sure it is set to `false`.
 
 After that is done, you should be able to compose email as you
 otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
@@ -629,14 +629,14 @@
 --------
 
 * Extract commits between revisions R1 and R2, and apply them on top of
-the current branch using 'git am' to cherry-pick them:
+  the current branch using 'git am' to cherry-pick them:
 +
 ------------
 $ git format-patch -k --stdout R1..R2 | git am -3 -k
 ------------
 
 * Extract all commits which are in the current branch but not in the
-origin branch:
+  origin branch:
 +
 ------------
 $ git format-patch origin
@@ -645,7 +645,7 @@
 For each commit a separate file is created in the current directory.
 
 * Extract all commits that lead to 'origin' since the inception of the
-project:
+  project:
 +
 ------------
 $ git format-patch --root origin
@@ -664,7 +664,7 @@
 use it only when you know the recipient uses Git to apply your patch.
 
 * Extract three topmost commits from the current branch and format them
-as e-mailable patches:
+  as e-mailable patches:
 +
 ------------
 $ git format-patch -3
diff --git a/Documentation/git-help.txt b/Documentation/git-help.txt
index aab5453..c318bf8 100644
--- a/Documentation/git-help.txt
+++ b/Documentation/git-help.txt
@@ -118,9 +118,9 @@
 
 * "man": use the 'man' program as usual,
 * "woman": use 'emacsclient' to launch the "woman" mode in emacs
-(this only works starting with emacsclient versions 22),
+  (this only works starting with emacsclient versions 22),
 * "konqueror": use 'kfmclient' to open the man page in a new konqueror
-tab (see 'Note about konqueror' below).
+  tab (see 'Note about konqueror' below).
 
 Values for other tools can be used if there is a corresponding
 `man.<tool>.cmd` configuration entry (see below).
diff --git a/Documentation/git-init.txt b/Documentation/git-init.txt
index 057076c..32880aa 100644
--- a/Documentation/git-init.txt
+++ b/Documentation/git-init.txt
@@ -128,7 +128,7 @@
 The default template directory includes some directory structure, suggested
 "exclude patterns" (see linkgit:gitignore[5]), and sample hook files.
 
-The sample hooks are all disabled by default, To enable one of the
+The sample hooks are all disabled by default. To enable one of the
 sample hooks rename it by removing its `.sample` suffix.
 
 See linkgit:githooks[5] for more general info on hook execution.
diff --git a/Documentation/git-instaweb.txt b/Documentation/git-instaweb.txt
index e8ecdbf..a54fe44 100644
--- a/Documentation/git-instaweb.txt
+++ b/Documentation/git-instaweb.txt
@@ -29,7 +29,8 @@
 	The HTTP daemon command-line that will be executed.
 	Command-line options may be specified here, and the
 	configuration file will be added at the end of the command-line.
-	Currently apache2, lighttpd, mongoose, plackup and webrick are supported.
+	Currently apache2, lighttpd, mongoose, plackup, python and
+	webrick are supported.
 	(Default: lighttpd)
 
 -m::
diff --git a/Documentation/git-p4.txt b/Documentation/git-p4.txt
index f0a0280..3494a1d 100644
--- a/Documentation/git-p4.txt
+++ b/Documentation/git-p4.txt
@@ -71,12 +71,12 @@
 ------------
 This:
 
-1.   Creates an empty Git repository in a subdirectory called 'project'.
+1. Creates an empty Git repository in a subdirectory called 'project'.
 +
-2.   Imports the full contents of the head revision from the given p4
-depot path into a single commit in the Git branch 'refs/remotes/p4/master'.
+2. Imports the full contents of the head revision from the given p4
+   depot path into a single commit in the Git branch 'refs/remotes/p4/master'.
 +
-3.   Creates a local branch, 'master' from this remote and checks it out.
+3. Creates a local branch, 'master' from this remote and checks it out.
 
 To reproduce the entire p4 history in Git, use the '@all' modifier on
 the depot path:
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index d284155..7e695b3 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -462,6 +462,12 @@
 +
 See also INCOMPATIBLE OPTIONS below.
 
+-y <cmd>::
+	This is the same as passing `--reschedule-failed-exec` before
+	`-x <cmd>`, i.e. it appends the specified `exec` command and
+	turns on the mode where failed `exec` commands are automatically
+	rescheduled.
+
 --root::
 	Rebase all commits reachable from <branch>, instead of
 	limiting them with an <upstream>.  This allows you to rebase
@@ -501,18 +507,15 @@
 	with care: the final stash application after a successful
 	rebase might result in non-trivial conflicts.
 
+--reschedule-failed-exec::
+--no-reschedule-failed-exec::
+	Automatically reschedule `exec` commands that failed. This only makes
+	sense in interactive mode (or when an `--exec` option was provided).
+
 INCOMPATIBLE OPTIONS
 --------------------
 
-git-rebase has many flags that are incompatible with each other,
-predominantly due to the fact that it has three different underlying
-implementations:
-
- * one based on linkgit:git-am[1] (the default)
- * one based on git-merge-recursive (merge backend)
- * one based on linkgit:git-cherry-pick[1] (interactive backend)
-
-Flags only understood by the am backend:
+The following options:
 
  * --committer-date-is-author-date
  * --ignore-date
@@ -520,15 +523,12 @@
  * --ignore-whitespace
  * -C
 
-Flags understood by both merge and interactive backends:
+are incompatible with the following options:
 
  * --merge
  * --strategy
  * --strategy-option
  * --allow-empty-message
-
-Flags only understood by the interactive backend:
-
  * --[no-]autosquash
  * --rebase-merges
  * --preserve-merges
@@ -539,7 +539,7 @@
  * --edit-todo
  * --root when used in combination with --onto
 
-Other incompatible flag pairs:
+In addition, the following pairs of options are incompatible:
 
  * --preserve-merges and --interactive
  * --preserve-merges and --signoff
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index 9f69ae8..132f8e5 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -115,17 +115,17 @@
 ------------
 +
 <1> You are happily working on something, and find the changes
-in these files are in good order.  You do not want to see them
-when you run `git diff`, because you plan to work on other files
-and changes with these files are distracting.
+    in these files are in good order.  You do not want to see them
+    when you run `git diff`, because you plan to work on other files
+    and changes with these files are distracting.
 <2> Somebody asks you to pull, and the changes sound worthy of merging.
 <3> However, you already dirtied the index (i.e. your index does
-not match the `HEAD` commit).  But you know the pull you are going
-to make does not affect `frotz.c` or `filfre.c`, so you revert the
-index changes for these two files.  Your changes in working tree
-remain there.
+    not match the `HEAD` commit).  But you know the pull you are going
+    to make does not affect `frotz.c` or `filfre.c`, so you revert the
+    index changes for these two files.  Your changes in working tree
+    remain there.
 <4> Then you can pull and merge, leaving `frotz.c` and `filfre.c`
-changes still in the working tree.
+    changes still in the working tree.
 
 Undo a commit and redo::
 +
@@ -137,12 +137,12 @@
 ------------
 +
 <1> This is most often done when you remembered what you
-just committed is incomplete, or you misspelled your commit
-message, or both.  Leaves working tree as it was before "reset".
+    just committed is incomplete, or you misspelled your commit
+    message, or both.  Leaves working tree as it was before "reset".
 <2> Make corrections to working tree files.
 <3> "reset" copies the old head to `.git/ORIG_HEAD`; redo the
-commit by starting with its log message.  If you do not need to
-edit the message further, you can give `-C` option instead.
+    commit by starting with its log message.  If you do not need to
+    edit the message further, you can give `-C` option instead.
 +
 See also the `--amend` option to linkgit:git-commit[1].
 
@@ -155,9 +155,9 @@
 ------------
 +
 <1> You have made some commits, but realize they were premature
-to be in the `master` branch.  You want to continue polishing
-them in a topic branch, so create `topic/wip` branch off of the
-current `HEAD`.
+    to be in the `master` branch.  You want to continue polishing
+    them in a topic branch, so create `topic/wip` branch off of the
+    current `HEAD`.
 <2> Rewind the master branch to get rid of those three commits.
 <3> Switch to `topic/wip` branch and keep working.
 
@@ -169,10 +169,10 @@
 ------------
 +
 <1> The last three commits (`HEAD`, `HEAD^`, and `HEAD~2`) were bad
-and you do not want to ever see them again.  Do *not* do this if
-you have already given these commits to somebody else.  (See the
-"RECOVERING FROM UPSTREAM REBASE" section in linkgit:git-rebase[1] for
-the implications of doing so.)
+    and you do not want to ever see them again.  Do *not* do this if
+    you have already given these commits to somebody else.  (See the
+    "RECOVERING FROM UPSTREAM REBASE" section in linkgit:git-rebase[1]
+    for the implications of doing so.)
 
 Undo a merge or pull::
 +
@@ -189,18 +189,18 @@
 ------------
 +
 <1> Try to update from the upstream resulted in a lot of
-conflicts; you were not ready to spend a lot of time merging
-right now, so you decide to do that later.
+    conflicts; you were not ready to spend a lot of time merging
+    right now, so you decide to do that later.
 <2> "pull" has not made merge commit, so `git reset --hard`
-which is a synonym for `git reset --hard HEAD` clears the mess
-from the index file and the working tree.
+    which is a synonym for `git reset --hard HEAD` clears the mess
+    from the index file and the working tree.
 <3> Merge a topic branch into the current branch, which resulted
-in a fast-forward.
+    in a fast-forward.
 <4> But you decided that the topic branch is not ready for public
-consumption yet.  "pull" or "merge" always leaves the original
-tip of the current branch in `ORIG_HEAD`, so resetting hard to it
-brings your index file and the working tree back to that state,
-and resets the tip of the branch to that commit.
+    consumption yet.  "pull" or "merge" always leaves the original
+    tip of the current branch in `ORIG_HEAD`, so resetting hard to it
+    brings your index file and the working tree back to that state,
+    and resets the tip of the branch to that commit.
 
 Undo a merge or pull inside a dirty working tree::
 +
@@ -214,14 +214,14 @@
 ------------
 +
 <1> Even if you may have local modifications in your
-working tree, you can safely say `git pull` when you know
-that the change in the other branch does not overlap with
-them.
+    working tree, you can safely say `git pull` when you know
+    that the change in the other branch does not overlap with
+    them.
 <2> After inspecting the result of the merge, you may find
-that the change in the other branch is unsatisfactory.  Running
-`git reset --hard ORIG_HEAD` will let you go back to where you
-were, but it will discard your local changes, which you do not
-want.  `git reset --merge` keeps your local changes.
+    that the change in the other branch is unsatisfactory.  Running
+    `git reset --hard ORIG_HEAD` will let you go back to where you
+    were, but it will discard your local changes, which you do not
+    want.  `git reset --merge` keeps your local changes.
 
 
 Interrupted workflow::
diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index 62c6c76..1afe9fc 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt
@@ -33,7 +33,7 @@
 formatting are ignored.
 
 2. The original format used by Greg Kroah-Hartman's 'send_lots_of_email.pl'
-script
+   script
 +
 This format expects the first line of the file to contain the "Cc:" value
 and the "Subject:" of the message as the second line.
diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
index f2d644e..a74e7b9 100644
--- a/Documentation/git-tag.txt
+++ b/Documentation/git-tag.txt
@@ -237,16 +237,16 @@
 the old tag. In that case you can do one of two things:
 
 . The sane thing.
-Just admit you screwed up, and use a different name. Others have
-already seen one tag-name, and if you keep the same name, you
-may be in the situation that two people both have "version X",
-but they actually have 'different' "X"'s.  So just call it "X.1"
-and be done with it.
+  Just admit you screwed up, and use a different name. Others have
+  already seen one tag-name, and if you keep the same name, you
+  may be in the situation that two people both have "version X",
+  but they actually have 'different' "X"'s.  So just call it "X.1"
+  and be done with it.
 
 . The insane thing.
-You really want to call the new version "X" too, 'even though'
-others have already seen the old one. So just use 'git tag -f'
-again, as if you hadn't already published the old one.
+  You really want to call the new version "X" too, 'even though'
+  others have already seen the old one. So just use 'git tag -f'
+  again, as if you hadn't already published the old one.
 
 However, Git does *not* (and it should not) change tags behind
 users back. So if somebody already got the old tag, doing a
diff --git a/Documentation/git-upload-pack.txt b/Documentation/git-upload-pack.txt
index 998f52d..9822c1e 100644
--- a/Documentation/git-upload-pack.txt
+++ b/Documentation/git-upload-pack.txt
@@ -22,7 +22,6 @@
 program pair is meant to be used to pull updates from a remote
 repository.  For push operations, see 'git send-pack'.
 
-
 OPTIONS
 -------
 
diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 417b638..de69531 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -134,6 +134,8 @@
 - '%cI': committer date, strict ISO 8601 format
 - '%d': ref names, like the --decorate option of linkgit:git-log[1]
 - '%D': ref names without the " (", ")" wrapping.
+- '%S': ref name given on the command line by which the commit was reached
+  (like `git log --source`), only works with `git log`
 - '%e': encoding
 - '%s': subject
 - '%f': sanitized subject line, suitable for a filename
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 98b538b..8a48679 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -270,13 +270,13 @@
 +
 --
 1. If the starting point is specified as `ref@{Nth}`, show the index
-format.
+   format.
 +
 2. If the starting point was specified as `ref@{now}`, show the
-timestamp format.
+   timestamp format.
 +
 3. If neither was used, but `--date` was given on the command line, show
-the timestamp in the format requested by `--date`.
+   the timestamp in the format requested by `--date`.
 +
 4. Otherwise, show the index format.
 --
@@ -730,8 +730,13 @@
 +
 The form '--filter=tree:<depth>' omits all blobs and trees whose depth
 from the root tree is >= <depth> (minimum depth if an object is located
-at multiple depths in the commits traversed). Currently, only <depth>=0
-is supported, which omits all blobs and trees.
+at multiple depths in the commits traversed). <depth>=0 will not include
+any trees or blobs unless included explicitly in the command-line (or
+standard input when --stdin is used). <depth>=1 will include only the
+tree and blobs which are referenced directly by a commit reachable from
+<commit> or an explicitly-given object. <depth>=2 is like <depth>=1
+while also including trees and blobs one more level removed from an
+explicitly-given commit or tree.
 
 --no-filter::
 	Turn off any previous `--filter=` argument.
diff --git a/Documentation/technical/api-oid-array.txt b/Documentation/technical/api-oid-array.txt
index 9febfb1..c97428c 100644
--- a/Documentation/technical/api-oid-array.txt
+++ b/Documentation/technical/api-oid-array.txt
@@ -48,6 +48,11 @@
 	is not sorted, this function has the side effect of sorting
 	it.
 
+`oid_array_filter`::
+	Apply the callback function `want` to each entry in the array,
+	retaining only the entries for which the function returns true.
+	Preserve the order of the entries that are retained.
+
 Examples
 --------
 
diff --git a/Documentation/technical/commit-graph-format.txt b/Documentation/technical/commit-graph-format.txt
index cc0474b..16452a0 100644
--- a/Documentation/technical/commit-graph-format.txt
+++ b/Documentation/technical/commit-graph-format.txt
@@ -76,7 +76,7 @@
       of the ith commit. Stores value 0x7000000 if no parent in that
       position. If there are more than two parents, the second value
       has its most-significant bit on and the other bits store an array
-      position into the Large Edge List chunk.
+      position into the Extra Edge List chunk.
     * The next 8 bytes store the generation number of the commit and
       the commit time in seconds since EPOCH. The generation number
       uses the higher 30 bits of the first 4 bytes, while the commit
@@ -84,7 +84,7 @@
       2 bits of the lowest byte, storing the 33rd and 34th bit of the
       commit time.
 
-  Large Edge List (ID: {'E', 'D', 'G', 'E'}) [Optional]
+  Extra Edge List (ID: {'E', 'D', 'G', 'E'}) [Optional]
       This list of 4-byte values store the second through nth parents for
       all octopus merges. The second parent value in the commit data stores
       an array position within this list along with the most-significant bit
diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt
index 6ac774d..7a2375a 100644
--- a/Documentation/technical/pack-protocol.txt
+++ b/Documentation/technical/pack-protocol.txt
@@ -22,6 +22,16 @@
 otherwise noted the usual pkt-line LF rules apply: the sender SHOULD
 include a LF, but the receiver MUST NOT complain if it is not present.
 
+An error packet is a special pkt-line that contains an error string.
+
+----
+  error-line     =  PKT-LINE("ERR" SP explanation-text)
+----
+
+Throughout the protocol, where `PKT-LINE(...)` is expected, an error packet MAY
+be sent. Once this packet is sent by a client or a server, the data transfer
+process defined in this protocol is terminated.
+
 Transports
 ----------
 There are three transports over which the packfile protocol is
@@ -89,13 +99,6 @@
      "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" |
      nc -v example.com 9418
 
-If the server refuses the request for some reasons, it could abort
-gracefully with an error message.
-
-----
-  error-line     =  PKT-LINE("ERR" SP explanation-text)
-----
-
 
 SSH Transport
 -------------
@@ -398,12 +401,11 @@
 Then the server will start sending its packfile data.
 
 ----
-  server-response = *ack_multi ack / nak / error-line
+  server-response = *ack_multi ack / nak
   ack_multi       = PKT-LINE("ACK" SP obj-id ack_status)
   ack_status      = "continue" / "common" / "ready"
   ack             = PKT-LINE("ACK" SP obj-id)
   nak             = PKT-LINE("NAK")
-  error-line     =  PKT-LINE("ERR" SP explanation-text)
 ----
 
 A simple clone may look like this (with no 'have' lines):
diff --git a/Documentation/technical/partial-clone.txt b/Documentation/technical/partial-clone.txt
index 1ef66bd..896c7b3 100644
--- a/Documentation/technical/partial-clone.txt
+++ b/Documentation/technical/partial-clone.txt
@@ -114,7 +114,7 @@
   that it has, either because the local repository has that object in one of
   its promisor packfiles, or because another promisor object refers to it.
 +
-When Git encounters a missing object, Git can see if it a promisor object
+When Git encounters a missing object, Git can see if it is a promisor object
 and handle it appropriately.  If not, Git can report a corruption.
 +
 This means that there is no need for the client to explicitly maintain an
diff --git a/Documentation/technical/protocol-v2.txt b/Documentation/technical/protocol-v2.txt
index 09e4e02..ead85ce 100644
--- a/Documentation/technical/protocol-v2.txt
+++ b/Documentation/technical/protocol-v2.txt
@@ -296,7 +296,13 @@
 	Request that various objects from the packfile be omitted
 	using one of several filtering techniques. These are intended
 	for use with partial clone and partial fetch operations. See
-	`rev-list` for possible "filter-spec" values.
+	`rev-list` for possible "filter-spec" values. When communicating
+	with other processes, senders SHOULD translate scaled integers
+	(e.g. "1k") into a fully-expanded form (e.g. "1024") to aid
+	interoperability with older receivers that may not understand
+	newly-invented scaling suffixes. However, receivers SHOULD
+	accept the following suffixes: 'k', 'm', and 'g' for 1024,
+	1048576, and 1073741824, respectively.
 
 If the 'ref-in-want' feature is advertised, the following argument can
 be included in the client's request as well as the potential addition of
@@ -307,6 +313,16 @@
 	particular ref, where <ref> is the full name of a ref on the
 	server.
 
+If the 'sideband-all' feature is advertised, the following argument can be
+included in the client's request:
+
+    sideband-all
+	Instruct the server to send the whole response multiplexed, not just
+	the packfile section. All non-flush and non-delim PKT-LINE in the
+	response (not only in the packfile section) will then start with a byte
+	indicating its sideband (1, 2, or 3), and the server may send "0005\2"
+	(a PKT-LINE of sideband 2 with no payload) as a keepalive packet.
+
 The response of `fetch` is broken into a number of sections separated by
 delimiter packets (0001), with each section beginning with its section
 header.
diff --git a/Makefile b/Makefile
index 1a44c81..afa411d 100644
--- a/Makefile
+++ b/Makefile
@@ -186,6 +186,12 @@
 # in one call to the platform's SHA1_Update(). e.g. APPLE_COMMON_CRYPTO
 # wants 'SHA1_MAX_BLOCK_SIZE=1024L*1024L*1024L' defined.
 #
+# Define BLK_SHA256 to use the built-in SHA-256 routines.
+#
+# Define GCRYPT_SHA256 to use the SHA-256 routines in libgcrypt.
+#
+# Define OPENSSL_SHA256 to use the SHA-256 routines in OpenSSL.
+#
 # Define NEEDS_CRYPTO_WITH_SSL if you need -lcrypto when using -lssl (Darwin).
 #
 # Define NEEDS_SSL_WITH_CRYPTO if you need -lssl when using -lcrypto (Darwin).
@@ -628,7 +634,6 @@
 SCRIPT_LIB += git-rebase--am
 SCRIPT_LIB += git-rebase--common
 SCRIPT_LIB += git-rebase--preserve-merges
-SCRIPT_LIB += git-rebase--merge
 SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
 
@@ -684,6 +689,7 @@
 
 ETAGS_TARGET = TAGS
 
+FUZZ_OBJS += fuzz-commit-graph.o
 FUZZ_OBJS += fuzz-pack-headers.o
 FUZZ_OBJS += fuzz-pack-idx.o
 
@@ -724,7 +730,9 @@
 TEST_BUILTINS_OBJS += test-dump-untracked-cache.o
 TEST_BUILTINS_OBJS += test-example-decorate.o
 TEST_BUILTINS_OBJS += test-genrandom.o
+TEST_BUILTINS_OBJS += test-hash.o
 TEST_BUILTINS_OBJS += test-hashmap.o
+TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-index-version.o
 TEST_BUILTINS_OBJS += test-json-writer.o
 TEST_BUILTINS_OBJS += test-lazy-init-name-hash.o
@@ -747,6 +755,7 @@
 TEST_BUILTINS_OBJS += test-scrap-cache-tree.o
 TEST_BUILTINS_OBJS += test-sha1.o
 TEST_BUILTINS_OBJS += test-sha1-array.o
+TEST_BUILTINS_OBJS += test-sha256.o
 TEST_BUILTINS_OBJS += test-sigchain.o
 TEST_BUILTINS_OBJS += test-strcmp-offset.o
 TEST_BUILTINS_OBJS += test-string-list.o
@@ -1646,6 +1655,19 @@
 endif
 endif
 
+ifdef OPENSSL_SHA256
+	EXTLIBS += $(LIB_4_CRYPTO)
+	BASIC_CFLAGS += -DSHA256_OPENSSL
+else
+ifdef GCRYPT_SHA256
+	BASIC_CFLAGS += -DSHA256_GCRYPT
+	EXTLIBS += -lgcrypt
+else
+	LIB_OBJS += sha256/block/sha256.o
+	BASIC_CFLAGS += -DSHA256_BLK
+endif
+endif
+
 ifdef SHA1_MAX_BLOCK_SIZE
 	LIB_OBJS += compat/sha1-chunked.o
 	BASIC_CFLAGS += -DSHA1_MAX_BLOCK_SIZE="$(SHA1_MAX_BLOCK_SIZE)"
@@ -3103,7 +3125,7 @@
 # An example command to build against libFuzzer from LLVM 4.0.0:
 #
 # make CC=clang CXX=clang++ \
-#      FUZZ_CXXFLAGS="-fsanitize-coverage=trace-pc-guard -fsanitize=address" \
+#      CFLAGS="-fsanitize-coverage=trace-pc-guard -fsanitize=address" \
 #      LIB_FUZZING_ENGINE=/usr/lib/llvm-4.0/lib/libFuzzer.a \
 #      fuzz-all
 #
diff --git a/alloc.c b/alloc.c
index e7aa81b..1c64c4d 100644
--- a/alloc.c
+++ b/alloc.c
@@ -99,18 +99,23 @@
 	return obj;
 }
 
-unsigned int alloc_commit_index(struct repository *r)
+static unsigned int alloc_commit_index(struct repository *r)
 {
 	return r->parsed_objects->commit_count++;
 }
 
+void init_commit_node(struct repository *r, struct commit *c)
+{
+	c->object.type = OBJ_COMMIT;
+	c->index = alloc_commit_index(r);
+	c->graph_pos = COMMIT_NOT_FROM_GRAPH;
+	c->generation = GENERATION_NUMBER_INFINITY;
+}
+
 void *alloc_commit_node(struct repository *r)
 {
 	struct commit *c = alloc_node(r->parsed_objects->commit_state, sizeof(struct commit));
-	c->object.type = OBJ_COMMIT;
-	c->index = alloc_commit_index(r);
-	c->graph_pos = COMMIT_NOT_FROM_GRAPH;
-	c->generation = GENERATION_NUMBER_INFINITY;
+	init_commit_node(r, c);
 	return c;
 }
 
diff --git a/alloc.h b/alloc.h
index ba356ed..ed1071c 100644
--- a/alloc.h
+++ b/alloc.h
@@ -9,11 +9,11 @@
 
 void *alloc_blob_node(struct repository *r);
 void *alloc_tree_node(struct repository *r);
+void init_commit_node(struct repository *r, struct commit *c);
 void *alloc_commit_node(struct repository *r);
 void *alloc_tag_node(struct repository *r);
 void *alloc_object_node(struct repository *r);
 void alloc_report(struct repository *r);
-unsigned int alloc_commit_index(struct repository *r);
 
 struct alloc_state *allocate_alloc_state(void);
 void clear_alloc_state(struct alloc_state *s);
diff --git a/attr.c b/attr.c
index b63fe0f..0cba789 100644
--- a/attr.c
+++ b/attr.c
@@ -1092,7 +1092,7 @@
 			       const char *path,
 			       struct attr_check *check)
 {
-	int i, pathlen, rem, dirlen;
+	int pathlen, rem, dirlen;
 	const char *cp, *last_slash = NULL;
 	int basename_offset;
 
@@ -1113,20 +1113,6 @@
 	all_attrs_init(&g_attr_hashmap, check);
 	determine_macros(check->all_attrs, check->stack);
 
-	if (check->nr) {
-		rem = 0;
-		for (i = 0; i < check->nr; i++) {
-			int n = check->items[i].attr->attr_nr;
-			struct all_attrs_item *item = &check->all_attrs[n];
-			if (item->macro) {
-				item->value = ATTR__UNSET;
-				rem++;
-			}
-		}
-		if (rem == check->nr)
-			return;
-	}
-
 	rem = check->all_attrs_nr;
 	fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
 }
diff --git a/builtin/add.c b/builtin/add.c
index 12247b4..7c2a7c5 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -137,7 +137,7 @@
 			continue; /* do not touch non blobs */
 		if (pathspec && !ce_path_match(&the_index, ce, pathspec, NULL))
 			continue;
-		retval |= add_file_to_cache(ce->name, flags | HASH_RENORMALIZE);
+		retval |= add_file_to_cache(ce->name, flags | ADD_CACHE_RENORMALIZE);
 	}
 
 	return retval;
@@ -239,7 +239,7 @@
 	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 	rev.diffopt.use_color = 0;
 	rev.diffopt.flags.ignore_dirty_submodules = 1;
-	out = open(file, O_CREAT | O_WRONLY, 0666);
+	out = open(file, O_CREAT | O_WRONLY | O_TRUNC, 0666);
 	if (out < 0)
 		die(_("Could not open '%s' for writing."), file);
 	rev.diffopt.file = xfdopen(out, "w");
diff --git a/builtin/am.c b/builtin/am.c
index 9537031..6d1c6d3 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -2000,6 +2000,15 @@
 	if (clean_index(&head, &head))
 		die(_("failed to clean index"));
 
+	if (state->rebasing) {
+		FILE *fp = xfopen(am_path(state, "rewritten"), "a");
+
+		assert(!is_null_oid(&state->orig_commit));
+		fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
+		fprintf(fp, "%s\n", oid_to_hex(&head));
+		fclose(fp);
+	}
+
 	am_next(state);
 	am_load(state);
 	am_run(state, 0);
diff --git a/builtin/archive.c b/builtin/archive.c
index d245523..45d1166 100644
--- a/builtin/archive.c
+++ b/builtin/archive.c
@@ -27,10 +27,10 @@
 			       const char *remote, const char *exec,
 			       const char *name_hint)
 {
-	char *buf;
 	int fd[2], i, rv;
 	struct transport *transport;
 	struct remote *_remote;
+	struct packet_reader reader;
 
 	_remote = remote_get(remote);
 	if (!_remote->url[0])
@@ -53,18 +53,19 @@
 		packet_write_fmt(fd[1], "argument %s\n", argv[i]);
 	packet_flush(fd[1]);
 
-	buf = packet_read_line(fd[0], NULL);
-	if (!buf)
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+
+	if (packet_reader_read(&reader) != PACKET_READ_NORMAL)
 		die(_("git archive: expected ACK/NAK, got a flush packet"));
-	if (strcmp(buf, "ACK")) {
-		if (starts_with(buf, "NACK "))
-			die(_("git archive: NACK %s"), buf + 5);
-		if (starts_with(buf, "ERR "))
-			die(_("remote error: %s"), buf + 4);
+	if (strcmp(reader.line, "ACK")) {
+		if (starts_with(reader.line, "NACK "))
+			die(_("git archive: NACK %s"), reader.line + 5);
 		die(_("git archive: protocol error"));
 	}
 
-	if (packet_read_line(fd[0], NULL))
+	if (packet_reader_read(&reader) != PACKET_READ_FLUSH)
 		die(_("git archive: expected a flush"));
 
 	/* Now, start reading from fd[0] and spit it out to stdout */
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 6fadf41..9f8f346 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -592,6 +592,14 @@
 	 * Remaining variables are not checkout options but used to track state
 	 */
 
+	 /*
+	  * Do the merge if this is the initial checkout. We cannot use
+	  * is_cache_unborn() here because the index hasn't been loaded yet
+	  * so cache_nr and timestamp.sec are always zero.
+	  */
+	if (!file_exists(get_index_file()))
+		return 0;
+
 	return 1;
 }
 
diff --git a/builtin/clone.c b/builtin/clone.c
index 7c7f98c..739de68 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1136,9 +1136,13 @@
 				     option_upload_pack);
 
 	if (filter_options.choice) {
+		struct strbuf expanded_filter_spec = STRBUF_INIT;
+		expand_list_objects_filter_spec(&filter_options,
+						&expanded_filter_spec);
 		transport_set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
-				     filter_options.filter_spec);
+				     expanded_filter_spec.buf);
 		transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+		strbuf_release(&expanded_filter_spec);
 	}
 
 	if (transport->smart_options && !deepen && !filter_options.choice)
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index c02a3f1..4ae5027 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -110,8 +110,8 @@
 		printf(" oid_lookup");
 	if (graph->chunk_commit_data)
 		printf(" commit_metadata");
-	if (graph->chunk_large_edges)
-		printf(" large_edges");
+	if (graph->chunk_extra_edges)
+		printf(" extra_edges");
 	printf("\n");
 
 	UNLEAK(graph);
diff --git a/builtin/commit.c b/builtin/commit.c
index 004b816..7d2e0b6 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -351,7 +351,7 @@
 		if (write_locked_index(&the_index, &index_lock, 0))
 			die(_("unable to create temporary index"));
 
-		old_index_env = getenv(INDEX_ENVIRONMENT);
+		old_index_env = xstrdup_or_null(getenv(INDEX_ENVIRONMENT));
 		setenv(INDEX_ENVIRONMENT, get_lock_file_path(&index_lock), 1);
 
 		if (interactive_add(argc, argv, prefix, patch_interactive) != 0)
@@ -361,6 +361,7 @@
 			setenv(INDEX_ENVIRONMENT, old_index_env, 1);
 		else
 			unsetenv(INDEX_ENVIRONMENT);
+		FREE_AND_NULL(old_index_env);
 
 		discard_cache();
 		read_cache_from(get_lock_file_path(&index_lock));
diff --git a/builtin/config.c b/builtin/config.c
index 99bc7ef..98d65bc 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -599,7 +599,7 @@
 	int nongit = !startup_info->have_repository;
 	char *value;
 
-	given_config_source.file = getenv(CONFIG_ENVIRONMENT);
+	given_config_source.file = xstrdup_or_null(getenv(CONFIG_ENVIRONMENT));
 
 	argc = parse_options(argc, argv, prefix, builtin_config_options,
 			     builtin_config_usage,
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 63e69a5..153a2bd 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -55,6 +55,7 @@
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
 	struct packet_reader reader;
+	enum protocol_version version;
 
 	fetch_if_missing = 0;
 
@@ -217,11 +218,14 @@
 
 	packet_reader_init(&reader, fd[0], NULL, 0,
 			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
 
-	switch (discover_version(&reader)) {
+	version = discover_version(&reader);
+	switch (version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		get_remote_refs(fd[1], &reader, &ref, 0, NULL, NULL);
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &ref, 0, NULL, &shallow);
@@ -231,7 +235,7 @@
 	}
 
 	ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
-			 &shallow, pack_lockfile_ptr, protocol_v0);
+			 &shallow, pack_lockfile_ptr, version);
 	if (pack_lockfile) {
 		printf("lock %s\n", pack_lockfile);
 		fflush(stdout);
diff --git a/builtin/fetch.c b/builtin/fetch.c
index e014032..39c4210 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -629,9 +629,14 @@
 			    const char *needle,
 			    const char *placeholder)
 {
-	const char *p = strstr(haystack->buf, needle);
+	const char *p = NULL;
 	int plen, nlen;
 
+	nlen = strlen(needle);
+	if (ends_with(haystack->buf, needle))
+		p = haystack->buf + haystack->len - nlen;
+	else
+		p = strstr(haystack->buf, needle);
 	if (!p)
 		return 0;
 
@@ -639,7 +644,6 @@
 		return 0;
 
 	plen = strlen(p);
-	nlen = strlen(needle);
 	if (plen > nlen && p[nlen] != '/')
 		return 0;
 
@@ -763,9 +767,6 @@
 			what = _("[new ref]");
 		}
 
-		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
-		    (recurse_submodules != RECURSE_SUBMODULES_ON))
-			check_for_new_submodule_commits(&ref->new_oid);
 		r = s_update_ref(msg, ref, 0);
 		format_display(display, r ? '!' : '*', what,
 			       r ? _("unable to update local ref") : NULL,
@@ -779,9 +780,6 @@
 		strbuf_add_unique_abbrev(&quickref, &current->object.oid, DEFAULT_ABBREV);
 		strbuf_addstr(&quickref, "..");
 		strbuf_add_unique_abbrev(&quickref, &ref->new_oid, DEFAULT_ABBREV);
-		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
-		    (recurse_submodules != RECURSE_SUBMODULES_ON))
-			check_for_new_submodule_commits(&ref->new_oid);
 		r = s_update_ref("fast-forward", ref, 1);
 		format_display(display, r ? '!' : ' ', quickref.buf,
 			       r ? _("unable to update local ref") : NULL,
@@ -794,9 +792,6 @@
 		strbuf_add_unique_abbrev(&quickref, &current->object.oid, DEFAULT_ABBREV);
 		strbuf_addstr(&quickref, "...");
 		strbuf_add_unique_abbrev(&quickref, &ref->new_oid, DEFAULT_ABBREV);
-		if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
-		    (recurse_submodules != RECURSE_SUBMODULES_ON))
-			check_for_new_submodule_commits(&ref->new_oid);
 		r = s_update_ref("forced-update", ref, 1);
 		format_display(display, r ? '!' : '+', quickref.buf,
 			       r ? _("unable to update local ref") : _("forced update"),
@@ -892,6 +887,8 @@
 				ref->force = rm->peer_ref->force;
 			}
 
+			if (recurse_submodules != RECURSE_SUBMODULES_OFF)
+				check_for_new_submodule_commits(&rm->old_oid);
 
 			if (!strcmp(rm->name, "HEAD")) {
 				kind = "";
@@ -1172,6 +1169,7 @@
 static struct transport *prepare_transport(struct remote *remote, int deepen)
 {
 	struct transport *transport;
+
 	transport = transport_get(remote, NULL);
 	transport_set_verbosity(transport, verbosity, progress);
 	transport->family = family;
@@ -1191,9 +1189,13 @@
 	if (update_shallow)
 		set_option(transport, TRANS_OPT_UPDATE_SHALLOW, "yes");
 	if (filter_options.choice) {
+		struct strbuf expanded_filter_spec = STRBUF_INIT;
+		expand_list_objects_filter_spec(&filter_options,
+						&expanded_filter_spec);
 		set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
-			   filter_options.filter_spec);
+			   expanded_filter_spec.buf);
 		set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+		strbuf_release(&expanded_filter_spec);
 	}
 	if (negotiation_tip.nr) {
 		if (transport->smart_options)
@@ -1478,7 +1480,8 @@
 	 */
 	if (strcmp(remote->name, repository_format_partial_clone)) {
 		if (filter_options.choice)
-			die(_("--filter can only be used with the remote configured in core.partialClone"));
+			die(_("--filter can only be used with the remote "
+			      "configured in extensions.partialclone"));
 		return;
 	}
 
@@ -1646,7 +1649,8 @@
 		result = fetch_one(remote, argc, argv, prune_tags_ok);
 	} else {
 		if (filter_options.choice)
-			die(_("--filter can only be used with the remote configured in core.partialClone"));
+			die(_("--filter can only be used with the remote "
+			      "configured in extensions.partialclone"));
 		/* TODO should this also die if we have a previous partial-clone? */
 		result = fetch_multiple(&list);
 	}
diff --git a/builtin/fsck.c b/builtin/fsck.c
index bf5ddff..9c4c11d 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -401,7 +401,8 @@
 	if (obj->type == OBJ_TREE)
 		free_tree_buffer((struct tree *)obj);
 	if (obj->type == OBJ_COMMIT)
-		free_commit_buffer((struct commit *)obj);
+		free_commit_buffer(the_repository->parsed_objects,
+				   (struct commit *)obj);
 	return err;
 }
 
diff --git a/builtin/grep.c b/builtin/grep.c
index 4748195..dd52ea9 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -404,7 +404,10 @@
 			  const struct object_id *oid,
 			  const char *filename, const char *path)
 {
-	struct repository submodule;
+	struct repository subrepo;
+	const struct submodule *sub = submodule_from_path(superproject,
+							  &null_oid, path);
+
 	int hit;
 
 	/*
@@ -420,12 +423,12 @@
 		return 0;
 	}
 
-	if (repo_submodule_init(&submodule, superproject, path)) {
+	if (repo_submodule_init(&subrepo, superproject, sub)) {
 		grep_read_unlock();
 		return 0;
 	}
 
-	repo_read_gitmodules(&submodule);
+	repo_read_gitmodules(&subrepo);
 
 	/*
 	 * NEEDSWORK: This adds the submodule's object directory to the list of
@@ -437,7 +440,7 @@
 	 * store is no longer global and instead is a member of the repository
 	 * object.
 	 */
-	add_to_alternates_memory(submodule.objects->odb->path);
+	add_to_alternates_memory(subrepo.objects->odb->path);
 	grep_read_unlock();
 
 	if (oid) {
@@ -462,14 +465,14 @@
 
 		init_tree_desc(&tree, data, size);
 		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
-				object->type == OBJ_COMMIT, &submodule);
+				object->type == OBJ_COMMIT, &subrepo);
 		strbuf_release(&base);
 		free(data);
 	} else {
-		hit = grep_cache(opt, &submodule, pathspec, 1);
+		hit = grep_cache(opt, &subrepo, pathspec, 1);
 	}
 
-	repo_clear(&submodule);
+	repo_clear(&subrepo);
 	return hit;
 }
 
@@ -567,7 +570,7 @@
 		strbuf_add(base, entry.path, te_len);
 
 		if (S_ISREG(entry.mode)) {
-			hit |= grep_oid(opt, entry.oid, base->buf, tn_len,
+			hit |= grep_oid(opt, &entry.oid, base->buf, tn_len,
 					 check_attr ? base->buf + tn_len : NULL);
 		} else if (S_ISDIR(entry.mode)) {
 			enum object_type type;
@@ -575,10 +578,10 @@
 			void *data;
 			unsigned long size;
 
-			data = lock_and_read_oid_file(entry.oid, &type, &size);
+			data = lock_and_read_oid_file(&entry.oid, &type, &size);
 			if (!data)
 				die(_("unable to read tree (%s)"),
-				    oid_to_hex(entry.oid));
+				    oid_to_hex(&entry.oid));
 
 			strbuf_addch(base, '/');
 			init_tree_desc(&sub, data, size);
@@ -586,7 +589,7 @@
 					 check_attr, repo);
 			free(data);
 		} else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
-			hit |= grep_submodule(opt, repo, pathspec, entry.oid,
+			hit |= grep_submodule(opt, repo, pathspec, &entry.oid,
 					      base->buf, base->buf + tn_len);
 		}
 
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 41faffd..93eff76 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -542,8 +542,8 @@
 	 * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 	 * without --bare.  Catch the error early.
 	 */
-	git_dir = getenv(GIT_DIR_ENVIRONMENT);
-	work_tree = getenv(GIT_WORK_TREE_ENVIRONMENT);
+	git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
+	work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 	if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 		die(_("%s (or --work-tree=<directory>) not allowed without "
 			  "specifying %s (or --git-dir=<directory>)"),
@@ -582,6 +582,8 @@
 	}
 
 	UNLEAK(real_git_dir);
+	UNLEAK(git_dir);
+	UNLEAK(work_tree);
 
 	flags |= INIT_DB_EXIST_OK;
 	return init_db(git_dir, real_git_dir, template_dir, flags);
diff --git a/builtin/log.c b/builtin/log.c
index 3e145fe..c91a59d 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -203,7 +203,7 @@
 	    rev->diffopt.filter || rev->diffopt.flags.follow_renames)
 		rev->always_show_header = 0;
 
-	if (source) {
+	if (source || w.source) {
 		init_revision_sources(&revision_sources);
 		rev->sources = &revision_sources;
 	}
@@ -397,7 +397,8 @@
 			 * We may show a given commit multiple times when
 			 * walking the reflogs.
 			 */
-			free_commit_buffer(commit);
+			free_commit_buffer(the_repository->parsed_objects,
+					   commit);
 			free_commit_list(commit->parents);
 			commit->parents = NULL;
 		}
@@ -1940,7 +1941,8 @@
 		    open_next_file(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
 			die(_("Failed to create output files"));
 		shown = log_tree_commit(&rev, commit);
-		free_commit_buffer(commit);
+		free_commit_buffer(the_repository->parsed_objects,
+				   commit);
 
 		/* We put one extra blank line between formatted
 		 * patches and this flag is used by log-tree code
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 7e0dcaa..cde87cb 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -206,17 +206,19 @@
 static void show_submodule(struct repository *superproject,
 			   struct dir_struct *dir, const char *path)
 {
-	struct repository submodule;
+	struct repository subrepo;
+	const struct submodule *sub = submodule_from_path(superproject,
+							  &null_oid, path);
 
-	if (repo_submodule_init(&submodule, superproject, path))
+	if (repo_submodule_init(&subrepo, superproject, sub))
 		return;
 
-	if (repo_read_index(&submodule) < 0)
+	if (repo_read_index(&subrepo) < 0)
 		die("index file corrupt");
 
-	show_files(&submodule, dir);
+	show_files(&subrepo, dir);
 
-	repo_clear(&submodule);
+	repo_clear(&subrepo);
 }
 
 static void show_ce(struct repository *repo, struct dir_struct *dir,
diff --git a/builtin/merge-recursive.c b/builtin/merge-recursive.c
index 9b2f707..7545136 100644
--- a/builtin/merge-recursive.c
+++ b/builtin/merge-recursive.c
@@ -7,16 +7,16 @@
 static const char builtin_merge_recursive_usage[] =
 	"git %s <base>... -- <head> <remote> ...";
 
-static const char *better_branch_name(const char *branch)
+static char *better_branch_name(const char *branch)
 {
 	static char githead_env[8 + GIT_MAX_HEXSZ + 1];
 	char *name;
 
 	if (strlen(branch) != the_hash_algo->hexsz)
-		return branch;
+		return xstrdup(branch);
 	xsnprintf(githead_env, sizeof(githead_env), "GITHEAD_%s", branch);
 	name = getenv(githead_env);
-	return name ? name : branch;
+	return xstrdup(name ? name : branch);
 }
 
 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
@@ -26,6 +26,7 @@
 	int i, failed;
 	struct object_id h1, h2;
 	struct merge_options o;
+	char *better1, *better2;
 	struct commit *result;
 
 	init_merge_options(&o);
@@ -70,13 +71,17 @@
 	if (get_oid(o.branch2, &h2))
 		die(_("could not resolve ref '%s'"), o.branch2);
 
-	o.branch1 = better_branch_name(o.branch1);
-	o.branch2 = better_branch_name(o.branch2);
+	o.branch1 = better1 = better_branch_name(o.branch1);
+	o.branch2 = better2 = better_branch_name(o.branch2);
 
 	if (o.verbosity >= 3)
 		printf(_("Merging %s with %s\n"), o.branch1, o.branch2);
 
 	failed = merge_recursive_generic(&o, &h1, &h2, bases_count, bases, &result);
+
+	free(better1);
+	free(better2);
+
 	if (failed < 0)
 		return 128; /* die() error code */
 	return failed;
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 4984b7e..5541ad0 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -154,15 +154,15 @@
 /* An empty entry never compares same, not even to another empty entry */
 static int same_entry(struct name_entry *a, struct name_entry *b)
 {
-	return	a->oid &&
-		b->oid &&
-		oideq(a->oid, b->oid) &&
+	return	!is_null_oid(&a->oid) &&
+		!is_null_oid(&b->oid) &&
+		oideq(&a->oid, &b->oid) &&
 		a->mode == b->mode;
 }
 
 static int both_empty(struct name_entry *a, struct name_entry *b)
 {
-	return !(a->oid || b->oid);
+	return is_null_oid(&a->oid) && is_null_oid(&b->oid);
 }
 
 static struct merge_list *create_entry(unsigned stage, unsigned mode, const struct object_id *oid, const char *path)
@@ -178,7 +178,7 @@
 
 static char *traverse_path(const struct traverse_info *info, const struct name_entry *n)
 {
-	char *path = xmallocz(traverse_path_len(info, n));
+	char *path = xmallocz(traverse_path_len(info, n) + the_hash_algo->rawsz);
 	return make_traverse_path(path, info, n);
 }
 
@@ -192,8 +192,8 @@
 		return;
 
 	path = traverse_path(info, result);
-	orig = create_entry(2, ours->mode, ours->oid, path);
-	final = create_entry(0, result->mode, result->oid, path);
+	orig = create_entry(2, ours->mode, &ours->oid, path);
+	final = create_entry(0, result->mode, &result->oid, path);
 
 	final->link = orig;
 
@@ -217,7 +217,7 @@
 
 	newbase = traverse_path(info, p);
 
-#define ENTRY_OID(e) (((e)->mode && S_ISDIR((e)->mode)) ? (e)->oid : NULL)
+#define ENTRY_OID(e) (((e)->mode && S_ISDIR((e)->mode)) ? &(e)->oid : NULL)
 	buf0 = fill_tree_descriptor(t + 0, ENTRY_OID(n + 0));
 	buf1 = fill_tree_descriptor(t + 1, ENTRY_OID(n + 1));
 	buf2 = fill_tree_descriptor(t + 2, ENTRY_OID(n + 2));
@@ -243,7 +243,7 @@
 		path = entry->path;
 	else
 		path = traverse_path(info, n);
-	link = create_entry(stage, n->mode, n->oid, path);
+	link = create_entry(stage, n->mode, &n->oid, path);
 	link->link = entry;
 	return link;
 }
@@ -318,7 +318,7 @@
 	}
 
 	if (same_entry(entry+0, entry+1)) {
-		if (entry[2].oid && !S_ISDIR(entry[2].mode)) {
+		if (!is_null_oid(&entry[2].oid) && !S_ISDIR(entry[2].mode)) {
 			/* We did not touch, they modified -- take theirs */
 			resolve(info, entry+1, entry+2);
 			return mask;
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 889df2c..8eb5391 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1334,7 +1334,7 @@
 		if (cmp < 0)
 			return;
 		if (name[cmplen] != '/') {
-			add_object_entry(entry.oid,
+			add_object_entry(&entry.oid,
 					 object_type(entry.mode),
 					 fullname, 1);
 			return;
@@ -1345,7 +1345,7 @@
 			const char *down = name+cmplen+1;
 			int downlen = name_cmp_len(down);
 
-			tree = pbase_tree_get(entry.oid);
+			tree = pbase_tree_get(&entry.oid);
 			if (!tree)
 				return;
 			init_tree_desc(&sub, tree->tree_data, tree->tree_size);
@@ -1953,11 +1953,6 @@
 	return 0;
 }
 
-/* Protect access to object database */
-static pthread_mutex_t read_mutex;
-#define read_lock()		pthread_mutex_lock(&read_mutex)
-#define read_unlock()		pthread_mutex_unlock(&read_mutex)
-
 /* Protect delta_cache_size */
 static pthread_mutex_t cache_mutex;
 #define cache_lock()		pthread_mutex_lock(&cache_mutex)
@@ -1993,11 +1988,11 @@
 	unsigned long used, avail, size;
 
 	if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
-		read_lock();
+		packing_data_lock(&to_pack);
 		if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
 			die(_("unable to get size of %s"),
 			    oid_to_hex(&e->idx.oid));
-		read_unlock();
+		packing_data_unlock(&to_pack);
 		return size;
 	}
 
@@ -2005,7 +2000,7 @@
 	if (!p)
 		BUG("when e->type is a delta, it must belong to a pack");
 
-	read_lock();
+	packing_data_lock(&to_pack);
 	w_curs = NULL;
 	buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
 	used = unpack_object_header_buffer(buf, avail, &type, &size);
@@ -2014,7 +2009,7 @@
 		    oid_to_hex(&e->idx.oid));
 
 	unuse_pack(&w_curs);
-	read_unlock();
+	packing_data_unlock(&to_pack);
 	return size;
 }
 
@@ -2076,9 +2071,9 @@
 
 	/* Load data if not already done */
 	if (!trg->data) {
-		read_lock();
+		packing_data_lock(&to_pack);
 		trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
-		read_unlock();
+		packing_data_unlock(&to_pack);
 		if (!trg->data)
 			die(_("object %s cannot be read"),
 			    oid_to_hex(&trg_entry->idx.oid));
@@ -2089,9 +2084,9 @@
 		*mem_usage += sz;
 	}
 	if (!src->data) {
-		read_lock();
+		packing_data_lock(&to_pack);
 		src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
-		read_unlock();
+		packing_data_unlock(&to_pack);
 		if (!src->data) {
 			if (src_entry->preferred_base) {
 				static int warned = 0;
@@ -2337,9 +2332,9 @@
 
 static void try_to_free_from_threads(size_t size)
 {
-	read_lock();
+	packing_data_lock(&to_pack);
 	release_pack_memory(size);
-	read_unlock();
+	packing_data_unlock(&to_pack);
 }
 
 static try_to_free_t old_try_to_free_routine;
@@ -2381,7 +2376,6 @@
  */
 static void init_threaded_search(void)
 {
-	init_recursive_mutex(&read_mutex);
 	pthread_mutex_init(&cache_mutex, NULL);
 	pthread_mutex_init(&progress_mutex, NULL);
 	pthread_cond_init(&progress_cond, NULL);
@@ -2392,7 +2386,6 @@
 {
 	set_try_to_free_routine(old_try_to_free_routine);
 	pthread_cond_destroy(&progress_cond);
-	pthread_mutex_destroy(&read_mutex);
 	pthread_mutex_destroy(&cache_mutex);
 	pthread_mutex_destroy(&progress_mutex);
 }
diff --git a/builtin/rebase--interactive.c b/builtin/rebase--interactive.c
index dd2a55a..c2c2d51 100644
--- a/builtin/rebase--interactive.c
+++ b/builtin/rebase--interactive.c
@@ -193,6 +193,8 @@
 		OPT_STRING(0, "onto-name", &onto_name, N_("onto-name"), N_("onto name")),
 		OPT_STRING(0, "cmd", &cmd, N_("cmd"), N_("the command to run")),
 		OPT_RERERE_AUTOUPDATE(&opts.allow_rerere_auto),
+		OPT_BOOL(0, "reschedule-failed-exec", &opts.reschedule_failed_exec,
+			 N_("automatically re-schedule any `exec` that fails")),
 		OPT_END()
 	};
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 00de703..3f9b26f 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -104,6 +104,7 @@
 	int rebase_merges, rebase_cousins;
 	char *strategy, *strategy_opts;
 	struct strbuf git_format_patch_opt;
+	int reschedule_failed_exec;
 };
 
 static int is_interactive(struct rebase_options *opts)
@@ -122,7 +123,7 @@
 	case REBASE_PRESERVE_MERGES:
 		break;
 	case REBASE_MERGE:
-		/* we silently *upgrade* --merge to --interactive if needed */
+		/* we now implement --merge via --interactive */
 	default:
 		opts->type = REBASE_INTERACTIVE; /* implied */
 		break;
@@ -185,10 +186,7 @@
 	if (get_oid(buf.buf, &opts->orig_head))
 		return error(_("invalid orig-head: '%s'"), buf.buf);
 
-	strbuf_reset(&buf);
-	if (read_one(state_dir_path("quiet", opts), &buf))
-		return -1;
-	if (buf.len)
+	if (file_exists(state_dir_path("quiet", opts)))
 		opts->flags &= ~REBASE_NO_QUIET;
 	else
 		opts->flags |= REBASE_NO_QUIET;
@@ -354,7 +352,8 @@
 		argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
 				 resolvemsg);
 		if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
-			argv_array_push(&child.env_array, "GIT_EDITOR=:");
+			argv_array_push(&child.env_array,
+					"GIT_SEQUENCE_EDITOR=:");
 			opts->autosquash = 0;
 		}
 
@@ -415,6 +414,8 @@
 			argv_array_push(&child.args, opts->gpg_sign_opt);
 		if (opts->signoff)
 			argv_array_push(&child.args, "--signoff");
+		if (opts->reschedule_failed_exec)
+			argv_array_push(&child.args, "--reschedule-failed-exec");
 
 		status = run_command(&child);
 		goto finished_rebase;
@@ -475,7 +476,7 @@
 	if (is_interactive(opts) &&
 	    !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
 		strbuf_addstr(&script_snippet,
-			      "GIT_EDITOR=:; export GIT_EDITOR; ");
+			      "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
 		opts->autosquash = 0;
 	}
 
@@ -484,10 +485,6 @@
 		backend = "git-rebase--am";
 		backend_func = "git_rebase__am";
 		break;
-	case REBASE_MERGE:
-		backend = "git-rebase--merge";
-		backend_func = "git_rebase__merge";
-		break;
 	case REBASE_PRESERVE_MERGES:
 		backend = "git-rebase--preserve-merges";
 		backend_func = "git_rebase__preserve_merges";
@@ -530,6 +527,7 @@
 
 #define RESET_HEAD_DETACH (1<<0)
 #define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
 
 static int reset_head(struct object_id *oid, const char *action,
 		      const char *switch_to_branch, unsigned flags,
@@ -537,6 +535,7 @@
 {
 	unsigned detach_head = flags & RESET_HEAD_DETACH;
 	unsigned reset_hard = flags & RESET_HEAD_HARD;
+	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
 	struct object_id head_oid;
 	struct tree_desc desc[2] = { { NULL }, { NULL } };
 	struct lock_file lock = LOCK_INIT;
@@ -636,6 +635,10 @@
 			ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
 					 UPDATE_REFS_MSG_ON_ERR);
 	}
+	if (run_hook)
+		run_hook_le(NULL, "post-checkout",
+			    oid_to_hex(orig ? orig : &null_oid),
+			    oid_to_hex(oid), "1", NULL);
 
 leave_reset_head:
 	strbuf_release(&msg);
@@ -674,6 +677,11 @@
 		return 0;
 	}
 
+	if (!strcmp(var, "rebase.reschedulefailedexec")) {
+		opts->reschedule_failed_exec = git_config_bool(var, value);
+		return 0;
+	}
+
 	return git_default_config(var, value, data);
 }
 
@@ -746,6 +754,23 @@
 	return 0;
 }
 
+struct opt_y {
+	struct string_list *list;
+	struct rebase_options *options;
+};
+
+static int parse_opt_y(const struct option *opt, const char *arg, int unset)
+{
+	struct opt_y *o = opt->value;
+
+	if (unset || !arg)
+		return -1;
+
+	o->options->reschedule_failed_exec = 1;
+	string_list_append(o->list, arg);
+	return 0;
+}
+
 static void NORETURN error_on_missing_default_upstream(void)
 {
 	struct branch *current_branch = branch_get(NULL);
@@ -826,6 +851,7 @@
 	struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 	struct object_id squash_onto;
 	char *squash_onto_name = NULL;
+	struct opt_y opt_y = { .list = &exec, .options = &options };
 	struct option builtin_rebase_options[] = {
 		OPT_STRING(0, "onto", &options.onto_name,
 			   N_("revision"),
@@ -903,6 +929,9 @@
 		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 				N_("add exec lines after each commit of the "
 				   "editable list")),
+		{ OPTION_CALLBACK, 'y', NULL, &opt_y, N_("<cmd>"),
+			N_("same as --reschedule-failed-exec -x <cmd>"),
+			PARSE_OPT_NONEG, parse_opt_y },
 		OPT_BOOL(0, "allow-empty-message",
 			 &options.allow_empty_message,
 			 N_("allow rebasing commits with empty messages")),
@@ -920,6 +949,9 @@
 				   "strategy")),
 		OPT_BOOL(0, "root", &options.root,
 			 N_("rebase all reachable commits up to the root(s)")),
+		OPT_BOOL(0, "reschedule-failed-exec",
+			 &options.reschedule_failed_exec,
+			 N_("automatically re-schedule any `exec` that fails")),
 		OPT_END(),
 	};
 	int i;
@@ -1194,6 +1226,9 @@
 		}
 	}
 
+	if (options.type == REBASE_MERGE)
+		imply_interactive(&options, "--merge");
+
 	if (options.root && !options.onto_name)
 		imply_interactive(&options, "--root without --onto");
 
@@ -1216,6 +1251,9 @@
 		break;
 	}
 
+	if (options.reschedule_failed_exec && !is_interactive(&options))
+		die(_("--reschedule-failed-exec requires an interactive rebase"));
+
 	if (options.git_am_opts.argc) {
 		/* all am options except -q are compatible only with --am */
 		for (i = options.git_am_opts.argc - 1; i >= 0; i--)
@@ -1223,14 +1261,8 @@
 				break;
 
 		if (is_interactive(&options) && i >= 0)
-			die(_("error: cannot combine interactive options "
-			      "(--interactive, --exec, --rebase-merges, "
-			      "--preserve-merges, --keep-empty, --root + "
-			      "--onto) with am options (%s)"), buf.buf);
-		if (options.type == REBASE_MERGE && i >= 0)
-			die(_("error: cannot combine merge options (--merge, "
-			      "--strategy, --strategy-option) with am options "
-			      "(%s)"), buf.buf);
+			die(_("cannot combine am options with either "
+			      "interactive or merge options"));
 	}
 
 	if (options.signoff) {
@@ -1241,22 +1273,27 @@
 		options.flags |= REBASE_FORCE;
 	}
 
-	if (options.type == REBASE_PRESERVE_MERGES)
+	if (options.type == REBASE_PRESERVE_MERGES) {
 		/*
 		 * Note: incompatibility with --signoff handled in signoff block above
 		 * Note: incompatibility with --interactive is just a strong warning;
 		 *       git-rebase.txt caveats with "unless you know what you are doing"
 		 */
 		if (options.rebase_merges)
-			die(_("error: cannot combine '--preserve-merges' with "
+			die(_("cannot combine '--preserve-merges' with "
 			      "'--rebase-merges'"));
 
+		if (options.reschedule_failed_exec)
+			die(_("error: cannot combine '--preserve-merges' with "
+			      "'--reschedule-failed-exec'"));
+	}
+
 	if (options.rebase_merges) {
 		if (strategy_options.nr)
-			die(_("error: cannot combine '--rebase-merges' with "
+			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy-option'"));
 		if (options.strategy)
-			die(_("error: cannot combine '--rebase-merges' with "
+			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy'"));
 	}
 
@@ -1466,7 +1503,8 @@
 					    getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
 					    options.switch_to);
 				if (reset_head(&oid, "checkout",
-					       options.head_name, 0,
+					       options.head_name,
+					       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
 					       NULL, buf.buf) < 0) {
 					ret = !!error(_("could not switch to "
 							"%s"),
@@ -1540,7 +1578,8 @@
 	strbuf_addf(&msg, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
 	if (reset_head(&options.onto->object.oid, "checkout", NULL,
-		       RESET_HEAD_DETACH, NULL, msg.buf))
+		       RESET_HEAD_DETACH | RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
+		       NULL, msg.buf))
 		die(_("Could not detach HEAD"));
 	strbuf_release(&msg);
 
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 33187bd..d58b775 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1569,30 +1569,29 @@
 	}
 }
 
-static struct command *read_head_info(struct oid_array *shallow)
+static struct command *read_head_info(struct packet_reader *reader,
+				      struct oid_array *shallow)
 {
 	struct command *commands = NULL;
 	struct command **p = &commands;
 	for (;;) {
-		char *line;
-		int len, linelen;
+		int linelen;
 
-		line = packet_read_line(0, &len);
-		if (!line)
+		if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 			break;
 
-		if (len > 8 && starts_with(line, "shallow ")) {
+		if (reader->pktlen > 8 && starts_with(reader->line, "shallow ")) {
 			struct object_id oid;
-			if (get_oid_hex(line + 8, &oid))
+			if (get_oid_hex(reader->line + 8, &oid))
 				die("protocol error: expected shallow sha, got '%s'",
-				    line + 8);
+				    reader->line + 8);
 			oid_array_append(shallow, &oid);
 			continue;
 		}
 
-		linelen = strlen(line);
-		if (linelen < len) {
-			const char *feature_list = line + linelen + 1;
+		linelen = strlen(reader->line);
+		if (linelen < reader->pktlen) {
+			const char *feature_list = reader->line + linelen + 1;
 			if (parse_feature_request(feature_list, "report-status"))
 				report_status = 1;
 			if (parse_feature_request(feature_list, "side-band-64k"))
@@ -1607,28 +1606,32 @@
 				use_push_options = 1;
 		}
 
-		if (!strcmp(line, "push-cert")) {
+		if (!strcmp(reader->line, "push-cert")) {
 			int true_flush = 0;
-			char certbuf[1024];
+			int saved_options = reader->options;
+			reader->options &= ~PACKET_READ_CHOMP_NEWLINE;
 
 			for (;;) {
-				len = packet_read(0, NULL, NULL,
-						  certbuf, sizeof(certbuf), 0);
-				if (!len) {
+				packet_reader_read(reader);
+				if (reader->status == PACKET_READ_FLUSH) {
 					true_flush = 1;
 					break;
 				}
-				if (!strcmp(certbuf, "push-cert-end\n"))
+				if (reader->status != PACKET_READ_NORMAL) {
+					die("protocol error: got an unexpected packet");
+				}
+				if (!strcmp(reader->line, "push-cert-end\n"))
 					break; /* end of cert */
-				strbuf_addstr(&push_cert, certbuf);
+				strbuf_addstr(&push_cert, reader->line);
 			}
+			reader->options = saved_options;
 
 			if (true_flush)
 				break;
 			continue;
 		}
 
-		p = queue_command(p, line, linelen);
+		p = queue_command(p, reader->line, linelen);
 	}
 
 	if (push_cert.len)
@@ -1637,18 +1640,14 @@
 	return commands;
 }
 
-static void read_push_options(struct string_list *options)
+static void read_push_options(struct packet_reader *reader,
+			      struct string_list *options)
 {
 	while (1) {
-		char *line;
-		int len;
-
-		line = packet_read_line(0, &len);
-
-		if (!line)
+		if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 			break;
 
-		string_list_append(options, line);
+		string_list_append(options, reader->line);
 	}
 }
 
@@ -1924,6 +1923,7 @@
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct oid_array ref = OID_ARRAY_INIT;
 	struct shallow_info si;
+	struct packet_reader reader;
 
 	struct option options[] = {
 		OPT__QUIET(&quiet, N_("quiet")),
@@ -1986,12 +1986,16 @@
 	if (advertise_refs)
 		return 0;
 
-	if ((commands = read_head_info(&shallow)) != NULL) {
+	packet_reader_init(&reader, 0, NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+
+	if ((commands = read_head_info(&reader, &shallow)) != NULL) {
 		const char *unpack_status = NULL;
 		struct string_list push_options = STRING_LIST_INIT_DUP;
 
 		if (use_push_options)
-			read_push_options(&push_options);
+			read_push_options(&reader, &push_options);
 		if (!check_cert_push_options(&push_options)) {
 			struct command *cmd;
 			for (cmd = commands; cmd; cmd = cmd->next)
diff --git a/builtin/reflog.c b/builtin/reflog.c
index 64a8df4..1f1010e 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -94,8 +94,8 @@
 	init_tree_desc(&desc, tree->buffer, tree->size);
 	complete = 1;
 	while (tree_entry(&desc, &entry)) {
-		if (!has_sha1_file(entry.oid->hash) ||
-		    (S_ISDIR(entry.mode) && !tree_is_complete(entry.oid))) {
+		if (!has_sha1_file(entry.oid.hash) ||
+		    (S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
 			tree->object.flags |= INCOMPLETE;
 			complete = 0;
 		}
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 51e9e12..14ef659 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -197,7 +197,8 @@
 		free_commit_list(commit->parents);
 		commit->parents = NULL;
 	}
-	free_commit_buffer(commit);
+	free_commit_buffer(the_repository->parsed_objects,
+			   commit);
 }
 
 static inline void finish_object__ma(struct object *obj)
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 8e3c749..098ebf2 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -250,7 +250,8 @@
 
 	packet_reader_init(&reader, fd[0], NULL, 0,
 			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
 
 	switch (discover_version(&reader)) {
 	case protocol_v2:
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6881b6a..0e140f1 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -2056,7 +2056,7 @@
 	if (!sub)
 		BUG("We could get the submodule handle before?");
 
-	if (repo_submodule_init(&subrepo, the_repository, path))
+	if (repo_submodule_init(&subrepo, the_repository, sub))
 		die(_("could not get a repository handle for submodule '%s'"), path);
 
 	if (!repo_config_get_string(&subrepo, "core.worktree", &cw)) {
diff --git a/cache-tree.c b/cache-tree.c
index eabb8fb..c4b8a1f 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -675,7 +675,7 @@
 			cnt++;
 		else {
 			struct cache_tree_sub *sub;
-			struct tree *subtree = lookup_tree(r, entry.oid);
+			struct tree *subtree = lookup_tree(r, &entry.oid);
 			if (!subtree->object.parsed)
 				parse_tree(subtree);
 			sub = cache_tree_sub(it, entry.path);
@@ -724,7 +724,7 @@
 
 	it = find_cache_tree_from_traversal(root, info);
 	it = cache_tree_find(it, ent->path);
-	if (it && it->entry_count > 0 && oideq(ent->oid, &it->oid))
+	if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 		return it->entry_count;
 	return 0;
 }
diff --git a/cache.h b/cache.h
index 70652e9..156a839 100644
--- a/cache.h
+++ b/cache.h
@@ -45,10 +45,20 @@
 /* The length in bytes and in hex digits of an object name (SHA-1 value). */
 #define GIT_SHA1_RAWSZ 20
 #define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
+/* The block size of SHA-1. */
+#define GIT_SHA1_BLKSZ 64
+
+/* The length in bytes and in hex digits of an object name (SHA-256 value). */
+#define GIT_SHA256_RAWSZ 32
+#define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ)
+/* The block size of SHA-256. */
+#define GIT_SHA256_BLKSZ 64
 
 /* The length in byte and in hex digits of the largest possible hash value. */
-#define GIT_MAX_RAWSZ GIT_SHA1_RAWSZ
-#define GIT_MAX_HEXSZ GIT_SHA1_HEXSZ
+#define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ
+#define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ
+/* The largest possible block size for any supported hash. */
+#define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ
 
 struct object_id {
 	unsigned char hash[GIT_MAX_RAWSZ];
@@ -745,6 +755,7 @@
 #define ADD_CACHE_JUST_APPEND 8		/* Append only; tree.c::read_tree() */
 #define ADD_CACHE_NEW_ONLY 16		/* Do not replace existing ones */
 #define ADD_CACHE_KEEP_CACHE_TREE 32	/* Do not invalidate cache-tree */
+#define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
 extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
 extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
 
@@ -1028,16 +1039,12 @@
 static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 {
 	/*
-	 * This is a temporary optimization hack. By asserting the size here,
-	 * we let the compiler know that it's always going to be 20, which lets
-	 * it turn this fixed-size memcmp into a few inline instructions.
-	 *
-	 * This will need to be extended or ripped out when we learn about
-	 * hashes of different sizes.
+	 * Teach the compiler that there are only two possibilities of hash size
+	 * here, so that it can optimize for this case as much as possible.
 	 */
-	if (the_hash_algo->rawsz != 20)
-		BUG("hash size not yet supported by hashcmp");
-	return memcmp(sha1, sha2, the_hash_algo->rawsz);
+	if (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
+		return memcmp(sha1, sha2, GIT_MAX_RAWSZ);
+	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
 }
 
 static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
@@ -1047,7 +1054,13 @@
 
 static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2)
 {
-	return !hashcmp(sha1, sha2);
+	/*
+	 * We write this here instead of deferring to hashcmp so that the
+	 * compiler can properly inline it and avoid calling memcmp.
+	 */
+	if (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
+		return !memcmp(sha1, sha2, GIT_MAX_RAWSZ);
+	return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
 }
 
 static inline int oideq(const struct object_id *oid1, const struct object_id *oid2)
@@ -1072,7 +1085,7 @@
 
 static inline void oidcpy(struct object_id *dst, const struct object_id *src)
 {
-	hashcpy(dst->hash, src->hash);
+	memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
 }
 
 static inline struct object_id *oiddup(const struct object_id *src)
@@ -1383,9 +1396,9 @@
 extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
 
 /*
- * Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
+ * Convert a binary hash to its hex equivalent. The `_r` variant is reentrant,
  * and writes the NUL-terminated output to the buffer `out`, which must be at
- * least `GIT_SHA1_HEXSZ + 1` bytes, and returns a pointer to out for
+ * least `GIT_MAX_HEXSZ + 1` bytes, and returns a pointer to out for
  * convenience.
  *
  * The non-`_r` variant returns a static buffer, but uses a ring of 4
@@ -1393,10 +1406,13 @@
  *
  *   printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
  */
-extern char *sha1_to_hex_r(char *out, const unsigned char *sha1);
-extern char *oid_to_hex_r(char *out, const struct object_id *oid);
-extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
-extern char *oid_to_hex(const struct object_id *oid);	/* same static buffer as sha1_to_hex */
+char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash, const struct git_hash_algo *);
+char *sha1_to_hex_r(char *out, const unsigned char *sha1);
+char *oid_to_hex_r(char *out, const struct object_id *oid);
+char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *);	/* static buffer result! */
+char *sha1_to_hex(const unsigned char *sha1);						/* same static buffer */
+char *hash_to_hex(const unsigned char *hash);						/* same static buffer */
+char *oid_to_hex(const struct object_id *oid);						/* same static buffer */
 
 /*
  * Parse a 40-character hexadecimal object ID starting from hex, updating the
diff --git a/combine-diff.c b/combine-diff.c
index a143c00..23d8fab 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -1321,6 +1321,14 @@
 	return path->path;
 }
 
+/*
+ * Diff stat formats which we always compute solely against the first parent.
+ */
+#define STAT_FORMAT_MASK (DIFF_FORMAT_NUMSTAT \
+			  | DIFF_FORMAT_SHORTSTAT \
+			  | DIFF_FORMAT_SUMMARY \
+			  | DIFF_FORMAT_DIRSTAT \
+			  | DIFF_FORMAT_DIFFSTAT)
 
 /* find set of paths that every parent touches */
 static struct combine_diff_path *find_paths_generic(const struct object_id *oid,
@@ -1342,8 +1350,7 @@
 		 * show stat against the first parent even when doing
 		 * combined diff.
 		 */
-		int stat_opt = (output_format &
-				(DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
+		int stat_opt = output_format & STAT_FORMAT_MASK;
 		if (i == 0 && stat_opt)
 			opt->output_format = stat_opt;
 		else
@@ -1470,8 +1477,7 @@
 		 * show stat against the first parent even
 		 * when doing combined diff.
 		 */
-		stat_opt = (opt->output_format &
-				(DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
+		stat_opt = opt->output_format & STAT_FORMAT_MASK;
 		if (stat_opt) {
 			diffopts.output_format = stat_opt;
 
@@ -1515,8 +1521,7 @@
 				show_raw_diff(p, num_parent, rev);
 			needsep = 1;
 		}
-		else if (opt->output_format &
-			 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
+		else if (opt->output_format & STAT_FORMAT_MASK)
 			needsep = 1;
 		else if (opt->output_format & DIFF_FORMAT_CALLBACK)
 			handle_combined_callback(opt, paths, num_parent, num_paths);
diff --git a/commit-graph.c b/commit-graph.c
index 0d6ba6d..47e9be0 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -21,19 +21,14 @@
 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
 #define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
-#define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
+#define GRAPH_CHUNKID_EXTRAEDGES 0x45444745 /* "EDGE" */
 
-#define GRAPH_DATA_WIDTH 36
+#define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
 
 #define GRAPH_VERSION_1 0x1
 #define GRAPH_VERSION GRAPH_VERSION_1
 
-#define GRAPH_OID_VERSION_SHA1 1
-#define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ
-#define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1
-#define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1
-
-#define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
+#define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
 #define GRAPH_PARENT_NONE 0x70000000
 
@@ -43,13 +38,18 @@
 #define GRAPH_FANOUT_SIZE (4 * 256)
 #define GRAPH_CHUNKLOOKUP_WIDTH 12
 #define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
-			+ GRAPH_FANOUT_SIZE + GRAPH_OID_LEN)
+			+ GRAPH_FANOUT_SIZE + the_hash_algo->rawsz)
 
 char *get_commit_graph_filename(const char *obj_dir)
 {
 	return xstrfmt("%s/info/commit-graph", obj_dir);
 }
 
+static uint8_t oid_version(void)
+{
+	return 1;
+}
+
 static struct commit_graph *alloc_commit_graph(void)
 {
 	struct commit_graph *g = xcalloc(1, sizeof(*g));
@@ -83,16 +83,10 @@
 struct commit_graph *load_commit_graph_one(const char *graph_file)
 {
 	void *graph_map;
-	const unsigned char *data, *chunk_lookup;
 	size_t graph_size;
 	struct stat st;
-	uint32_t i;
-	struct commit_graph *graph;
+	struct commit_graph *ret;
 	int fd = git_open(graph_file);
-	uint64_t last_chunk_offset;
-	uint32_t last_chunk_id;
-	uint32_t graph_signature;
-	unsigned char graph_version, hash_version;
 
 	if (fd < 0)
 		return NULL;
@@ -107,32 +101,60 @@
 		die(_("graph file %s is too small"), graph_file);
 	}
 	graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	ret = parse_commit_graph(graph_map, fd, graph_size);
+
+	if (!ret) {
+		munmap(graph_map, graph_size);
+		close(fd);
+		exit(1);
+	}
+
+	return ret;
+}
+
+struct commit_graph *parse_commit_graph(void *graph_map, int fd,
+					size_t graph_size)
+{
+	const unsigned char *data, *chunk_lookup;
+	uint32_t i;
+	struct commit_graph *graph;
+	uint64_t last_chunk_offset;
+	uint32_t last_chunk_id;
+	uint32_t graph_signature;
+	unsigned char graph_version, hash_version;
+
+	if (!graph_map)
+		return NULL;
+
+	if (graph_size < GRAPH_MIN_SIZE)
+		return NULL;
+
 	data = (const unsigned char *)graph_map;
 
 	graph_signature = get_be32(data);
 	if (graph_signature != GRAPH_SIGNATURE) {
 		error(_("graph signature %X does not match signature %X"),
 		      graph_signature, GRAPH_SIGNATURE);
-		goto cleanup_fail;
+		return NULL;
 	}
 
 	graph_version = *(unsigned char*)(data + 4);
 	if (graph_version != GRAPH_VERSION) {
 		error(_("graph version %X does not match version %X"),
 		      graph_version, GRAPH_VERSION);
-		goto cleanup_fail;
+		return NULL;
 	}
 
 	hash_version = *(unsigned char*)(data + 5);
-	if (hash_version != GRAPH_OID_VERSION) {
+	if (hash_version != oid_version()) {
 		error(_("hash version %X does not match version %X"),
-		      hash_version, GRAPH_OID_VERSION);
-		goto cleanup_fail;
+		      hash_version, oid_version());
+		return NULL;
 	}
 
 	graph = alloc_commit_graph();
 
-	graph->hash_len = GRAPH_OID_LEN;
+	graph->hash_len = the_hash_algo->rawsz;
 	graph->num_chunks = *(unsigned char*)(data + 6);
 	graph->graph_fd = fd;
 	graph->data = graph_map;
@@ -142,16 +164,27 @@
 	last_chunk_offset = 8;
 	chunk_lookup = data + 8;
 	for (i = 0; i < graph->num_chunks; i++) {
-		uint32_t chunk_id = get_be32(chunk_lookup + 0);
-		uint64_t chunk_offset = get_be64(chunk_lookup + 4);
+		uint32_t chunk_id;
+		uint64_t chunk_offset;
 		int chunk_repeated = 0;
 
+		if (data + graph_size - chunk_lookup <
+		    GRAPH_CHUNKLOOKUP_WIDTH) {
+			error(_("chunk lookup table entry missing; graph file may be incomplete"));
+			free(graph);
+			return NULL;
+		}
+
+		chunk_id = get_be32(chunk_lookup + 0);
+		chunk_offset = get_be64(chunk_lookup + 4);
+
 		chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
 
-		if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {
+		if (chunk_offset > graph_size - the_hash_algo->rawsz) {
 			error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
 			      (uint32_t)chunk_offset);
-			goto cleanup_fail;
+			free(graph);
+			return NULL;
 		}
 
 		switch (chunk_id) {
@@ -176,17 +209,18 @@
 				graph->chunk_commit_data = data + chunk_offset;
 			break;
 
-		case GRAPH_CHUNKID_LARGEEDGES:
-			if (graph->chunk_large_edges)
+		case GRAPH_CHUNKID_EXTRAEDGES:
+			if (graph->chunk_extra_edges)
 				chunk_repeated = 1;
 			else
-				graph->chunk_large_edges = data + chunk_offset;
+				graph->chunk_extra_edges = data + chunk_offset;
 			break;
 		}
 
 		if (chunk_repeated) {
 			error(_("chunk id %08x appears multiple times"), chunk_id);
-			goto cleanup_fail;
+			free(graph);
+			return NULL;
 		}
 
 		if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
@@ -200,11 +234,6 @@
 	}
 
 	return graph;
-
-cleanup_fail:
-	munmap(graph_map, graph_size);
-	close(fd);
-	exit(1);
 }
 
 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
@@ -288,7 +317,8 @@
 			    g->chunk_oid_lookup, g->hash_len, pos);
 }
 
-static struct commit_list **insert_parent_or_die(struct commit_graph *g,
+static struct commit_list **insert_parent_or_die(struct repository *r,
+						 struct commit_graph *g,
 						 uint64_t pos,
 						 struct commit_list **pptr)
 {
@@ -299,7 +329,7 @@
 		die("invalid parent position %"PRIu64, pos);
 
 	hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
-	c = lookup_commit(the_repository, &oid);
+	c = lookup_commit(r, &oid);
 	if (!c)
 		die(_("could not find commit %s"), oid_to_hex(&oid));
 	c->graph_pos = pos;
@@ -313,7 +343,9 @@
 	item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 }
 
-static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
+static int fill_commit_in_graph(struct repository *r,
+				struct commit *item,
+				struct commit_graph *g, uint32_t pos)
 {
 	uint32_t edge_value;
 	uint32_t *parent_data_ptr;
@@ -337,21 +369,21 @@
 	edge_value = get_be32(commit_data + g->hash_len);
 	if (edge_value == GRAPH_PARENT_NONE)
 		return 1;
-	pptr = insert_parent_or_die(g, edge_value, pptr);
+	pptr = insert_parent_or_die(r, g, edge_value, pptr);
 
 	edge_value = get_be32(commit_data + g->hash_len + 4);
 	if (edge_value == GRAPH_PARENT_NONE)
 		return 1;
-	if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
-		pptr = insert_parent_or_die(g, edge_value, pptr);
+	if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
+		pptr = insert_parent_or_die(r, g, edge_value, pptr);
 		return 1;
 	}
 
-	parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
+	parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
 			  4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 	do {
 		edge_value = get_be32(parent_data_ptr);
-		pptr = insert_parent_or_die(g,
+		pptr = insert_parent_or_die(r, g,
 					    edge_value & GRAPH_EDGE_LAST_MASK,
 					    pptr);
 		parent_data_ptr++;
@@ -370,7 +402,9 @@
 	}
 }
 
-static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
+static int parse_commit_in_graph_one(struct repository *r,
+				     struct commit_graph *g,
+				     struct commit *item)
 {
 	uint32_t pos;
 
@@ -378,7 +412,7 @@
 		return 1;
 
 	if (find_commit_in_graph(item, g, &pos))
-		return fill_commit_in_graph(item, g, pos);
+		return fill_commit_in_graph(r, item, g, pos);
 
 	return 0;
 }
@@ -387,7 +421,7 @@
 {
 	if (!prepare_commit_graph(r))
 		return 0;
-	return parse_commit_in_graph_one(r->objects->commit_graph, item);
+	return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 }
 
 void load_commit_graph_info(struct repository *r, struct commit *item)
@@ -399,19 +433,22 @@
 		fill_commit_graph_info(item, r->objects->commit_graph, pos);
 }
 
-static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
+static struct tree *load_tree_for_commit(struct repository *r,
+					 struct commit_graph *g,
+					 struct commit *c)
 {
 	struct object_id oid;
 	const unsigned char *commit_data = g->chunk_commit_data +
 					   GRAPH_DATA_WIDTH * (c->graph_pos);
 
 	hashcpy(oid.hash, commit_data);
-	c->maybe_tree = lookup_tree(the_repository, &oid);
+	c->maybe_tree = lookup_tree(r, &oid);
 
 	return c->maybe_tree;
 }
 
-static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
+static struct tree *get_commit_tree_in_graph_one(struct repository *r,
+						 struct commit_graph *g,
 						 const struct commit *c)
 {
 	if (c->maybe_tree)
@@ -419,17 +456,19 @@
 	if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 		BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 
-	return load_tree_for_commit(g, (struct commit *)c);
+	return load_tree_for_commit(r, g, (struct commit *)c);
 }
 
 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 {
-	return get_commit_tree_in_graph_one(r->objects->commit_graph, c);
+	return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 }
 
 static void write_graph_chunk_fanout(struct hashfile *f,
 				     struct commit **commits,
-				     int nr_commits)
+				     int nr_commits,
+				     struct progress *progress,
+				     uint64_t *progress_cnt)
 {
 	int i, count = 0;
 	struct commit **list = commits;
@@ -443,6 +482,7 @@
 		while (count < nr_commits) {
 			if ((*list)->object.oid.hash[0] != i)
 				break;
+			display_progress(progress, ++*progress_cnt);
 			count++;
 			list++;
 		}
@@ -452,12 +492,16 @@
 }
 
 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
-				   struct commit **commits, int nr_commits)
+				   struct commit **commits, int nr_commits,
+				   struct progress *progress,
+				   uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	int count;
-	for (count = 0; count < nr_commits; count++, list++)
+	for (count = 0; count < nr_commits; count++, list++) {
+		display_progress(progress, ++*progress_cnt);
 		hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
+	}
 }
 
 static const unsigned char *commit_to_sha1(size_t index, void *table)
@@ -467,7 +511,9 @@
 }
 
 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
-				   struct commit **commits, int nr_commits)
+				   struct commit **commits, int nr_commits,
+				   struct progress *progress,
+				   uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	struct commit **last = commits + nr_commits;
@@ -477,6 +523,7 @@
 		struct commit_list *parent;
 		int edge_value;
 		uint32_t packedDate[2];
+		display_progress(progress, ++*progress_cnt);
 
 		parse_commit(*list);
 		hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
@@ -505,7 +552,7 @@
 		if (!parent)
 			edge_value = GRAPH_PARENT_NONE;
 		else if (parent->next)
-			edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
+			edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
 		else {
 			edge_value = sha1_pos(parent->item->object.oid.hash,
 					      commits,
@@ -519,7 +566,7 @@
 
 		hashwrite_be32(f, edge_value);
 
-		if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
+		if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
 			do {
 				num_extra_edges++;
 				parent = parent->next;
@@ -540,9 +587,11 @@
 	}
 }
 
-static void write_graph_chunk_large_edges(struct hashfile *f,
+static void write_graph_chunk_extra_edges(struct hashfile *f,
 					  struct commit **commits,
-					  int nr_commits)
+					  int nr_commits,
+					  struct progress *progress,
+					  uint64_t *progress_cnt)
 {
 	struct commit **list = commits;
 	struct commit **last = commits + nr_commits;
@@ -550,6 +599,9 @@
 
 	while (list < last) {
 		int num_parents = 0;
+
+		display_progress(progress, ++*progress_cnt);
+
 		for (parent = (*list)->parents; num_parents < 3 && parent;
 		     parent = parent->next)
 			num_parents++;
@@ -643,15 +695,15 @@
 
 static void close_reachable(struct packed_oid_list *oids, int report_progress)
 {
-	int i, j;
+	int i;
 	struct commit *commit;
 	struct progress *progress = NULL;
 
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Loading known commits in commit graph"), j = 0);
+			_("Loading known commits in commit graph"), oids->nr);
 	for (i = 0; i < oids->nr; i++) {
-		display_progress(progress, ++j);
+		display_progress(progress, i + 1);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 		if (commit)
 			commit->object.flags |= UNINTERESTING;
@@ -665,9 +717,9 @@
 	 */
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Expanding reachable commits in commit graph"), j = 0);
+			_("Expanding reachable commits in commit graph"), oids->nr);
 	for (i = 0; i < oids->nr; i++) {
-		display_progress(progress, ++j);
+		display_progress(progress, i + 1);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 
 		if (commit && !parse_commit(commit))
@@ -677,9 +729,9 @@
 
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Clearing commit marks in commit graph"), j = 0);
+			_("Clearing commit marks in commit graph"), oids->nr);
 	for (i = 0; i < oids->nr; i++) {
-		display_progress(progress, ++j);
+		display_progress(progress, i + 1);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 
 		if (commit)
@@ -773,12 +825,17 @@
 	int num_extra_edges;
 	struct commit_list *parent;
 	struct progress *progress = NULL;
+	const unsigned hashsz = the_hash_algo->rawsz;
+	uint64_t progress_cnt = 0;
+	struct strbuf progress_title = STRBUF_INIT;
+	unsigned long approx_nr_objects;
 
 	if (!commit_graph_compatible(the_repository))
 		return;
 
 	oids.nr = 0;
-	oids.alloc = approximate_object_count() / 32;
+	approx_nr_objects = approximate_object_count();
+	oids.alloc = approx_nr_objects / 32;
 	oids.progress = NULL;
 	oids.progress_done = 0;
 
@@ -808,8 +865,12 @@
 		strbuf_addf(&packname, "%s/pack/", obj_dir);
 		dirlen = packname.len;
 		if (report_progress) {
-			oids.progress = start_delayed_progress(
-				_("Finding commits for commit graph"), 0);
+			strbuf_addf(&progress_title,
+				    Q_("Finding commits for commit graph in %d pack",
+				       "Finding commits for commit graph in %d packs",
+				       pack_indexes->nr),
+				    pack_indexes->nr);
+			oids.progress = start_delayed_progress(progress_title.buf, 0);
 			oids.progress_done = 0;
 		}
 		for (i = 0; i < pack_indexes->nr; i++) {
@@ -821,19 +882,26 @@
 				die(_("error adding pack %s"), packname.buf);
 			if (open_pack_index(p))
 				die(_("error opening index for %s"), packname.buf);
-			for_each_object_in_pack(p, add_packed_commits, &oids, 0);
+			for_each_object_in_pack(p, add_packed_commits, &oids,
+						FOR_EACH_OBJECT_PACK_ORDER);
 			close_pack(p);
 			free(p);
 		}
 		stop_progress(&oids.progress);
+		strbuf_reset(&progress_title);
 		strbuf_release(&packname);
 	}
 
 	if (commit_hex) {
-		if (report_progress)
-			progress = start_delayed_progress(
-				_("Finding commits for commit graph"),
-				commit_hex->nr);
+		if (report_progress) {
+			strbuf_addf(&progress_title,
+				    Q_("Finding commits for commit graph from %d ref",
+				       "Finding commits for commit graph from %d refs",
+				       commit_hex->nr),
+				    commit_hex->nr);
+			progress = start_delayed_progress(progress_title.buf,
+							  commit_hex->nr);
+		}
 		for (i = 0; i < commit_hex->nr; i++) {
 			const char *end;
 			struct object_id oid;
@@ -853,25 +921,36 @@
 			}
 		}
 		stop_progress(&progress);
+		strbuf_reset(&progress_title);
 	}
 
 	if (!pack_indexes && !commit_hex) {
 		if (report_progress)
 			oids.progress = start_delayed_progress(
-				_("Finding commits for commit graph"), 0);
-		for_each_packed_object(add_packed_commits, &oids, 0);
+				_("Finding commits for commit graph among packed objects"),
+				approx_nr_objects);
+		for_each_packed_object(add_packed_commits, &oids,
+				       FOR_EACH_OBJECT_PACK_ORDER);
+		if (oids.progress_done < approx_nr_objects)
+			display_progress(oids.progress, approx_nr_objects);
 		stop_progress(&oids.progress);
 	}
 
 	close_reachable(&oids, report_progress);
 
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Counting distinct commits in commit graph"),
+			oids.nr);
+	display_progress(progress, 0); /* TODO: Measure QSORT() progress */
 	QSORT(oids.list, oids.nr, commit_compare);
-
 	count_distinct = 1;
 	for (i = 1; i < oids.nr; i++) {
+		display_progress(progress, i + 1);
 		if (!oideq(&oids.list[i - 1], &oids.list[i]))
 			count_distinct++;
 	}
+	stop_progress(&progress);
 
 	if (count_distinct >= GRAPH_EDGE_LAST_MASK)
 		die(_("the commit graph format cannot write %d commits"), count_distinct);
@@ -881,8 +960,13 @@
 	ALLOC_ARRAY(commits.list, commits.alloc);
 
 	num_extra_edges = 0;
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Finding extra edges in commit graph"),
+			oids.nr);
 	for (i = 0; i < oids.nr; i++) {
 		int num_parents = 0;
+		display_progress(progress, i + 1);
 		if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
 			continue;
 
@@ -899,6 +983,7 @@
 		commits.nr++;
 	}
 	num_chunks = num_extra_edges ? 4 : 3;
+	stop_progress(&progress);
 
 	if (commits.nr >= GRAPH_EDGE_LAST_MASK)
 		die(_("too many commits to write graph"));
@@ -918,7 +1003,7 @@
 	hashwrite_be32(f, GRAPH_SIGNATURE);
 
 	hashwrite_u8(f, GRAPH_VERSION);
-	hashwrite_u8(f, GRAPH_OID_VERSION);
+	hashwrite_u8(f, oid_version());
 	hashwrite_u8(f, num_chunks);
 	hashwrite_u8(f, 0); /* unused padding byte */
 
@@ -926,15 +1011,15 @@
 	chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
 	chunk_ids[2] = GRAPH_CHUNKID_DATA;
 	if (num_extra_edges)
-		chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
+		chunk_ids[3] = GRAPH_CHUNKID_EXTRAEDGES;
 	else
 		chunk_ids[3] = 0;
 	chunk_ids[4] = 0;
 
 	chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
 	chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
-	chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
-	chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
+	chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
+	chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
 	chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
 
 	for (i = 0; i <= num_chunks; i++) {
@@ -946,10 +1031,23 @@
 		hashwrite(f, chunk_write, 12);
 	}
 
-	write_graph_chunk_fanout(f, commits.list, commits.nr);
-	write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
-	write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
-	write_graph_chunk_large_edges(f, commits.list, commits.nr);
+	if (report_progress) {
+		strbuf_addf(&progress_title,
+			    Q_("Writing out commit graph in %d pass",
+			       "Writing out commit graph in %d passes",
+			       num_chunks),
+			    num_chunks);
+		progress = start_delayed_progress(
+			progress_title.buf,
+			num_chunks * commits.nr);
+	}
+	write_graph_chunk_fanout(f, commits.list, commits.nr, progress, &progress_cnt);
+	write_graph_chunk_oids(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
+	write_graph_chunk_data(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
+	if (num_extra_edges)
+		write_graph_chunk_extra_edges(f, commits.list, commits.nr, progress, &progress_cnt);
+	stop_progress(&progress);
+	strbuf_release(&progress_title);
 
 	close_commit_graph(the_repository);
 	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
@@ -1034,7 +1132,7 @@
 		}
 
 		graph_commit = lookup_commit(r, &cur_oid);
-		if (!parse_commit_in_graph_one(g, graph_commit))
+		if (!parse_commit_in_graph_one(r, g, graph_commit))
 			graph_report("failed to parse %s from commit-graph",
 				     oid_to_hex(&cur_oid));
 	}
@@ -1070,7 +1168,7 @@
 			continue;
 		}
 
-		if (!oideq(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
+		if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
 			   get_commit_tree_oid(odb_commit)))
 			graph_report("root tree OID for commit %s in commit-graph is %s != %s",
 				     oid_to_hex(&cur_oid),
diff --git a/commit-graph.h b/commit-graph.h
index 9db40b4..096d8ba 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -49,11 +49,14 @@
 	const uint32_t *chunk_oid_fanout;
 	const unsigned char *chunk_oid_lookup;
 	const unsigned char *chunk_commit_data;
-	const unsigned char *chunk_large_edges;
+	const unsigned char *chunk_extra_edges;
 };
 
 struct commit_graph *load_commit_graph_one(const char *graph_file);
 
+struct commit_graph *parse_commit_graph(void *graph_map, int fd,
+					size_t graph_size);
+
 /*
  * Return 1 if and only if the repository has a commit-graph
  * file and generation numbers are computed in that file.
diff --git a/commit-reach.c b/commit-reach.c
index d5a39de..3ea1747 100644
--- a/commit-reach.c
+++ b/commit-reach.c
@@ -30,7 +30,8 @@
 }
 
 /* all input commits in one and twos[] must have been parsed! */
-static struct commit_list *paint_down_to_common(struct commit *one, int n,
+static struct commit_list *paint_down_to_common(struct repository *r,
+						struct commit *one, int n,
 						struct commit **twos,
 						int min_generation)
 {
@@ -83,7 +84,7 @@
 			parents = parents->next;
 			if ((p->object.flags & flags) == flags)
 				continue;
-			if (parse_commit(p))
+			if (repo_parse_commit(r, p))
 				return NULL;
 			p->object.flags |= flags;
 			prio_queue_put(&queue, p);
@@ -94,7 +95,9 @@
 	return result;
 }
 
-static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
+static struct commit_list *merge_bases_many(struct repository *r,
+					    struct commit *one, int n,
+					    struct commit **twos)
 {
 	struct commit_list *list = NULL;
 	struct commit_list *result = NULL;
@@ -109,14 +112,14 @@
 			return commit_list_insert(one, &result);
 	}
 
-	if (parse_commit(one))
+	if (repo_parse_commit(r, one))
 		return NULL;
 	for (i = 0; i < n; i++) {
-		if (parse_commit(twos[i]))
+		if (repo_parse_commit(r, twos[i]))
 			return NULL;
 	}
 
-	list = paint_down_to_common(one, n, twos, 0);
+	list = paint_down_to_common(r, one, n, twos, 0);
 
 	while (list) {
 		struct commit *commit = pop_commit(&list);
@@ -153,7 +156,7 @@
 	return ret;
 }
 
-static int remove_redundant(struct commit **array, int cnt)
+static int remove_redundant(struct repository *r, struct commit **array, int cnt)
 {
 	/*
 	 * Some commit in the array may be an ancestor of
@@ -171,7 +174,7 @@
 	ALLOC_ARRAY(filled_index, cnt - 1);
 
 	for (i = 0; i < cnt; i++)
-		parse_commit(array[i]);
+		repo_parse_commit(r, array[i]);
 	for (i = 0; i < cnt; i++) {
 		struct commit_list *common;
 		uint32_t min_generation = array[i]->generation;
@@ -187,8 +190,8 @@
 			if (array[j]->generation < min_generation)
 				min_generation = array[j]->generation;
 		}
-		common = paint_down_to_common(array[i], filled, work,
-					      min_generation);
+		common = paint_down_to_common(r, array[i], filled,
+					      work, min_generation);
 		if (array[i]->object.flags & PARENT2)
 			redundant[i] = 1;
 		for (j = 0; j < filled; j++)
@@ -213,7 +216,8 @@
 	return filled;
 }
 
-static struct commit_list *get_merge_bases_many_0(struct commit *one,
+static struct commit_list *get_merge_bases_many_0(struct repository *r,
+						  struct commit *one,
 						  int n,
 						  struct commit **twos,
 						  int cleanup)
@@ -223,7 +227,7 @@
 	struct commit_list *result;
 	int cnt, i;
 
-	result = merge_bases_many(one, n, twos);
+	result = merge_bases_many(r, one, n, twos);
 	for (i = 0; i < n; i++) {
 		if (one == twos[i])
 			return result;
@@ -246,7 +250,7 @@
 	clear_commit_marks(one, all_flags);
 	clear_commit_marks_many(n, twos, all_flags);
 
-	cnt = remove_redundant(rslt, cnt);
+	cnt = remove_redundant(r, rslt, cnt);
 	result = NULL;
 	for (i = 0; i < cnt; i++)
 		commit_list_insert_by_date(rslt[i], &result);
@@ -254,23 +258,27 @@
 	return result;
 }
 
-struct commit_list *get_merge_bases_many(struct commit *one,
-					 int n,
-					 struct commit **twos)
+struct commit_list *repo_get_merge_bases_many(struct repository *r,
+					      struct commit *one,
+					      int n,
+					      struct commit **twos)
 {
-	return get_merge_bases_many_0(one, n, twos, 1);
+	return get_merge_bases_many_0(r, one, n, twos, 1);
 }
 
-struct commit_list *get_merge_bases_many_dirty(struct commit *one,
-					       int n,
-					       struct commit **twos)
+struct commit_list *repo_get_merge_bases_many_dirty(struct repository *r,
+						    struct commit *one,
+						    int n,
+						    struct commit **twos)
 {
-	return get_merge_bases_many_0(one, n, twos, 0);
+	return get_merge_bases_many_0(r, one, n, twos, 0);
 }
 
-struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
+struct commit_list *repo_get_merge_bases(struct repository *r,
+					 struct commit *one,
+					 struct commit *two)
 {
-	return get_merge_bases_many_0(one, 1, &two, 1);
+	return get_merge_bases_many_0(r, one, 1, &two, 1);
 }
 
 /*
@@ -304,16 +312,17 @@
 /*
  * Is "commit" an ancestor of one of the "references"?
  */
-int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
+int repo_in_merge_bases_many(struct repository *r, struct commit *commit,
+			     int nr_reference, struct commit **reference)
 {
 	struct commit_list *bases;
 	int ret = 0, i;
 	uint32_t min_generation = GENERATION_NUMBER_INFINITY;
 
-	if (parse_commit(commit))
+	if (repo_parse_commit(r, commit))
 		return ret;
 	for (i = 0; i < nr_reference; i++) {
-		if (parse_commit(reference[i]))
+		if (repo_parse_commit(r, reference[i]))
 			return ret;
 		if (reference[i]->generation < min_generation)
 			min_generation = reference[i]->generation;
@@ -322,7 +331,9 @@
 	if (commit->generation > min_generation)
 		return ret;
 
-	bases = paint_down_to_common(commit, nr_reference, reference, commit->generation);
+	bases = paint_down_to_common(r, commit,
+				     nr_reference, reference,
+				     commit->generation);
 	if (commit->object.flags & PARENT2)
 		ret = 1;
 	clear_commit_marks(commit, all_flags);
@@ -334,9 +345,11 @@
 /*
  * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
  */
-int in_merge_bases(struct commit *commit, struct commit *reference)
+int repo_in_merge_bases(struct repository *r,
+			struct commit *commit,
+			struct commit *reference)
 {
-	return in_merge_bases_many(commit, 1, &reference);
+	return repo_in_merge_bases_many(r, commit, 1, &reference);
 }
 
 struct commit_list *reduce_heads(struct commit_list *heads)
@@ -365,7 +378,7 @@
 			p->item->object.flags &= ~STALE;
 		}
 	}
-	num_head = remove_redundant(array, num_head);
+	num_head = remove_redundant(the_repository, array, num_head);
 	for (i = 0; i < num_head; i++)
 		tail = &commit_list_insert(array[i], tail)->next;
 	free(array);
diff --git a/commit-reach.h b/commit-reach.h
index fb8082a..99a43e8 100644
--- a/commit-reach.h
+++ b/commit-reach.h
@@ -9,21 +9,35 @@
 struct object_id;
 struct object_array;
 
-struct commit_list *get_merge_bases_many(struct commit *one,
-					 int n,
-					 struct commit **twos);
-struct commit_list *get_merge_bases_many_dirty(struct commit *one,
-					       int n,
-					       struct commit **twos);
-struct commit_list *get_merge_bases(struct commit *one, struct commit *two);
+struct commit_list *repo_get_merge_bases(struct repository *r,
+					 struct commit *rev1,
+					 struct commit *rev2);
+struct commit_list *repo_get_merge_bases_many(struct repository *r,
+					      struct commit *one, int n,
+					      struct commit **twos);
+/* To be used only when object flags after this call no longer matter */
+struct commit_list *repo_get_merge_bases_many_dirty(struct repository *r,
+						    struct commit *one, int n,
+						    struct commit **twos);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define get_merge_bases(r1, r2)           repo_get_merge_bases(the_repository, r1, r2)
+#define get_merge_bases_many(one, n, two) repo_get_merge_bases_many(the_repository, one, n, two)
+#define get_merge_bases_many_dirty(one, n, twos) repo_get_merge_bases_many_dirty(the_repository, one, n, twos)
+#endif
+
 struct commit_list *get_octopus_merge_bases(struct commit_list *in);
 
-/* To be used only when object flags after this call no longer matter */
-struct commit_list *get_merge_bases_many_dirty(struct commit *one, int n, struct commit **twos);
-
 int is_descendant_of(struct commit *commit, struct commit_list *with_commit);
-int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference);
-int in_merge_bases(struct commit *commit, struct commit *reference);
+int repo_in_merge_bases(struct repository *r,
+			struct commit *commit,
+			struct commit *reference);
+int repo_in_merge_bases_many(struct repository *r,
+			     struct commit *commit,
+			     int nr_reference, struct commit **reference);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define in_merge_bases(c1, c2) repo_in_merge_bases(the_repository, c1, c2)
+#define in_merge_bases_many(c1, n, cs) repo_in_merge_bases_many(the_repository, c1, n, cs)
+#endif
 
 /*
  * Takes a list of commits and returns a new list where those
diff --git a/commit.c b/commit.c
index d13a7bc..a5333c7 100644
--- a/commit.c
+++ b/commit.c
@@ -299,13 +299,15 @@
 	return v->buffer;
 }
 
-const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
+const void *repo_get_commit_buffer(struct repository *r,
+				   const struct commit *commit,
+				   unsigned long *sizep)
 {
-	const void *ret = get_cached_commit_buffer(the_repository, commit, sizep);
+	const void *ret = get_cached_commit_buffer(r, commit, sizep);
 	if (!ret) {
 		enum object_type type;
 		unsigned long size;
-		ret = read_object_file(&commit->object.oid, &type, &size);
+		ret = repo_read_object_file(r, &commit->object.oid, &type, &size);
 		if (!ret)
 			die("cannot read commit object %s",
 			    oid_to_hex(&commit->object.oid));
@@ -318,18 +320,20 @@
 	return ret;
 }
 
-void unuse_commit_buffer(const struct commit *commit, const void *buffer)
+void repo_unuse_commit_buffer(struct repository *r,
+			      const struct commit *commit,
+			      const void *buffer)
 {
 	struct commit_buffer *v = buffer_slab_peek(
-		the_repository->parsed_objects->buffer_slab, commit);
+		r->parsed_objects->buffer_slab, commit);
 	if (!(v && v->buffer == buffer))
 		free((void *)buffer);
 }
 
-void free_commit_buffer(struct commit *commit)
+void free_commit_buffer(struct parsed_object_pool *pool, struct commit *commit)
 {
 	struct commit_buffer *v = buffer_slab_peek(
-		the_repository->parsed_objects->buffer_slab, commit);
+		pool->buffer_slab, commit);
 	if (v) {
 		FREE_AND_NULL(v->buffer);
 		v->size = 0;
@@ -352,13 +356,12 @@
 	return &get_commit_tree(commit)->object.oid;
 }
 
-void release_commit_memory(struct commit *c)
+void release_commit_memory(struct parsed_object_pool *pool, struct commit *c)
 {
 	c->maybe_tree = NULL;
 	c->index = 0;
-	free_commit_buffer(c);
+	free_commit_buffer(pool, c);
 	free_commit_list(c->parents);
-	/* TODO: what about commit->util? */
 
 	c->object.parsed = 0;
 }
@@ -445,7 +448,10 @@
 	return 0;
 }
 
-int parse_commit_internal(struct commit *item, int quiet_on_missing, int use_commit_graph)
+int repo_parse_commit_internal(struct repository *r,
+			       struct commit *item,
+			       int quiet_on_missing,
+			       int use_commit_graph)
 {
 	enum object_type type;
 	void *buffer;
@@ -456,9 +462,9 @@
 		return -1;
 	if (item->object.parsed)
 		return 0;
-	if (use_commit_graph && parse_commit_in_graph(the_repository, item))
+	if (use_commit_graph && parse_commit_in_graph(r, item))
 		return 0;
-	buffer = read_object_file(&item->object.oid, &type, &size);
+	buffer = repo_read_object_file(r, &item->object.oid, &type, &size);
 	if (!buffer)
 		return quiet_on_missing ? -1 :
 			error("Could not read %s",
@@ -469,18 +475,19 @@
 			     oid_to_hex(&item->object.oid));
 	}
 
-	ret = parse_commit_buffer(the_repository, item, buffer, size, 0);
+	ret = parse_commit_buffer(r, item, buffer, size, 0);
 	if (save_commit_buffer && !ret) {
-		set_commit_buffer(the_repository, item, buffer, size);
+		set_commit_buffer(r, item, buffer, size);
 		return 0;
 	}
 	free(buffer);
 	return ret;
 }
 
-int parse_commit_gently(struct commit *item, int quiet_on_missing)
+int repo_parse_commit_gently(struct repository *r,
+			     struct commit *item, int quiet_on_missing)
 {
-	return parse_commit_internal(item, quiet_on_missing, 1);
+	return repo_parse_commit_internal(r, item, quiet_on_missing, 1);
 }
 
 void parse_commit_or_die(struct commit *item)
diff --git a/commit.h b/commit.h
index 9866453..42728c2 100644
--- a/commit.h
+++ b/commit.h
@@ -80,12 +80,21 @@
 struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name);
 
 int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph);
-int parse_commit_internal(struct commit *item, int quiet_on_missing, int use_commit_graph);
-int parse_commit_gently(struct commit *item, int quiet_on_missing);
-static inline int parse_commit(struct commit *item)
+int repo_parse_commit_internal(struct repository *r, struct commit *item,
+			       int quiet_on_missing, int use_commit_graph);
+int repo_parse_commit_gently(struct repository *r,
+			     struct commit *item,
+			     int quiet_on_missing);
+static inline int repo_parse_commit(struct repository *r, struct commit *item)
 {
-	return parse_commit_gently(item, 0);
+	return repo_parse_commit_gently(r, item, 0);
 }
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define parse_commit_internal(item, quiet, use) repo_parse_commit_internal(the_repository, item, quiet, use)
+#define parse_commit_gently(item, quiet) repo_parse_commit_gently(the_repository, item, quiet)
+#define parse_commit(item) repo_parse_commit(the_repository, item)
+#endif
+
 void parse_commit_or_die(struct commit *item);
 
 struct buffer_slab;
@@ -109,7 +118,12 @@
  * from disk. The resulting memory should not be modified, and must be given
  * to unuse_commit_buffer when the caller is done.
  */
-const void *get_commit_buffer(const struct commit *, unsigned long *size);
+const void *repo_get_commit_buffer(struct repository *r,
+				   const struct commit *,
+				   unsigned long *size);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define get_commit_buffer(c, s) repo_get_commit_buffer(the_repository, c, s)
+#endif
 
 /*
  * Tell the commit subsytem that we are done with a particular commit buffer.
@@ -117,12 +131,17 @@
  * from an earlier call to get_commit_buffer.  The buffer may or may not be
  * freed by this call; callers should not access the memory afterwards.
  */
-void unuse_commit_buffer(const struct commit *, const void *buffer);
+void repo_unuse_commit_buffer(struct repository *r,
+			      const struct commit *,
+			      const void *buffer);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define unuse_commit_buffer(c, b) repo_unuse_commit_buffer(the_repository, c, b)
+#endif
 
 /*
  * Free any cached object buffer associated with the commit.
  */
-void free_commit_buffer(struct commit *);
+void free_commit_buffer(struct parsed_object_pool *pool, struct commit *);
 
 struct tree *get_commit_tree(const struct commit *);
 struct object_id *get_commit_tree_oid(const struct commit *);
@@ -131,7 +150,7 @@
  * Release memory related to a commit, including the parent list and
  * any cached object buffer.
  */
-void release_commit_memory(struct commit *c);
+void release_commit_memory(struct parsed_object_pool *pool, struct commit *c);
 
 /*
  * Disassociate any cached object buffer from the commit, but do not free it.
@@ -162,6 +181,14 @@
 extern const char *logmsg_reencode(const struct commit *commit,
 				   char **commit_encoding,
 				   const char *output_encoding);
+const char *repo_logmsg_reencode(struct repository *r,
+				 const struct commit *commit,
+				 char **commit_encoding,
+				 const char *output_encoding);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define logmsg_reencode(c, enc, out) repo_logmsg_reencode(the_repository, c, enc, out)
+#endif
+
 extern const char *skip_blank_lines(const char *msg);
 
 /** Removes the first commit from a list sorted by date, and adds all
diff --git a/compat/mingw.c b/compat/mingw.c
index b459e1a..0af8684 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -7,6 +7,7 @@
 #include "../cache.h"
 #include "win32/lazyload.h"
 #include "../config.h"
+#include "dir.h"
 
 #define HCAST(type, handle) ((type)(intptr_t)handle)
 
@@ -1031,7 +1032,7 @@
  * See "Parsing C++ Command-Line Arguments" at Microsoft's Docs:
  * https://docs.microsoft.com/en-us/cpp/cpp/parsing-cpp-command-line-arguments
  */
-static const char *quote_arg(const char *arg)
+static const char *quote_arg_msvc(const char *arg)
 {
 	/* count chars to quote */
 	int len = 0, n = 0;
@@ -1086,6 +1087,37 @@
 	return q;
 }
 
+#include "quote.h"
+
+static const char *quote_arg_msys2(const char *arg)
+{
+	struct strbuf buf = STRBUF_INIT;
+	const char *p2 = arg, *p;
+
+	for (p = arg; *p; p++) {
+		int ws = isspace(*p);
+		if (!ws && *p != '\\' && *p != '"' && *p != '{')
+			continue;
+		if (!buf.len)
+			strbuf_addch(&buf, '"');
+		if (p != p2)
+			strbuf_add(&buf, p2, p - p2);
+		if (!ws && *p != '{')
+			strbuf_addch(&buf, '\\');
+		p2 = p;
+	}
+
+	if (p == arg)
+		strbuf_addch(&buf, '"');
+	else if (!buf.len)
+		return arg;
+	else
+		strbuf_add(&buf, p2, p - p2),
+
+	strbuf_addch(&buf, '"');
+	return strbuf_detach(&buf, 0);
+}
+
 static const char *parse_interpreter(const char *cmd)
 {
 	static char buf[100];
@@ -1317,6 +1349,47 @@
 static struct pinfo_t *pinfo = NULL;
 CRITICAL_SECTION pinfo_cs;
 
+/* Used to match and chomp off path components */
+static inline int match_last_path_component(const char *path, size_t *len,
+					    const char *component)
+{
+	size_t component_len = strlen(component);
+	if (*len < component_len + 1 ||
+	    !is_dir_sep(path[*len - component_len - 1]) ||
+	    fspathncmp(path + *len - component_len, component, component_len))
+		return 0;
+	*len -= component_len + 1;
+	/* chomp off repeated dir separators */
+	while (*len > 0 && is_dir_sep(path[*len - 1]))
+		(*len)--;
+	return 1;
+}
+
+static int is_msys2_sh(const char *cmd)
+{
+	if (cmd && !strcmp(cmd, "sh")) {
+		static int ret = -1;
+		char *p;
+
+		if (ret >= 0)
+			return ret;
+
+		p = path_lookup(cmd, 0);
+		if (!p)
+			ret = 0;
+		else {
+			size_t len = strlen(p);
+
+			ret = match_last_path_component(p, &len, "sh.exe") &&
+				match_last_path_component(p, &len, "bin") &&
+				match_last_path_component(p, &len, "usr");
+			free(p);
+		}
+		return ret;
+	}
+	return 0;
+}
+
 static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaenv,
 			      const char *dir,
 			      int prepend_cmd, int fhin, int fhout, int fherr)
@@ -1328,6 +1401,8 @@
 	unsigned flags = CREATE_UNICODE_ENVIRONMENT;
 	BOOL ret;
 	HANDLE cons;
+	const char *(*quote_arg)(const char *arg) =
+		is_msys2_sh(*argv) ? quote_arg_msys2 : quote_arg_msvc;
 
 	do_unset_environment_variables();
 
diff --git a/compat/obstack.c b/compat/obstack.c
index 4d1d95b..27cd5c1 100644
--- a/compat/obstack.c
+++ b/compat/obstack.c
@@ -112,15 +112,15 @@
 
 # define CALL_CHUNKFUN(h, size) \
   (((h) -> use_extra_arg) \
-   ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
-   : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
+   ? (*(h)->chunkfun.extra) ((h)->extra_arg, (size)) \
+   : (*(h)->chunkfun.plain) ((size)))
 
 # define CALL_FREEFUN(h, old_chunk) \
   do { \
     if ((h) -> use_extra_arg) \
-      (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
+      (*(h)->freefun.extra) ((h)->extra_arg, (old_chunk)); \
     else \
-      (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
+      (*(h)->freefun.plain) ((old_chunk)); \
   } while (0)
 
 
@@ -159,8 +159,8 @@
       size = 4096 - extra;
     }
 
-  h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
-  h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
+  h->chunkfun.plain = chunkfun;
+  h->freefun.plain = freefun;
   h->chunk_size = size;
   h->alignment_mask = alignment - 1;
   h->use_extra_arg = 0;
@@ -206,8 +206,9 @@
       size = 4096 - extra;
     }
 
-  h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
-  h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
+  h->chunkfun.extra = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
+  h->freefun.extra = (void (*) (void *, struct _obstack_chunk *)) freefun;
+
   h->chunk_size = size;
   h->alignment_mask = alignment - 1;
   h->extra_arg = arg;
diff --git a/compat/obstack.h b/compat/obstack.h
index 6bc24b7..ced94d0 100644
--- a/compat/obstack.h
+++ b/compat/obstack.h
@@ -160,11 +160,15 @@
     void *tempptr;
   } temp;			/* Temporary for some macros.  */
   int   alignment_mask;		/* Mask of alignment for each object. */
-  /* These prototypes vary based on `use_extra_arg', and we use
-     casts to the prototypeless function type in all assignments,
-     but having prototypes here quiets -Wstrict-prototypes.  */
-  struct _obstack_chunk *(*chunkfun) (void *, long);
-  void (*freefun) (void *, struct _obstack_chunk *);
+  /* These prototypes vary based on `use_extra_arg'. */
+  union {
+    void *(*plain) (long);
+    struct _obstack_chunk *(*extra) (void *, long);
+  } chunkfun;
+  union {
+    void (*plain) (void *);
+    void (*extra) (void *, struct _obstack_chunk *);
+  } freefun;
   void *extra_arg;		/* first arg for chunk alloc/dealloc funcs */
   unsigned use_extra_arg:1;	/* chunk alloc/dealloc funcs take extra arg */
   unsigned maybe_empty_object:1;/* There is a possibility that the current
@@ -235,10 +239,10 @@
 		    (void (*) (void *, void *)) (freefun), (arg))
 
 #define obstack_chunkfun(h, newchunkfun) \
-  ((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))
+  ((h)->chunkfun.extra = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))
 
 #define obstack_freefun(h, newfreefun) \
-  ((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
+  ((h)->freefun.extra = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
 
 #define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))
 
diff --git a/connect.c b/connect.c
index 24281b6..4813f00 100644
--- a/connect.c
+++ b/connect.c
@@ -296,7 +296,6 @@
 	struct ref **orig_list = list;
 	int len = 0;
 	enum get_remote_heads_state state = EXPECTING_FIRST_REF;
-	const char *arg;
 
 	*list = NULL;
 
@@ -306,8 +305,6 @@
 			die_initial_contact(1);
 		case PACKET_READ_NORMAL:
 			len = reader->pktlen;
-			if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))
-				die(_("remote error: %s"), arg);
 			break;
 		case PACKET_READ_FLUSH:
 			state = EXPECTING_DONE;
diff --git a/contrib/coccinelle/object_id.cocci b/contrib/coccinelle/object_id.cocci
index 6a7cf3e..3e536a9 100644
--- a/contrib/coccinelle/object_id.cocci
+++ b/contrib/coccinelle/object_id.cocci
@@ -87,36 +87,6 @@
 + oidcmp(&OID, OIDPTR)
 
 @@
-struct object_id OID1, OID2;
-@@
-- hashcpy(OID1.hash, OID2.hash)
-+ oidcpy(&OID1, &OID2)
-
-@@
-identifier f != oidcpy;
-struct object_id *OIDPTR1;
-struct object_id *OIDPTR2;
-@@
-  f(...) {<...
-- hashcpy(OIDPTR1->hash, OIDPTR2->hash)
-+ oidcpy(OIDPTR1, OIDPTR2)
-  ...>}
-
-@@
-struct object_id *OIDPTR;
-struct object_id OID;
-@@
-- hashcpy(OIDPTR->hash, OID.hash)
-+ oidcpy(OIDPTR, &OID)
-
-@@
-struct object_id *OIDPTR;
-struct object_id OID;
-@@
-- hashcpy(OID.hash, OIDPTR->hash)
-+ oidcpy(&OID, OIDPTR)
-
-@@
 struct object_id *OIDPTR1;
 struct object_id *OIDPTR2;
 @@
diff --git a/contrib/coccinelle/strbuf.cocci b/contrib/coccinelle/strbuf.cocci
index e34eada..d9ada69 100644
--- a/contrib/coccinelle/strbuf.cocci
+++ b/contrib/coccinelle/strbuf.cocci
@@ -13,6 +13,36 @@
   );
 
 @@
+expression E;
+struct strbuf SB;
+format F =~ "s";
+@@
+- strbuf_addf(E, "%@F@", SB.buf);
++ strbuf_addbuf(E, &SB);
+
+@@
+expression E;
+struct strbuf *SBP;
+format F =~ "s";
+@@
+- strbuf_addf(E, "%@F@", SBP->buf);
++ strbuf_addbuf(E, SBP);
+
+@@
+expression E;
+struct strbuf SB;
+@@
+- strbuf_addstr(E, SB.buf);
++ strbuf_addbuf(E, &SB);
+
+@@
+expression E;
+struct strbuf *SBP;
+@@
+- strbuf_addstr(E, SBP->buf);
++ strbuf_addbuf(E, SBP);
+
+@@
 expression E1, E2;
 format F =~ "s";
 @@
diff --git a/contrib/coccinelle/the_repository.pending.cocci b/contrib/coccinelle/the_repository.pending.cocci
new file mode 100644
index 0000000..2ee702e
--- /dev/null
+++ b/contrib/coccinelle/the_repository.pending.cocci
@@ -0,0 +1,144 @@
+// This file is used for the ongoing refactoring of
+// bringing the index or repository struct in all of
+// our code base.
+
+@@
+expression E;
+expression F;
+expression G;
+@@
+- read_object_file(
++ repo_read_object_file(the_repository,
+  E, F, G)
+
+@@
+expression E;
+@@
+- has_sha1_file(
++ repo_has_sha1_file(the_repository,
+  E)
+
+@@
+expression E;
+expression F;
+@@
+- has_sha1_file_with_flags(
++ repo_has_sha1_file_with_flags(the_repository,
+  E)
+
+@@
+expression E;
+@@
+- has_object_file(
++ repo_has_object_file(the_repository,
+  E)
+
+@@
+expression E;
+expression F;
+@@
+- has_object_file_with_flags(
++ repo_has_object_file_with_flags(the_repository,
+  E)
+
+@@
+expression E;
+expression F;
+expression G;
+@@
+- parse_commit_internal(
++ repo_parse_commit_internal(the_repository,
+  E, F, G)
+
+@@
+expression E;
+expression F;
+@@
+- parse_commit_gently(
++ repo_parse_commit_gently(the_repository,
+  E, F)
+
+@@
+expression E;
+@@
+- parse_commit(
++ repo_parse_commit(the_repository,
+  E)
+
+@@
+expression E;
+expression F;
+@@
+- get_merge_bases(
++ repo_get_merge_bases(the_repository,
+  E, F);
+
+@@
+expression E;
+expression F;
+expression G;
+@@
+- get_merge_bases_many(
++ repo_get_merge_bases_many(the_repository,
+  E, F, G);
+
+@@
+expression E;
+expression F;
+expression G;
+@@
+- get_merge_bases_many_dirty(
++ repo_get_merge_bases_many_dirty(the_repository,
+  E, F, G);
+
+@@
+expression E;
+expression F;
+@@
+- in_merge_bases(
++ repo_in_merge_bases(the_repository,
+  E, F);
+
+@@
+expression E;
+expression F;
+expression G;
+@@
+- in_merge_bases_many(
++ repo_in_merge_bases_many(the_repository,
+  E, F, G);
+
+@@
+expression E;
+expression F;
+@@
+- get_commit_buffer(
++ repo_get_commit_buffer(the_repository,
+  E, F);
+
+@@
+expression E;
+expression F;
+@@
+- unuse_commit_buffer(
++ repo_unuse_commit_buffer(the_repository,
+  E, F);
+
+@@
+expression E;
+expression F;
+expression G;
+@@
+- logmsg_reencode(
++ repo_logmsg_reencode(the_repository,
+  E, F, G);
+
+@@
+expression E;
+expression F;
+expression G;
+expression H;
+@@
+- format_commit_message(
++ repo_format_commit_message(the_repository,
+  E, F, G, H);
diff --git a/delta-islands.c b/delta-islands.c
index 191a930..2186bd0 100644
--- a/delta-islands.c
+++ b/delta-islands.c
@@ -296,7 +296,7 @@
 			if (S_ISGITLINK(entry.mode))
 				continue;
 
-			obj = lookup_object(r, entry.oid->hash);
+			obj = lookup_object(r, entry.oid.hash);
 			if (!obj)
 				continue;
 
diff --git a/diff.c b/diff.c
index 1b5f276..5306c48 100644
--- a/diff.c
+++ b/diff.c
@@ -304,7 +304,9 @@
 		strbuf_addstr(&sb, i->string);
 		strbuf_trim(&sb);
 
-		if (!strcmp(sb.buf, "ignore-space-change"))
+		if (!strcmp(sb.buf, "no"))
+			ret = 0;
+		else if (!strcmp(sb.buf, "ignore-space-change"))
 			ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 		else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 			ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
@@ -322,7 +324,7 @@
 
 	if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 	    (ret & XDF_WHITESPACE_FLAGS)) {
-		error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
+		error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 		ret |= COLOR_MOVED_WS_ERROR;
 	}
 
@@ -493,7 +495,7 @@
 
 	if (done_preparing)
 		return external_diff_cmd;
-	external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
+	external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 	if (!external_diff_cmd)
 		external_diff_cmd = external_diff_cmd_cfg;
 	done_preparing = 1;
@@ -754,6 +756,8 @@
 	const char *line;
 	int len;
 	int flags;
+	int indent_off;   /* Offset to first non-whitespace character */
+	int indent_width; /* The visual width of the indentation */
 	enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -784,44 +788,85 @@
 	struct moved_entry *next_line;
 };
 
-/**
- * The struct ws_delta holds white space differences between moved lines, i.e.
- * between '+' and '-' lines that have been detected to be a move.
- * The string contains the difference in leading white spaces, before the
- * rest of the line is compared using the white space config for move
- * coloring. The current_longer indicates if the first string in the
- * comparision is longer than the second.
- */
-struct ws_delta {
-	char *string;
-	unsigned int current_longer : 1;
-};
-#define WS_DELTA_INIT { NULL, 0 }
-
 struct moved_block {
 	struct moved_entry *match;
-	struct ws_delta wsd;
+	int wsd; /* The whitespace delta of this block */
 };
 
 static void moved_block_clear(struct moved_block *b)
 {
-	FREE_AND_NULL(b->wsd.string);
-	b->match = NULL;
+	memset(b, 0, sizeof(*b));
+}
+
+#define INDENT_BLANKLINE INT_MIN
+
+static void fill_es_indent_data(struct emitted_diff_symbol *es)
+{
+	unsigned int off = 0, i;
+	int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
+	const char *s = es->line;
+	const int len = es->len;
+
+	/* skip any \v \f \r at start of indentation */
+	while (s[off] == '\f' || s[off] == '\v' ||
+	       (s[off] == '\r' && off < len - 1))
+		off++;
+
+	/* calculate the visual width of indentation */
+	while(1) {
+		if (s[off] == ' ') {
+			width++;
+			off++;
+		} else if (s[off] == '\t') {
+			width += tab_width - (width % tab_width);
+			while (s[++off] == '\t')
+				width += tab_width;
+		} else {
+			break;
+		}
+	}
+
+	/* check if this line is blank */
+	for (i = off; i < len; i++)
+		if (!isspace(s[i]))
+		    break;
+
+	if (i == len) {
+		es->indent_width = INDENT_BLANKLINE;
+		es->indent_off = len;
+	} else {
+		es->indent_off = off;
+		es->indent_width = width;
+	}
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
-			     const struct emitted_diff_symbol *b,
-			     struct ws_delta *out)
+			    const struct emitted_diff_symbol *b,
+			    int *out)
 {
-	const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
-	const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
-	int d = longer->len - shorter->len;
+	int a_len = a->len,
+	    b_len = b->len,
+	    a_off = a->indent_off,
+	    a_width = a->indent_width,
+	    b_off = b->indent_off,
+	    b_width = b->indent_width;
+	int delta;
 
-	if (strncmp(longer->line + d, shorter->line, shorter->len))
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
+		*out = INDENT_BLANKLINE;
+		return 1;
+	}
+
+	if (a->s == DIFF_SYMBOL_PLUS)
+		delta = a_width - b_width;
+	else
+		delta = b_width - a_width;
+
+	if (a_len - a_off != b_len - b_off ||
+	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 		return 0;
 
-	out->string = xmemdupz(longer->line, d);
-	out->current_longer = (a == longer);
+	*out = delta;
 
 	return 1;
 }
@@ -833,51 +878,53 @@
 				 int n)
 {
 	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-	int al = cur->es->len, cl = l->len;
+	int al = cur->es->len, bl = match->es->len, cl = l->len;
 	const char *a = cur->es->line,
 		   *b = match->es->line,
 		   *c = l->line;
-
-	int wslen;
+	int a_off = cur->es->indent_off,
+	    a_width = cur->es->indent_width,
+	    c_off = l->indent_off,
+	    c_width = l->indent_width;
+	int delta;
 
 	/*
-	 * We need to check if 'cur' is equal to 'match'.
-	 * As those are from the same (+/-) side, we do not need to adjust for
-	 * indent changes. However these were found using fuzzy matching
-	 * so we do have to check if they are equal.
+	 * We need to check if 'cur' is equal to 'match'.  As those
+	 * are from the same (+/-) side, we do not need to adjust for
+	 * indent changes. However these were found using fuzzy
+	 * matching so we do have to check if they are equal. Here we
+	 * just check the lengths. We delay calling memcmp() to check
+	 * the contents until later as if the length comparison for a
+	 * and c fails we can avoid the call all together.
 	 */
-	if (strcmp(a, b))
+	if (al != bl)
 		return 1;
 
-	if (!pmb->wsd.string)
-		/*
-		 * The white space delta is not active? This can happen
-		 * when we exit early in this function.
-		 */
-		return 1;
+	/* If 'l' and 'cur' are both blank then they match. */
+	if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+		return 0;
 
 	/*
-	 * The indent changes of the block are known and stored in
-	 * pmb->wsd; however we need to check if the indent changes of the
-	 * current line are still the same as before.
-	 *
-	 * To do so we need to compare 'l' to 'cur', adjusting the
-	 * one of them for the white spaces, depending which was longer.
+	 * The indent changes of the block are known and stored in pmb->wsd;
+	 * however we need to check if the indent changes of the current line
+	 * match those of the current block and that the text of 'l' and 'cur'
+	 * after the indentation match.
 	 */
+	if (cur->es->s == DIFF_SYMBOL_PLUS)
+		delta = a_width - c_width;
+	else
+		delta = c_width - a_width;
 
-	wslen = strlen(pmb->wsd.string);
-	if (pmb->wsd.current_longer) {
-		c += wslen;
-		cl -= wslen;
-	} else {
-		a += wslen;
-		al -= wslen;
-	}
+	/*
+	 * If the previous lines of this block were all blank then set its
+	 * whitespace delta.
+	 */
+	if (pmb->wsd == INDENT_BLANKLINE)
+		pmb->wsd = delta;
 
-	if (al != cl || memcmp(a, c, al))
-		return 1;
-
-	return 0;
+	return !(delta == pmb->wsd && al - a_off == cl - c_off &&
+		 !memcmp(a, b, al) && !
+		 memcmp(a + a_off, c + c_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -943,6 +990,9 @@
 			continue;
 		}
 
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			fill_es_indent_data(&o->emitted_symbols->buf[n]);
 		key = prepare_entry(o, n);
 		if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 			prev_line->next_line = key;
@@ -1021,8 +1071,7 @@
 
 		if (lp < pmb_nr && rp > -1 && lp < rp) {
 			pmb[lp] = pmb[rp];
-			pmb[rp].match = NULL;
-			pmb[rp].wsd.string = NULL;
+			memset(&pmb[rp], 0, sizeof(pmb[rp]));
 			rp--;
 			lp++;
 		}
@@ -1042,14 +1091,17 @@
  * The last block consists of the (n - block_length)'th line up to but not
  * including the nth line.
  *
+ * Returns 0 if the last block is empty or is unset by this function, non zero
+ * otherwise.
+ *
  * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
  * Think of a way to unify them.
  */
-static void adjust_last_block(struct diff_options *o, int n, int block_length)
+static int adjust_last_block(struct diff_options *o, int n, int block_length)
 {
 	int i, alnum_count = 0;
 	if (o->color_moved == COLOR_MOVED_PLAIN)
-		return;
+		return block_length;
 	for (i = 1; i < block_length + 1; i++) {
 		const char *c = o->emitted_symbols->buf[n - i].line;
 		for (; *c; c++) {
@@ -1057,11 +1109,12 @@
 				continue;
 			alnum_count++;
 			if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
-				return;
+				return 1;
 		}
 	}
 	for (i = 1; i < block_length + 1; i++)
 		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+	return 0;
 }
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
@@ -1071,7 +1124,7 @@
 {
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
-	int n, flipped_block = 1, block_length = 0;
+	int n, flipped_block = 0, block_length = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1079,6 +1132,7 @@
 		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+		enum diff_symbol last_symbol = 0;
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
@@ -1094,7 +1148,7 @@
 			free(key);
 			break;
 		default:
-			flipped_block = 1;
+			flipped_block = 0;
 		}
 
 		if (!match) {
@@ -1105,13 +1159,16 @@
 				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
 			block_length = 0;
+			flipped_block = 0;
+			last_symbol = l->s;
 			continue;
 		}
 
-		l->flags |= DIFF_SYMBOL_MOVED_LINE;
-
-		if (o->color_moved == COLOR_MOVED_PLAIN)
+		if (o->color_moved == COLOR_MOVED_PLAIN) {
+			last_symbol = l->s;
+			l->flags |= DIFF_SYMBOL_MOVED_LINE;
 			continue;
+		}
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -1134,21 +1191,27 @@
 							     &pmb[pmb_nr].wsd))
 						pmb[pmb_nr++].match = match;
 				} else {
-					pmb[pmb_nr].wsd.string = NULL;
+					pmb[pmb_nr].wsd = 0;
 					pmb[pmb_nr++].match = match;
 				}
 			}
 
-			flipped_block = (flipped_block + 1) % 2;
+			if (adjust_last_block(o, n, block_length) &&
+			    pmb_nr && last_symbol != l->s)
+				flipped_block = (flipped_block + 1) % 2;
+			else
+				flipped_block = 0;
 
-			adjust_last_block(o, n, block_length);
 			block_length = 0;
 		}
 
-		block_length++;
-
-		if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
-			l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+		if (pmb_nr) {
+			block_length++;
+			l->flags |= DIFF_SYMBOL_MOVED_LINE;
+			if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
+				l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+		}
+		last_symbol = l->s;
 	}
 	adjust_last_block(o, n, block_length);
 
@@ -1492,7 +1555,7 @@
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len, unsigned flags)
 {
-	struct emitted_diff_symbol e = {line, len, flags, s};
+	struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
 
 	if (o->emitted_symbols)
 		append_emitted_diff_symbol(o, &e);
@@ -3481,7 +3544,7 @@
 		o->found_changes = 1;
 	} else {
 		/* Crazy xdl interfaces.. */
-		const char *diffopts = getenv("GIT_DIFF_OPTS");
+		const char *diffopts;
 		const char *v;
 		xpparam_t xpp;
 		xdemitconf_t xecfg;
@@ -3524,12 +3587,15 @@
 			xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
 		if (pe)
 			xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
+
+		diffopts = getenv("GIT_DIFF_OPTS");
 		if (!diffopts)
 			;
 		else if (skip_prefix(diffopts, "--unified=", &v))
 			xecfg.ctxlen = strtoul(v, NULL, 10);
 		else if (skip_prefix(diffopts, "-u", &v))
 			xecfg.ctxlen = strtoul(v, NULL, 10);
+
 		if (o->word_diff)
 			init_diff_words_data(&ecbdata, o, one, two);
 		if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
@@ -5042,6 +5108,8 @@
 		if (cm < 0)
 			return error("bad --color-moved argument: %s", arg);
 		options->color_moved = cm;
+	} else if (!strcmp(arg, "--no-color-moved-ws")) {
+		options->color_moved_ws_handling = 0;
 	} else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
 		unsigned cm = parse_color_moved_ws(arg);
 		if (cm & COLOR_MOVED_WS_ERROR)
@@ -5894,8 +5962,10 @@
 
 		for (i = 0; i < esm.nr; i++)
 			free((void *)esm.buf[i].line);
+		esm.nr = 0;
+
+		o->emitted_symbols = NULL;
 	}
-	esm.nr = 0;
 }
 
 void diff_flush(struct diff_options *options)
diff --git a/environment.c b/environment.c
index 0e37741..89af47c 100644
--- a/environment.c
+++ b/environment.c
@@ -107,7 +107,7 @@
 
 static char *git_namespace;
 
-static const char *super_prefix;
+static char *super_prefix;
 
 /*
  * Repository-local GIT_* environment variables; see cache.h for details.
@@ -240,7 +240,7 @@
 {
 	static int initialized;
 	if (!initialized) {
-		super_prefix = getenv(GIT_SUPER_PREFIX_ENVIRONMENT);
+		super_prefix = xstrdup_or_null(getenv(GIT_SUPER_PREFIX_ENVIRONMENT));
 		initialized = 1;
 	}
 	return super_prefix;
diff --git a/fetch-pack.c b/fetch-pack.c
index dd6700b..08b3b35 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -135,38 +135,42 @@
 	ACK_ready
 };
 
-static void consume_shallow_list(struct fetch_pack_args *args, int fd)
+static void consume_shallow_list(struct fetch_pack_args *args,
+				 struct packet_reader *reader)
 {
 	if (args->stateless_rpc && args->deepen) {
 		/* If we sent a depth we will get back "duplicate"
 		 * shallow and unshallow commands every time there
 		 * is a block of have lines exchanged.
 		 */
-		char *line;
-		while ((line = packet_read_line(fd, NULL))) {
-			if (starts_with(line, "shallow "))
+		while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+			if (starts_with(reader->line, "shallow "))
 				continue;
-			if (starts_with(line, "unshallow "))
+			if (starts_with(reader->line, "unshallow "))
 				continue;
 			die(_("git fetch-pack: expected shallow list"));
 		}
+		if (reader->status != PACKET_READ_FLUSH)
+			die(_("git fetch-pack: expected a flush packet after shallow list"));
 	}
 }
 
-static enum ack_type get_ack(int fd, struct object_id *result_oid)
+static enum ack_type get_ack(struct packet_reader *reader,
+			     struct object_id *result_oid)
 {
 	int len;
-	char *line = packet_read_line(fd, &len);
 	const char *arg;
 
-	if (!line)
+	if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 		die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
-	if (!strcmp(line, "NAK"))
+	len = reader->pktlen;
+
+	if (!strcmp(reader->line, "NAK"))
 		return NAK;
-	if (skip_prefix(line, "ACK ", &arg)) {
+	if (skip_prefix(reader->line, "ACK ", &arg)) {
 		if (!get_oid_hex(arg, result_oid)) {
 			arg += 40;
-			len -= arg - line;
+			len -= arg - reader->line;
 			if (len < 1)
 				return ACK;
 			if (strstr(arg, "continue"))
@@ -178,9 +182,7 @@
 			return ACK;
 		}
 	}
-	if (skip_prefix(line, "ERR ", &arg))
-		die(_("remote error: %s"), arg);
-	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
+	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 }
 
 static void send_request(struct fetch_pack_args *args,
@@ -248,10 +250,15 @@
 	int got_ready = 0;
 	struct strbuf req_buf = STRBUF_INIT;
 	size_t state_len = 0;
+	struct packet_reader reader;
 
 	if (args->stateless_rpc && multi_ack == 1)
 		die(_("--stateless-rpc requires multi_ack_detailed"));
 
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+
 	if (!args->no_dependents) {
 		mark_tips(negotiator, args->negotiation_tips);
 		for_each_cached_alternate(negotiator, insert_one_alternate_object);
@@ -329,38 +336,42 @@
 			packet_buf_write(&req_buf, "deepen-not %s", s->string);
 		}
 	}
-	if (server_supports_filtering && args->filter_options.choice)
+	if (server_supports_filtering && args->filter_options.choice) {
+		struct strbuf expanded_filter_spec = STRBUF_INIT;
+		expand_list_objects_filter_spec(&args->filter_options,
+						&expanded_filter_spec);
 		packet_buf_write(&req_buf, "filter %s",
-				 args->filter_options.filter_spec);
+				 expanded_filter_spec.buf);
+		strbuf_release(&expanded_filter_spec);
+	}
 	packet_buf_flush(&req_buf);
 	state_len = req_buf.len;
 
 	if (args->deepen) {
-		char *line;
 		const char *arg;
 		struct object_id oid;
 
 		send_request(args, fd[1], &req_buf);
-		while ((line = packet_read_line(fd[0], NULL))) {
-			if (skip_prefix(line, "shallow ", &arg)) {
+		while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
+			if (skip_prefix(reader.line, "shallow ", &arg)) {
 				if (get_oid_hex(arg, &oid))
-					die(_("invalid shallow line: %s"), line);
+					die(_("invalid shallow line: %s"), reader.line);
 				register_shallow(the_repository, &oid);
 				continue;
 			}
-			if (skip_prefix(line, "unshallow ", &arg)) {
+			if (skip_prefix(reader.line, "unshallow ", &arg)) {
 				if (get_oid_hex(arg, &oid))
-					die(_("invalid unshallow line: %s"), line);
+					die(_("invalid unshallow line: %s"), reader.line);
 				if (!lookup_object(the_repository, oid.hash))
-					die(_("object not found: %s"), line);
+					die(_("object not found: %s"), reader.line);
 				/* make sure that it is parsed as shallow */
 				if (!parse_object(the_repository, &oid))
-					die(_("error in object: %s"), line);
+					die(_("error in object: %s"), reader.line);
 				if (unregister_shallow(&oid))
-					die(_("no shallow found: %s"), line);
+					die(_("no shallow found: %s"), reader.line);
 				continue;
 			}
-			die(_("expected shallow/unshallow, got %s"), line);
+			die(_("expected shallow/unshallow, got %s"), reader.line);
 		}
 	} else if (!args->stateless_rpc)
 		send_request(args, fd[1], &req_buf);
@@ -397,9 +408,9 @@
 			if (!args->stateless_rpc && count == INITIAL_FLUSH)
 				continue;
 
-			consume_shallow_list(args, fd[0]);
+			consume_shallow_list(args, &reader);
 			do {
-				ack = get_ack(fd[0], result_oid);
+				ack = get_ack(&reader, result_oid);
 				if (ack)
 					print_verbose(args, _("got %s %d %s"), "ack",
 						      ack, oid_to_hex(result_oid));
@@ -469,9 +480,9 @@
 	strbuf_release(&req_buf);
 
 	if (!got_ready || !no_done)
-		consume_shallow_list(args, fd[0]);
+		consume_shallow_list(args, &reader);
 	while (flushes || multi_ack) {
-		int ack = get_ack(fd[0], result_oid);
+		int ack = get_ack(&reader, result_oid);
 		if (ack) {
 			print_verbose(args, _("got %s (%d) %s"), "ack",
 				      ack, oid_to_hex(result_oid));
@@ -1007,6 +1018,8 @@
 			packet_buf_write(req_buf, "deepen-not %s", s->string);
 		}
 	}
+	if (args->deepen_relative)
+		packet_buf_write(req_buf, "deepen-relative\n");
 }
 
 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
@@ -1084,7 +1097,8 @@
 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
 			      const struct fetch_pack_args *args,
 			      const struct ref *wants, struct oidset *common,
-			      int *haves_to_send, int *in_vain)
+			      int *haves_to_send, int *in_vain,
+			      int sideband_all)
 {
 	int ret = 0;
 	struct strbuf req_buf = STRBUF_INIT;
@@ -1110,6 +1124,8 @@
 		packet_buf_write(&req_buf, "include-tag");
 	if (prefer_ofs_delta)
 		packet_buf_write(&req_buf, "ofs-delta");
+	if (sideband_all)
+		packet_buf_write(&req_buf, "sideband-all");
 
 	/* Add shallow-info and deepen request */
 	if (server_supports_feature("fetch", "shallow", 0))
@@ -1120,9 +1136,13 @@
 	/* Add filter */
 	if (server_supports_feature("fetch", "filter", 0) &&
 	    args->filter_options.choice) {
+		struct strbuf expanded_filter_spec = STRBUF_INIT;
 		print_verbose(args, _("Server supports filter"));
+		expand_list_objects_filter_spec(&args->filter_options,
+						&expanded_filter_spec);
 		packet_buf_write(&req_buf, "filter %s",
-				 args->filter_options.filter_spec);
+				 expanded_filter_spec.buf);
+		strbuf_release(&expanded_filter_spec);
 	} else if (args->filter_options.choice) {
 		warning("filtering not recognized by server, ignoring");
 	}
@@ -1232,6 +1252,8 @@
 static void receive_shallow_info(struct fetch_pack_args *args,
 				 struct packet_reader *reader)
 {
+	int line_received = 0;
+
 	process_section_header(reader, "shallow-info", 0);
 	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 		const char *arg;
@@ -1241,6 +1263,7 @@
 			if (get_oid_hex(arg, &oid))
 				die(_("invalid shallow line: %s"), reader->line);
 			register_shallow(the_repository, &oid);
+			line_received = 1;
 			continue;
 		}
 		if (skip_prefix(reader->line, "unshallow ", &arg)) {
@@ -1253,6 +1276,7 @@
 				die(_("error in object: %s"), reader->line);
 			if (unregister_shallow(&oid))
 				die(_("no shallow found: %s"), reader->line);
+			line_received = 1;
 			continue;
 		}
 		die(_("expected shallow/unshallow, got %s"), reader->line);
@@ -1262,8 +1286,11 @@
 	    reader->status != PACKET_READ_DELIM)
 		die(_("error processing shallow info: %d"), reader->status);
 
-	setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
-	args->deepen = 1;
+	if (line_received) {
+		setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
+					NULL);
+		args->deepen = 1;
+	}
 }
 
 static void receive_wanted_refs(struct packet_reader *reader,
@@ -1316,7 +1343,13 @@
 	struct fetch_negotiator negotiator;
 	fetch_negotiator_init(&negotiator, negotiation_algorithm);
 	packet_reader_init(&reader, fd[0], NULL, 0,
-			   PACKET_READ_CHOMP_NEWLINE);
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+	if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
+	    server_supports_feature("fetch", "sideband-all", 0)) {
+		reader.use_sideband = 1;
+		reader.me = "fetch-pack";
+	}
 
 	while (state != FETCH_DONE) {
 		switch (state) {
@@ -1350,7 +1383,8 @@
 		case FETCH_SEND_REQUEST:
 			if (send_fetch_request(&negotiator, fd[1], args, ref,
 					       &common,
-					       &haves_to_send, &in_vain))
+					       &haves_to_send, &in_vain,
+					       reader.use_sideband))
 				state = FETCH_GET_PACK;
 			else
 				state = FETCH_PROCESS_ACKS;
diff --git a/fsck.c b/fsck.c
index 68502ce..2260adb 100644
--- a/fsck.c
+++ b/fsck.c
@@ -410,14 +410,14 @@
 			continue;
 
 		if (S_ISDIR(entry.mode)) {
-			obj = (struct object *)lookup_tree(the_repository, entry.oid);
+			obj = (struct object *)lookup_tree(the_repository, &entry.oid);
 			if (name && obj)
 				put_object_name(options, obj, "%s%s/", name,
 					entry.path);
 			result = options->walk(obj, OBJ_TREE, data, options);
 		}
 		else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
-			obj = (struct object *)lookup_blob(the_repository, entry.oid);
+			obj = (struct object *)lookup_blob(the_repository, &entry.oid);
 			if (name && obj)
 				put_object_name(options, obj, "%s%s", name,
 					entry.path);
diff --git a/fuzz-commit-graph.c b/fuzz-commit-graph.c
new file mode 100644
index 0000000..cf790c9
--- /dev/null
+++ b/fuzz-commit-graph.c
@@ -0,0 +1,16 @@
+#include "commit-graph.h"
+
+struct commit_graph *parse_commit_graph(void *graph_map, int fd,
+					size_t graph_size);
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+	struct commit_graph *g;
+
+	g = parse_commit_graph((void *)data, -1, size);
+	free(g);
+
+	return 0;
+}
diff --git a/git-instaweb.sh b/git-instaweb.sh
index eec264e..7c55229 100755
--- a/git-instaweb.sh
+++ b/git-instaweb.sh
@@ -67,6 +67,13 @@
 		httpd_only="${httpd%% *}" # cut on first space
 		return
 		;;
+	*python*)
+		# server is started by running via generated gitweb.py in
+		# $fqgitdir/gitweb
+		full_httpd="$fqgitdir/gitweb/gitweb.py"
+		httpd_only="${httpd%% *}" # cut on first space
+		return
+		;;
 	esac
 
 	httpd_only="$(echo $httpd | cut -f1 -d' ')"
@@ -110,7 +117,7 @@
 
 	# don't quote $full_httpd, there can be arguments to it (-f)
 	case "$httpd" in
-	*mongoose*|*plackup*)
+	*mongoose*|*plackup*|*python*)
 		#These servers don't have a daemon mode so we'll have to fork it
 		$full_httpd "$conf" &
 		#Save the pid before doing anything else (we'll print it later)
@@ -595,6 +602,121 @@
 	rm -f "$conf"
 }
 
+python_conf() {
+	# Python's builtin http.server and its CGI support is very limited.
+	# CGI handler is capable of running CGI script only from inside a directory.
+	# Trying to set cgi_directories=["/"] will add double slash to SCRIPT_NAME
+	# and that in turn breaks gitweb's relative link generation.
+
+	# create a simple web root where $fqgitdir/gitweb/$httpd_only is our root
+	mkdir -p "$fqgitdir/gitweb/$httpd_only/cgi-bin"
+	# Python http.server follows the symlinks
+	ln -sf "$root/gitweb.cgi" "$fqgitdir/gitweb/$httpd_only/cgi-bin/gitweb.cgi"
+	ln -sf "$root/static" "$fqgitdir/gitweb/$httpd_only/"
+
+	# generate a standalone 'python http.server' script in $fqgitdir/gitweb
+	# This asumes that python is in user's $PATH
+	# This script is Python 2 and 3 compatible
+	cat > "$fqgitdir/gitweb/gitweb.py" <<EOF
+#!/usr/bin/env python
+import os
+import sys
+
+# Open log file in line buffering mode
+accesslogfile = open("$fqgitdir/gitweb/access.log", 'a', buffering=1)
+errorlogfile = open("$fqgitdir/gitweb/error.log", 'a', buffering=1)
+
+# and replace our stdout and stderr with log files
+# also do a lowlevel duplicate of the logfile file descriptors so that
+# our CGI child process writes any stderr warning also to the log file
+_orig_stdout_fd = sys.stdout.fileno()
+sys.stdout.close()
+os.dup2(accesslogfile.fileno(), _orig_stdout_fd)
+sys.stdout = accesslogfile
+
+_orig_stderr_fd = sys.stderr.fileno()
+sys.stderr.close()
+os.dup2(errorlogfile.fileno(), _orig_stderr_fd)
+sys.stderr = errorlogfile
+
+from functools import partial
+
+if sys.version_info < (3, 0):  # Python 2
+	from CGIHTTPServer import CGIHTTPRequestHandler
+	from BaseHTTPServer import HTTPServer as ServerClass
+else:  # Python 3
+	from http.server import CGIHTTPRequestHandler
+	from http.server import HTTPServer as ServerClass
+
+
+# Those environment variables will be passed to the cgi script
+os.environ.update({
+	"GIT_EXEC_PATH": "$GIT_EXEC_PATH",
+	"GIT_DIR": "$GIT_DIR",
+	"GITWEB_CONFIG": "$GITWEB_CONFIG"
+})
+
+
+class GitWebRequestHandler(CGIHTTPRequestHandler):
+
+	def log_message(self, format, *args):
+		# Write access logs to stdout
+		sys.stdout.write("%s - - [%s] %s\n" %
+				(self.address_string(),
+				self.log_date_time_string(),
+				format%args))
+
+	def do_HEAD(self):
+		self.redirect_path()
+		CGIHTTPRequestHandler.do_HEAD(self)
+
+	def do_GET(self):
+		if self.path == "/":
+			self.send_response(303, "See Other")
+			self.send_header("Location", "/cgi-bin/gitweb.cgi")
+			self.end_headers()
+			return
+		self.redirect_path()
+		CGIHTTPRequestHandler.do_GET(self)
+
+	def do_POST(self):
+		self.redirect_path()
+		CGIHTTPRequestHandler.do_POST(self)
+
+	# rewrite path of every request that is not gitweb.cgi to out of cgi-bin
+	def redirect_path(self):
+		if not self.path.startswith("/cgi-bin/gitweb.cgi"):
+			self.path = self.path.replace("/cgi-bin/", "/")
+
+	# gitweb.cgi is the only thing that is ever going to be run here.
+	# Ignore everything else
+	def is_cgi(self):
+		result = False
+		if self.path.startswith('/cgi-bin/gitweb.cgi'):
+			result = CGIHTTPRequestHandler.is_cgi(self)
+		return result
+
+
+bind = "127.0.0.1"
+if "$local" == "true":
+	bind = "0.0.0.0"
+
+# Set our http root directory
+# This is a work around for a missing directory argument in older Python versions
+# as this was added to SimpleHTTPRequestHandler in Python 3.7
+os.chdir("$fqgitdir/gitweb/$httpd_only/")
+
+GitWebRequestHandler.protocol_version = "HTTP/1.0"
+httpd = ServerClass((bind, $port), GitWebRequestHandler)
+
+sa = httpd.socket.getsockname()
+print("Serving HTTP on", sa[0], "port", sa[1], "...")
+httpd.serve_forever()
+EOF
+
+	chmod a+x "$fqgitdir/gitweb/gitweb.py"
+}
+
 gitweb_conf() {
 	cat > "$fqgitdir/gitweb/gitweb_config.perl" <<EOF
 #!@@PERL@@
@@ -623,6 +745,9 @@
 	*plackup*)
 		plackup_conf
 		;;
+	*python*)
+		python_conf
+		;;
 	*)
 		echo "Unknown httpd specified: $httpd"
 		exit 1
diff --git a/git-legacy-rebase.sh b/git-legacy-rebase.sh
index b4c7dbf..8d6c9ac 100755
--- a/git-legacy-rebase.sh
+++ b/git-legacy-rebase.sh
@@ -26,6 +26,7 @@
 m,merge!           use merging strategies to rebase
 i,interactive!     let the user edit the list of commits to rebase
 x,exec=!           add exec lines after each commit of the editable list
+y=!                same as --reschedule-failed-exec -x
 k,keep-empty	   preserve empty commits during rebase
 allow-empty-message allow rebasing commits with empty messages
 stat!              display a diffstat of what changed upstream
@@ -48,6 +49,7 @@
 edit-todo!         edit the todo list during an interactive rebase
 quit!              abort but keep HEAD where it is
 show-current-patch! show the patch file being applied or merged
+reschedule-failed-exec automatically reschedule failed exec commands
 "
 . git-sh-setup
 set_reflog_action rebase
@@ -92,11 +94,14 @@
 keep_empty=
 allow_empty_message=--allow-empty-message
 signoff=
+reschedule_failed_exec=
 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
 case "$(git config --bool commit.gpgsign)" in
 true)	gpg_sign_opt=-S ;;
 *)	gpg_sign_opt= ;;
 esac
+test "$(git config --bool rebase.reschedulefailedexec)" = "true" &&
+reschedule_failed_exec=--reschedule-failed-exec
 . git-rebase--common
 
 read_basic_state () {
@@ -113,7 +118,7 @@
 	else
 		orig_head=$(cat "$state_dir"/head)
 	fi &&
-	GIT_QUIET=$(cat "$state_dir"/quiet) &&
+	test -f "$state_dir"/quiet && GIT_QUIET=t
 	test -f "$state_dir"/verbose && verbose=t
 	test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
 	test -f "$state_dir"/strategy_opts &&
@@ -126,6 +131,8 @@
 		signoff="$(cat "$state_dir"/signoff)"
 		force_rebase=t
 	}
+	test -f "$state_dir"/reschedule-failed-exec &&
+		reschedule_failed_exec=t
 }
 
 finish_rebase () {
@@ -163,13 +170,14 @@
 		"$allow_empty_message" "$autosquash" "$verbose" \
 		"$force_rebase" "$onto_name" "$head_name" "$strategy" \
 		"$strategy_opts" "$cmd" "$switch_to" \
-		"$allow_rerere_autoupdate" "$gpg_sign_opt" "$signoff"
+		"$allow_rerere_autoupdate" "$gpg_sign_opt" "$signoff" \
+		"$reschedule_failed_exec"
 }
 
 run_specific_rebase () {
 	if [ "$interactive_rebase" = implied ]; then
-		GIT_EDITOR=:
-		export GIT_EDITOR
+		GIT_SEQUENCE_EDITOR=:
+		export GIT_SEQUENCE_EDITOR
 		autosquash=
 	fi
 
@@ -218,6 +226,7 @@
 	state_dir="$apply_dir"
 elif test -d "$merge_dir"
 then
+	type=interactive
 	if test -d "$merge_dir"/rewritten
 	then
 		type=preserve-merges
@@ -225,10 +234,7 @@
 		preserve_merges=t
 	elif test -f "$merge_dir"/interactive
 	then
-		type=interactive
 		interactive_rebase=explicit
-	else
-		type=merge
 	fi
 	state_dir="$merge_dir"
 fi
@@ -255,6 +261,11 @@
 		cmd="${cmd}exec ${1#--exec=}${LF}"
 		test -z "$interactive_rebase" && interactive_rebase=implied
 		;;
+	-y*)
+		reschedule_failed_exec=--reschedule-failed-exec
+		cmd="${cmd}exec ${1#-y}${LF}"
+		test -z "$interactive_rebase" && interactive_rebase=implied
+		;;
 	--interactive)
 		interactive_rebase=explicit
 		;;
@@ -378,6 +389,12 @@
 	--gpg-sign=*)
 		gpg_sign_opt="-S${1#--gpg-sign=}"
 		;;
+	--reschedule-failed-exec)
+		reschedule_failed_exec=--reschedule-failed-exec
+		;;
+	--no-reschedule-failed-exec)
+		reschedule_failed_exec=
+		;;
 	--)
 		shift
 		break
@@ -477,6 +494,7 @@
 	test -z "$interactive_rebase" && interactive_rebase=implied
 fi
 
+actually_interactive=
 if test -n "$interactive_rebase"
 then
 	if test -z "$preserve_merges"
@@ -485,11 +503,12 @@
 	else
 		type=preserve-merges
 	fi
-
+	actually_interactive=t
 	state_dir="$merge_dir"
 elif test -n "$do_merge"
 then
-	type=merge
+	interactive_rebase=implied
+	type=interactive
 	state_dir="$merge_dir"
 else
 	type=am
@@ -501,28 +520,20 @@
 	git_format_patch_opt="$git_format_patch_opt --progress"
 fi
 
-if test -n "$git_am_opt"; then
-	incompatible_opts=$(echo " $git_am_opt " | \
-			    sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
-	if test -n "$interactive_rebase"
+incompatible_opts=$(echo " $git_am_opt " | \
+		    sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
+if test -n "$incompatible_opts"
+then
+	if test -n "$actually_interactive" || test "$do_merge"
 	then
-		if test -n "$incompatible_opts"
-		then
-			die "$(gettext "error: cannot combine interactive options (--interactive, --exec, --rebase-merges, --preserve-merges, --keep-empty, --root + --onto) with am options ($incompatible_opts)")"
-		fi
-	fi
-	if test -n "$do_merge"; then
-		if test -n "$incompatible_opts"
-		then
-			die "$(gettext "error: cannot combine merge options (--merge, --strategy, --strategy-option) with am options ($incompatible_opts)")"
-		fi
+		die "$(gettext "fatal: cannot combine am options with either interactive or merge options")"
 	fi
 fi
 
 if test -n "$signoff"
 then
 	test -n "$preserve_merges" &&
-		die "$(gettext "error: cannot combine '--signoff' with '--preserve-merges'")"
+		die "$(gettext "fatal: cannot combine '--signoff' with '--preserve-merges'")"
 	git_am_opt="$git_am_opt $signoff"
 	force_rebase=t
 fi
@@ -533,15 +544,18 @@
 	# Note: incompatibility with --interactive is just a strong warning;
 	#       git-rebase.txt caveats with "unless you know what you are doing"
 	test -n "$rebase_merges" &&
-		die "$(gettext "error: cannot combine '--preserve-merges' with '--rebase-merges'")"
+		die "$(gettext "fatal: cannot combine '--preserve-merges' with '--rebase-merges'")"
+
+	test -n "$reschedule_failed_exec" &&
+		die "$(gettext "error: cannot combine '--preserve-merges' with '--reschedule-failed-exec'")"
 fi
 
 if test -n "$rebase_merges"
 then
 	test -n "$strategy_opts" &&
-		die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy-option'")"
+		die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy-option'")"
 	test -n "$strategy" &&
-		die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy'")"
+		die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy'")"
 fi
 
 if test -z "$rebase_root"
@@ -680,7 +694,7 @@
 # but this should be done only when upstream and onto are the same
 # and if this is not an interactive rebase.
 mb=$(git merge-base "$onto" "$orig_head")
-if test -z "$interactive_rebase" && test "$upstream" = "$onto" &&
+if test -z "$actually_interactive" && test "$upstream" = "$onto" &&
 	test "$mb" = "$onto" && test -z "$restrict_revision" &&
 	# linear history?
 	! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
@@ -730,6 +744,19 @@
 	GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
 fi
 
+if test -z "$actually_interactive" && test "$mb" = "$orig_head"
+then
+	say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
+	GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
+		git checkout -q "$onto^0" || die "could not detach HEAD"
+	# If the $onto is a proper descendant of the tip of the branch, then
+	# we just fast-forwarded.
+	git update-ref ORIG_HEAD $orig_head
+	move_to_original_branch
+	finish_rebase
+	exit 0
+fi
+
 test -n "$interactive_rebase" && run_specific_rebase
 
 # Detach HEAD and reset the tree
@@ -739,16 +766,6 @@
 	git checkout -q "$onto^0" || die "could not detach HEAD"
 git update-ref ORIG_HEAD $orig_head
 
-# If the $onto is a proper descendant of the tip of the branch, then
-# we just fast-forwarded.
-if test "$mb" = "$orig_head"
-then
-	say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
-	move_to_original_branch
-	finish_rebase
-	exit 0
-fi
-
 if test -n "$rebase_root"
 then
 	revisions="$onto..$orig_head"
diff --git a/git-p4.py b/git-p4.py
index 3e12774..5b79920 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -1861,6 +1861,7 @@
                     filesToAdd.remove(path)
             elif modifier == "C":
                 src, dest = diff['src'], diff['dst']
+                all_files.append(dest)
                 p4_integrate(src, dest)
                 pureRenameCopy.add(dest)
                 if diff['src_sha1'] != diff['dst_sha1']:
@@ -1877,6 +1878,7 @@
                 editedFiles.add(dest)
             elif modifier == "R":
                 src, dest = diff['src'], diff['dst']
+                all_files.append(dest)
                 if self.p4HasMoveCommand:
                     p4_edit(src)        # src must be open before move
                     p4_move(src, dest)  # opens for (move/delete, move/add)
diff --git a/git-rebase--am.sh b/git-rebase--am.sh
index 99b8c17..6416716 100644
--- a/git-rebase--am.sh
+++ b/git-rebase--am.sh
@@ -36,7 +36,7 @@
 
 git format-patch -k --stdout --full-index --cherry-pick --right-only \
 	--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
-	--pretty=mboxrd \
+	--pretty=mboxrd --topo-order \
 	$git_format_patch_opt \
 	"$revisions" ${restrict_revision+^$restrict_revision} \
 	>"$GIT_DIR/rebased-patches"
diff --git a/git-rebase--common.sh b/git-rebase--common.sh
index 7e39d22..f00e13e 100644
--- a/git-rebase--common.sh
+++ b/git-rebase--common.sh
@@ -10,7 +10,7 @@
 	echo "$head_name" > "$state_dir"/head-name &&
 	echo "$onto" > "$state_dir"/onto &&
 	echo "$orig_head" > "$state_dir"/orig-head &&
-	echo "$GIT_QUIET" > "$state_dir"/quiet &&
+	test t = "$GIT_QUIET" && : > "$state_dir"/quiet
 	test t = "$verbose" && : > "$state_dir"/verbose
 	test -n "$strategy" && echo "$strategy" > "$state_dir"/strategy
 	test -n "$strategy_opts" && echo "$strategy_opts" > \
@@ -19,6 +19,7 @@
 		"$state_dir"/allow_rerere_autoupdate
 	test -n "$gpg_sign_opt" && echo "$gpg_sign_opt" > "$state_dir"/gpg_sign_opt
 	test -n "$signoff" && echo "$signoff" >"$state_dir"/signoff
+	test -n "$reschedule_failed_exec" && : > "$state_dir"/reschedule-failed-exec
 }
 
 apply_autostash () {
diff --git a/git-rebase--merge.sh b/git-rebase--merge.sh
deleted file mode 100644
index aa2f2f0..0000000
--- a/git-rebase--merge.sh
+++ /dev/null
@@ -1,164 +0,0 @@
-# This shell script fragment is sourced by git-rebase to implement
-# its merge-based non-interactive mode that copes well with renamed
-# files.
-#
-# Copyright (c) 2010 Junio C Hamano.
-#
-
-prec=4
-
-read_state () {
-	onto_name=$(cat "$state_dir"/onto_name) &&
-	end=$(cat "$state_dir"/end) &&
-	msgnum=$(cat "$state_dir"/msgnum)
-}
-
-continue_merge () {
-	test -d "$state_dir" || die "$state_dir directory does not exist"
-
-	unmerged=$(git ls-files -u)
-	if test -n "$unmerged"
-	then
-		echo "You still have unmerged paths in your index"
-		echo "did you forget to use git add?"
-		die "$resolvemsg"
-	fi
-
-	cmt=$(cat "$state_dir/current")
-	if ! git diff-index --quiet --ignore-submodules HEAD --
-	then
-		if ! git commit ${gpg_sign_opt:+"$gpg_sign_opt"} $signoff $allow_empty_message \
-			--no-verify -C "$cmt"
-		then
-			echo "Commit failed, please do not call \"git commit\""
-			echo "directly, but instead do one of the following: "
-			die "$resolvemsg"
-		fi
-		if test -z "$GIT_QUIET"
-		then
-			printf "Committed: %0${prec}d " $msgnum
-		fi
-		echo "$cmt $(git rev-parse HEAD^0)" >> "$state_dir/rewritten"
-	else
-		if test -z "$GIT_QUIET"
-		then
-			printf "Already applied: %0${prec}d " $msgnum
-		fi
-	fi
-	test -z "$GIT_QUIET" &&
-	GIT_PAGER='' git log --format=%s -1 "$cmt"
-
-	# onto the next patch:
-	msgnum=$(($msgnum + 1))
-	echo "$msgnum" >"$state_dir/msgnum"
-}
-
-call_merge () {
-	msgnum="$1"
-	echo "$msgnum" >"$state_dir/msgnum"
-	cmt="$(cat "$state_dir/cmt.$msgnum")"
-	echo "$cmt" > "$state_dir/current"
-	git update-ref REBASE_HEAD "$cmt"
-	hd=$(git rev-parse --verify HEAD)
-	cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
-	eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
-	eval GITHEAD_$hd='$onto_name'
-	export GITHEAD_$cmt GITHEAD_$hd
-	if test -n "$GIT_QUIET"
-	then
-		GIT_MERGE_VERBOSITY=1 && export GIT_MERGE_VERBOSITY
-	fi
-	test -z "$strategy" && strategy=recursive
-	# If cmt doesn't have a parent, don't include it as a base
-	base=$(git rev-parse --verify --quiet $cmt^)
-	eval 'git merge-$strategy' $strategy_opts $base ' -- "$hd" "$cmt"'
-	rv=$?
-	case "$rv" in
-	0)
-		unset GITHEAD_$cmt GITHEAD_$hd
-		return
-		;;
-	1)
-		git rerere $allow_rerere_autoupdate
-		die "$resolvemsg"
-		;;
-	2)
-		echo "Strategy: $strategy failed, try another" 1>&2
-		die "$resolvemsg"
-		;;
-	*)
-		die "Unknown exit code ($rv) from command:" \
-			"git merge-$strategy $cmt^ -- HEAD $cmt"
-		;;
-	esac
-}
-
-finish_rb_merge () {
-	move_to_original_branch
-	if test -s "$state_dir"/rewritten
-	then
-		git notes copy --for-rewrite=rebase <"$state_dir"/rewritten
-		hook="$(git rev-parse --git-path hooks/post-rewrite)"
-		test -x "$hook" && "$hook" rebase <"$state_dir"/rewritten
-	fi
-	say All done.
-}
-
-git_rebase__merge () {
-
-case "$action" in
-continue)
-	read_state
-	continue_merge
-	while test "$msgnum" -le "$end"
-	do
-		call_merge "$msgnum"
-		continue_merge
-	done
-	finish_rb_merge
-	return
-	;;
-skip)
-	read_state
-	git rerere clear
-	msgnum=$(($msgnum + 1))
-	while test "$msgnum" -le "$end"
-	do
-		call_merge "$msgnum"
-		continue_merge
-	done
-	finish_rb_merge
-	return
-	;;
-show-current-patch)
-	exec git show REBASE_HEAD --
-	;;
-esac
-
-mkdir -p "$state_dir"
-echo "$onto_name" > "$state_dir/onto_name"
-write_basic_state
-rm -f "$(git rev-parse --git-path REBASE_HEAD)"
-
-msgnum=0
-for cmt in $(git rev-list --reverse --no-merges "$revisions")
-do
-	msgnum=$(($msgnum + 1))
-	echo "$cmt" > "$state_dir/cmt.$msgnum"
-done
-
-echo 1 >"$state_dir/msgnum"
-echo $msgnum >"$state_dir/end"
-
-end=$msgnum
-msgnum=1
-
-while test "$msgnum" -le "$end"
-do
-	call_merge "$msgnum"
-	continue_merge
-done
-
-finish_rb_merge
-
-}
diff --git a/hash.h b/hash.h
index 7c8238b..adde708 100644
--- a/hash.h
+++ b/hash.h
@@ -15,6 +15,14 @@
 #include "block-sha1/sha1.h"
 #endif
 
+#if defined(SHA256_GCRYPT)
+#include "sha256/gcrypt.h"
+#elif defined(SHA256_OPENSSL)
+#include <openssl/sha.h>
+#else
+#include "sha256/block/sha256.h"
+#endif
+
 #ifndef platform_SHA_CTX
 /*
  * platform's underlying implementation of SHA-1; could be OpenSSL,
@@ -34,6 +42,18 @@
 #define git_SHA1_Update		platform_SHA1_Update
 #define git_SHA1_Final		platform_SHA1_Final
 
+#ifndef platform_SHA256_CTX
+#define platform_SHA256_CTX	SHA256_CTX
+#define platform_SHA256_Init	SHA256_Init
+#define platform_SHA256_Update	SHA256_Update
+#define platform_SHA256_Final	SHA256_Final
+#endif
+
+#define git_SHA256_CTX		platform_SHA256_CTX
+#define git_SHA256_Init		platform_SHA256_Init
+#define git_SHA256_Update	platform_SHA256_Update
+#define git_SHA256_Final	platform_SHA256_Final
+
 #ifdef SHA1_MAX_BLOCK_SIZE
 #include "compat/sha1-chunked.h"
 #undef git_SHA1_Update
@@ -52,12 +72,15 @@
 #define GIT_HASH_UNKNOWN 0
 /* SHA-1 */
 #define GIT_HASH_SHA1 1
+/* SHA-256  */
+#define GIT_HASH_SHA256 2
 /* Number of algorithms supported (including unknown). */
-#define GIT_HASH_NALGOS (GIT_HASH_SHA1 + 1)
+#define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1)
 
 /* A suitably aligned type for stack allocations of hash contexts. */
 union git_hash_ctx {
 	git_SHA_CTX sha1;
+	git_SHA256_CTX sha256;
 };
 typedef union git_hash_ctx git_hash_ctx;
 
@@ -81,6 +104,9 @@
 	/* The length of the hash in hex characters. */
 	size_t hexsz;
 
+	/* The block size of the hash. */
+	size_t blksz;
+
 	/* The hash initialization function. */
 	git_hash_init_fn init_fn;
 
@@ -98,4 +124,17 @@
 };
 extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS];
 
+/*
+ * Return a GIT_HASH_* constant based on the name.  Returns GIT_HASH_UNKNOWN if
+ * the name doesn't match a known algorithm.
+ */
+int hash_algo_by_name(const char *name);
+/* Identical, except based on the format ID. */
+int hash_algo_by_id(uint32_t format_id);
+/* Identical, except for a pointer to struct git_hash_algo. */
+static inline int hash_algo_by_ptr(const struct git_hash_algo *p)
+{
+	return p - hash_algos;
+}
+
 #endif
diff --git a/hex.c b/hex.c
index 10af1a2..7850a88 100644
--- a/hex.c
+++ b/hex.c
@@ -73,14 +73,15 @@
 	return ret;
 }
 
-char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
+char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
+			  const struct git_hash_algo *algop)
 {
 	static const char hex[] = "0123456789abcdef";
 	char *buf = buffer;
 	int i;
 
-	for (i = 0; i < the_hash_algo->rawsz; i++) {
-		unsigned int val = *sha1++;
+	for (i = 0; i < algop->rawsz; i++) {
+		unsigned int val = *hash++;
 		*buf++ = hex[val >> 4];
 		*buf++ = hex[val & 0xf];
 	}
@@ -89,20 +90,35 @@
 	return buffer;
 }
 
-char *oid_to_hex_r(char *buffer, const struct object_id *oid)
+char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
 {
-	return sha1_to_hex_r(buffer, oid->hash);
+	return hash_to_hex_algop_r(buffer, sha1, &hash_algos[GIT_HASH_SHA1]);
 }
 
-char *sha1_to_hex(const unsigned char *sha1)
+char *oid_to_hex_r(char *buffer, const struct object_id *oid)
+{
+	return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
+}
+
+char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
 {
 	static int bufno;
 	static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
 	bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
-	return sha1_to_hex_r(hexbuffer[bufno], sha1);
+	return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
+}
+
+char *sha1_to_hex(const unsigned char *sha1)
+{
+	return hash_to_hex_algop(sha1, &hash_algos[GIT_HASH_SHA1]);
+}
+
+char *hash_to_hex(const unsigned char *hash)
+{
+	return hash_to_hex_algop(hash, the_hash_algo);
 }
 
 char *oid_to_hex(const struct object_id *oid)
 {
-	return sha1_to_hex(oid->hash);
+	return hash_to_hex_algop(oid->hash, the_hash_algo);
 }
diff --git a/http-push.c b/http-push.c
index cd48590..bb802d8 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1311,11 +1311,11 @@
 	while (tree_entry(&desc, &entry))
 		switch (object_type(entry.mode)) {
 		case OBJ_TREE:
-			p = process_tree(lookup_tree(the_repository, entry.oid),
+			p = process_tree(lookup_tree(the_repository, &entry.oid),
 					 p);
 			break;
 		case OBJ_BLOB:
-			p = process_blob(lookup_blob(the_repository, entry.oid),
+			p = process_blob(lookup_blob(the_repository, &entry.oid),
 					 p);
 			break;
 		default:
diff --git a/http.c b/http.c
index 0b6807c..954bebf 100644
--- a/http.c
+++ b/http.c
@@ -1876,8 +1876,6 @@
 	strbuf_addstr(&buf, "Pragma:");
 	if (options && options->no_cache)
 		strbuf_addstr(&buf, " no-cache");
-	if (options && options->keep_error)
-		curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 	if (options && options->initial_request &&
 	    http_follow_config == HTTP_FOLLOW_INITIAL)
 		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
@@ -1895,6 +1893,7 @@
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
+	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
 	ret = run_one_slot(slot, &results);
 
@@ -1989,19 +1988,26 @@
 		return ret;
 
 	/*
-	 * If we are using KEEP_ERROR, the previous request may have
-	 * put cruft into our output stream; we should clear it out before
-	 * making our next request. We only know how to do this for
-	 * the strbuf case, but that is enough to satisfy current callers.
+	 * The previous request may have put cruft into our output stream; we
+	 * should clear it out before making our next request.
 	 */
-	if (options && options->keep_error) {
-		switch (target) {
-		case HTTP_REQUEST_STRBUF:
-			strbuf_reset(result);
-			break;
-		default:
-			BUG("HTTP_KEEP_ERROR is only supported with strbufs");
+	switch (target) {
+	case HTTP_REQUEST_STRBUF:
+		strbuf_reset(result);
+		break;
+	case HTTP_REQUEST_FILE:
+		if (fflush(result)) {
+			error_errno("unable to flush a file");
+			return HTTP_START_FAILED;
 		}
+		rewind(result);
+		if (ftruncate(fileno(result), 0) < 0) {
+			error_errno("unable to truncate a file");
+			return HTTP_START_FAILED;
+		}
+		break;
+	default:
+		BUG("Unknown http_request target");
 	}
 
 	credential_fill(&http_auth);
diff --git a/http.h b/http.h
index d305ca1..eebf406 100644
--- a/http.h
+++ b/http.h
@@ -146,7 +146,6 @@
 /* Options for http_get_*() */
 struct http_get_options {
 	unsigned no_cache:1,
-		 keep_error:1,
 		 initial_request:1;
 
 	/* If non-NULL, returns the content-type of the response. */
diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index e8da2e8..9efb3e9 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c
@@ -18,8 +18,9 @@
  * See Documentation/rev-list-options.txt for allowed values for <arg>.
  *
  * Capture the given arg as the "filter_spec".  This can be forwarded to
- * subordinate commands when necessary.  We also "intern" the arg for
- * the convenience of the current command.
+ * subordinate commands when necessary (although it's better to pass it through
+ * expand_list_objects_filter_spec() first).  We also "intern" the arg for the
+ * convenience of the current command.
  */
 static int gently_parse_list_objects_filter(
 	struct list_objects_filter_options *filter_options,
@@ -50,16 +51,15 @@
 		}
 
 	} else if (skip_prefix(arg, "tree:", &v0)) {
-		unsigned long depth;
-		if (!git_parse_ulong(v0, &depth) || depth != 0) {
+		if (!git_parse_ulong(v0, &filter_options->tree_exclude_depth)) {
 			if (errbuf) {
 				strbuf_addstr(
 					errbuf,
-					_("only 'tree:0' is supported"));
+					_("expected 'tree:<depth>'"));
 			}
 			return 1;
 		}
-		filter_options->choice = LOFC_TREE_NONE;
+		filter_options->choice = LOFC_TREE_DEPTH;
 		return 0;
 
 	} else if (skip_prefix(arg, "sparse:oid=", &v0)) {
@@ -112,6 +112,21 @@
 	return parse_list_objects_filter(filter_options, arg);
 }
 
+void expand_list_objects_filter_spec(
+	const struct list_objects_filter_options *filter,
+	struct strbuf *expanded_spec)
+{
+	strbuf_init(expanded_spec, strlen(filter->filter_spec));
+	if (filter->choice == LOFC_BLOB_LIMIT)
+		strbuf_addf(expanded_spec, "blob:limit=%lu",
+			    filter->blob_limit_value);
+	else if (filter->choice == LOFC_TREE_DEPTH)
+		strbuf_addf(expanded_spec, "tree:%lu",
+			    filter->tree_exclude_depth);
+	else
+		strbuf_addstr(expanded_spec, filter->filter_spec);
+}
+
 void list_objects_filter_release(
 	struct list_objects_filter_options *filter_options)
 {
diff --git a/list-objects-filter-options.h b/list-objects-filter-options.h
index af64e5c..e3adc78 100644
--- a/list-objects-filter-options.h
+++ b/list-objects-filter-options.h
@@ -2,6 +2,7 @@
 #define LIST_OBJECTS_FILTER_OPTIONS_H
 
 #include "parse-options.h"
+#include "strbuf.h"
 
 /*
  * The list of defined filters for list-objects.
@@ -10,7 +11,7 @@
 	LOFC_DISABLED = 0,
 	LOFC_BLOB_NONE,
 	LOFC_BLOB_LIMIT,
-	LOFC_TREE_NONE,
+	LOFC_TREE_DEPTH,
 	LOFC_SPARSE_OID,
 	LOFC_SPARSE_PATH,
 	LOFC__COUNT /* must be last */
@@ -20,8 +21,9 @@
 	/*
 	 * 'filter_spec' is the raw argument value given on the command line
 	 * or protocol request.  (The part after the "--keyword=".)  For
-	 * commands that launch filtering sub-processes, this value should be
-	 * passed to them as received by the current process.
+	 * commands that launch filtering sub-processes, or for communication
+	 * over the network, don't use this value; use the result of
+	 * expand_list_objects_filter_spec() instead.
 	 */
 	char *filter_spec;
 
@@ -44,6 +46,7 @@
 	struct object_id *sparse_oid_value;
 	char *sparse_path_value;
 	unsigned long blob_limit_value;
+	unsigned long tree_exclude_depth;
 };
 
 /* Normalized command line arguments */
@@ -61,6 +64,17 @@
 	  N_("object filtering"), 0, \
 	  opt_parse_list_objects_filter }
 
+/*
+ * Translates abbreviated numbers in the filter's filter_spec into their
+ * fully-expanded forms (e.g., "limit:blob=1k" becomes "limit:blob=1024").
+ *
+ * This form should be used instead of the raw filter_spec field when
+ * communicating with a remote process or subprocess.
+ */
+void expand_list_objects_filter_spec(
+	const struct list_objects_filter_options *filter,
+	struct strbuf *expanded_spec);
+
 void list_objects_filter_release(
 	struct list_objects_filter_options *filter_options);
 
diff --git a/list-objects-filter.c b/list-objects-filter.c
index a62624a..ee449de 100644
--- a/list-objects-filter.c
+++ b/list-objects-filter.c
@@ -10,6 +10,7 @@
 #include "list-objects.h"
 #include "list-objects-filter.h"
 #include "list-objects-filter-options.h"
+#include "oidmap.h"
 #include "oidset.h"
 #include "object-store.h"
 
@@ -84,11 +85,44 @@
  * A filter for list-objects to omit ALL trees and blobs from the traversal.
  * Can OPTIONALLY collect a list of the omitted OIDs.
  */
-struct filter_trees_none_data {
+struct filter_trees_depth_data {
 	struct oidset *omits;
+
+	/*
+	 * Maps trees to the minimum depth at which they were seen. It is not
+	 * necessary to re-traverse a tree at deeper or equal depths than it has
+	 * already been traversed.
+	 *
+	 * We can't use LOFR_MARK_SEEN for tree objects since this will prevent
+	 * it from being traversed at shallower depths.
+	 */
+	struct oidmap seen_at_depth;
+
+	unsigned long exclude_depth;
+	unsigned long current_depth;
 };
 
-static enum list_objects_filter_result filter_trees_none(
+struct seen_map_entry {
+	struct oidmap_entry base;
+	size_t depth;
+};
+
+/* Returns 1 if the oid was in the omits set before it was invoked. */
+static int filter_trees_update_omits(
+	struct object *obj,
+	struct filter_trees_depth_data *filter_data,
+	int include_it)
+{
+	if (!filter_data->omits)
+		return 0;
+
+	if (include_it)
+		return oidset_remove(filter_data->omits, &obj->oid);
+	else
+		return oidset_insert(filter_data->omits, &obj->oid);
+}
+
+static enum list_objects_filter_result filter_trees_depth(
 	struct repository *r,
 	enum list_objects_filter_situation filter_situation,
 	struct object *obj,
@@ -96,43 +130,91 @@
 	const char *filename,
 	void *filter_data_)
 {
-	struct filter_trees_none_data *filter_data = filter_data_;
+	struct filter_trees_depth_data *filter_data = filter_data_;
+	struct seen_map_entry *seen_info;
+	int include_it = filter_data->current_depth <
+		filter_data->exclude_depth;
+	int filter_res;
+	int already_seen;
+
+	/*
+	 * Note that we do not use _MARK_SEEN in order to allow re-traversal in
+	 * case we encounter a tree or blob again at a shallower depth.
+	 */
 
 	switch (filter_situation) {
 	default:
 		BUG("unknown filter_situation: %d", filter_situation);
 
-	case LOFS_BEGIN_TREE:
-	case LOFS_BLOB:
-		if (filter_data->omits) {
-			oidset_insert(filter_data->omits, &obj->oid);
-			/* _MARK_SEEN but not _DO_SHOW (hard omit) */
-			return LOFR_MARK_SEEN;
-		} else {
-			/*
-			 * Not collecting omits so no need to to traverse tree.
-			 */
-			return LOFR_SKIP_TREE | LOFR_MARK_SEEN;
-		}
-
 	case LOFS_END_TREE:
 		assert(obj->type == OBJ_TREE);
+		filter_data->current_depth--;
 		return LOFR_ZERO;
 
+	case LOFS_BLOB:
+		filter_trees_update_omits(obj, filter_data, include_it);
+		return include_it ? LOFR_MARK_SEEN | LOFR_DO_SHOW : LOFR_ZERO;
+
+	case LOFS_BEGIN_TREE:
+		seen_info = oidmap_get(
+			&filter_data->seen_at_depth, &obj->oid);
+		if (!seen_info) {
+			seen_info = xcalloc(1, sizeof(*seen_info));
+			oidcpy(&seen_info->base.oid, &obj->oid);
+			seen_info->depth = filter_data->current_depth;
+			oidmap_put(&filter_data->seen_at_depth, seen_info);
+			already_seen = 0;
+		} else {
+			already_seen =
+				filter_data->current_depth >= seen_info->depth;
+		}
+
+		if (already_seen) {
+			filter_res = LOFR_SKIP_TREE;
+		} else {
+			int been_omitted = filter_trees_update_omits(
+				obj, filter_data, include_it);
+			seen_info->depth = filter_data->current_depth;
+
+			if (include_it)
+				filter_res = LOFR_DO_SHOW;
+			else if (filter_data->omits && !been_omitted)
+				/*
+				 * Must update omit information of children
+				 * recursively; they have not been omitted yet.
+				 */
+				filter_res = LOFR_ZERO;
+			else
+				filter_res = LOFR_SKIP_TREE;
+		}
+
+		filter_data->current_depth++;
+		return filter_res;
 	}
 }
 
-static void* filter_trees_none__init(
+static void filter_trees_free(void *filter_data) {
+	struct filter_trees_depth_data *d = filter_data;
+	if (!d)
+		return;
+	oidmap_free(&d->seen_at_depth, 1);
+	free(d);
+}
+
+static void *filter_trees_depth__init(
 	struct oidset *omitted,
 	struct list_objects_filter_options *filter_options,
 	filter_object_fn *filter_fn,
 	filter_free_fn *filter_free_fn)
 {
-	struct filter_trees_none_data *d = xcalloc(1, sizeof(*d));
+	struct filter_trees_depth_data *d = xcalloc(1, sizeof(*d));
 	d->omits = omitted;
+	oidmap_init(&d->seen_at_depth, 0);
+	d->exclude_depth = filter_options->tree_exclude_depth;
+	d->current_depth = 0;
 
-	*filter_fn = filter_trees_none;
-	*filter_free_fn = free;
+	*filter_fn = filter_trees_depth;
+	*filter_free_fn = filter_trees_free;
 	return d;
 }
 
@@ -430,7 +512,7 @@
 	NULL,
 	filter_blobs_none__init,
 	filter_blobs_limit__init,
-	filter_trees_none__init,
+	filter_trees_depth__init,
 	filter_sparse_oid__init,
 	filter_sparse_path__init,
 };
diff --git a/list-objects.c b/list-objects.c
index 4e27897..a2296a8 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -124,15 +124,15 @@
 		}
 
 		if (S_ISDIR(entry.mode)) {
-			struct tree *t = lookup_tree(ctx->revs->repo, entry.oid);
+			struct tree *t = lookup_tree(ctx->revs->repo, &entry.oid);
 			t->object.flags |= NOT_USER_GIVEN;
 			process_tree(ctx, t, base, entry.path);
 		}
 		else if (S_ISGITLINK(entry.mode))
-			process_gitlink(ctx, entry.oid->hash,
+			process_gitlink(ctx, entry.oid.hash,
 					base, entry.path);
 		else {
-			struct blob *b = lookup_blob(ctx->revs->repo, entry.oid);
+			struct blob *b = lookup_blob(ctx->revs->repo, &entry.oid);
 			b->object.flags |= NOT_USER_GIVEN;
 			process_blob(ctx, b, base, entry.path);
 		}
diff --git a/log-tree.c b/log-tree.c
index 10680c1..3cb1425 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -700,6 +700,7 @@
 	ctx.color = opt->diffopt.use_color;
 	ctx.expand_tabs_in_log = opt->expand_tabs_in_log;
 	ctx.output_encoding = get_log_output_encoding();
+	ctx.rev = opt;
 	if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
 		ctx.from_ident = &opt->from_ident;
 	if (opt->graph)
diff --git a/ls-refs.c b/ls-refs.c
index a06f12e..0a7dbc6 100644
--- a/ls-refs.c
+++ b/ls-refs.c
@@ -5,6 +5,7 @@
 #include "argv-array.h"
 #include "ls-refs.h"
 #include "pkt-line.h"
+#include "config.h"
 
 /*
  * Check if one of the prefixes is a prefix of the ref.
@@ -40,7 +41,10 @@
 	const char *refname_nons = strip_namespace(refname);
 	struct strbuf refline = STRBUF_INIT;
 
-	if (!ref_match(&data->prefixes, refname))
+	if (ref_is_hidden(refname_nons, refname))
+		return 0;
+
+	if (!ref_match(&data->prefixes, refname_nons))
 		return 0;
 
 	strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons);
@@ -69,6 +73,16 @@
 	return 0;
 }
 
+static int ls_refs_config(const char *var, const char *value, void *data)
+{
+	/*
+	 * We only serve fetches over v2 for now, so respect only "uploadpack"
+	 * config. This may need to eventually be expanded to "receive", but we
+	 * don't yet know how that information will be passed to ls-refs.
+	 */
+	return parse_hide_refs_config(var, value, "uploadpack");
+}
+
 int ls_refs(struct repository *r, struct argv_array *keys,
 	    struct packet_reader *request)
 {
@@ -76,6 +90,8 @@
 
 	memset(&data, 0, sizeof(data));
 
+	git_config(ls_refs_config, NULL);
+
 	while (packet_reader_read(request) != PACKET_READ_FLUSH) {
 		const char *arg = request->line;
 		const char *out;
diff --git a/match-trees.c b/match-trees.c
index 2b6d31e..18ab825 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -106,7 +106,7 @@
 			update_tree_entry(&two);
 		} else {
 			/* path appears in both */
-			if (!oideq(one.entry.oid, two.entry.oid)) {
+			if (!oideq(&one.entry.oid, &two.entry.oid)) {
 				/* they are different */
 				score += score_differs(one.entry.mode,
 						       two.entry.mode,
@@ -179,7 +179,7 @@
 	char *buf;
 	unsigned long sz;
 	struct tree_desc desc;
-	struct object_id *rewrite_here;
+	unsigned char *rewrite_here;
 	const struct object_id *rewrite_with;
 	struct object_id subtree;
 	enum object_type type;
@@ -199,15 +199,26 @@
 	while (desc.size) {
 		const char *name;
 		unsigned mode;
-		const struct object_id *oid;
 
-		oid = tree_entry_extract(&desc, &name, &mode);
+		tree_entry_extract(&desc, &name, &mode);
 		if (strlen(name) == toplen &&
 		    !memcmp(name, prefix, toplen)) {
 			if (!S_ISDIR(mode))
 				die("entry %s in tree %s is not a tree", name,
 				    oid_to_hex(oid1));
-			rewrite_here = (struct object_id *)oid;
+
+			/*
+			 * We cast here for two reasons:
+			 *
+			 *   - to flip the "char *" (for the path) to "unsigned
+			 *     char *" (for the hash stored after it)
+			 *
+			 *   - to discard the "const"; this is OK because we
+			 *     know it points into our non-const "buf"
+			 */
+			rewrite_here = (unsigned char *)(desc.entry.path +
+							 strlen(desc.entry.path) +
+							 1);
 			break;
 		}
 		update_tree_entry(&desc);
@@ -216,14 +227,16 @@
 		die("entry %.*s not found in tree %s", toplen, prefix,
 		    oid_to_hex(oid1));
 	if (*subpath) {
-		status = splice_tree(rewrite_here, subpath, oid2, &subtree);
+		struct object_id tree_oid;
+		hashcpy(tree_oid.hash, rewrite_here);
+		status = splice_tree(&tree_oid, subpath, oid2, &subtree);
 		if (status)
 			return status;
 		rewrite_with = &subtree;
 	} else {
 		rewrite_with = oid2;
 	}
-	oidcpy(rewrite_here, rewrite_with);
+	hashcpy(rewrite_here, rewrite_with->hash);
 	status = write_object_file(buf, sz, tree_type, result);
 	free(buf);
 	return status;
diff --git a/notes.c b/notes.c
index 25cdce2..7f7cc4d 100644
--- a/notes.c
+++ b/notes.c
@@ -450,7 +450,7 @@
 
 		l = xcalloc(1, sizeof(*l));
 		oidcpy(&l->key_oid, &object_oid);
-		oidcpy(&l->val_oid, entry.oid);
+		oidcpy(&l->val_oid, &entry.oid);
 		if (note_tree_insert(t, node, n, l, type,
 				     combine_notes_concatenate))
 			die("Failed to load %s %s into notes tree "
@@ -481,7 +481,7 @@
 			}
 			strbuf_addstr(&non_note_path, entry.path);
 			add_non_note(t, strbuf_detach(&non_note_path, NULL),
-				     entry.mode, entry.oid->hash);
+				     entry.mode, entry.oid.hash);
 		}
 	}
 	free(buf);
diff --git a/object-store.h b/object-store.h
index e16aa38..ba57630 100644
--- a/object-store.h
+++ b/object-store.h
@@ -160,13 +160,20 @@
 
 void *map_sha1_file(struct repository *r, const unsigned char *sha1, unsigned long *size);
 
-extern void *read_object_file_extended(const struct object_id *oid,
+extern void *read_object_file_extended(struct repository *r,
+				       const struct object_id *oid,
 				       enum object_type *type,
 				       unsigned long *size, int lookup_replace);
-static inline void *read_object_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
+static inline void *repo_read_object_file(struct repository *r,
+					  const struct object_id *oid,
+					  enum object_type *type,
+					  unsigned long *size)
 {
-	return read_object_file_extended(oid, type, size, 1);
+	return read_object_file_extended(r, oid, type, size, 1);
 }
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define read_object_file(oid, type, size) repo_read_object_file(the_repository, oid, type, size)
+#endif
 
 /* Read and unpack an object file into memory, write memory to an object file */
 int oid_object_info(struct repository *r, const struct object_id *, unsigned long *);
@@ -204,15 +211,27 @@
  * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
  * nonzero flags to also set other flags.
  */
-extern int has_sha1_file_with_flags(const unsigned char *sha1, int flags);
-static inline int has_sha1_file(const unsigned char *sha1)
+int repo_has_sha1_file_with_flags(struct repository *r,
+				  const unsigned char *sha1, int flags);
+static inline int repo_has_sha1_file(struct repository *r,
+				     const unsigned char *sha1)
 {
-	return has_sha1_file_with_flags(sha1, 0);
+	return repo_has_sha1_file_with_flags(r, sha1, 0);
 }
 
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define has_sha1_file_with_flags(sha1, flags) repo_has_sha1_file_with_flags(the_repository, sha1, flags)
+#define has_sha1_file(sha1) repo_has_sha1_file(the_repository, sha1)
+#endif
+
 /* Same as the above, except for struct object_id. */
-extern int has_object_file(const struct object_id *oid);
-extern int has_object_file_with_flags(const struct object_id *oid, int flags);
+int repo_has_object_file(struct repository *r, const struct object_id *oid);
+int repo_has_object_file_with_flags(struct repository *r,
+				    const struct object_id *oid, int flags);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define has_object_file(oid) repo_has_object_file(the_repository, oid)
+#define has_object_file_with_flags(oid, flags) repo_has_object_file_with_flags(the_repository, oid, flags)
+#endif
 
 /*
  * Return true iff an alternate object database has a loose object
diff --git a/object.c b/object.c
index a5c5cf8..5dc5eec 100644
--- a/object.c
+++ b/object.c
@@ -164,8 +164,9 @@
 		return obj;
 	else if (obj->type == OBJ_NONE) {
 		if (type == OBJ_COMMIT)
-			((struct commit *)obj)->index = alloc_commit_index(r);
-		obj->type = type;
+			init_commit_node(r, (struct commit *) obj);
+		else
+			obj->type = type;
 		return obj;
 	}
 	else {
@@ -259,8 +260,8 @@
 	if (obj && obj->parsed)
 		return obj;
 
-	if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
-	    (!obj && has_object_file(oid) &&
+	if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
+	    (!obj && repo_has_object_file(r, oid) &&
 	     oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 		if (check_object_signature(repl, NULL, 0, NULL) < 0) {
 			error(_("sha1 mismatch %s"), oid_to_hex(oid));
@@ -270,7 +271,7 @@
 		return lookup_object(r, oid->hash);
 	}
 
-	buffer = read_object_file(oid, &type, &size);
+	buffer = repo_read_object_file(r, oid, &type, &size);
 	if (buffer) {
 		if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
 			free(buffer);
@@ -540,7 +541,7 @@
 		if (obj->type == OBJ_TREE)
 			free_tree_buffer((struct tree*)obj);
 		else if (obj->type == OBJ_COMMIT)
-			release_commit_memory((struct commit*)obj);
+			release_commit_memory(o, (struct commit*)obj);
 		else if (obj->type == OBJ_TAG)
 			release_tag_memory((struct tag*)obj);
 	}
diff --git a/pack-objects.c b/pack-objects.c
index 9c45842..e7cd337 100644
--- a/pack-objects.c
+++ b/pack-objects.c
@@ -150,9 +150,7 @@
 					     1U << OE_SIZE_BITS);
 	pdata->oe_delta_size_limit = git_env_ulong("GIT_TEST_OE_DELTA_SIZE",
 						   1UL << OE_DELTA_SIZE_BITS);
-#ifndef NO_PTHREADS
-	pthread_mutex_init(&pdata->lock, NULL);
-#endif
+	init_recursive_mutex(&pdata->odb_lock);
 }
 
 struct object_entry *packlist_alloc(struct packing_data *pdata,
diff --git a/pack-objects.h b/pack-objects.h
index 3cd8d1f..6bfacc7 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -148,7 +148,11 @@
 	struct packed_git **in_pack_by_idx;
 	struct packed_git **in_pack;
 
-	pthread_mutex_t lock;
+	/*
+	 * During packing with multiple threads, protect the in-core
+	 * object database from concurrent accesses.
+	 */
+	pthread_mutex_t odb_lock;
 
 	/*
 	 * This list contains entries for bases which we know the other side
@@ -168,13 +172,14 @@
 
 void prepare_packing_data(struct repository *r, struct packing_data *pdata);
 
+/* Protect access to object database */
 static inline void packing_data_lock(struct packing_data *pdata)
 {
-	pthread_mutex_lock(&pdata->lock);
+	pthread_mutex_lock(&pdata->odb_lock);
 }
 static inline void packing_data_unlock(struct packing_data *pdata)
 {
-	pthread_mutex_unlock(&pdata->lock);
+	pthread_mutex_unlock(&pdata->odb_lock);
 }
 
 struct object_entry *packlist_alloc(struct packing_data *pdata,
diff --git a/packfile.c b/packfile.c
index 0fe9c21..16bcb75 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1148,12 +1148,13 @@
 	p->num_bad_objects++;
 }
 
-const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
+const struct packed_git *has_packed_and_bad(struct repository *r,
+					    const unsigned char *sha1)
 {
 	struct packed_git *p;
 	unsigned i;
 
-	for (p = the_repository->objects->packed_git; p; p = p->next)
+	for (p = r->objects->packed_git; p; p = p->next)
 		for (i = 0; i < p->num_bad_objects; i++)
 			if (hasheq(sha1,
 				   p->bad_object_sha1 + the_hash_algo->rawsz * i))
@@ -2097,7 +2098,7 @@
 			 */
 			return 0;
 		while (tree_entry_gently(&desc, &entry))
-			oidset_insert(set, entry.oid);
+			oidset_insert(set, &entry.oid);
 	} else if (obj->type == OBJ_COMMIT) {
 		struct commit *commit = (struct commit *) obj;
 		struct commit_list *parents = commit->parents;
diff --git a/packfile.h b/packfile.h
index 6c40376..d70c6d9 100644
--- a/packfile.h
+++ b/packfile.h
@@ -146,7 +146,7 @@
 			      off_t offset, struct object_info *);
 
 extern void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1);
-extern const struct packed_git *has_packed_and_bad(const unsigned char *sha1);
+extern const struct packed_git *has_packed_and_bad(struct repository *r, const unsigned char *sha1);
 
 /*
  * Iff a pack file in the given repository contains the object named by sha1,
diff --git a/path.h b/path.h
index b654ea8..651e615 100644
--- a/path.h
+++ b/path.h
@@ -165,7 +165,7 @@
 	const char *git_path_##var(struct repository *r) \
 	{ \
 		if (!r->cached_paths.var) \
-			r->cached_paths.var = git_pathdup(filename); \
+			r->cached_paths.var = repo_git_path(r, filename); \
 		return r->cached_paths.var; \
 	}
 
diff --git a/pkt-line.c b/pkt-line.c
index 04d10bb..d4b71d3 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -129,12 +129,14 @@
 	#undef hex
 }
 
-static void format_packet(struct strbuf *out, const char *fmt, va_list args)
+static void format_packet(struct strbuf *out, const char *prefix,
+			  const char *fmt, va_list args)
 {
 	size_t orig_len, n;
 
 	orig_len = out->len;
 	strbuf_addstr(out, "0000");
+	strbuf_addstr(out, prefix);
 	strbuf_vaddf(out, fmt, args);
 	n = out->len - orig_len;
 
@@ -145,13 +147,13 @@
 	packet_trace(out->buf + orig_len + 4, n - 4, 1);
 }
 
-static int packet_write_fmt_1(int fd, int gently,
+static int packet_write_fmt_1(int fd, int gently, const char *prefix,
 			      const char *fmt, va_list args)
 {
 	static struct strbuf buf = STRBUF_INIT;
 
 	strbuf_reset(&buf);
-	format_packet(&buf, fmt, args);
+	format_packet(&buf, prefix, fmt, args);
 	if (write_in_full(fd, buf.buf, buf.len) < 0) {
 		if (!gently) {
 			check_pipe(errno);
@@ -168,7 +170,7 @@
 	va_list args;
 
 	va_start(args, fmt);
-	packet_write_fmt_1(fd, 0, fmt, args);
+	packet_write_fmt_1(fd, 0, "", fmt, args);
 	va_end(args);
 }
 
@@ -178,7 +180,7 @@
 	va_list args;
 
 	va_start(args, fmt);
-	status = packet_write_fmt_1(fd, 1, fmt, args);
+	status = packet_write_fmt_1(fd, 1, "", fmt, args);
 	va_end(args);
 	return status;
 }
@@ -211,7 +213,7 @@
 	va_list args;
 
 	va_start(args, fmt);
-	format_packet(buf, fmt, args);
+	format_packet(buf, "", fmt, args);
 	va_end(args);
 }
 
@@ -346,6 +348,10 @@
 		return PACKET_READ_EOF;
 	}
 
+	if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
+	    starts_with(buffer, "ERR "))
+		die(_("remote error: %s"), buffer + 4);
+
 	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 	    len && buffer[len-1] == '\n')
 		len--;
@@ -433,6 +439,29 @@
 	return sb_out->len - orig_len;
 }
 
+int recv_sideband(const char *me, int in_stream, int out)
+{
+	char buf[LARGE_PACKET_MAX + 1];
+	int len;
+	struct strbuf scratch = STRBUF_INIT;
+	enum sideband_type sideband_type;
+
+	while (1) {
+		len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX,
+				  0);
+		if (!demultiplex_sideband(me, buf, len, 0, &scratch,
+					  &sideband_type))
+			continue;
+		switch (sideband_type) {
+		case SIDEBAND_PRIMARY:
+			write_or_die(out, buf + 1, len - 1);
+			break;
+		default: /* errors: message already written */
+			return sideband_type;
+		}
+	}
+}
+
 /* Packet Reader Functions */
 void packet_reader_init(struct packet_reader *reader, int fd,
 			char *src_buffer, size_t src_len,
@@ -446,25 +475,43 @@
 	reader->buffer = packet_buffer;
 	reader->buffer_size = sizeof(packet_buffer);
 	reader->options = options;
+	reader->me = "git";
 }
 
 enum packet_read_status packet_reader_read(struct packet_reader *reader)
 {
+	struct strbuf scratch = STRBUF_INIT;
+
 	if (reader->line_peeked) {
 		reader->line_peeked = 0;
 		return reader->status;
 	}
 
-	reader->status = packet_read_with_status(reader->fd,
-						 &reader->src_buffer,
-						 &reader->src_len,
-						 reader->buffer,
-						 reader->buffer_size,
-						 &reader->pktlen,
-						 reader->options);
+	/*
+	 * Consume all progress packets until a primary payload packet is
+	 * received
+	 */
+	while (1) {
+		enum sideband_type sideband_type;
+		reader->status = packet_read_with_status(reader->fd,
+							 &reader->src_buffer,
+							 &reader->src_len,
+							 reader->buffer,
+							 reader->buffer_size,
+							 &reader->pktlen,
+							 reader->options);
+		if (!reader->use_sideband)
+			break;
+		if (demultiplex_sideband(reader->me, reader->buffer,
+					 reader->pktlen, 1, &scratch,
+					 &sideband_type))
+			break;
+	}
 
 	if (reader->status == PACKET_READ_NORMAL)
-		reader->line = reader->buffer;
+		/* Skip the sideband designator if sideband is used */
+		reader->line = reader->use_sideband ?
+			reader->buffer + 1 : reader->buffer;
 	else
 		reader->line = NULL;
 
@@ -482,3 +529,39 @@
 	reader->line_peeked = 1;
 	return reader->status;
 }
+
+void packet_writer_init(struct packet_writer *writer, int dest_fd)
+{
+	writer->dest_fd = dest_fd;
+	writer->use_sideband = 0;
+}
+
+void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	packet_write_fmt_1(writer->dest_fd, 0,
+			   writer->use_sideband ? "\001" : "", fmt, args);
+	va_end(args);
+}
+
+void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	packet_write_fmt_1(writer->dest_fd, 0,
+			   writer->use_sideband ? "\003" : "ERR ", fmt, args);
+	va_end(args);
+}
+
+void packet_writer_delim(struct packet_writer *writer)
+{
+	packet_delim(writer->dest_fd);
+}
+
+void packet_writer_flush(struct packet_writer *writer)
+{
+	packet_flush(writer->dest_fd);
+}
diff --git a/pkt-line.h b/pkt-line.h
index 5b28d43..ad9a4a2 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -3,6 +3,7 @@
 
 #include "git-compat-util.h"
 #include "strbuf.h"
+#include "sideband.h"
 
 /*
  * Write a packetized stream, where each line is preceded by
@@ -62,9 +63,13 @@
  *
  * If options contains PACKET_READ_CHOMP_NEWLINE, a trailing newline (if
  * present) is removed from the buffer before returning.
+ *
+ * If options contains PACKET_READ_DIE_ON_ERR_PACKET, it dies when it sees an
+ * ERR packet.
  */
-#define PACKET_READ_GENTLE_ON_EOF (1u<<0)
-#define PACKET_READ_CHOMP_NEWLINE (1u<<1)
+#define PACKET_READ_GENTLE_ON_EOF     (1u<<0)
+#define PACKET_READ_CHOMP_NEWLINE     (1u<<1)
+#define PACKET_READ_DIE_ON_ERR_PACKET (1u<<2)
 int packet_read(int fd, char **src_buffer, size_t *src_len, char
 		*buffer, unsigned size, int options);
 
@@ -116,6 +121,21 @@
  */
 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out);
 
+/*
+ * Receive multiplexed output stream over git native protocol.
+ * in_stream is the input stream from the remote, which carries data
+ * in pkt_line format with band designator.  Demultiplex it into out
+ * and err and return error appropriately.  Band #1 carries the
+ * primary payload.  Things coming over band #2 is not necessarily
+ * error; they are usually informative message on the standard error
+ * stream, aka "verbose").  A message over band #3 is a signal that
+ * the remote died unexpectedly.  A flush() concludes the stream.
+ *
+ * Returns SIDEBAND_FLUSH upon a normal conclusion, and SIDEBAND_PROTOCOL_ERROR
+ * or SIDEBAND_REMOTE_ERROR if an error occurred.
+ */
+int recv_sideband(const char *me, int in_stream, int out);
+
 struct packet_reader {
 	/* source file descriptor */
 	int fd;
@@ -142,6 +162,9 @@
 
 	/* indicates if a line has been peeked */
 	int line_peeked;
+
+	unsigned use_sideband : 1;
+	const char *me;
 };
 
 /*
@@ -179,4 +202,19 @@
 #define LARGE_PACKET_DATA_MAX (LARGE_PACKET_MAX - 4)
 extern char packet_buffer[LARGE_PACKET_MAX];
 
+struct packet_writer {
+	int dest_fd;
+	unsigned use_sideband : 1;
+};
+
+void packet_writer_init(struct packet_writer *writer, int dest_fd);
+
+/* These functions die upon failure. */
+__attribute__((format (printf, 2, 3)))
+void packet_writer_write(struct packet_writer *writer, const char *fmt, ...);
+__attribute__((format (printf, 2, 3)))
+void packet_writer_error(struct packet_writer *writer, const char *fmt, ...);
+void packet_writer_delim(struct packet_writer *writer);
+void packet_writer_flush(struct packet_writer *writer);
+
 #endif
diff --git a/pretty.c b/pretty.c
index b83a3ec..0ab45d1 100644
--- a/pretty.c
+++ b/pretty.c
@@ -595,14 +595,15 @@
 	return strbuf_detach(&tmp, NULL);
 }
 
-const char *logmsg_reencode(const struct commit *commit,
-			    char **commit_encoding,
-			    const char *output_encoding)
+const char *repo_logmsg_reencode(struct repository *r,
+				 const struct commit *commit,
+				 char **commit_encoding,
+				 const char *output_encoding)
 {
 	static const char *utf8 = "UTF-8";
 	const char *use_encoding;
 	char *encoding;
-	const char *msg = get_commit_buffer(commit, NULL);
+	const char *msg = repo_get_commit_buffer(r, commit, NULL);
 	char *out;
 
 	if (!output_encoding || !*output_encoding) {
@@ -630,7 +631,7 @@
 		 * the cached copy from get_commit_buffer, we need to duplicate it
 		 * to avoid munging the cached copy.
 		 */
-		if (msg == get_cached_commit_buffer(the_repository, commit, NULL))
+		if (msg == get_cached_commit_buffer(r, commit, NULL))
 			out = xstrdup(msg);
 		else
 			out = (char *)msg;
@@ -644,7 +645,7 @@
 		 */
 		out = reencode_string(msg, output_encoding, use_encoding);
 		if (out)
-			unuse_commit_buffer(commit, msg);
+			repo_unuse_commit_buffer(r, commit, msg);
 	}
 
 	/*
@@ -1084,6 +1085,7 @@
 	struct commit_list *p;
 	const char *arg;
 	int ch;
+	char **slot;
 
 	/* these are independent of the commit */
 	switch (placeholder[0]) {
@@ -1194,6 +1196,14 @@
 		load_ref_decorations(NULL, DECORATE_SHORT_REFS);
 		format_decorations_extended(sb, commit, c->auto_color, "", ", ", "");
 		return 1;
+	case 'S':		/* tag/branch like --source */
+		if (!(c->pretty_ctx->rev && c->pretty_ctx->rev->sources))
+			return 0;
+		slot = revision_sources_at(c->pretty_ctx->rev->sources, commit);
+		if (!(slot && *slot))
+			return 0;
+		strbuf_addstr(sb, *slot);
+		return 1;
 	case 'g':		/* reflog info */
 		switch(placeholder[1]) {
 		case 'd':	/* reflog selector */
@@ -1498,6 +1508,9 @@
 	case 'N':
 		w->notes = 1;
 		break;
+	case 'S':
+		w->source = 1;
+		break;
 	}
 	return 0;
 }
@@ -1515,9 +1528,10 @@
 	strbuf_release(&dummy);
 }
 
-void format_commit_message(const struct commit *commit,
-			   const char *format, struct strbuf *sb,
-			   const struct pretty_print_context *pretty_ctx)
+void repo_format_commit_message(struct repository *r,
+				const struct commit *commit,
+				const char *format, struct strbuf *sb,
+				const struct pretty_print_context *pretty_ctx)
 {
 	struct format_commit_context context;
 	const char *output_enc = pretty_ctx->output_encoding;
@@ -1531,9 +1545,9 @@
 	 * convert a commit message to UTF-8 first
 	 * as far as 'format_commit_item' assumes it in UTF-8
 	 */
-	context.message = logmsg_reencode(commit,
-					  &context.commit_encoding,
-					  utf8);
+	context.message = repo_logmsg_reencode(r, commit,
+					       &context.commit_encoding,
+					       utf8);
 
 	strbuf_expand(sb, format, format_commit_item, &context);
 	rewrap_message_tail(sb, &context, 0, 0, 0);
@@ -1557,7 +1571,7 @@
 	}
 
 	free(context.commit_encoding);
-	unuse_commit_buffer(commit, context.message);
+	repo_unuse_commit_buffer(r, commit, context.message);
 }
 
 static void pp_header(struct pretty_print_context *pp,
diff --git a/pretty.h b/pretty.h
index 7359d31..4ad1fc3 100644
--- a/pretty.h
+++ b/pretty.h
@@ -60,6 +60,7 @@
 
 struct userformat_want {
 	unsigned notes:1;
+	unsigned source:1;
 };
 
 /* Set the flag "w->notes" if there is placeholder %N in "fmt". */
@@ -103,9 +104,14 @@
  * Put the result to "sb".
  * Please use this function for custom formats.
  */
-void format_commit_message(const struct commit *commit,
+void repo_format_commit_message(struct repository *r,
+			const struct commit *commit,
 			const char *format, struct strbuf *sb,
 			const struct pretty_print_context *context);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define format_commit_message(c, f, s, con) \
+	repo_format_commit_message(the_repository, c, f, s, con)
+#endif
 
 /*
  * Parse given arguments from "arg", check it for correctness and
diff --git a/read-cache.c b/read-cache.c
index bfff271..9783c49 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -703,10 +703,10 @@
 	int intent_only = flags & ADD_CACHE_INTENT;
 	int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
 			  (intent_only ? ADD_CACHE_NEW_ONLY : 0));
-	int newflags = HASH_WRITE_OBJECT;
+	int hash_flags = HASH_WRITE_OBJECT;
 
-	if (flags & HASH_RENORMALIZE)
-		newflags |= HASH_RENORMALIZE;
+	if (flags & ADD_CACHE_RENORMALIZE)
+		hash_flags |= HASH_RENORMALIZE;
 
 	if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
 		return error(_("%s: can only add regular files, symbolic links or git-directories"), path);
@@ -762,7 +762,7 @@
 		}
 	}
 	if (!intent_only) {
-		if (index_path(istate, &ce->oid, path, st, newflags)) {
+		if (index_path(istate, &ce->oid, path, st, hash_flags)) {
 			discard_cache_entry(ce);
 			return error(_("unable to index file '%s'"), path);
 		}
diff --git a/remote-curl.c b/remote-curl.c
index 90d565c..2e04d53 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -204,7 +204,8 @@
 
 	packet_reader_init(&reader, -1, heads->buf, heads->len,
 			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
 
 	heads->version = discover_version(&reader);
 	switch (heads->version) {
@@ -380,7 +381,6 @@
 	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
-	http_options.keep_error = 1;
 
 	http_ret = http_get_strbuf(refs_url.buf, &buffer, &http_options);
 	switch (http_ret) {
@@ -409,28 +409,37 @@
 	if (maybe_smart &&
 	    (5 <= last->len && last->buf[4] == '#') &&
 	    !strbuf_cmp(&exp, &type)) {
-		char *line;
+		struct packet_reader reader;
+		packet_reader_init(&reader, -1, last->buf, last->len,
+				   PACKET_READ_CHOMP_NEWLINE |
+				   PACKET_READ_DIE_ON_ERR_PACKET);
 
 		/*
 		 * smart HTTP response; validate that the service
 		 * pkt-line matches our request.
 		 */
-		line = packet_read_line_buf(&last->buf, &last->len, NULL);
-		if (!line)
+		if (packet_reader_read(&reader) != PACKET_READ_NORMAL)
 			die("invalid server response; expected service, got flush packet");
 
 		strbuf_reset(&exp);
 		strbuf_addf(&exp, "# service=%s", service);
-		if (strcmp(line, exp.buf))
-			die("invalid server response; got '%s'", line);
+		if (strcmp(reader.line, exp.buf))
+			die("invalid server response; got '%s'", reader.line);
 		strbuf_release(&exp);
 
 		/* The header can include additional metadata lines, up
 		 * until a packet flush marker.  Ignore these now, but
 		 * in the future we might start to scan them.
 		 */
-		while (packet_read_line_buf(&last->buf, &last->len, NULL))
-			;
+		for (;;) {
+			packet_reader_read(&reader);
+			if (reader.pktlen <= 0) {
+				break;
+			}
+		}
+
+		last->buf = reader.src_buffer;
+		last->len = reader.src_len;
 
 		last->proto_git = 1;
 	} else if (maybe_smart &&
@@ -546,14 +555,30 @@
 }
 #endif
 
+struct rpc_in_data {
+	struct rpc_state *rpc;
+	struct active_request_slot *slot;
+};
+
+/*
+ * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
+ * from ptr.
+ */
 static size_t rpc_in(char *ptr, size_t eltsize,
 		size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
-	struct rpc_state *rpc = buffer_;
+	struct rpc_in_data *data = buffer_;
+	long response_code;
+
+	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
+			      &response_code) != CURLE_OK)
+		return size;
+	if (response_code >= 300)
+		return size;
 	if (size)
-		rpc->any_written = 1;
-	write_or_die(rpc->in, ptr, size);
+		data->rpc->any_written = 1;
+	write_or_die(data->rpc->in, ptr, size);
 	return size;
 }
 
@@ -634,6 +659,7 @@
 	size_t gzip_size = 0;
 	int err, large_request = 0;
 	int needs_100_continue = 0;
+	struct rpc_in_data rpc_in_data;
 
 	/* Try to load the entire request, if we can fit it into the
 	 * allocated buffer space we can use HTTP/1.0 and avoid the
@@ -766,7 +792,10 @@
 
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
+	rpc_in_data.rpc = rpc;
+	rpc_in_data.slot = slot;
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
+	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
 
 	rpc->any_written = 0;
@@ -1175,7 +1204,8 @@
 		p->headers = curl_slist_append(p->headers, buf.buf);
 
 	packet_reader_init(&p->reader, p->in, NULL, 0,
-			   PACKET_READ_GENTLE_ON_EOF);
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
 
 	strbuf_release(&buf);
 }
diff --git a/remote.c b/remote.c
index 670dd44..9cc3b07 100644
--- a/remote.c
+++ b/remote.c
@@ -337,14 +337,14 @@
 		if (!name)
 			return 0;
 		if (!strcmp(subkey, "insteadof")) {
-			rewrite = make_rewrite(&rewrites, name, namelen);
 			if (!value)
 				return config_error_nonbool(key);
+			rewrite = make_rewrite(&rewrites, name, namelen);
 			add_instead_of(rewrite, xstrdup(value));
 		} else if (!strcmp(subkey, "pushinsteadof")) {
-			rewrite = make_rewrite(&rewrites_push, name, namelen);
 			if (!value)
 				return config_error_nonbool(key);
+			rewrite = make_rewrite(&rewrites_push, name, namelen);
 			add_instead_of(rewrite, xstrdup(value));
 		}
 	}
diff --git a/repository.c b/repository.c
index 7b02e1d..20c509a 100644
--- a/repository.c
+++ b/repository.c
@@ -172,30 +172,23 @@
 	return -1;
 }
 
-/*
- * Initialize 'submodule' as the submodule given by 'path' in parent repository
- * 'superproject'.
- * Return 0 upon success and a non-zero value upon failure.
- */
-int repo_submodule_init(struct repository *submodule,
+int repo_submodule_init(struct repository *subrepo,
 			struct repository *superproject,
-			const char *path)
+			const struct submodule *sub)
 {
-	const struct submodule *sub;
 	struct strbuf gitdir = STRBUF_INIT;
 	struct strbuf worktree = STRBUF_INIT;
 	int ret = 0;
 
-	sub = submodule_from_path(superproject, &null_oid, path);
 	if (!sub) {
 		ret = -1;
 		goto out;
 	}
 
-	strbuf_repo_worktree_path(&gitdir, superproject, "%s/.git", path);
-	strbuf_repo_worktree_path(&worktree, superproject, "%s", path);
+	strbuf_repo_worktree_path(&gitdir, superproject, "%s/.git", sub->path);
+	strbuf_repo_worktree_path(&worktree, superproject, "%s", sub->path);
 
-	if (repo_init(submodule, gitdir.buf, worktree.buf)) {
+	if (repo_init(subrepo, gitdir.buf, worktree.buf)) {
 		/*
 		 * If initilization fails then it may be due to the submodule
 		 * not being populated in the superproject's worktree.  Instead
@@ -207,16 +200,16 @@
 		strbuf_repo_git_path(&gitdir, superproject,
 				     "modules/%s", sub->name);
 
-		if (repo_init(submodule, gitdir.buf, NULL)) {
+		if (repo_init(subrepo, gitdir.buf, NULL)) {
 			ret = -1;
 			goto out;
 		}
 	}
 
-	submodule->submodule_prefix = xstrfmt("%s%s/",
-					      superproject->submodule_prefix ?
-					      superproject->submodule_prefix :
-					      "", path);
+	subrepo->submodule_prefix = xstrfmt("%s%s/",
+					    superproject->submodule_prefix ?
+					    superproject->submodule_prefix :
+					    "", sub->path);
 
 out:
 	strbuf_release(&gitdir);
diff --git a/repository.h b/repository.h
index 9f16c42..0e482b7 100644
--- a/repository.h
+++ b/repository.h
@@ -116,9 +116,17 @@
 void repo_set_hash_algo(struct repository *repo, int algo);
 void initialize_the_repository(void);
 int repo_init(struct repository *r, const char *gitdir, const char *worktree);
-int repo_submodule_init(struct repository *submodule,
+
+/*
+ * Initialize the repository 'subrepo' as the submodule given by the
+ * struct submodule 'sub' in parent repository 'superproject'.
+ * Return 0 upon success and a non-zero value upon failure, which may happen
+ * if the submodule is not found, or 'sub' is NULL.
+ */
+struct submodule;
+int repo_submodule_init(struct repository *subrepo,
 			struct repository *superproject,
-			const char *path);
+			const struct submodule *sub);
 void repo_clear(struct repository *repo);
 
 /*
diff --git a/revision.c b/revision.c
index 13cfb59..8f886fe 100644
--- a/revision.c
+++ b/revision.c
@@ -67,10 +67,10 @@
 	while (tree_entry(&desc, &entry)) {
 		switch (object_type(entry.mode)) {
 		case OBJ_TREE:
-			mark_tree_uninteresting(r, lookup_tree(r, entry.oid));
+			mark_tree_uninteresting(r, lookup_tree(r, &entry.oid));
 			break;
 		case OBJ_BLOB:
-			mark_blob_uninteresting(lookup_blob(r, entry.oid));
+			mark_blob_uninteresting(lookup_blob(r, &entry.oid));
 			break;
 		default:
 			/* Subproject commit - not in this repository */
@@ -213,7 +213,20 @@
 {
 	struct object *object;
 
-	object = parse_object(revs->repo, oid);
+	/*
+	 * If the repository has commit graphs, repo_parse_commit() avoids
+	 * reading the object buffer, so use it whenever possible.
+	 */
+	if (oid_object_info(revs->repo, oid, NULL) == OBJ_COMMIT) {
+		struct commit *c = lookup_commit(revs->repo, oid);
+		if (!repo_parse_commit(revs->repo, c))
+			object = (struct object *) c;
+		else
+			object = NULL;
+	} else {
+		object = parse_object(revs->repo, oid);
+	}
+
 	if (!object) {
 		if (revs->ignore_missing)
 			return object;
diff --git a/send-pack.c b/send-pack.c
index f692686..7b9829f 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -135,38 +135,36 @@
 	return 0;
 }
 
-static int receive_unpack_status(int in)
+static int receive_unpack_status(struct packet_reader *reader)
 {
-	const char *line = packet_read_line(in, NULL);
-	if (!line)
+	if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 		return error(_("unexpected flush packet while reading remote unpack status"));
-	if (!skip_prefix(line, "unpack ", &line))
-		return error(_("unable to parse remote unpack status: %s"), line);
-	if (strcmp(line, "ok"))
-		return error(_("remote unpack failed: %s"), line);
+	if (!skip_prefix(reader->line, "unpack ", &reader->line))
+		return error(_("unable to parse remote unpack status: %s"), reader->line);
+	if (strcmp(reader->line, "ok"))
+		return error(_("remote unpack failed: %s"), reader->line);
 	return 0;
 }
 
-static int receive_status(int in, struct ref *refs)
+static int receive_status(struct packet_reader *reader, struct ref *refs)
 {
 	struct ref *hint;
 	int ret;
 
 	hint = NULL;
-	ret = receive_unpack_status(in);
+	ret = receive_unpack_status(reader);
 	while (1) {
-		char *refname;
+		const char *refname;
 		char *msg;
-		char *line = packet_read_line(in, NULL);
-		if (!line)
+		if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 			break;
-		if (!starts_with(line, "ok ") && !starts_with(line, "ng ")) {
-			error("invalid ref status from remote: %s", line);
+		if (!starts_with(reader->line, "ok ") && !starts_with(reader->line, "ng ")) {
+			error("invalid ref status from remote: %s", reader->line);
 			ret = -1;
 			break;
 		}
 
-		refname = line + 3;
+		refname = reader->line + 3;
 		msg = strchr(refname, ' ');
 		if (msg)
 			*msg++ = '\0';
@@ -187,7 +185,7 @@
 			continue;
 		}
 
-		if (line[0] == 'o' && line[1] == 'k')
+		if (reader->line[0] == 'o' && reader->line[1] == 'k')
 			hint->status = REF_STATUS_OK;
 		else {
 			hint->status = REF_STATUS_REMOTE_REJECT;
@@ -390,6 +388,7 @@
 	int ret;
 	struct async demux;
 	const char *push_cert_nonce = NULL;
+	struct packet_reader reader;
 
 	/* Does the other end support the reporting? */
 	if (server_supports("report-status"))
@@ -559,6 +558,10 @@
 		in = demux.out;
 	}
 
+	packet_reader_init(&reader, in, NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+
 	if (need_pack_data && cmds_sent) {
 		if (pack_objects(out, remote_refs, extra_have, args) < 0) {
 			for (ref = remote_refs; ref; ref = ref->next)
@@ -573,7 +576,7 @@
 			 * are failing, and just want the error() side effects.
 			 */
 			if (status_report)
-				receive_unpack_status(in);
+				receive_unpack_status(&reader);
 
 			if (use_sideband) {
 				close(demux.out);
@@ -590,7 +593,7 @@
 		packet_flush(out);
 
 	if (status_report && cmds_sent)
-		ret = receive_status(in, remote_refs);
+		ret = receive_status(&reader, remote_refs);
 	else
 		ret = 0;
 	if (args->stateless_rpc)
diff --git a/sequencer.c b/sequencer.c
index f5370f4..a6333ab 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -150,6 +150,7 @@
 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
+static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
 static GIT_PATH_FUNC(rebase_path_signoff, "rebase-merge/signoff")
 static GIT_PATH_FUNC(rebase_path_head_name, "rebase-merge/head-name")
 static GIT_PATH_FUNC(rebase_path_onto, "rebase-merge/onto")
@@ -157,7 +158,7 @@
 static GIT_PATH_FUNC(rebase_path_strategy, "rebase-merge/strategy")
 static GIT_PATH_FUNC(rebase_path_strategy_opts, "rebase-merge/strategy_opts")
 static GIT_PATH_FUNC(rebase_path_allow_rerere_autoupdate, "rebase-merge/allow_rerere_autoupdate")
-static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
+static GIT_PATH_FUNC(rebase_path_reschedule_failed_exec, "rebase-merge/reschedule-failed-exec")
 
 static int git_sequencer_config(const char *k, const char *v, void *cb)
 {
@@ -2389,11 +2390,17 @@
 		if (file_exists(rebase_path_verbose()))
 			opts->verbose = 1;
 
+		if (file_exists(rebase_path_quiet()))
+			opts->quiet = 1;
+
 		if (file_exists(rebase_path_signoff())) {
 			opts->allow_ff = 0;
 			opts->signoff = 1;
 		}
 
+		if (file_exists(rebase_path_reschedule_failed_exec()))
+			opts->reschedule_failed_exec = 1;
+
 		read_strategy_opts(opts, &buf);
 		strbuf_release(&buf);
 
@@ -2456,9 +2463,6 @@
 
 	if (quiet)
 		write_file(rebase_path_quiet(), "%s\n", quiet);
-	else
-		write_file(rebase_path_quiet(), "\n");
-
 	if (opts->verbose)
 		write_file(rebase_path_verbose(), "%s", "");
 	if (opts->strategy)
@@ -2475,6 +2479,8 @@
 		write_file(rebase_path_gpg_sign_opt(), "-S%s\n", opts->gpg_sign);
 	if (opts->signoff)
 		write_file(rebase_path_signoff(), "--signoff\n");
+	if (opts->reschedule_failed_exec)
+		write_file(rebase_path_reschedule_failed_exec(), "%s", "");
 
 	return 0;
 }
@@ -3549,10 +3555,11 @@
 					fprintf(f, "%d\n", todo_list->done_nr);
 					fclose(f);
 				}
-				fprintf(stderr, "Rebasing (%d/%d)%s",
-					todo_list->done_nr,
-					todo_list->total_nr,
-					opts->verbose ? "\n" : "\r");
+				if (!opts->quiet)
+					fprintf(stderr, "Rebasing (%d/%d)%s",
+						todo_list->done_nr,
+						todo_list->total_nr,
+						opts->verbose ? "\n" : "\r");
 			}
 			unlink(rebase_path_message());
 			unlink(rebase_path_author_script());
@@ -3632,9 +3639,10 @@
 			*end_of_arg = saved;
 
 			/* Reread the todo file if it has changed. */
-			if (res)
-				; /* fall through */
-			else if (stat(get_todo_path(opts), &st))
+			if (res) {
+				if (opts->reschedule_failed_exec)
+					reschedule = 1;
+			} else if (stat(get_todo_path(opts), &st))
 				res = error_errno(_("could not stat '%s'"),
 						  get_todo_path(opts));
 			else if (match_stat_data(&todo_list->stat, &st)) {
@@ -3785,8 +3793,10 @@
 		}
 		apply_autostash(opts);
 
-		fprintf(stderr, "Successfully rebased and updated %s.\n",
-			head_ref.buf);
+		if (!opts->quiet)
+			fprintf(stderr,
+				"Successfully rebased and updated %s.\n",
+				head_ref.buf);
 
 		strbuf_release(&buf);
 		strbuf_release(&head_ref);
diff --git a/sequencer.h b/sequencer.h
index 9d83f0f..53b8679 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -40,6 +40,8 @@
 	int allow_empty_message;
 	int keep_redundant_commits;
 	int verbose;
+	int quiet;
+	int reschedule_failed_exec;
 
 	int mainline;
 
diff --git a/serve.c b/serve.c
index bda085f..317256c 100644
--- a/serve.c
+++ b/serve.c
@@ -167,7 +167,8 @@
 
 	packet_reader_init(&reader, 0, NULL, 0,
 			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
 
 	/*
 	 * Check to see if the client closed their end before sending another
@@ -175,7 +176,7 @@
 	 */
 	if (packet_reader_peek(&reader) == PACKET_READ_EOF)
 		return 1;
-	reader.options = PACKET_READ_CHOMP_NEWLINE;
+	reader.options &= ~PACKET_READ_GENTLE_ON_EOF;
 
 	while (state != PROCESS_REQUEST_DONE) {
 		switch (packet_reader_peek(&reader)) {
diff --git a/setup.c b/setup.c
index 12bf25a..ca9e8a9 100644
--- a/setup.c
+++ b/setup.c
@@ -39,7 +39,7 @@
 	off = offset_1st_component(path);
 
 	/* check if work tree is already the prefix */
-	if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
+	if (wtlen <= len && !fspathncmp(path, work_tree, wtlen)) {
 		if (path[wtlen] == '/') {
 			memmove(path, path + wtlen + 1, len - wtlen);
 			return 0;
@@ -59,7 +59,7 @@
 		path++;
 		if (*path == '/') {
 			*path = '\0';
-			if (strcmp(real_path(path0), work_tree) == 0) {
+			if (fspathcmp(real_path(path0), work_tree) == 0) {
 				memmove(path0, path + 1, len - (path - path0));
 				return 0;
 			}
@@ -68,7 +68,7 @@
 	}
 
 	/* check whole path */
-	if (strcmp(real_path(path0), work_tree) == 0) {
+	if (fspathcmp(real_path(path0), work_tree) == 0) {
 		*path0 = '\0';
 		return 0;
 	}
diff --git a/sha1-array.c b/sha1-array.c
index b94e0ec..d922e94 100644
--- a/sha1-array.c
+++ b/sha1-array.c
@@ -77,3 +77,20 @@
 	}
 	return 0;
 }
+
+void oid_array_filter(struct oid_array *array,
+		      for_each_oid_fn want,
+		      void *cb_data)
+{
+	unsigned nr = array->nr, src, dst;
+	struct object_id *oids = array->oid;
+
+	for (src = dst = 0; src < nr; src++) {
+		if (want(&oids[src], cb_data)) {
+			if (src != dst)
+				oidcpy(&oids[dst], &oids[src]);
+			dst++;
+		}
+	}
+	array->nr = dst;
+}
diff --git a/sha1-array.h b/sha1-array.h
index 232bf95..55d016c 100644
--- a/sha1-array.h
+++ b/sha1-array.h
@@ -22,5 +22,8 @@
 int oid_array_for_each_unique(struct oid_array *array,
 			      for_each_oid_fn fn,
 			      void *data);
+void oid_array_filter(struct oid_array *array,
+		      for_each_oid_fn want,
+		      void *cbdata);
 
 #endif /* SHA1_ARRAY_H */
diff --git a/sha1-file.c b/sha1-file.c
index 386b96e..c8da9f3 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -40,10 +40,20 @@
 #define EMPTY_TREE_SHA1_BIN_LITERAL \
 	 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
 	 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
+#define EMPTY_TREE_SHA256_BIN_LITERAL \
+	"\x6e\xf1\x9b\x41\x22\x5c\x53\x69\xf1\xc1" \
+	"\x04\xd4\x5d\x8d\x85\xef\xa9\xb0\x57\xb5" \
+	"\x3b\x14\xb4\xb9\xb9\x39\xdd\x74\xde\xcc" \
+	"\x53\x21"
 
 #define EMPTY_BLOB_SHA1_BIN_LITERAL \
 	"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
 	"\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
+#define EMPTY_BLOB_SHA256_BIN_LITERAL \
+	"\x47\x3a\x0f\x4c\x3b\xe8\xa9\x36\x81\xa2" \
+	"\x67\xe3\xb1\xe9\xa7\xdc\xda\x11\x85\x43" \
+	"\x6f\xe1\x41\xf7\x74\x91\x20\xa3\x03\x72" \
+	"\x18\x13"
 
 const unsigned char null_sha1[GIT_MAX_RAWSZ];
 const struct object_id null_oid;
@@ -53,6 +63,12 @@
 static const struct object_id empty_blob_oid = {
 	EMPTY_BLOB_SHA1_BIN_LITERAL
 };
+static const struct object_id empty_tree_oid_sha256 = {
+	EMPTY_TREE_SHA256_BIN_LITERAL
+};
+static const struct object_id empty_blob_oid_sha256 = {
+	EMPTY_BLOB_SHA256_BIN_LITERAL
+};
 
 static void git_hash_sha1_init(git_hash_ctx *ctx)
 {
@@ -69,6 +85,22 @@
 	git_SHA1_Final(hash, &ctx->sha1);
 }
 
+
+static void git_hash_sha256_init(git_hash_ctx *ctx)
+{
+	git_SHA256_Init(&ctx->sha256);
+}
+
+static void git_hash_sha256_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+	git_SHA256_Update(&ctx->sha256, data, len);
+}
+
+static void git_hash_sha256_final(unsigned char *hash, git_hash_ctx *ctx)
+{
+	git_SHA256_Final(hash, &ctx->sha256);
+}
+
 static void git_hash_unknown_init(git_hash_ctx *ctx)
 {
 	BUG("trying to init unknown hash");
@@ -90,6 +122,7 @@
 		0x00000000,
 		0,
 		0,
+		0,
 		git_hash_unknown_init,
 		git_hash_unknown_update,
 		git_hash_unknown_final,
@@ -97,17 +130,31 @@
 		NULL,
 	},
 	{
-		"sha-1",
+		"sha1",
 		/* "sha1", big-endian */
 		0x73686131,
 		GIT_SHA1_RAWSZ,
 		GIT_SHA1_HEXSZ,
+		GIT_SHA1_BLKSZ,
 		git_hash_sha1_init,
 		git_hash_sha1_update,
 		git_hash_sha1_final,
 		&empty_tree_oid,
 		&empty_blob_oid,
 	},
+	{
+		"sha256",
+		/* "s256", big-endian */
+		0x73323536,
+		GIT_SHA256_RAWSZ,
+		GIT_SHA256_HEXSZ,
+		GIT_SHA256_BLKSZ,
+		git_hash_sha256_init,
+		git_hash_sha256_update,
+		git_hash_sha256_final,
+		&empty_tree_oid_sha256,
+		&empty_blob_oid_sha256,
+	}
 };
 
 const char *empty_tree_oid_hex(void)
@@ -122,6 +169,27 @@
 	return oid_to_hex_r(buf, the_hash_algo->empty_blob);
 }
 
+int hash_algo_by_name(const char *name)
+{
+	int i;
+	if (!name)
+		return GIT_HASH_UNKNOWN;
+	for (i = 1; i < GIT_HASH_NALGOS; i++)
+		if (!strcmp(name, hash_algos[i].name))
+			return i;
+	return GIT_HASH_UNKNOWN;
+}
+
+int hash_algo_by_id(uint32_t format_id)
+{
+	int i;
+	for (i = 1; i < GIT_HASH_NALGOS; i++)
+		if (format_id == hash_algos[i].format_id)
+			return i;
+	return GIT_HASH_UNKNOWN;
+}
+
+
 /*
  * This is meant to hold a *small* number of objects that you would
  * want read_sha1_file() to be able to return, but yet you do not want
@@ -1353,7 +1421,9 @@
 	return type;
 }
 
-static void *read_object(const unsigned char *sha1, enum object_type *type,
+static void *read_object(struct repository *r,
+			 const unsigned char *sha1,
+			 enum object_type *type,
 			 unsigned long *size)
 {
 	struct object_id oid;
@@ -1365,7 +1435,7 @@
 
 	hashcpy(oid.hash, sha1);
 
-	if (oid_object_info_extended(the_repository, &oid, &oi, 0) < 0)
+	if (oid_object_info_extended(r, &oid, &oi, 0) < 0)
 		return NULL;
 	return content;
 }
@@ -1393,7 +1463,8 @@
  * deal with them should arrange to call read_object() and give error
  * messages themselves.
  */
-void *read_object_file_extended(const struct object_id *oid,
+void *read_object_file_extended(struct repository *r,
+				const struct object_id *oid,
 				enum object_type *type,
 				unsigned long *size,
 				int lookup_replace)
@@ -1403,10 +1474,10 @@
 	const char *path;
 	struct stat st;
 	const struct object_id *repl = lookup_replace ?
-		lookup_replace_object(the_repository, oid) : oid;
+		lookup_replace_object(r, oid) : oid;
 
 	errno = 0;
-	data = read_object(repl->hash, type, size);
+	data = read_object(r, repl->hash, type, size);
 	if (data)
 		return data;
 
@@ -1418,11 +1489,11 @@
 		die(_("replacement %s not found for %s"),
 		    oid_to_hex(repl), oid_to_hex(oid));
 
-	if (!stat_sha1_file(the_repository, repl->hash, &st, &path))
+	if (!stat_sha1_file(r, repl->hash, &st, &path))
 		die(_("loose object %s (stored in %s) is corrupt"),
 		    oid_to_hex(repl), path);
 
-	if ((p = has_packed_and_bad(repl->hash)) != NULL)
+	if ((p = has_packed_and_bad(r, repl->hash)) != NULL)
 		die(_("packed object %s (stored in %s) is corrupt"),
 		    oid_to_hex(repl), p->pack_name);
 
@@ -1746,7 +1817,7 @@
 
 	if (has_loose_object(oid))
 		return 0;
-	buf = read_object(oid->hash, &type, &len);
+	buf = read_object(the_repository, oid->hash, &type, &len);
 	if (!buf)
 		return error(_("cannot read sha1_file for %s"), oid_to_hex(oid));
 	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
@@ -1756,24 +1827,27 @@
 	return ret;
 }
 
-int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
+int repo_has_sha1_file_with_flags(struct repository *r,
+				  const unsigned char *sha1, int flags)
 {
 	struct object_id oid;
 	if (!startup_info->have_repository)
 		return 0;
 	hashcpy(oid.hash, sha1);
-	return oid_object_info_extended(the_repository, &oid, NULL,
+	return oid_object_info_extended(r, &oid, NULL,
 					flags | OBJECT_INFO_SKIP_CACHED) >= 0;
 }
 
-int has_object_file(const struct object_id *oid)
+int repo_has_object_file(struct repository *r,
+			 const struct object_id *oid)
 {
-	return has_sha1_file(oid->hash);
+	return repo_has_sha1_file(r, oid->hash);
 }
 
-int has_object_file_with_flags(const struct object_id *oid, int flags)
+int repo_has_object_file_with_flags(struct repository *r,
+				    const struct object_id *oid, int flags)
 {
-	return has_sha1_file_with_flags(oid->hash, flags);
+	return repo_has_sha1_file_with_flags(r, oid->hash, flags);
 }
 
 static void check_tree(const void *buf, size_t size)
diff --git a/sha256/block/sha256.c b/sha256/block/sha256.c
new file mode 100644
index 0000000..37850b4
--- /dev/null
+++ b/sha256/block/sha256.c
@@ -0,0 +1,196 @@
+#include "git-compat-util.h"
+#include "./sha256.h"
+
+#undef RND
+#undef BLKSIZE
+
+#define BLKSIZE blk_SHA256_BLKSIZE
+
+void blk_SHA256_Init(blk_SHA256_CTX *ctx)
+{
+	ctx->offset = 0;
+	ctx->size = 0;
+	ctx->state[0] = 0x6a09e667ul;
+	ctx->state[1] = 0xbb67ae85ul;
+	ctx->state[2] = 0x3c6ef372ul;
+	ctx->state[3] = 0xa54ff53aul;
+	ctx->state[4] = 0x510e527ful;
+	ctx->state[5] = 0x9b05688cul;
+	ctx->state[6] = 0x1f83d9abul;
+	ctx->state[7] = 0x5be0cd19ul;
+}
+
+static inline uint32_t ror(uint32_t x, unsigned n)
+{
+	return (x >> n) | (x << (32 - n));
+}
+
+static inline uint32_t ch(uint32_t x, uint32_t y, uint32_t z)
+{
+	return z ^ (x & (y ^ z));
+}
+
+static inline uint32_t maj(uint32_t x, uint32_t y, uint32_t z)
+{
+	return ((x | y) & z) | (x & y);
+}
+
+static inline uint32_t sigma0(uint32_t x)
+{
+	return ror(x, 2) ^ ror(x, 13) ^ ror(x, 22);
+}
+
+static inline uint32_t sigma1(uint32_t x)
+{
+	return ror(x, 6) ^ ror(x, 11) ^ ror(x, 25);
+}
+
+static inline uint32_t gamma0(uint32_t x)
+{
+	return ror(x, 7) ^ ror(x, 18) ^ (x >> 3);
+}
+
+static inline uint32_t gamma1(uint32_t x)
+{
+	return ror(x, 17) ^ ror(x, 19) ^ (x >> 10);
+}
+
+static void blk_SHA256_Transform(blk_SHA256_CTX *ctx, const unsigned char *buf)
+{
+
+	uint32_t S[8], W[64], t0, t1;
+	int i;
+
+	/* copy state into S */
+	for (i = 0; i < 8; i++)
+		S[i] = ctx->state[i];
+
+	/* copy the state into 512-bits into W[0..15] */
+	for (i = 0; i < 16; i++, buf += sizeof(uint32_t))
+		W[i] = get_be32(buf);
+
+	/* fill W[16..63] */
+	for (i = 16; i < 64; i++)
+		W[i] = gamma1(W[i - 2]) + W[i - 7] + gamma0(W[i - 15]) + W[i - 16];
+
+#define RND(a,b,c,d,e,f,g,h,i,ki)                    \
+	t0 = h + sigma1(e) + ch(e, f, g) + ki + W[i];   \
+	t1 = sigma0(a) + maj(a, b, c);                  \
+	d += t0;                                        \
+	h  = t0 + t1;
+
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],0,0x428a2f98);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],1,0x71374491);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],2,0xb5c0fbcf);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],3,0xe9b5dba5);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],4,0x3956c25b);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],5,0x59f111f1);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],6,0x923f82a4);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],7,0xab1c5ed5);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],8,0xd807aa98);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],9,0x12835b01);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],10,0x243185be);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],11,0x550c7dc3);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],12,0x72be5d74);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],13,0x80deb1fe);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],14,0x9bdc06a7);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],15,0xc19bf174);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],16,0xe49b69c1);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],17,0xefbe4786);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],18,0x0fc19dc6);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],19,0x240ca1cc);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],20,0x2de92c6f);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],21,0x4a7484aa);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],22,0x5cb0a9dc);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],23,0x76f988da);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],24,0x983e5152);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],25,0xa831c66d);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],26,0xb00327c8);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],27,0xbf597fc7);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],28,0xc6e00bf3);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],29,0xd5a79147);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],30,0x06ca6351);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],31,0x14292967);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],32,0x27b70a85);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],33,0x2e1b2138);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],34,0x4d2c6dfc);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],35,0x53380d13);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],36,0x650a7354);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],37,0x766a0abb);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],38,0x81c2c92e);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],39,0x92722c85);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],40,0xa2bfe8a1);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],41,0xa81a664b);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],42,0xc24b8b70);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],43,0xc76c51a3);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],44,0xd192e819);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],45,0xd6990624);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],46,0xf40e3585);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],47,0x106aa070);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],48,0x19a4c116);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],49,0x1e376c08);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],50,0x2748774c);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],51,0x34b0bcb5);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],52,0x391c0cb3);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],53,0x4ed8aa4a);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],54,0x5b9cca4f);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],55,0x682e6ff3);
+	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],56,0x748f82ee);
+	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],57,0x78a5636f);
+	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],58,0x84c87814);
+	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],59,0x8cc70208);
+	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],60,0x90befffa);
+	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],61,0xa4506ceb);
+	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],62,0xbef9a3f7);
+	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],63,0xc67178f2);
+
+	for (i = 0; i < 8; i++)
+		ctx->state[i] += S[i];
+}
+
+void blk_SHA256_Update(blk_SHA256_CTX *ctx, const void *data, size_t len)
+{
+	unsigned int len_buf = ctx->size & 63;
+
+	ctx->size += len;
+
+	/* Read the data into buf and process blocks as they get full */
+	if (len_buf) {
+		unsigned int left = 64 - len_buf;
+		if (len < left)
+			left = len;
+		memcpy(len_buf + ctx->buf, data, left);
+		len_buf = (len_buf + left) & 63;
+		len -= left;
+		data = ((const char *)data + left);
+		if (len_buf)
+			return;
+		blk_SHA256_Transform(ctx, ctx->buf);
+	}
+	while (len >= 64) {
+		blk_SHA256_Transform(ctx, data);
+		data = ((const char *)data + 64);
+		len -= 64;
+	}
+	if (len)
+		memcpy(ctx->buf, data, len);
+}
+
+void blk_SHA256_Final(unsigned char *digest, blk_SHA256_CTX *ctx)
+{
+	static const unsigned char pad[64] = { 0x80 };
+	unsigned int padlen[2];
+	int i;
+
+	/* Pad with a binary 1 (ie 0x80), then zeroes, then length */
+	padlen[0] = htonl((uint32_t)(ctx->size >> 29));
+	padlen[1] = htonl((uint32_t)(ctx->size << 3));
+
+	i = ctx->size & 63;
+	blk_SHA256_Update(ctx, pad, 1 + (63 & (55 - i)));
+	blk_SHA256_Update(ctx, padlen, 8);
+
+	/* copy output */
+	for (i = 0; i < 8; i++, digest += sizeof(uint32_t))
+		put_be32(digest, ctx->state[i]);
+}
diff --git a/sha256/block/sha256.h b/sha256/block/sha256.h
new file mode 100644
index 0000000..5099d64
--- /dev/null
+++ b/sha256/block/sha256.h
@@ -0,0 +1,24 @@
+#ifndef SHA256_BLOCK_SHA256_H
+#define SHA256_BLOCK_SHA256_H
+
+#define blk_SHA256_BLKSIZE 64
+
+struct blk_SHA256_CTX {
+	uint32_t state[8];
+	uint64_t size;
+	uint32_t offset;
+	uint8_t buf[blk_SHA256_BLKSIZE];
+};
+
+typedef struct blk_SHA256_CTX blk_SHA256_CTX;
+
+void blk_SHA256_Init(blk_SHA256_CTX *ctx);
+void blk_SHA256_Update(blk_SHA256_CTX *ctx, const void *data, size_t len);
+void blk_SHA256_Final(unsigned char *digest, blk_SHA256_CTX *ctx);
+
+#define platform_SHA256_CTX blk_SHA256_CTX
+#define platform_SHA256_Init blk_SHA256_Init
+#define platform_SHA256_Update blk_SHA256_Update
+#define platform_SHA256_Final blk_SHA256_Final
+
+#endif
diff --git a/sha256/gcrypt.h b/sha256/gcrypt.h
new file mode 100644
index 0000000..09bd8bb
--- /dev/null
+++ b/sha256/gcrypt.h
@@ -0,0 +1,30 @@
+#ifndef SHA256_GCRYPT_H
+#define SHA256_GCRYPT_H
+
+#include <gcrypt.h>
+
+#define SHA256_DIGEST_SIZE 32
+
+typedef gcry_md_hd_t gcrypt_SHA256_CTX;
+
+inline void gcrypt_SHA256_Init(gcrypt_SHA256_CTX *ctx)
+{
+	gcry_md_open(ctx, GCRY_MD_SHA256, 0);
+}
+
+inline void gcrypt_SHA256_Update(gcrypt_SHA256_CTX *ctx, const void *data, size_t len)
+{
+	gcry_md_write(*ctx, data, len);
+}
+
+inline void gcrypt_SHA256_Final(unsigned char *digest, gcrypt_SHA256_CTX *ctx)
+{
+	memcpy(digest, gcry_md_read(*ctx, GCRY_MD_SHA256), SHA256_DIGEST_SIZE);
+}
+
+#define platform_SHA256_CTX gcrypt_SHA256_CTX
+#define platform_SHA256_Init gcrypt_SHA256_Init
+#define platform_SHA256_Update gcrypt_SHA256_Update
+#define platform_SHA256_Final gcrypt_SHA256_Final
+
+#endif
diff --git a/shallow.c b/shallow.c
index 02fdbfc..ce45297 100644
--- a/shallow.c
+++ b/shallow.c
@@ -43,6 +43,13 @@
 
 int is_repository_shallow(struct repository *r)
 {
+	/*
+	 * NEEDSWORK: This function updates
+	 * r->parsed_objects->{is_shallow,shallow_stat} as a side effect but
+	 * there is no corresponding function to clear them when the shallow
+	 * file is updated.
+	 */
+
 	FILE *fp;
 	char buf[1024];
 	const char *path = r->parsed_objects->alternate_shallow_file;
diff --git a/sideband.c b/sideband.c
index 7c3d33d..ef85111 100644
--- a/sideband.c
+++ b/sideband.c
@@ -1,7 +1,6 @@
 #include "cache.h"
 #include "color.h"
 #include "config.h"
-#include "pkt-line.h"
 #include "sideband.h"
 #include "help.h"
 
@@ -110,109 +109,104 @@
 }
 
 
-/*
- * Receive multiplexed output stream over git native protocol.
- * in_stream is the input stream from the remote, which carries data
- * in pkt_line format with band designator.  Demultiplex it into out
- * and err and return error appropriately.  Band #1 carries the
- * primary payload.  Things coming over band #2 is not necessarily
- * error; they are usually informative message on the standard error
- * stream, aka "verbose").  A message over band #3 is a signal that
- * the remote died unexpectedly.  A flush() concludes the stream.
- */
-
 #define DISPLAY_PREFIX "remote: "
 
 #define ANSI_SUFFIX "\033[K"
 #define DUMB_SUFFIX "        "
 
-int recv_sideband(const char *me, int in_stream, int out)
+int demultiplex_sideband(const char *me, char *buf, int len,
+			 int die_on_error,
+			 struct strbuf *scratch,
+			 enum sideband_type *sideband_type)
 {
-	const char *suffix;
-	char buf[LARGE_PACKET_MAX + 1];
-	struct strbuf outbuf = STRBUF_INIT;
-	int retval = 0;
+	static const char *suffix;
+	const char *b, *brk;
+	int band;
 
-	if (isatty(2) && !is_terminal_dumb())
-		suffix = ANSI_SUFFIX;
-	else
-		suffix = DUMB_SUFFIX;
-
-	while (!retval) {
-		const char *b, *brk;
-		int band, len;
-		len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX, 0);
-		if (len == 0)
-			break;
-		if (len < 1) {
-			strbuf_addf(&outbuf,
-				    "%s%s: protocol error: no band designator",
-				    outbuf.len ? "\n" : "", me);
-			retval = SIDEBAND_PROTOCOL_ERROR;
-			break;
-		}
-		band = buf[0] & 0xff;
-		buf[len] = '\0';
-		len--;
-		switch (band) {
-		case 3:
-			strbuf_addf(&outbuf, "%s%s", outbuf.len ? "\n" : "",
-				    DISPLAY_PREFIX);
-			maybe_colorize_sideband(&outbuf, buf + 1, len);
-
-			retval = SIDEBAND_REMOTE_ERROR;
-			break;
-		case 2:
-			b = buf + 1;
-
-			/*
-			 * Append a suffix to each nonempty line to clear the
-			 * end of the screen line.
-			 *
-			 * The output is accumulated in a buffer and
-			 * each line is printed to stderr using
-			 * write(2) to ensure inter-process atomicity.
-			 */
-			while ((brk = strpbrk(b, "\n\r"))) {
-				int linelen = brk - b;
-
-				if (!outbuf.len)
-					strbuf_addstr(&outbuf, DISPLAY_PREFIX);
-				if (linelen > 0) {
-					maybe_colorize_sideband(&outbuf, b, linelen);
-					strbuf_addstr(&outbuf, suffix);
-				}
-
-				strbuf_addch(&outbuf, *brk);
-				xwrite(2, outbuf.buf, outbuf.len);
-				strbuf_reset(&outbuf);
-
-				b = brk + 1;
-			}
-
-			if (*b) {
-				strbuf_addstr(&outbuf, outbuf.len ?
-					    "" : DISPLAY_PREFIX);
-				maybe_colorize_sideband(&outbuf, b, strlen(b));
-			}
-			break;
-		case 1:
-			write_or_die(out, buf + 1, len);
-			break;
-		default:
-			strbuf_addf(&outbuf, "%s%s: protocol error: bad band #%d",
-				    outbuf.len ? "\n" : "", me, band);
-			retval = SIDEBAND_PROTOCOL_ERROR;
-			break;
-		}
+	if (!suffix) {
+		if (isatty(2) && !is_terminal_dumb())
+			suffix = ANSI_SUFFIX;
+		else
+			suffix = DUMB_SUFFIX;
 	}
 
-	if (outbuf.len) {
-		strbuf_addch(&outbuf, '\n');
-		xwrite(2, outbuf.buf, outbuf.len);
+	if (len == 0) {
+		*sideband_type = SIDEBAND_FLUSH;
+		goto cleanup;
 	}
-	strbuf_release(&outbuf);
-	return retval;
+	if (len < 1) {
+		strbuf_addf(scratch,
+			    "%s%s: protocol error: no band designator",
+			    scratch->len ? "\n" : "", me);
+		*sideband_type = SIDEBAND_PROTOCOL_ERROR;
+		goto cleanup;
+	}
+	band = buf[0] & 0xff;
+	buf[len] = '\0';
+	len--;
+	switch (band) {
+	case 3:
+		if (die_on_error)
+			die("remote error: %s", buf + 1);
+		strbuf_addf(scratch, "%s%s", scratch->len ? "\n" : "",
+			    DISPLAY_PREFIX);
+		maybe_colorize_sideband(scratch, buf + 1, len);
+
+		*sideband_type = SIDEBAND_REMOTE_ERROR;
+		break;
+	case 2:
+		b = buf + 1;
+
+		/*
+		 * Append a suffix to each nonempty line to clear the
+		 * end of the screen line.
+		 *
+		 * The output is accumulated in a buffer and
+		 * each line is printed to stderr using
+		 * write(2) to ensure inter-process atomicity.
+		 */
+		while ((brk = strpbrk(b, "\n\r"))) {
+			int linelen = brk - b;
+
+			if (!scratch->len)
+				strbuf_addstr(scratch, DISPLAY_PREFIX);
+			if (linelen > 0) {
+				maybe_colorize_sideband(scratch, b, linelen);
+				strbuf_addstr(scratch, suffix);
+			}
+
+			strbuf_addch(scratch, *brk);
+			xwrite(2, scratch->buf, scratch->len);
+			strbuf_reset(scratch);
+
+			b = brk + 1;
+		}
+
+		if (*b) {
+			strbuf_addstr(scratch, scratch->len ?
+				    "" : DISPLAY_PREFIX);
+			maybe_colorize_sideband(scratch, b, strlen(b));
+		}
+		return 0;
+	case 1:
+		*sideband_type = SIDEBAND_PRIMARY;
+		break;
+	default:
+		strbuf_addf(scratch, "%s%s: protocol error: bad band #%d",
+			    scratch->len ? "\n" : "", me, band);
+		*sideband_type = SIDEBAND_PROTOCOL_ERROR;
+		break;
+	}
+
+cleanup:
+	if (die_on_error && *sideband_type == SIDEBAND_PROTOCOL_ERROR)
+		die("%s", scratch->buf);
+	if (scratch->len) {
+		strbuf_addch(scratch, '\n');
+		xwrite(2, scratch->buf, scratch->len);
+	}
+	strbuf_release(scratch);
+	return 1;
 }
 
 /*
diff --git a/sideband.h b/sideband.h
index 7a8146f..227740a 100644
--- a/sideband.h
+++ b/sideband.h
@@ -1,10 +1,29 @@
 #ifndef SIDEBAND_H
 #define SIDEBAND_H
 
-#define SIDEBAND_PROTOCOL_ERROR -2
-#define SIDEBAND_REMOTE_ERROR -1
+enum sideband_type {
+	SIDEBAND_PROTOCOL_ERROR = -2,
+	SIDEBAND_REMOTE_ERROR = -1,
+	SIDEBAND_FLUSH = 0,
+	SIDEBAND_PRIMARY = 1
+};
 
-int recv_sideband(const char *me, int in_stream, int out);
+/*
+ * Inspects a multiplexed packet read from the remote. If this packet is a
+ * progress packet and thus should not be processed by the caller, returns 0.
+ * Otherwise, returns 1, releases scratch, and sets sideband_type.
+ *
+ * If this packet is SIDEBAND_PROTOCOL_ERROR, SIDEBAND_REMOTE_ERROR, or a
+ * progress packet, also prints a message to stderr.
+ *
+ * scratch must be a struct strbuf allocated by the caller. It is used to store
+ * progress messages split across multiple packets.
+ */
+int demultiplex_sideband(const char *me, char *buf, int len,
+			 int die_on_error,
+			 struct strbuf *scratch,
+			 enum sideband_type *sideband_type);
+
 void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max);
 
 #endif
diff --git a/streaming.c b/streaming.c
index ac7c7a2..891f82f 100644
--- a/streaming.c
+++ b/streaming.c
@@ -499,7 +499,7 @@
 
 static open_method_decl(incore)
 {
-	st->u.incore.buf = read_object_file_extended(oid, type, &st->size, 0);
+	st->u.incore.buf = read_object_file_extended(the_repository, oid, type, &st->size, 0);
 	st->u.incore.read_ptr = 0;
 	st->vtbl = &incore_vtbl;
 
diff --git a/submodule.c b/submodule.c
index d393e94..a5f2694 100644
--- a/submodule.c
+++ b/submodule.c
@@ -25,7 +25,6 @@
 #include "commit-reach.h"
 
 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
-static struct string_list changed_submodule_names = STRING_LIST_INIT_DUP;
 static int initialized_fetch_ref_tips;
 static struct oid_array ref_tips_before_fetch;
 static struct oid_array ref_tips_after_fetch;
@@ -457,7 +456,7 @@
 	return prepare_revision_walk(rev);
 }
 
-static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
+static void print_submodule_summary(struct repository *r, struct rev_info *rev, struct diff_options *o)
 {
 	static const char format[] = "  %m %s";
 	struct strbuf sb = STRBUF_INIT;
@@ -468,7 +467,8 @@
 		ctx.date_mode = rev->date_mode;
 		ctx.output_encoding = get_log_output_encoding();
 		strbuf_setlen(&sb, 0);
-		format_commit_message(commit, format, &sb, &ctx);
+		repo_format_commit_message(r, commit, format, &sb,
+				      &ctx);
 		strbuf_addch(&sb, '\n');
 		if (commit->object.flags & SYMMETRIC_LEFT)
 			diff_emit_submodule_del(o, sb.buf);
@@ -495,14 +495,52 @@
 			 DEFAULT_GIT_DIR_ENVIRONMENT);
 }
 
-/* Helper function to display the submodule header line prior to the full
- * summary output. If it can locate the submodule objects directory it will
- * attempt to lookup both the left and right commits and put them into the
- * left and right pointers.
+static void prepare_submodule_repo_env_in_gitdir(struct argv_array *out)
+{
+	prepare_submodule_repo_env_no_git_dir(out);
+	argv_array_pushf(out, "%s=.", GIT_DIR_ENVIRONMENT);
+}
+
+/*
+ * Initialize a repository struct for a submodule based on the provided 'path'.
+ *
+ * Unlike repo_submodule_init, this tolerates submodules not present
+ * in .gitmodules. This function exists only to preserve historical behavior,
+ *
+ * Returns the repository struct on success,
+ * NULL when the submodule is not present.
  */
-static void show_submodule_header(struct diff_options *o, const char *path,
+static struct repository *open_submodule(const char *path)
+{
+	struct strbuf sb = STRBUF_INIT;
+	struct repository *out = xmalloc(sizeof(*out));
+
+	if (submodule_to_gitdir(&sb, path) || repo_init(out, sb.buf, NULL)) {
+		strbuf_release(&sb);
+		free(out);
+		return NULL;
+	}
+
+	/* Mark it as a submodule */
+	out->submodule_prefix = xstrdup(path);
+
+	strbuf_release(&sb);
+	return out;
+}
+
+/*
+ * Helper function to display the submodule header line prior to the full
+ * summary output.
+ *
+ * If it can locate the submodule git directory it will create a repository
+ * handle for the submodule and lookup both the left and right commits and
+ * put them into the left and right pointers.
+ */
+static void show_submodule_header(struct diff_options *o,
+		const char *path,
 		struct object_id *one, struct object_id *two,
 		unsigned dirty_submodule,
+		struct repository *sub,
 		struct commit **left, struct commit **right,
 		struct commit_list **merge_bases)
 {
@@ -521,7 +559,7 @@
 	else if (is_null_oid(two))
 		message = "(submodule deleted)";
 
-	if (add_submodule_odb(path)) {
+	if (!sub) {
 		if (!message)
 			message = "(commits not present)";
 		goto output_header;
@@ -531,8 +569,8 @@
 	 * Attempt to lookup the commit references, and determine if this is
 	 * a fast forward or fast backwards update.
 	 */
-	*left = lookup_commit_reference(the_repository, one);
-	*right = lookup_commit_reference(the_repository, two);
+	*left = lookup_commit_reference(sub, one);
+	*right = lookup_commit_reference(sub, two);
 
 	/*
 	 * Warn about missing commits in the submodule project, but only if
@@ -542,7 +580,7 @@
 	     (!is_null_oid(two) && !*right))
 		message = "(commits not present)";
 
-	*merge_bases = get_merge_bases(*left, *right);
+	*merge_bases = repo_get_merge_bases(sub, *left, *right);
 	if (*merge_bases) {
 		if ((*merge_bases)->item == *left)
 			fast_forward = 1;
@@ -576,16 +614,18 @@
 	struct rev_info rev;
 	struct commit *left = NULL, *right = NULL;
 	struct commit_list *merge_bases = NULL;
+	struct repository *sub;
 
+	sub = open_submodule(path);
 	show_submodule_header(o, path, one, two, dirty_submodule,
-			      &left, &right, &merge_bases);
+			      sub, &left, &right, &merge_bases);
 
 	/*
 	 * If we don't have both a left and a right pointer, there is no
 	 * reason to try and display a summary. The header line should contain
 	 * all the information the user needs.
 	 */
-	if (!left || !right)
+	if (!left || !right || !sub)
 		goto out;
 
 	/* Treat revision walker failure the same as missing commits */
@@ -594,13 +634,17 @@
 		goto out;
 	}
 
-	print_submodule_summary(&rev, o);
+	print_submodule_summary(sub, &rev, o);
 
 out:
 	if (merge_bases)
 		free_commit_list(merge_bases);
 	clear_commit_marks(left, ~0);
 	clear_commit_marks(right, ~0);
+	if (sub) {
+		repo_clear(sub);
+		free(sub);
+	}
 }
 
 void show_submodule_inline_diff(struct diff_options *o, const char *path,
@@ -612,9 +656,11 @@
 	struct commit_list *merge_bases = NULL;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct strbuf sb = STRBUF_INIT;
+	struct repository *sub;
 
+	sub = open_submodule(path);
 	show_submodule_header(o, path, one, two, dirty_submodule,
-			      &left, &right, &merge_bases);
+			      sub, &left, &right, &merge_bases);
 
 	/* We need a valid left and right commit to display a difference */
 	if (!(left || is_null_oid(one)) ||
@@ -675,6 +721,10 @@
 		clear_commit_marks(left, ~0);
 	if (right)
 		clear_commit_marks(right, ~0);
+	if (sub) {
+		repo_clear(sub);
+		free(sub);
+	}
 }
 
 int should_update_submodules(void)
@@ -999,9 +1049,6 @@
 			  const struct string_list *push_options,
 			  int dry_run)
 {
-	if (add_submodule_odb(path))
-		return 1;
-
 	if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 		struct child_process cp = CHILD_PROCESS_INIT;
 		argv_array_push(&cp.args, "push");
@@ -1136,11 +1183,11 @@
 	oid_array_append(&ref_tips_after_fetch, oid);
 }
 
-static void calculate_changed_submodule_paths(struct repository *r)
+static void calculate_changed_submodule_paths(struct repository *r,
+		struct string_list *changed_submodule_names)
 {
 	struct argv_array argv = ARGV_ARRAY_INIT;
-	struct string_list changed_submodules = STRING_LIST_INIT_DUP;
-	const struct string_list_item *name;
+	struct string_list_item *name;
 
 	/* No need to check if there are no submodules configured */
 	if (!submodule_from_path(r, NULL, NULL))
@@ -1157,9 +1204,9 @@
 	 * Collect all submodules (whether checked out or not) for which new
 	 * commits have been recorded upstream in "changed_submodule_names".
 	 */
-	collect_changed_submodules(r, &changed_submodules, &argv);
+	collect_changed_submodules(r, changed_submodule_names, &argv);
 
-	for_each_string_list_item(name, &changed_submodules) {
+	for_each_string_list_item(name, changed_submodule_names) {
 		struct oid_array *commits = name->util;
 		const struct submodule *submodule;
 		const char *path = NULL;
@@ -1173,11 +1220,14 @@
 		if (!path)
 			continue;
 
-		if (!submodule_has_commits(r, path, commits))
-			string_list_append(&changed_submodule_names, name->string);
+		if (submodule_has_commits(r, path, commits)) {
+			oid_array_clear(commits);
+			*name->string = '\0';
+		}
 	}
 
-	free_submodules_oids(&changed_submodules);
+	string_list_remove_empty_items(changed_submodule_names, 1);
+
 	argv_array_clear(&argv);
 	oid_array_clear(&ref_tips_before_fetch);
 	oid_array_clear(&ref_tips_after_fetch);
@@ -1221,8 +1271,16 @@
 	int default_option;
 	int quiet;
 	int result;
+
+	struct string_list changed_submodule_names;
+
+	/* Pending fetches by OIDs */
+	struct fetch_task **oid_fetch_tasks;
+	int oid_fetch_tasks_nr, oid_fetch_tasks_alloc;
 };
-#define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
+#define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0, \
+		  STRING_LIST_INIT_DUP, \
+		  NULL, 0, 0}
 
 static int get_fetch_recurse_config(const struct submodule *submodule,
 				    struct submodule_parallel_fetch *spf)
@@ -1249,40 +1307,126 @@
 	return spf->default_option;
 }
 
+/*
+ * Fetch in progress (if callback data) or
+ * pending (if in oid_fetch_tasks in struct submodule_parallel_fetch)
+ */
+struct fetch_task {
+	struct repository *repo;
+	const struct submodule *sub;
+	unsigned free_sub : 1; /* Do we need to free the submodule? */
+
+	struct oid_array *commits; /* Ensure these commits are fetched */
+};
+
+/**
+ * When a submodule is not defined in .gitmodules, we cannot access it
+ * via the regular submodule-config. Create a fake submodule, which we can
+ * work on.
+ */
+static const struct submodule *get_non_gitmodules_submodule(const char *path)
+{
+	struct submodule *ret = NULL;
+	const char *name = default_name_or_path(path);
+
+	if (!name)
+		return NULL;
+
+	ret = xmalloc(sizeof(*ret));
+	memset(ret, 0, sizeof(*ret));
+	ret->path = name;
+	ret->name = name;
+
+	return (const struct submodule *) ret;
+}
+
+static struct fetch_task *fetch_task_create(struct repository *r,
+					    const char *path)
+{
+	struct fetch_task *task = xmalloc(sizeof(*task));
+	memset(task, 0, sizeof(*task));
+
+	task->sub = submodule_from_path(r, &null_oid, path);
+	if (!task->sub) {
+		/*
+		 * No entry in .gitmodules? Technically not a submodule,
+		 * but historically we supported repositories that happen to be
+		 * in-place where a gitlink is. Keep supporting them.
+		 */
+		task->sub = get_non_gitmodules_submodule(path);
+		if (!task->sub) {
+			free(task);
+			return NULL;
+		}
+
+		task->free_sub = 1;
+	}
+
+	return task;
+}
+
+static void fetch_task_release(struct fetch_task *p)
+{
+	if (p->free_sub)
+		free((void*)p->sub);
+	p->free_sub = 0;
+	p->sub = NULL;
+
+	if (p->repo)
+		repo_clear(p->repo);
+	FREE_AND_NULL(p->repo);
+}
+
+static struct repository *get_submodule_repo_for(struct repository *r,
+						 const struct submodule *sub)
+{
+	struct repository *ret = xmalloc(sizeof(*ret));
+
+	if (repo_submodule_init(ret, r, sub)) {
+		/*
+		 * No entry in .gitmodules? Technically not a submodule,
+		 * but historically we supported repositories that happen to be
+		 * in-place where a gitlink is. Keep supporting them.
+		 */
+		struct strbuf gitdir = STRBUF_INIT;
+		strbuf_repo_worktree_path(&gitdir, r, "%s/.git", sub->path);
+		if (repo_init(ret, gitdir.buf, NULL)) {
+			strbuf_release(&gitdir);
+			free(ret);
+			return NULL;
+		}
+		strbuf_release(&gitdir);
+	}
+
+	return ret;
+}
+
 static int get_next_submodule(struct child_process *cp,
 			      struct strbuf *err, void *data, void **task_cb)
 {
-	int ret = 0;
 	struct submodule_parallel_fetch *spf = data;
 
 	for (; spf->count < spf->r->index->cache_nr; spf->count++) {
-		struct strbuf submodule_path = STRBUF_INIT;
-		struct strbuf submodule_git_dir = STRBUF_INIT;
-		struct strbuf submodule_prefix = STRBUF_INIT;
 		const struct cache_entry *ce = spf->r->index->cache[spf->count];
-		const char *git_dir, *default_argv;
-		const struct submodule *submodule;
-		struct submodule default_submodule = SUBMODULE_INIT;
+		const char *default_argv;
+		struct fetch_task *task;
 
 		if (!S_ISGITLINK(ce->ce_mode))
 			continue;
 
-		submodule = submodule_from_path(spf->r, &null_oid, ce->name);
-		if (!submodule) {
-			const char *name = default_name_or_path(ce->name);
-			if (name) {
-				default_submodule.path = default_submodule.name = name;
-				submodule = &default_submodule;
-			}
-		}
+		task = fetch_task_create(spf->r, ce->name);
+		if (!task)
+			continue;
 
-		switch (get_fetch_recurse_config(submodule, spf))
+		switch (get_fetch_recurse_config(task->sub, spf))
 		{
 		default:
 		case RECURSE_SUBMODULES_DEFAULT:
 		case RECURSE_SUBMODULES_ON_DEMAND:
-			if (!submodule || !unsorted_string_list_lookup(&changed_submodule_names,
-							 submodule->name))
+			if (!task->sub ||
+			    !string_list_lookup(
+					&spf->changed_submodule_names,
+					task->sub->name))
 				continue;
 			default_argv = "on-demand";
 			break;
@@ -1293,16 +1437,12 @@
 			continue;
 		}
 
-		strbuf_repo_worktree_path(&submodule_path, spf->r, "%s", ce->name);
-		strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
-		strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
-		git_dir = read_gitfile(submodule_git_dir.buf);
-		if (!git_dir)
-			git_dir = submodule_git_dir.buf;
-		if (is_directory(git_dir)) {
+		task->repo = get_submodule_repo_for(spf->r, task->sub);
+		if (task->repo) {
+			struct strbuf submodule_prefix = STRBUF_INIT;
 			child_process_init(cp);
-			cp->dir = strbuf_detach(&submodule_path, NULL);
-			prepare_submodule_repo_env(&cp->env_array);
+			cp->dir = task->repo->gitdir;
+			prepare_submodule_repo_env_in_gitdir(&cp->env_array);
 			cp->git_cmd = 1;
 			if (!spf->quiet)
 				strbuf_addf(err, "Fetching submodule %s%s\n",
@@ -1311,17 +1451,66 @@
 			argv_array_pushv(&cp->args, spf->args.argv);
 			argv_array_push(&cp->args, default_argv);
 			argv_array_push(&cp->args, "--submodule-prefix");
+
+			strbuf_addf(&submodule_prefix, "%s%s/",
+						       spf->prefix,
+						       task->sub->path);
 			argv_array_push(&cp->args, submodule_prefix.buf);
-			ret = 1;
-		}
-		strbuf_release(&submodule_path);
-		strbuf_release(&submodule_git_dir);
-		strbuf_release(&submodule_prefix);
-		if (ret) {
+
 			spf->count++;
+			*task_cb = task;
+
+			strbuf_release(&submodule_prefix);
 			return 1;
+		} else {
+
+			fetch_task_release(task);
+			free(task);
+
+			/*
+			 * An empty directory is normal,
+			 * the submodule is not initialized
+			 */
+			if (S_ISGITLINK(ce->ce_mode) &&
+			    !is_empty_dir(ce->name)) {
+				spf->result = 1;
+				strbuf_addf(err,
+					    _("Could not access submodule '%s'"),
+					    ce->name);
+			}
 		}
 	}
+
+	if (spf->oid_fetch_tasks_nr) {
+		struct fetch_task *task =
+			spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr - 1];
+		struct strbuf submodule_prefix = STRBUF_INIT;
+		spf->oid_fetch_tasks_nr--;
+
+		strbuf_addf(&submodule_prefix, "%s%s/",
+			    spf->prefix, task->sub->path);
+
+		child_process_init(cp);
+		prepare_submodule_repo_env_in_gitdir(&cp->env_array);
+		cp->git_cmd = 1;
+		cp->dir = task->repo->gitdir;
+
+		argv_array_init(&cp->args);
+		argv_array_pushv(&cp->args, spf->args.argv);
+		argv_array_push(&cp->args, "on-demand");
+		argv_array_push(&cp->args, "--submodule-prefix");
+		argv_array_push(&cp->args, submodule_prefix.buf);
+
+		/* NEEDSWORK: have get_default_remote from submodule--helper */
+		argv_array_push(&cp->args, "origin");
+		oid_array_for_each_unique(task->commits,
+					  append_oid_to_argv, &cp->args);
+
+		*task_cb = task;
+		strbuf_release(&submodule_prefix);
+		return 1;
+	}
+
 	return 0;
 }
 
@@ -1329,20 +1518,66 @@
 			       void *cb, void *task_cb)
 {
 	struct submodule_parallel_fetch *spf = cb;
+	struct fetch_task *task = task_cb;
 
 	spf->result = 1;
 
+	fetch_task_release(task);
 	return 0;
 }
 
+static int commit_missing_in_sub(const struct object_id *oid, void *data)
+{
+	struct repository *subrepo = data;
+
+	enum object_type type = oid_object_info(subrepo, oid, NULL);
+
+	return type != OBJ_COMMIT;
+}
+
 static int fetch_finish(int retvalue, struct strbuf *err,
 			void *cb, void *task_cb)
 {
 	struct submodule_parallel_fetch *spf = cb;
+	struct fetch_task *task = task_cb;
+
+	struct string_list_item *it;
+	struct oid_array *commits;
 
 	if (retvalue)
 		spf->result = 1;
 
+	if (!task || !task->sub)
+		BUG("callback cookie bogus");
+
+	/* Is this the second time we process this submodule? */
+	if (task->commits)
+		goto out;
+
+	it = string_list_lookup(&spf->changed_submodule_names, task->sub->name);
+	if (!it)
+		/* Could be an unchanged submodule, not contained in the list */
+		goto out;
+
+	commits = it->util;
+	oid_array_filter(commits,
+			 commit_missing_in_sub,
+			 task->repo);
+
+	/* Are there commits we want, but do not exist? */
+	if (commits->nr) {
+		task->commits = commits;
+		ALLOC_GROW(spf->oid_fetch_tasks,
+			   spf->oid_fetch_tasks_nr + 1,
+			   spf->oid_fetch_tasks_alloc);
+		spf->oid_fetch_tasks[spf->oid_fetch_tasks_nr] = task;
+		spf->oid_fetch_tasks_nr++;
+		return 0;
+	}
+
+out:
+	fetch_task_release(task);
+
 	return 0;
 }
 
@@ -1373,7 +1608,8 @@
 	argv_array_push(&spf.args, "--recurse-submodules-default");
 	/* default value, "--submodule-prefix" and its value are added later */
 
-	calculate_changed_submodule_paths(r);
+	calculate_changed_submodule_paths(r, &spf.changed_submodule_names);
+	string_list_sort(&spf.changed_submodule_names);
 	run_processes_parallel(max_parallel_jobs,
 			       get_next_submodule,
 			       fetch_start_failure,
@@ -1382,7 +1618,7 @@
 
 	argv_array_clear(&spf.args);
 out:
-	string_list_clear(&changed_submodule_names, 1);
+	free_submodules_oids(&spf.changed_submodule_names);
 	return spf.result;
 }
 
diff --git a/t/README b/t/README
index 11ce767..25864ec 100644
--- a/t/README
+++ b/t/README
@@ -374,6 +374,11 @@
 index to be written after every 'git repack' command, and overrides the
 'core.multiPackIndex' setting to true.
 
+GIT_TEST_SIDEBAND_ALL=<boolean>, when true, overrides the
+'uploadpack.allowSidebandAll' setting to true, and when false, forces
+fetch-pack to not request sideband-all (even if the server advertises
+sideband-all).
+
 Naming Tests
 ------------
 
diff --git a/t/helper/test-hash-speed.c b/t/helper/test-hash-speed.c
new file mode 100644
index 0000000..432233c
--- /dev/null
+++ b/t/helper/test-hash-speed.c
@@ -0,0 +1,61 @@
+#include "test-tool.h"
+#include "cache.h"
+
+#define NUM_SECONDS 3
+
+static inline void compute_hash(const struct git_hash_algo *algo, git_hash_ctx *ctx, uint8_t *final, const void *p, size_t len)
+{
+	algo->init_fn(ctx);
+	algo->update_fn(ctx, p, len);
+	algo->final_fn(final, ctx);
+}
+
+int cmd__hash_speed(int ac, const char **av)
+{
+	git_hash_ctx ctx;
+	unsigned char hash[GIT_MAX_RAWSZ];
+	clock_t initial, start, end;
+	unsigned bufsizes[] = { 64, 256, 1024, 8192, 16384 };
+	int i;
+	void *p;
+	const struct git_hash_algo *algo = NULL;
+
+	if (ac == 2) {
+		for (i = 1; i < GIT_HASH_NALGOS; i++) {
+			if (!strcmp(av[1], hash_algos[i].name)) {
+				algo = &hash_algos[i];
+				break;
+			}
+		}
+	}
+	if (!algo)
+		die("usage: test-tool hash-speed algo_name");
+
+	/* Use this as an offset to make overflow less likely. */
+	initial = clock();
+
+	printf("algo: %s\n", algo->name);
+
+	for (i = 0; i < ARRAY_SIZE(bufsizes); i++) {
+		unsigned long j, kb;
+		double kb_per_sec;
+		p = xcalloc(1, bufsizes[i]);
+		start = end = clock() - initial;
+		for (j = 0; ((end - start) / CLOCKS_PER_SEC) < NUM_SECONDS; j++) {
+			compute_hash(algo, &ctx, hash, p, bufsizes[i]);
+
+			/*
+			 * Only check elapsed time every 128 iterations to avoid
+			 * dominating the runtime with system calls.
+			 */
+			if (!(j & 127))
+				end = clock() - initial;
+		}
+		kb = j * bufsizes[i];
+		kb_per_sec = kb / (1024 * ((double)end - start) / CLOCKS_PER_SEC);
+		printf("size %u: %lu iters; %lu KiB; %0.2f KiB/s\n", bufsizes[i], j, kb, kb_per_sec);
+		free(p);
+	}
+
+	exit(0);
+}
diff --git a/t/helper/test-hash.c b/t/helper/test-hash.c
new file mode 100644
index 0000000..0a31de6
--- /dev/null
+++ b/t/helper/test-hash.c
@@ -0,0 +1,58 @@
+#include "test-tool.h"
+#include "cache.h"
+
+int cmd_hash_impl(int ac, const char **av, int algo)
+{
+	git_hash_ctx ctx;
+	unsigned char hash[GIT_MAX_HEXSZ];
+	unsigned bufsz = 8192;
+	int binary = 0;
+	char *buffer;
+	const struct git_hash_algo *algop = &hash_algos[algo];
+
+	if (ac == 2) {
+		if (!strcmp(av[1], "-b"))
+			binary = 1;
+		else
+			bufsz = strtoul(av[1], NULL, 10) * 1024 * 1024;
+	}
+
+	if (!bufsz)
+		bufsz = 8192;
+
+	while ((buffer = malloc(bufsz)) == NULL) {
+		fprintf(stderr, "bufsz %u is too big, halving...\n", bufsz);
+		bufsz /= 2;
+		if (bufsz < 1024)
+			die("OOPS");
+	}
+
+	algop->init_fn(&ctx);
+
+	while (1) {
+		ssize_t sz, this_sz;
+		char *cp = buffer;
+		unsigned room = bufsz;
+		this_sz = 0;
+		while (room) {
+			sz = xread(0, cp, room);
+			if (sz == 0)
+				break;
+			if (sz < 0)
+				die_errno("test-hash");
+			this_sz += sz;
+			cp += sz;
+			room -= sz;
+		}
+		if (this_sz == 0)
+			break;
+		algop->update_fn(&ctx, buffer, this_sz);
+	}
+	algop->final_fn(hash, &ctx);
+
+	if (binary)
+		fwrite(hash, 1, algop->rawsz, stdout);
+	else
+		puts(hash_to_hex_algop(hash, algop));
+	exit(0);
+}
diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
index e9e0541..799fc00 100644
--- a/t/helper/test-ref-store.c
+++ b/t/helper/test-ref-store.c
@@ -233,7 +233,7 @@
 {
 	const char *msg = notnull(*argv++, "msg");
 	const char *refname = notnull(*argv++, "refname");
-	const char *new_sha1_buf = notnull(*argv++, "old-sha1");
+	const char *new_sha1_buf = notnull(*argv++, "new-sha1");
 	const char *old_sha1_buf = notnull(*argv++, "old-sha1");
 	unsigned int flags = arg_flags(*argv++, "flags");
 	struct object_id old_oid;
diff --git a/t/helper/test-repository.c b/t/helper/test-repository.c
index 6a84a53..f7f8618 100644
--- a/t/helper/test-repository.c
+++ b/t/helper/test-repository.c
@@ -17,6 +17,11 @@
 
 	setup_git_env(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");
 
@@ -43,6 +48,11 @@
 
 	setup_git_env(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");
 
diff --git a/t/helper/test-sha1.c b/t/helper/test-sha1.c
index 1ba0675..d860c38 100644
--- a/t/helper/test-sha1.c
+++ b/t/helper/test-sha1.c
@@ -3,55 +3,5 @@
 
 int cmd__sha1(int ac, const char **av)
 {
-	git_SHA_CTX ctx;
-	unsigned char sha1[20];
-	unsigned bufsz = 8192;
-	int binary = 0;
-	char *buffer;
-
-	if (ac == 2) {
-		if (!strcmp(av[1], "-b"))
-			binary = 1;
-		else
-			bufsz = strtoul(av[1], NULL, 10) * 1024 * 1024;
-	}
-
-	if (!bufsz)
-		bufsz = 8192;
-
-	while ((buffer = malloc(bufsz)) == NULL) {
-		fprintf(stderr, "bufsz %u is too big, halving...\n", bufsz);
-		bufsz /= 2;
-		if (bufsz < 1024)
-			die("OOPS");
-	}
-
-	git_SHA1_Init(&ctx);
-
-	while (1) {
-		ssize_t sz, this_sz;
-		char *cp = buffer;
-		unsigned room = bufsz;
-		this_sz = 0;
-		while (room) {
-			sz = xread(0, cp, room);
-			if (sz == 0)
-				break;
-			if (sz < 0)
-				die_errno("test-sha1");
-			this_sz += sz;
-			cp += sz;
-			room -= sz;
-		}
-		if (this_sz == 0)
-			break;
-		git_SHA1_Update(&ctx, buffer, this_sz);
-	}
-	git_SHA1_Final(sha1, &ctx);
-
-	if (binary)
-		fwrite(sha1, 1, 20, stdout);
-	else
-		puts(sha1_to_hex(sha1));
-	exit(0);
+	return cmd_hash_impl(ac, av, GIT_HASH_SHA1);
 }
diff --git a/t/helper/test-sha256.c b/t/helper/test-sha256.c
new file mode 100644
index 0000000..0ac6a99
--- /dev/null
+++ b/t/helper/test-sha256.c
@@ -0,0 +1,7 @@
+#include "test-tool.h"
+#include "cache.h"
+
+int cmd__sha256(int ac, const char **av)
+{
+	return cmd_hash_impl(ac, av, GIT_HASH_SHA256);
+}
diff --git a/t/helper/test-submodule-nested-repo-config.c b/t/helper/test-submodule-nested-repo-config.c
index a31e2a9..bc97929 100644
--- a/t/helper/test-submodule-nested-repo-config.c
+++ b/t/helper/test-submodule-nested-repo-config.c
@@ -10,19 +10,21 @@
 
 int cmd__submodule_nested_repo_config(int argc, const char **argv)
 {
-	struct repository submodule;
+	struct repository subrepo;
+	const struct submodule *sub;
 
 	if (argc < 3)
 		die_usage(argc, argv, "Wrong number of arguments.");
 
 	setup_git_directory();
 
-	if (repo_submodule_init(&submodule, the_repository, argv[1])) {
+	sub = submodule_from_path(the_repository, &null_oid, argv[1]);
+	if (repo_submodule_init(&subrepo, the_repository, sub)) {
 		die_usage(argc, argv, "Submodule not found.");
 	}
 
 	/* Read the config of _child_ submodules. */
-	print_config_from_gitmodules(&submodule, argv[2]);
+	print_config_from_gitmodules(&subrepo, argv[2]);
 
 	submodule_free(the_repository);
 
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index bfb195b..5b13787 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -20,6 +20,7 @@
 	{ "example-decorate", cmd__example_decorate },
 	{ "genrandom", cmd__genrandom },
 	{ "hashmap", cmd__hashmap },
+	{ "hash-speed", cmd__hash_speed },
 	{ "index-version", cmd__index_version },
 	{ "json-writer", cmd__json_writer },
 	{ "lazy-init-name-hash", cmd__lazy_init_name_hash },
@@ -42,6 +43,7 @@
 	{ "scrap-cache-tree", cmd__scrap_cache_tree },
 	{ "sha1", cmd__sha1 },
 	{ "sha1-array", cmd__sha1_array },
+	{ "sha256", cmd__sha256 },
 	{ "sigchain", cmd__sigchain },
 	{ "strcmp-offset", cmd__strcmp_offset },
 	{ "string-list", cmd__string_list },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 042f124..ca5c88e 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -16,6 +16,7 @@
 int cmd__example_decorate(int argc, const char **argv);
 int cmd__genrandom(int argc, const char **argv);
 int cmd__hashmap(int argc, const char **argv);
+int cmd__hash_speed(int argc, const char **argv);
 int cmd__index_version(int argc, const char **argv);
 int cmd__json_writer(int argc, const char **argv);
 int cmd__lazy_init_name_hash(int argc, const char **argv);
@@ -38,6 +39,7 @@
 int cmd__scrap_cache_tree(int argc, const char **argv);
 int cmd__sha1(int argc, const char **argv);
 int cmd__sha1_array(int argc, const char **argv);
+int cmd__sha256(int argc, const char **argv);
 int cmd__sigchain(int argc, const char **argv);
 int cmd__strcmp_offset(int argc, const char **argv);
 int cmd__string_list(int argc, const char **argv);
@@ -51,4 +53,6 @@
 #endif
 int cmd__write_cache(int argc, const char **argv);
 
+int cmd_hash_impl(int ac, const char **av, int algo);
+
 #endif
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 581c010..5d63ed9 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -78,6 +78,7 @@
 PassEnv ASAN_OPTIONS
 PassEnv GIT_TRACE
 PassEnv GIT_CONFIG_NOSYSTEM
+PassEnv GIT_TEST_SIDEBAND_ALL
 
 SetEnvIf Git-Protocol ".*" GIT_PROTOCOL=$0
 
@@ -115,6 +116,7 @@
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
+ScriptAliasMatch /error_git_upload_pack/(.*)/git-upload-pack error.sh/
 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error/ error.sh/
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index 22499bc..71e63d8 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -322,4 +322,24 @@
 	)
 '
 
+test_expect_success 'binary macro expanded by -a' '
+	echo "file binary" >.gitattributes &&
+	cat >expect <<-\EOF &&
+	file: binary: set
+	file: diff: unset
+	file: merge: unset
+	file: text: unset
+	EOF
+	git check-attr -a file >actual &&
+	test_cmp expect actual
+'
+
+
+test_expect_success 'query binary macro directly' '
+	echo "file binary" >.gitattributes &&
+	echo file: binary: set >expect &&
+	git check-attr binary file >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0015-hash.sh b/t/t0015-hash.sh
new file mode 100755
index 0000000..291e906
--- /dev/null
+++ b/t/t0015-hash.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+test_description='test basic hash implementation'
+. ./test-lib.sh
+
+
+test_expect_success 'test basic SHA-1 hash values' '
+	test-tool sha1 </dev/null >actual &&
+	grep da39a3ee5e6b4b0d3255bfef95601890afd80709 actual &&
+	printf "a" | test-tool sha1 >actual &&
+	grep 86f7e437faa5a7fce15d1ddcb9eaeaea377667b8 actual &&
+	printf "abc" | test-tool sha1 >actual &&
+	grep a9993e364706816aba3e25717850c26c9cd0d89d actual &&
+	printf "message digest" | test-tool sha1 >actual &&
+	grep c12252ceda8be8994d5fa0290a47231c1d16aae3 actual &&
+	printf "abcdefghijklmnopqrstuvwxyz" | test-tool sha1 >actual &&
+	grep 32d10c7b8cf96570ca04ce37f2a19d84240d3a89 actual &&
+	perl -e "$| = 1; print q{aaaaaaaaaa} for 1..100000;" | \
+		test-tool sha1 >actual &&
+	grep 34aa973cd4c4daa4f61eeb2bdbad27316534016f actual &&
+	printf "blob 0\0" | test-tool sha1 >actual &&
+	grep e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 actual &&
+	printf "blob 3\0abc" | test-tool sha1 >actual &&
+	grep f2ba8f84ab5c1bce84a7b441cb1959cfc7093b7f actual &&
+	printf "tree 0\0" | test-tool sha1 >actual &&
+	grep 4b825dc642cb6eb9a060e54bf8d69288fbee4904 actual
+'
+
+test_expect_success 'test basic SHA-256 hash values' '
+	test-tool sha256 </dev/null >actual &&
+	grep e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 actual &&
+	printf "a" | test-tool sha256 >actual &&
+	grep ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb actual &&
+	printf "abc" | test-tool sha256 >actual &&
+	grep ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad actual &&
+	printf "message digest" | test-tool sha256 >actual &&
+	grep f7846f55cf23e14eebeab5b4e1550cad5b509e3348fbc4efa3a1413d393cb650 actual &&
+	printf "abcdefghijklmnopqrstuvwxyz" | test-tool sha256 >actual &&
+	grep 71c480df93d6ae2f1efad1447c66c9525e316218cf51fc8d9ed832f2daf18b73 actual &&
+	# Try to exercise the chunking code by turning autoflush on.
+	perl -e "$| = 1; print q{aaaaaaaaaa} for 1..100000;" | \
+		test-tool sha256 >actual &&
+	grep cdc76e5c9914fb9281a1c7e284d73e67f1809a48a497200e046d39ccc7112cd0 actual &&
+	perl -e "$| = 1; print q{abcdefghijklmnopqrstuvwxyz} for 1..100000;" | \
+		test-tool sha256 >actual &&
+	grep e406ba321ca712ad35a698bf0af8d61fc4dc40eca6bdcea4697962724ccbde35 actual &&
+	printf "blob 0\0" | test-tool sha256 >actual &&
+	grep 473a0f4c3be8a93681a267e3b1e9a7dcda1185436fe141f7749120a303721813 actual &&
+	printf "blob 3\0abc" | test-tool sha256 >actual &&
+	grep c1cf6e465077930e88dc5136641d402f72a229ddd996f627d60e9639eaba35a6 actual &&
+	printf "tree 0\0" | test-tool sha256 >actual &&
+	grep 6ef19b41225c5369f1c104d45d8d85efa9b057b53b14b4b9b939dd74decc5321 actual
+'
+
+test_done
diff --git a/t/t0025-crlf-renormalize.sh b/t/t0025-crlf-renormalize.sh
index 9d9e02a..e13363a 100755
--- a/t/t0025-crlf-renormalize.sh
+++ b/t/t0025-crlf-renormalize.sh
@@ -27,4 +27,13 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'ignore-errors not mistaken for renormalize' '
+	git reset --hard &&
+	echo "*.txt text=auto" >.gitattributes &&
+	git ls-files --eol >expect &&
+	git add --ignore-errors "*.txt" &&
+	git ls-files --eol >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 99a614b..9c7604d 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -199,4 +199,14 @@
 	)
 '
 
+test_expect_success MINGW 'verify curlies are quoted properly' '
+	: force the rev-parse through the MSYS2 Bash &&
+	git -c alias.r="!git rev-parse" r -- a{b}c >actual &&
+	cat >expect <<-\EOF &&
+	--
+	a{b}c
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
index 2131fb2..c5014ad 100755
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -198,4 +198,13 @@
 	test_dirty_mergeable
 '
 
+test_expect_success 'checkout -b after clone --no-checkout does a checkout of HEAD' '
+	git init src &&
+	test_commit -C src a &&
+	rev="$(git -C src rev-parse HEAD)" &&
+	git clone --no-checkout src dest &&
+	git -C dest checkout "$rev" -b branch &&
+	test_path_is_file dest/a.t
+'
+
 test_done
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 7a440e0..2b96174 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -156,6 +156,11 @@
 	! grep "Maybe git-rebase is broken" actual
 '
 
+test_expect_success 'implicit interactive rebase does not invoke sequence editor' '
+	test_when_finished "git rebase --abort ||:" &&
+	GIT_SEQUENCE_EDITOR="echo bad >" git rebase -x"echo one" @^
+'
+
 test_expect_success 'no changes are a nop' '
 	git checkout branch2 &&
 	set_fake_editor &&
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index f64b130..b393e1e 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -17,14 +17,9 @@
 	git tag start
 '
 
-cat >expect <<\EOF
-Already applied: 0001 A
-Already applied: 0002 B
-Committed: 0003 Z
-EOF
-
 test_expect_success 'rebase -m' '
 	git rebase -m master >report &&
+	>expect &&
 	sed -n -e "/^Already applied: /p" \
 		-e "/^Committed: /p" report >actual &&
 	test_cmp expect actual
diff --git a/t/t3418-rebase-continue.sh b/t/t3418-rebase-continue.sh
index 0210b2a..25aaaca 100755
--- a/t/t3418-rebase-continue.sh
+++ b/t/t3418-rebase-continue.sh
@@ -254,4 +254,18 @@
 	test_path_is_file execed
 '
 
+test_expect_success '--reschedule-failed-exec' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -x false --reschedule-failed-exec HEAD^ &&
+	grep "^exec false" .git/rebase-merge/git-rebase-todo &&
+	git rebase --abort &&
+	test_must_fail git -c rebase.rescheduleFailedExec=true \
+		rebase -x false HEAD^ 2>err &&
+	grep "^exec false" .git/rebase-merge/git-rebase-todo &&
+	test_i18ngrep "has been rescheduled" err &&
+	git rebase --abort &&
+	test_must_fail git rebase -y false HEAD^ 2>err &&
+	test_i18ngrep "has been rescheduled" err
+'
+
 test_done
diff --git a/t/t3420-rebase-autostash.sh b/t/t3420-rebase-autostash.sh
index 4c7494c..2d1094e 100755
--- a/t/t3420-rebase-autostash.sh
+++ b/t/t3420-rebase-autostash.sh
@@ -53,41 +53,6 @@
 	EOF
 }
 
-create_expected_success_merge () {
-	cat >expected <<-EOF
-	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\$" actual)
-	HEAD is now at $(git rev-parse --short feature-branch) third commit
-	First, rewinding head to replay your work on top of it...
-	Merging unrelated-onto-branch with HEAD~1
-	Merging:
-	$(git rev-parse --short unrelated-onto-branch) unrelated commit
-	$(git rev-parse --short feature-branch^) second commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~2) initial commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch~1)] second commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:14:13 2005 -0700
-	 2 files changed, 2 insertions(+)
-	 create mode 100644 file1
-	 create mode 100644 file2
-	Committed: 0001 second commit
-	Merging unrelated-onto-branch with HEAD~0
-	Merging:
-	$(git rev-parse --short rebased-feature-branch~1) second commit
-	$(git rev-parse --short feature-branch) third commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~1) second commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch)] third commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:15:13 2005 -0700
-	 1 file changed, 1 insertion(+)
-	 create mode 100644 file3
-	Committed: 0002 third commit
-	All done.
-	Applied autostash.
-	EOF
-}
-
 create_expected_failure_am () {
 	cat >expected <<-EOF
 	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\$" actual)
@@ -112,43 +77,6 @@
 	EOF
 }
 
-create_expected_failure_merge () {
-	cat >expected <<-EOF
-	$(grep "^Created autostash: [0-9a-f][0-9a-f]*\$" actual)
-	HEAD is now at $(git rev-parse --short feature-branch) third commit
-	First, rewinding head to replay your work on top of it...
-	Merging unrelated-onto-branch with HEAD~1
-	Merging:
-	$(git rev-parse --short unrelated-onto-branch) unrelated commit
-	$(git rev-parse --short feature-branch^) second commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~2) initial commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch~1)] second commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:14:13 2005 -0700
-	 2 files changed, 2 insertions(+)
-	 create mode 100644 file1
-	 create mode 100644 file2
-	Committed: 0001 second commit
-	Merging unrelated-onto-branch with HEAD~0
-	Merging:
-	$(git rev-parse --short rebased-feature-branch~1) second commit
-	$(git rev-parse --short feature-branch) third commit
-	found 1 common ancestor:
-	$(git rev-parse --short feature-branch~1) second commit
-	[detached HEAD $(git rev-parse --short rebased-feature-branch)] third commit
-	 Author: A U Thor <author@example.com>
-	 Date: Thu Apr 7 15:15:13 2005 -0700
-	 1 file changed, 1 insertion(+)
-	 create mode 100644 file3
-	Committed: 0002 third commit
-	All done.
-	Applying autostash resulted in conflicts.
-	Your changes are safe in the stash.
-	You can run "git stash pop" or "git stash drop" at any time.
-	EOF
-}
-
 testrebase () {
 	type=$1
 	dotest=$2
@@ -177,6 +105,9 @@
 	test_expect_success "rebase$type --autostash: check output" '
 		test_when_finished git branch -D rebased-feature-branch &&
 		suffix=${type#\ --} && suffix=${suffix:-am} &&
+		if test ${suffix} = "merge"; then
+			suffix=interactive
+		fi &&
 		create_expected_success_$suffix &&
 		test_i18ncmp expected actual
 	'
@@ -274,6 +205,9 @@
 	test_expect_success "rebase$type: check output with conflicting stash" '
 		test_when_finished git branch -D rebased-feature-branch &&
 		suffix=${type#\ --} && suffix=${suffix:-am} &&
+		if test ${suffix} = "merge"; then
+			suffix=interactive
+		fi &&
 		create_expected_failure_$suffix &&
 		test_i18ncmp expected actual
 	'
diff --git a/t/t3421-rebase-topology-linear.sh b/t/t3421-rebase-topology-linear.sh
index 23ad4cf..7274dca 100755
--- a/t/t3421-rebase-topology-linear.sh
+++ b/t/t3421-rebase-topology-linear.sh
@@ -111,7 +111,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -126,7 +126,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -141,7 +141,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -284,7 +284,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase success -p
 
@@ -315,7 +315,7 @@
 	"
 }
 test_run_rebase success ''
-test_run_rebase failure -m
+test_run_rebase success -m
 test_run_rebase success -i
 test_have_prereq !REBASE_P || test_run_rebase failure -p
 
diff --git a/t/t3425-rebase-topology-merges.sh b/t/t3425-rebase-topology-merges.sh
index 5f892e3..fd8efe8 100755
--- a/t/t3425-rebase-topology-merges.sh
+++ b/t/t3425-rebase-topology-merges.sh
@@ -70,9 +70,8 @@
 		test_linear_range "\'"$expected"\'" d..
 	"
 }
-#TODO: make order consistent across all flavors of rebase
-test_run_rebase success 'e n o' ''
-test_run_rebase success 'e n o' -m
+test_run_rebase success 'n o e' ''
+test_run_rebase success 'n o e' -m
 test_run_rebase success 'n o e' -i
 
 test_run_rebase () {
@@ -87,9 +86,8 @@
 		test_linear_range "\'"$expected"\'" c..
 	"
 }
-#TODO: make order consistent across all flavors of rebase
-test_run_rebase success 'd e n o' ''
-test_run_rebase success 'd e n o' -m
+test_run_rebase success 'd n o e' ''
+test_run_rebase success 'd n o e' -m
 test_run_rebase success 'd n o e' -i
 
 test_run_rebase () {
@@ -104,9 +102,8 @@
 		test_linear_range "\'"$expected"\'" c..
 	"
 }
-#TODO: make order consistent across all flavors of rebase
-test_run_rebase success 'd e n o' ''
-test_run_rebase success 'd e n o' -m
+test_run_rebase success 'd n o e' ''
+test_run_rebase success 'd n o e' -m
 test_run_rebase success 'd n o e' -i
 
 if ! test_have_prereq REBASE_P; then
diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index cc56468..4c69255 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -125,7 +125,7 @@
 	: >dont-overwrite-untracked.t &&
 	echo "reset refs/tags/dont-overwrite-untracked" >script-from-scratch &&
 	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
-	test_must_fail git rebase -r HEAD &&
+	test_must_fail git rebase -ir HEAD &&
 	git rebase --abort
 '
 
diff --git a/t/t3700-add.sh b/t/t3700-add.sh
index 37729ba..be582a5 100755
--- a/t/t3700-add.sh
+++ b/t/t3700-add.sh
@@ -402,4 +402,11 @@
 	test $(git ls-files --stage | grep ^100755 | wc -l) -eq 0
 '
 
+test_expect_success CASE_INSENSITIVE_FS 'path is case-insensitive' '
+	path="$(pwd)/BLUB" &&
+	touch "$path" &&
+	downcased="$(echo "$path" | tr A-Z a-z)" &&
+	git add "$downcased"
+'
+
 test_done
diff --git a/t/t4006-diff-mode.sh b/t/t4006-diff-mode.sh
index a8e01ec..03489af 100755
--- a/t/t4006-diff-mode.sh
+++ b/t/t4006-diff-mode.sh
@@ -32,28 +32,37 @@
 	git commit -m binbin
 '
 
-# test_expect_success '--stat output after text chmod' '
-# 	test_chmod -x rezrov &&
-# 	echo " 0 files changed" >expect &&
-# 	git diff HEAD --stat >actual &&
-#	test_i18ncmp expect actual
-# '
-#
-# test_expect_success '--shortstat output after text chmod' '
-# 	git diff HEAD --shortstat >actual &&
-# 	test_i18ncmp expect actual
-# '
-#
-# test_expect_success '--stat output after binary chmod' '
-# 	test_chmod +x binbin &&
-# 	echo " 0 files changed" >expect &&
-# 	git diff HEAD --stat >actual &&
-# 	test_i18ncmp expect actual
-# '
-#
-# test_expect_success '--shortstat output after binary chmod' '
-# 	git diff HEAD --shortstat >actual &&
-# 	test_i18ncmp expect actual
-# '
+test_expect_success '--stat output after text chmod' '
+	test_chmod -x rezrov &&
+	cat >expect <<-\EOF &&
+	 rezrov | 0
+	 1 file changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git diff HEAD --stat >actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success '--shortstat output after text chmod' '
+	tail -n 1 <expect >expect.short &&
+	git diff HEAD --shortstat >actual &&
+	test_i18ncmp expect.short actual
+'
+
+test_expect_success '--stat output after binary chmod' '
+	test_chmod +x binbin &&
+	cat >expect <<-EOF &&
+	 binbin | Bin
+	 rezrov |   0
+	 2 files changed, 0 insertions(+), 0 deletions(-)
+	EOF
+	git diff HEAD --stat >actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success '--shortstat output after binary chmod' '
+	tail -n 1 <expect >expect.short &&
+	git diff HEAD --shortstat >actual &&
+	test_i18ncmp expect.short actual
+'
 
 test_done
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 7d985ff..9f8f0e8 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -98,6 +98,12 @@
 	git commit -m "update mode" &&
 	git checkout -f master &&
 
+	# Same merge as master, but with parents reversed. Hide it in a
+	# pseudo-ref to avoid impacting tests with --all.
+	commit=$(echo reverse |
+		 git commit-tree -p master^2 -p master^1 master^{tree}) &&
+	git update-ref REVERSE $commit &&
+
 	git config diff.renames false &&
 
 	git show-branch
@@ -239,6 +245,8 @@
 # stat summary should show the diffstat and summary with the first parent
 diff-tree -c --stat --summary side
 diff-tree --cc --stat --summary side
+diff-tree --cc --shortstat master
+diff-tree --cc --summary REVERSE
 # improved by Timo's patch
 diff-tree --cc --patch-with-stat master
 # improved by Timo's patch
@@ -350,6 +358,7 @@
 diff --dirstat master~1 master~2
 diff --dirstat initial rearrange
 diff --dirstat-by-file initial rearrange
+diff --dirstat --cc master~1 master
 # No-index --abbrev and --no-abbrev
 diff --raw initial
 :noellipses diff --raw initial
diff --git a/t/t4013/diff.diff-tree_--cc_--shortstat_master b/t/t4013/diff.diff-tree_--cc_--shortstat_master
new file mode 100644
index 0000000..a4ca42d
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--cc_--shortstat_master
@@ -0,0 +1,4 @@
+$ git diff-tree --cc --shortstat master
+59d314ad6f356dd08601a4cd5e530381da3e3c64
+ 2 files changed, 5 insertions(+)
+$
diff --git a/t/t4013/diff.diff-tree_--cc_--summary_REVERSE b/t/t4013/diff.diff-tree_--cc_--summary_REVERSE
new file mode 100644
index 0000000..e208dd5
--- /dev/null
+++ b/t/t4013/diff.diff-tree_--cc_--summary_REVERSE
@@ -0,0 +1,6 @@
+$ git diff-tree --cc --summary REVERSE
+2562325a7ee916efb2481da93073b82cec801cbc
+ create mode 100644 file1
+ delete mode 100644 file2
+ delete mode 100644 file3
+$
diff --git a/t/t4013/diff.diff_--dirstat_--cc_master~1_master b/t/t4013/diff.diff_--dirstat_--cc_master~1_master
new file mode 100644
index 0000000..fba4e34
--- /dev/null
+++ b/t/t4013/diff.diff_--dirstat_--cc_master~1_master
@@ -0,0 +1,3 @@
+$ git diff --dirstat --cc master~1 master
+  40.0% dir/
+$
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 9a3e4fd..ab4670d 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1802,8 +1802,8 @@
 	<BOLD;MAGENTA>-a long line to exceed per-line minimum<RESET>
 	<BOLD;MAGENTA>-another long line to exceed per-line minimum<RESET>
 	<RED>-original file<RESET>
-	<BOLD;YELLOW>+<RESET>Q<BOLD;YELLOW>a long line to exceed per-line minimum<RESET>
-	<BOLD;YELLOW>+<RESET>Q<BOLD;YELLOW>another long line to exceed per-line minimum<RESET>
+	<BOLD;CYAN>+<RESET>Q<BOLD;CYAN>a long line to exceed per-line minimum<RESET>
+	<BOLD;CYAN>+<RESET>Q<BOLD;CYAN>another long line to exceed per-line minimum<RESET>
 	<GREEN>+<RESET><GREEN>new file<RESET>
 	EOF
 	test_cmp expected actual
@@ -1827,6 +1827,7 @@
 	QQQthat has similar lines
 	QQQto previous blocks, but with different indent
 	QQQYetQAnotherQoutlierQ
+	QLine with internal w h i t e s p a c e change
 	EOF
 
 	git add text.txt &&
@@ -1847,6 +1848,7 @@
 	QQthat has similar lines
 	QQto previous blocks, but with different indent
 	QQYetQAnotherQoutlier
+	QLine with internal whitespace change
 	EOF
 
 	git diff --color --color-moved --color-moved-ws=allow-indentation-change >actual.raw &&
@@ -1856,7 +1858,7 @@
 		<BOLD>diff --git a/text.txt b/text.txt<RESET>
 		<BOLD>--- a/text.txt<RESET>
 		<BOLD>+++ b/text.txt<RESET>
-		<CYAN>@@ -1,14 +1,14 @@<RESET>
+		<CYAN>@@ -1,15 +1,15 @@<RESET>
 		<BOLD;MAGENTA>-QIndented<RESET>
 		<BOLD;MAGENTA>-QText across<RESET>
 		<BOLD;MAGENTA>-Qsome lines<RESET>
@@ -1871,6 +1873,7 @@
 		<BOLD;MAGENTA>-QQQthat has similar lines<RESET>
 		<BOLD;MAGENTA>-QQQto previous blocks, but with different indent<RESET>
 		<RED>-QQQYetQAnotherQoutlierQ<RESET>
+		<RED>-QLine with internal w h i t e s p a c e change<RESET>
 		<BOLD;CYAN>+<RESET>QQ<BOLD;CYAN>Indented<RESET>
 		<BOLD;CYAN>+<RESET>QQ<BOLD;CYAN>Text across<RESET>
 		<BOLD;CYAN>+<RESET>QQ<BOLD;CYAN>some lines<RESET>
@@ -1885,6 +1888,7 @@
 		<BOLD;CYAN>+<RESET>QQ<BOLD;CYAN>that has similar lines<RESET>
 		<BOLD;CYAN>+<RESET>QQ<BOLD;CYAN>to previous blocks, but with different indent<RESET>
 		<GREEN>+<RESET>QQ<GREEN>YetQAnotherQoutlier<RESET>
+		<GREEN>+<RESET>Q<GREEN>Line with internal whitespace change<RESET>
 	EOF
 
 	test_cmp expected actual
@@ -1915,4 +1919,93 @@
 	test_i18ngrep allow-indentation-change err
 '
 
+EMPTY=''
+test_expect_success 'compare mixed whitespace delta across moved blocks' '
+
+	git reset --hard &&
+	tr Q_ "\t " <<-EOF >text.txt &&
+	${EMPTY}
+	____too short without
+	${EMPTY}
+	___being grouped across blank line
+	${EMPTY}
+	context
+	lines
+	to
+	anchor
+	____Indented text to
+	_Q____be further indented by four spaces across
+	____Qseveral lines
+	QQ____These two lines have had their
+	____indentation reduced by four spaces
+	Qdifferent indentation change
+	____too short
+	EOF
+
+	git add text.txt &&
+	git commit -m "add text.txt" &&
+
+	tr Q_ "\t " <<-EOF >text.txt &&
+	context
+	lines
+	to
+	anchor
+	QIndented text to
+	QQbe further indented by four spaces across
+	Q____several lines
+	${EMPTY}
+	QQtoo short without
+	${EMPTY}
+	Q_______being grouped across blank line
+	${EMPTY}
+	Q_QThese two lines have had their
+	indentation reduced by four spaces
+	QQdifferent indentation change
+	__Qtoo short
+	EOF
+
+	git -c color.diff.whitespace="normal red" \
+		-c core.whitespace=space-before-tab \
+		diff --color --color-moved --ws-error-highlight=all \
+		--color-moved-ws=allow-indentation-change >actual.raw &&
+	grep -v "index" actual.raw | test_decode_color >actual &&
+
+	cat <<-\EOF >expected &&
+	<BOLD>diff --git a/text.txt b/text.txt<RESET>
+	<BOLD>--- a/text.txt<RESET>
+	<BOLD>+++ b/text.txt<RESET>
+	<CYAN>@@ -1,16 +1,16 @@<RESET>
+	<BOLD;MAGENTA>-<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>    too short without<RESET>
+	<BOLD;MAGENTA>-<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>   being grouped across blank line<RESET>
+	<BOLD;MAGENTA>-<RESET>
+	 <RESET>context<RESET>
+	 <RESET>lines<RESET>
+	 <RESET>to<RESET>
+	 <RESET>anchor<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>    Indented text to<RESET>
+	<BOLD;MAGENTA>-<RESET><BRED> <RESET>	<BOLD;MAGENTA>    be further indented by four spaces across<RESET>
+	<BOLD;MAGENTA>-<RESET><BRED>    <RESET>	<BOLD;MAGENTA>several lines<RESET>
+	<BOLD;BLUE>-<RESET>		<BOLD;BLUE>    These two lines have had their<RESET>
+	<BOLD;BLUE>-<RESET><BOLD;BLUE>    indentation reduced by four spaces<RESET>
+	<BOLD;MAGENTA>-<RESET>	<BOLD;MAGENTA>different indentation change<RESET>
+	<RED>-<RESET><RED>    too short<RESET>
+	<BOLD;CYAN>+<RESET>	<BOLD;CYAN>Indented text to<RESET>
+	<BOLD;CYAN>+<RESET>		<BOLD;CYAN>be further indented by four spaces across<RESET>
+	<BOLD;CYAN>+<RESET>	<BOLD;CYAN>    several lines<RESET>
+	<BOLD;YELLOW>+<RESET>
+	<BOLD;YELLOW>+<RESET>		<BOLD;YELLOW>too short without<RESET>
+	<BOLD;YELLOW>+<RESET>
+	<BOLD;YELLOW>+<RESET>	<BOLD;YELLOW>       being grouped across blank line<RESET>
+	<BOLD;YELLOW>+<RESET>
+	<BOLD;CYAN>+<RESET>	<BRED> <RESET>	<BOLD;CYAN>These two lines have had their<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>indentation reduced by four spaces<RESET>
+	<BOLD;YELLOW>+<RESET>		<BOLD;YELLOW>different indentation change<RESET>
+	<GREEN>+<RESET><BRED>  <RESET>	<GREEN>too short<RESET>
+	EOF
+
+	test_cmp expected actual
+'
+
 test_done
diff --git a/t/t4066-diff-emit-delay.sh b/t/t4066-diff-emit-delay.sh
new file mode 100755
index 0000000..5df6b5e
--- /dev/null
+++ b/t/t4066-diff-emit-delay.sh
@@ -0,0 +1,79 @@
+#!/bin/sh
+
+test_description='test combined/stat/moved interaction'
+. ./test-lib.sh
+
+# This test covers a weird 3-way interaction between "--cc -p", which will run
+# the combined diff code, along with "--stat", which will be computed as a
+# first-parent stat during the combined diff, and "--color-moved", which
+# enables the emitted_symbols list to store the diff in memory.
+
+test_expect_success 'set up history with a merge' '
+	test_commit A &&
+	test_commit B &&
+	git checkout -b side HEAD^ &&
+	test_commit C &&
+	git merge -m M master &&
+	test_commit D
+'
+
+test_expect_success 'log --cc -p --stat --color-moved' '
+	cat >expect <<-\EOF &&
+	commit D
+	---
+	 D.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/D.t b/D.t
+	new file mode 100644
+	index 0000000..1784810
+	--- /dev/null
+	+++ b/D.t
+	@@ -0,0 +1 @@
+	+D
+	commit M
+
+	 B.t | 1 +
+	 1 file changed, 1 insertion(+)
+	commit C
+	---
+	 C.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/C.t b/C.t
+	new file mode 100644
+	index 0000000..3cc58df
+	--- /dev/null
+	+++ b/C.t
+	@@ -0,0 +1 @@
+	+C
+	commit B
+	---
+	 B.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/B.t b/B.t
+	new file mode 100644
+	index 0000000..223b783
+	--- /dev/null
+	+++ b/B.t
+	@@ -0,0 +1 @@
+	+B
+	commit A
+	---
+	 A.t | 1 +
+	 1 file changed, 1 insertion(+)
+
+	diff --git a/A.t b/A.t
+	new file mode 100644
+	index 0000000..f70f10e
+	--- /dev/null
+	+++ b/A.t
+	@@ -0,0 +1 @@
+	+A
+	EOF
+	git log --format="commit %s" --cc -p --stat --color-moved >actual &&
+	test_cmp expect actual
+'
+
+test_done
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 978a8a6..7df8c3d 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -621,4 +621,54 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'set up %S tests' '
+	git checkout --orphan source-a &&
+	test_commit one &&
+	test_commit two &&
+	git checkout -b source-b HEAD^ &&
+	test_commit three
+'
+
+test_expect_success 'log --format=%S paints branch names' '
+	cat >expect <<-\EOF &&
+	source-b
+	source-a
+	source-b
+	EOF
+	git log --format=%S source-a source-b >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --format=%S paints tag names' '
+	git tag -m tagged source-tag &&
+	cat >expect <<-\EOF &&
+	source-tag
+	source-a
+	source-tag
+	EOF
+	git log --format=%S source-tag source-a >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --format=%S paints symmetric ranges' '
+	cat >expect <<-\EOF &&
+	source-b
+	source-a
+	EOF
+	git log --format=%S source-a...source-b >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '%S in git log --format works with other placeholders (part 1)' '
+	git log --format="source-b %h" source-b >expect &&
+	git log --format="%S %h" source-b >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '%S in git log --format works with other placeholders (part 2)' '
+	git log --format="%h source-b" source-b >expect &&
+	git log --format="%h %S" source-b >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 5fe21db..16d10eb 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -122,7 +122,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "10" "large_edges"
+	graph_read_expect "10" "extra_edges"
 '
 
 graph_git_behavior 'merge 1 vs 2' full merge/1 merge/2
@@ -157,7 +157,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'full graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -167,7 +167,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'cleared graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -177,7 +177,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	cat new-idx | git commit-graph write --stdin-packs &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "9" "large_edges"
+	graph_read_expect "9" "extra_edges"
 '
 
 graph_git_behavior 'graph from pack, commit 8 vs merge 1' full commits/8 merge/1
@@ -200,7 +200,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git rev-parse merge/3 | git commit-graph write --stdin-commits --append &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "10" "large_edges"
+	graph_read_expect "10" "extra_edges"
 '
 
 graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -210,7 +210,7 @@
 	cd "$TRASH_DIRECTORY/full" &&
 	git commit-graph write --reachable &&
 	test_path_is_file $objdir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
@@ -231,7 +231,7 @@
 	cd "$TRASH_DIRECTORY/bare" &&
 	git commit-graph write &&
 	test_path_is_file $baredir/info/commit-graph &&
-	graph_read_expect "11" "large_edges"
+	graph_read_expect "11" "extra_edges"
 '
 
 graph_git_behavior 'bare repo with graph, commit 8 vs merge 1' bare commits/8 merge/1
@@ -366,9 +366,10 @@
 GRAPH_BYTE_OCTOPUS=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4))
 GRAPH_BYTE_FOOTER=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4 * $NUM_OCTOPUS_EDGES))
 
-# usage: corrupt_graph_and_verify <position> <data> <string>
+# usage: corrupt_graph_and_verify <position> <data> <string> [<zero_pos>]
 # Manipulates the commit-graph file at the position
-# by inserting the data, then runs 'git commit-graph verify'
+# by inserting the data, optionally zeroing the file
+# starting at <zero_pos>, then runs 'git commit-graph verify'
 # and places the output in the file 'err'. Test 'err' for
 # the given string.
 corrupt_graph_and_verify() {
@@ -376,11 +377,15 @@
 	data="${2:-\0}"
 	grepstr=$3
 	cd "$TRASH_DIRECTORY/full" &&
+	orig_size=$(wc -c < $objdir/info/commit-graph) &&
+	zero_pos=${4:-${orig_size}} &&
 	test_when_finished mv commit-graph-backup $objdir/info/commit-graph &&
 	cp $objdir/info/commit-graph commit-graph-backup &&
 	printf "$data" | dd of="$objdir/info/commit-graph" bs=1 seek="$pos" conv=notrunc &&
+	dd of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" count=0 &&
+	dd if=/dev/zero of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" count=$(($orig_size - $zero_pos)) &&
 	test_must_fail git commit-graph verify 2>test_err &&
-	grep -v "^+" test_err >err
+	grep -v "^+" test_err >err &&
 	test_i18ngrep "$grepstr" err
 }
 
@@ -484,6 +489,11 @@
 		"incorrect checksum"
 '
 
+test_expect_success 'detect incorrect chunk count' '
+	corrupt_graph_and_verify $GRAPH_BYTE_CHUNK_COUNT "\377" \
+		"chunk lookup table entry missing" $GRAPH_CHUNK_LOOKUP_OFFSET
+'
+
 test_expect_success 'git fsck (checks commit-graph)' '
 	cd "$TRASH_DIRECTORY/full" &&
 	git fsck &&
diff --git a/t/t5403-post-checkout-hook.sh b/t/t5403-post-checkout-hook.sh
index fc898c9..a539ffc 100755
--- a/t/t5403-post-checkout-hook.sh
+++ b/t/t5403-post-checkout-hook.sh
@@ -7,82 +7,70 @@
 . ./test-lib.sh
 
 test_expect_success setup '
-	echo Data for commit0. >a &&
-	echo Data for commit0. >b &&
-	git update-index --add a &&
-	git update-index --add b &&
-	tree0=$(git write-tree) &&
-	commit0=$(echo setup | git commit-tree $tree0) &&
-	git update-ref refs/heads/master $commit0 &&
-	git clone ./. clone1 &&
-	git clone ./. clone2 &&
-	GIT_DIR=clone2/.git git branch new2 &&
-	echo Data for commit1. >clone2/b &&
-	GIT_DIR=clone2/.git git add clone2/b &&
-	GIT_DIR=clone2/.git git commit -m new2
-'
-
-for clone in 1 2; do
-    cat >clone${clone}/.git/hooks/post-checkout <<'EOF'
-#!/bin/sh
-echo $@ > $GIT_DIR/post-checkout.args
-EOF
-    chmod u+x clone${clone}/.git/hooks/post-checkout
-done
-
-test_expect_success 'post-checkout runs as expected ' '
-	GIT_DIR=clone1/.git git checkout master &&
-	test -e clone1/.git/post-checkout.args
+	mkdir -p .git/hooks &&
+	write_script .git/hooks/post-checkout <<-\EOF &&
+	echo "$@" >.git/post-checkout.args
+	EOF
+	test_commit one &&
+	test_commit two &&
+	test_commit rebase-on-me &&
+	git reset --hard HEAD^ &&
+	test_commit three
 '
 
 test_expect_success 'post-checkout receives the right arguments with HEAD unchanged ' '
-	old=$(awk "{print \$1}" clone1/.git/post-checkout.args) &&
-	new=$(awk "{print \$2}" clone1/.git/post-checkout.args) &&
-	flag=$(awk "{print \$3}" clone1/.git/post-checkout.args) &&
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout master &&
+	read old new flag <.git/post-checkout.args &&
 	test $old = $new && test $flag = 1
 '
 
-test_expect_success 'post-checkout runs as expected ' '
-	GIT_DIR=clone1/.git git checkout master &&
-	test -e clone1/.git/post-checkout.args
-'
-
 test_expect_success 'post-checkout args are correct with git checkout -b ' '
-	GIT_DIR=clone1/.git git checkout -b new1 &&
-	old=$(awk "{print \$1}" clone1/.git/post-checkout.args) &&
-	new=$(awk "{print \$2}" clone1/.git/post-checkout.args) &&
-	flag=$(awk "{print \$3}" clone1/.git/post-checkout.args) &&
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout -b new1 &&
+	read old new flag <.git/post-checkout.args &&
 	test $old = $new && test $flag = 1
 '
 
 test_expect_success 'post-checkout receives the right args with HEAD changed ' '
-	GIT_DIR=clone2/.git git checkout new2 &&
-	old=$(awk "{print \$1}" clone2/.git/post-checkout.args) &&
-	new=$(awk "{print \$2}" clone2/.git/post-checkout.args) &&
-	flag=$(awk "{print \$3}" clone2/.git/post-checkout.args) &&
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout two &&
+	read old new flag <.git/post-checkout.args &&
 	test $old != $new && test $flag = 1
 '
 
 test_expect_success 'post-checkout receives the right args when not switching branches ' '
-	GIT_DIR=clone2/.git git checkout master b &&
-	old=$(awk "{print \$1}" clone2/.git/post-checkout.args) &&
-	new=$(awk "{print \$2}" clone2/.git/post-checkout.args) &&
-	flag=$(awk "{print \$3}" clone2/.git/post-checkout.args) &&
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout master -- three.t &&
+	read old new flag <.git/post-checkout.args &&
 	test $old = $new && test $flag = 0
 '
 
-if test "$(git config --bool core.filemode)" = true; then
-mkdir -p templates/hooks
-cat >templates/hooks/post-checkout <<'EOF'
-#!/bin/sh
-echo $@ > $GIT_DIR/post-checkout.args
-EOF
-chmod +x templates/hooks/post-checkout
+test_expect_success 'post-checkout is triggered on rebase' '
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout -b rebase-test master &&
+	rm -f .git/post-checkout.args &&
+	git rebase rebase-on-me &&
+	read old new flag <.git/post-checkout.args &&
+	test $old != $new && test $flag = 1
+'
+
+test_expect_success 'post-checkout is triggered on rebase with fast-forward' '
+	test_when_finished "rm -f .git/post-checkout.args" &&
+	git checkout -b ff-rebase-test rebase-on-me^ &&
+	rm -f .git/post-checkout.args &&
+	git rebase rebase-on-me &&
+	read old new flag <.git/post-checkout.args &&
+	test $old != $new && test $flag = 1
+'
 
 test_expect_success 'post-checkout hook is triggered by clone' '
+	mkdir -p templates/hooks &&
+	write_script templates/hooks/post-checkout <<-\EOF &&
+	echo "$@" >$GIT_DIR/post-checkout.args
+	EOF
 	git clone --template=templates . clone3 &&
 	test -f clone3/.git/post-checkout.args
 '
-fi
 
 test_done
diff --git a/t/t5407-post-rewrite-hook.sh b/t/t5407-post-rewrite-hook.sh
index 9b2a274..a4a5903 100755
--- a/t/t5407-post-rewrite-hook.sh
+++ b/t/t5407-post-rewrite-hook.sh
@@ -78,6 +78,7 @@
 	git rebase --continue &&
 	echo rebase >expected.args &&
 	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
 	$(git rev-parse D) $(git rev-parse HEAD)
 	EOF
 	verify_hook_input
@@ -91,6 +92,7 @@
 	echo rebase >expected.args &&
 	cat >expected.data <<-EOF &&
 	$(git rev-parse E) $(git rev-parse HEAD)
+	$(git rev-parse F) $(git rev-parse HEAD)
 	EOF
 	verify_hook_input
 '
@@ -120,6 +122,38 @@
 	git rebase --continue &&
 	echo rebase >expected.args &&
 	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
+	$(git rev-parse D) $(git rev-parse HEAD)
+	EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase with implicit use of interactive backend' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_must_fail git rebase --keep --onto A B &&
+	echo C > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
+	$(git rev-parse D) $(git rev-parse HEAD)
+	EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase --skip with implicit use of interactive backend' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_must_fail git rebase --keep --onto A B &&
+	test_must_fail git rebase --skip &&
+	echo D > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<-EOF &&
+	$(git rev-parse C) $(git rev-parse HEAD^)
 	$(git rev-parse D) $(git rev-parse HEAD)
 	EOF
 	verify_hook_input
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 086f2c4..49c540b 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -439,15 +439,23 @@
 	) >input.dup
 '
 
-test_expect_success 'fetch refs from cmdline' '
-	(
-		cd client &&
-		git fetch-pack --no-progress .. $(cat ../input)
-	) >output &&
-	cut -d " " -f 2 <output | sort >actual &&
-	test_cmp expect actual
+test_expect_success 'setup fetch refs from cmdline v[12]' '
+	cp -r client client1 &&
+	cp -r client client2
 '
 
+for version in '' 1 2
+do
+	test_expect_success "protocol.version=$version fetch refs from cmdline" "
+		(
+			cd client$version &&
+			GIT_TEST_PROTOCOL_VERSION=$version git fetch-pack --no-progress .. \$(cat ../input)
+		) >output &&
+		cut -d ' ' -f 2 <output | sort >actual &&
+		test_cmp expect actual
+	"
+done
+
 test_expect_success 'fetch refs from stdin' '
 	(
 		cd client &&
diff --git a/t/t5512-ls-remote.sh b/t/t5512-ls-remote.sh
index cd9e606..ced15ae 100755
--- a/t/t5512-ls-remote.sh
+++ b/t/t5512-ls-remote.sh
@@ -204,6 +204,12 @@
 	grep refs/tags/magic actual
 '
 
+test_expect_success 'protocol v2 supports hiderefs' '
+	test_config uploadpack.hiderefs refs/tags &&
+	git -c protocol.version=2 ls-remote . >actual &&
+	! grep refs/tags actual
+'
+
 test_expect_success 'ls-remote --symref' '
 	git fetch origin &&
 	cat >expect <<-EOF &&
diff --git a/t/t5526-fetch-submodules.sh b/t/t5526-fetch-submodules.sh
index a031755..63205df 100755
--- a/t/t5526-fetch-submodules.sh
+++ b/t/t5526-fetch-submodules.sh
@@ -602,4 +602,121 @@
 	test_cmp expect actual
 '
 
+test_expect_success "fetch new submodule commits on-demand outside standard refspec" '
+	# add a second submodule and ensure it is around in downstream first
+	git clone submodule sub1 &&
+	git submodule add ./sub1 &&
+	git commit -m "adding a second submodule" &&
+	git -C downstream pull &&
+	git -C downstream submodule update --init --recursive &&
+
+	git checkout --detach &&
+
+	C=$(git -C submodule commit-tree -m "new change outside refs/heads" HEAD^{tree}) &&
+	git -C submodule update-ref refs/changes/1 $C &&
+	git update-index --cacheinfo 160000 $C submodule &&
+	test_tick &&
+
+	D=$(git -C sub1 commit-tree -m "new change outside refs/heads" HEAD^{tree}) &&
+	git -C sub1 update-ref refs/changes/2 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+
+	git commit -m "updated submodules outside of refs/heads" &&
+	E=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/3 $E &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/3:refs/heads/my_branch &&
+		git -C submodule cat-file -t $C &&
+		git -C sub1 cat-file -t $D &&
+		git checkout --recurse-submodules FETCH_HEAD
+	)
+'
+
+test_expect_success 'fetch new submodule commit on-demand in FETCH_HEAD' '
+	# depends on the previous test for setup
+
+	C=$(git -C submodule commit-tree -m "another change outside refs/heads" HEAD^{tree}) &&
+	git -C submodule update-ref refs/changes/4 $C &&
+	git update-index --cacheinfo 160000 $C submodule &&
+	test_tick &&
+
+	D=$(git -C sub1 commit-tree -m "another change outside refs/heads" HEAD^{tree}) &&
+	git -C sub1 update-ref refs/changes/5 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+
+	git commit -m "updated submodules outside of refs/heads" &&
+	E=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/6 $E &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/6 &&
+		git -C submodule cat-file -t $C &&
+		git -C sub1 cat-file -t $D &&
+		git checkout --recurse-submodules FETCH_HEAD
+	)
+'
+
+test_expect_success 'fetch new submodule commits on-demand without .gitmodules entry' '
+	# depends on the previous test for setup
+
+	git config -f .gitmodules --remove-section submodule.sub1 &&
+	git add .gitmodules &&
+	git commit -m "delete gitmodules file" &&
+	git checkout -B master &&
+	git -C downstream fetch &&
+	git -C downstream checkout origin/master &&
+
+	C=$(git -C submodule commit-tree -m "yet another change outside refs/heads" HEAD^{tree}) &&
+	git -C submodule update-ref refs/changes/7 $C &&
+	git update-index --cacheinfo 160000 $C submodule &&
+	test_tick &&
+
+	D=$(git -C sub1 commit-tree -m "yet another change outside refs/heads" HEAD^{tree}) &&
+	git -C sub1 update-ref refs/changes/8 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+
+	git commit -m "updated submodules outside of refs/heads" &&
+	E=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/9 $E &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/9 &&
+		git -C submodule cat-file -t $C &&
+		git -C sub1 cat-file -t $D &&
+		git checkout --recurse-submodules FETCH_HEAD
+	)
+'
+
+test_expect_success 'fetch new submodule commit intermittently referenced by superproject' '
+	# depends on the previous test for setup
+
+	D=$(git -C sub1 commit-tree -m "change 10 outside refs/heads" HEAD^{tree}) &&
+	E=$(git -C sub1 commit-tree -m "change 11 outside refs/heads" HEAD^{tree}) &&
+	F=$(git -C sub1 commit-tree -m "change 12 outside refs/heads" HEAD^{tree}) &&
+
+	git -C sub1 update-ref refs/changes/10 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+	git commit -m "updated submodules outside of refs/heads" &&
+
+	git -C sub1 update-ref refs/changes/11 $E &&
+	git update-index --cacheinfo 160000 $E sub1 &&
+	git commit -m "updated submodules outside of refs/heads" &&
+
+	git -C sub1 update-ref refs/changes/12 $F &&
+	git update-index --cacheinfo 160000 $F sub1 &&
+	git commit -m "updated submodules outside of refs/heads" &&
+
+	G=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/13 $G &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/13 &&
+
+		git -C sub1 cat-file -t $D &&
+		git -C sub1 cat-file -t $E &&
+		git -C sub1 cat-file -t $F
+	)
+'
+
 test_done
diff --git a/t/t5537-fetch-shallow.sh b/t/t5537-fetch-shallow.sh
index 6faf17e..6caf628 100755
--- a/t/t5537-fetch-shallow.sh
+++ b/t/t5537-fetch-shallow.sh
@@ -243,7 +243,8 @@
 	       "$(git -C "$REPO" rev-parse HEAD)" \
 	       "$(git -C "$REPO" rev-parse HEAD^)" \
 	       >"$HTTPD_ROOT_PATH/one-time-sed" &&
-	test_must_fail git -C client fetch --depth=1 "$HTTPD_URL/one_time_sed/repo" \
+	test_must_fail env GIT_TEST_SIDEBAND_ALL=0 git -C client \
+		fetch --depth=1 "$HTTPD_URL/one_time_sed/repo" \
 		master:a_branch &&
 
 	# Ensure that the one-time-sed script was used.
diff --git a/t/t5580-clone-push-unc.sh b/t/t5580-clone-push-unc.sh
index ba548df..217adf3 100755
--- a/t/t5580-clone-push-unc.sh
+++ b/t/t5580-clone-push-unc.sh
@@ -40,6 +40,11 @@
 	git clone "file://$UNCPATH" clone
 '
 
+test_expect_success 'clone with backslashed path' '
+	BACKSLASHED="$(echo "$UNCPATH" | tr / \\\\)" &&
+	git clone "$BACKSLASHED" backslashed
+'
+
 test_expect_success push '
 	(
 		cd clone &&
diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
new file mode 100755
index 0000000..cd9283e
--- /dev/null
+++ b/t/t5581-http-curl-verbose.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='test GIT_CURL_VERBOSE'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" --bare init &&
+	git config push.default matching &&
+	echo content >file &&
+	git add file &&
+	git commit -m one &&
+	git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git push public master:master
+'
+
+test_expect_success 'failure in git-upload-pack is shown' '
+	test_might_fail env GIT_CURL_VERBOSE=1 \
+		git clone "$HTTPD_URL/error_git_upload_pack/smart/repo.git" \
+		2>curl_log &&
+	grep "< HTTP/1.1 500 Intentional Breakage" curl_log
+'
+
+stop_httpd
+
+test_done
diff --git a/t/t5701-git-serve.sh b/t/t5701-git-serve.sh
index ae79c6b..fe45bf8 100755
--- a/t/t5701-git-serve.sh
+++ b/t/t5701-git-serve.sh
@@ -14,7 +14,7 @@
 	0000
 	EOF
 
-	git serve --advertise-capabilities >out &&
+	GIT_TEST_SIDEBAND_ALL=0 git serve --advertise-capabilities >out &&
 	test-tool pkt-line unpack <out >actual &&
 	test_cmp expect actual
 '
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 0f2b09e..db4ae09 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -471,6 +471,53 @@
 	grep "fetch< version 2" trace
 '
 
+test_expect_success 'ensure that multiple fetches in same process from a shallow repo works' '
+	rm -rf server client trace &&
+
+	test_create_repo server &&
+	test_commit -C server one &&
+	test_commit -C server two &&
+	test_commit -C server three &&
+	git clone --shallow-exclude two "file://$(pwd)/server" client &&
+
+	git -C server tag -a -m "an annotated tag" twotag two &&
+
+	# Triggers tag following (thus, 2 fetches in one process)
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client -c protocol.version=2 \
+		fetch --shallow-exclude one origin &&
+	# Ensure that protocol v2 is used
+	grep "fetch< version 2" trace
+'
+
+test_expect_success 'deepen-relative' '
+	rm -rf server client trace &&
+
+	test_create_repo server &&
+	test_commit -C server one &&
+	test_commit -C server two &&
+	test_commit -C server three &&
+	git clone --depth 1 "file://$(pwd)/server" client &&
+	test_commit -C server four &&
+
+	# Sanity check that only "three" is downloaded
+	git -C client log --pretty=tformat:%s master >actual &&
+	echo three >expected &&
+	test_cmp expected actual &&
+
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client -c protocol.version=2 \
+		fetch --deepen=1 origin &&
+	# Ensure that protocol v2 is used
+	grep "fetch< version 2" trace &&
+
+	git -C client log --pretty=tformat:%s origin/master >actual &&
+	cat >expected <<-\EOF &&
+	four
+	three
+	two
+	EOF
+	test_cmp expected actual
+'
+
 # Test protocol v2 with 'http://' transport
 #
 . "$TEST_DIRECTORY"/lib-httpd.sh
@@ -514,6 +561,27 @@
 	grep "git< version 2" log
 '
 
+test_expect_success 'fetch from namespaced repo respects namespaces' '
+	test_when_finished "rm -f log" &&
+
+	git init "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" &&
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" one &&
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" two &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" \
+		update-ref refs/namespaces/ns/refs/heads/master one &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \
+		fetch "$HTTPD_URL/smart_namespace/nsrepo" \
+		refs/heads/master:refs/heads/theirs &&
+
+	# Server responded using protocol v2
+	grep "fetch< version 2" log &&
+
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/nsrepo" rev-parse one >expect &&
+	git -C http_child rev-parse theirs >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'push with http:// and a config of v2 does not request v2' '
 	test_when_finished "rm -f log" &&
 	# Till v2 for push is designed, make sure that if a client has
@@ -583,8 +651,8 @@
 	test_must_fail env GIT_TRACE_PACKET="$(pwd)/log" git -C http_child \
 		-c protocol.version=2 \
 		fetch "$HTTPD_URL/one_time_sed/http_parent" 2> err &&
-	grep "fetch< acknowledgments" log &&
-	! grep "fetch< ready" log &&
+	grep "fetch< .*acknowledgments" log &&
+	! grep "fetch< .*ready" log &&
 	test_i18ngrep "expected no other sections to be sent after no .ready." err
 '
 
diff --git a/t/t5703-upload-pack-ref-in-want.sh b/t/t5703-upload-pack-ref-in-want.sh
index 7053899..f87b2f6 100755
--- a/t/t5703-upload-pack-ref-in-want.sh
+++ b/t/t5703-upload-pack-ref-in-want.sh
@@ -208,7 +208,7 @@
 	cp -r "$LOCAL_PRISTINE" local &&
 	inconsistency master 1234567890123456789012345678901234567890 &&
 	test_must_fail git -C local fetch 2>err &&
-	test_i18ngrep "ERR upload-pack: not our ref" err
+	test_i18ngrep "fatal: remote error: upload-pack: not our ref" err
 '
 
 test_expect_success 'server is initially ahead - ref in want' '
@@ -254,7 +254,7 @@
 	echo "s/master/raster/" >"$HTTPD_ROOT_PATH/one-time-sed" &&
 	test_must_fail git -C local fetch 2>err &&
 
-	test_i18ngrep "ERR unknown ref refs/heads/raster" err
+	test_i18ngrep "fatal: remote error: unknown ref refs/heads/raster" err
 '
 
 stop_httpd
diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index ec42c2f..da113d9 100755
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -185,6 +185,10 @@
 	test_cmp expect actual
 '
 
+test_expect_success '%S is not a placeholder for rev-list yet' '
+	git rev-list --format="%S" -1 master | grep "%S"
+'
+
 test_expect_success 'advanced colors' '
 	cat >expect <<-EOF &&
 	commit $head2
diff --git a/t/t6042-merge-rename-corner-cases.sh b/t/t6042-merge-rename-corner-cases.sh
index 7cc34e7..09dfa8b 100755
--- a/t/t6042-merge-rename-corner-cases.sh
+++ b/t/t6042-merge-rename-corner-cases.sh
@@ -1175,7 +1175,7 @@
 
 		# Handle the left side
 		git checkout L &&
-		git mv one three &&
+		git rm one two &&
 		mv -f file_v2 three &&
 		mv -f file_v5 two &&
 		git add two three &&
@@ -1183,7 +1183,7 @@
 
 		# Handle the right side
 		git checkout R &&
-		git mv two three &&
+		git rm one two &&
 		mv -f file_v3 one &&
 		mv -f file_v6 three &&
 		git add one three &&
diff --git a/t/t6112-rev-list-filters-objects.sh b/t/t6112-rev-list-filters-objects.sh
index eb32505..9c11427 100755
--- a/t/t6112-rev-list-filters-objects.sh
+++ b/t/t6112-rev-list-filters-objects.sh
@@ -283,7 +283,7 @@
 
 # Make sure tree:0 does not iterate through any trees.
 
-test_expect_success 'filter a GIANT tree through tree:0' '
+test_expect_success 'verify skipping tree iteration when not collecting omits' '
 	GIT_TRACE=1 git -C r3 rev-list \
 		--objects --filter=tree:0 HEAD 2>filter_trace &&
 	grep "Skipping contents of tree [.][.][.]" filter_trace >actual &&
@@ -294,6 +294,126 @@
 	! grep "Skipping contents of tree [^.]" filter_trace
 '
 
+# Test tree:# filters.
+
+expect_has () {
+	commit=$1 &&
+	name=$2 &&
+
+	hash=$(git -C r3 rev-parse $commit:$name) &&
+	grep "^$hash $name$" actual
+}
+
+test_expect_success 'verify tree:1 includes root trees' '
+	git -C r3 rev-list --objects --filter=tree:1 HEAD >actual &&
+
+	# We should get two root directories and two commits.
+	expect_has HEAD "" &&
+	expect_has HEAD~1 ""  &&
+	test_line_count = 4 actual
+'
+
+test_expect_success 'verify tree:2 includes root trees and immediate children' '
+	git -C r3 rev-list --objects --filter=tree:2 HEAD >actual &&
+
+	expect_has HEAD "" &&
+	expect_has HEAD~1 "" &&
+	expect_has HEAD dir1 &&
+	expect_has HEAD pattern &&
+	expect_has HEAD sparse1 &&
+	expect_has HEAD sparse2 &&
+
+	# There are also 2 commit objects
+	test_line_count = 8 actual
+'
+
+test_expect_success 'verify tree:3 includes everything expected' '
+	git -C r3 rev-list --objects --filter=tree:3 HEAD >actual &&
+
+	expect_has HEAD "" &&
+	expect_has HEAD~1 "" &&
+	expect_has HEAD dir1 &&
+	expect_has HEAD dir1/sparse1 &&
+	expect_has HEAD dir1/sparse2 &&
+	expect_has HEAD pattern &&
+	expect_has HEAD sparse1 &&
+	expect_has HEAD sparse2 &&
+
+	# There are also 2 commit objects
+	test_line_count = 10 actual
+'
+
+# Test provisional omit collection logic with a repo that has objects appearing
+# at multiple depths - first deeper than the filter's threshold, then shallow.
+
+test_expect_success 'setup r4' '
+	git init r4 &&
+
+	echo foo > r4/foo &&
+	mkdir r4/subdir &&
+	echo bar > r4/subdir/bar &&
+
+	mkdir r4/filt &&
+	cp -r r4/foo r4/subdir r4/filt &&
+
+	git -C r4 add foo subdir filt &&
+	git -C r4 commit -m "commit msg"
+'
+
+expect_has_with_different_name () {
+	repo=$1 &&
+	name=$2 &&
+
+	hash=$(git -C $repo rev-parse HEAD:$name) &&
+	! grep "^$hash $name$" actual &&
+	grep "^$hash " actual &&
+	! grep "~$hash" actual
+}
+
+test_expect_success 'test tree:# filter provisional omit for blob and tree' '
+	git -C r4 rev-list --objects --filter-print-omitted --filter=tree:2 \
+		HEAD >actual &&
+	expect_has_with_different_name r4 filt/foo &&
+	expect_has_with_different_name r4 filt/subdir
+'
+
+test_expect_success 'verify skipping tree iteration when collecting omits' '
+	GIT_TRACE=1 git -C r4 rev-list --filter-print-omitted \
+		--objects --filter=tree:0 HEAD 2>filter_trace &&
+	grep "^Skipping contents of tree " filter_trace >actual &&
+
+	echo "Skipping contents of tree subdir/..." >expect &&
+	test_cmp expect actual
+'
+
+# Test tree:<depth> where a tree is iterated to twice - once where a subentry is
+# too deep to be included, and again where the blob inside it is shallow enough
+# to be included. This makes sure we don't use LOFR_MARK_SEEN incorrectly (we
+# can't use it because a tree can be iterated over again at a lower depth).
+
+test_expect_success 'tree:<depth> where we iterate over tree at two levels' '
+	git init r5 &&
+
+	mkdir -p r5/a/subdir/b &&
+	echo foo > r5/a/subdir/b/foo &&
+
+	mkdir -p r5/subdir/b &&
+	echo foo > r5/subdir/b/foo &&
+
+	git -C r5 add a subdir &&
+	git -C r5 commit -m "commit msg" &&
+
+	git -C r5 rev-list --objects --filter=tree:4 HEAD >actual &&
+	expect_has_with_different_name r5 a/subdir/b/foo
+'
+
+test_expect_success 'tree:<depth> which filters out blob but given as arg' '
+	blob_hash=$(git -C r4 rev-parse HEAD:subdir/bar) &&
+
+	git -C r4 rev-list --objects --filter=tree:1 HEAD $blob_hash >actual &&
+	grep ^$blob_hash actual
+'
+
 # Delete some loose objects and use rev-list, but WITHOUT any filtering.
 # This models previously omitted objects that we did not receive.
 
@@ -324,4 +444,21 @@
 	git -C r1 rev-list --quiet --missing=allow-any --objects HEAD
 '
 
+# Test expansion of filter specs.
+
+test_expect_success 'expand blob limit in protocol' '
+	git -C r2 config --local uploadpack.allowfilter 1 &&
+	GIT_TRACE_PACKET="$(pwd)/trace" git -c protocol.version=2 clone \
+		--filter=blob:limit=1k "file://$(pwd)/r2" limit &&
+	! grep "blob:limit=1k" trace &&
+	grep "blob:limit=1024" trace
+'
+
+test_expect_success 'expand tree depth limit in protocol' '
+	GIT_TRACE_PACKET="$(pwd)/tree_trace" git -c protocol.version=2 clone \
+		--filter=tree:0k "file://$(pwd)/r2" tree &&
+	! grep "tree:0k" tree_trace &&
+	grep "tree:0" tree_trace
+'
+
 test_done
diff --git a/t/t7505-prepare-commit-msg-hook.sh b/t/t7505-prepare-commit-msg-hook.sh
index ebfcad9..ba8bd1b 100755
--- a/t/t7505-prepare-commit-msg-hook.sh
+++ b/t/t7505-prepare-commit-msg-hook.sh
@@ -215,7 +215,7 @@
 test_rebase () {
 	expect=$1 &&
 	mode=$2 &&
-	test_expect_$expect C_LOCALE_OUTPUT "with hook (rebase $mode)" '
+	test_expect_$expect C_LOCALE_OUTPUT "with hook (rebase ${mode:--i})" '
 		test_when_finished "\
 			git rebase --abort
 			git checkout -f master
@@ -225,7 +225,7 @@
 		GIT_EDITOR="\"$FAKE_EDITOR\"" &&
 		(
 			export GIT_SEQUENCE_EDITOR GIT_EDITOR &&
-			test_must_fail git rebase $mode b &&
+			test_must_fail git rebase -i $mode b &&
 			echo x >a &&
 			git add a &&
 			test_must_fail git rebase --continue &&
@@ -241,18 +241,18 @@
 			git add b &&
 			git rebase --continue
 		) &&
-		if test $mode = -p # reword amended after pick
+		if test "$mode" = -p # reword amended after pick
 		then
 			n=18
 		else
 			n=17
 		fi &&
 		git log --pretty=%s -g -n$n HEAD@{1} >actual &&
-		test_cmp "$TEST_DIRECTORY/t7505/expected-rebase$mode" actual
+		test_cmp "$TEST_DIRECTORY/t7505/expected-rebase${mode:--i}" actual
 	'
 }
 
-test_rebase success -i
+test_rebase success
 test_have_prereq !REBASE_P || test_rebase success -p
 
 test_expect_success 'with hook (cherry-pick)' '
diff --git a/t/t9807-git-p4-submit.sh b/t/t9807-git-p4-submit.sh
index 2325599..850d979 100755
--- a/t/t9807-git-p4-submit.sh
+++ b/t/t9807-git-p4-submit.sh
@@ -500,6 +500,10 @@
 	)
 '
 
+last_shelve () {
+	p4 -G changes -s shelved -m 1 //depot/... | marshal_dump change
+}
+
 make_shelved_cl() {
 	test_commit "$1" >/dev/null &&
 	git p4 submit --origin HEAD^ --shelve >/dev/null &&
@@ -533,12 +537,59 @@
 	) &&
 	(
 		cd "$cli" &&
-		change=$(p4 -G changes -s shelved -m 1 //depot/... | \
-			 marshal_dump change) &&
+		change=$(last_shelve) &&
 		p4 unshelve -c $change -s $change &&
 		grep -q updated-line shelf.t &&
 		p4 describe -S $change | grep added-file.t &&
-		test_path_is_missing shelved-change-1.t
+		test_path_is_missing shelved-change-1.t &&
+		p4 revert ...
+	)
+'
+
+test_expect_success 'update a shelve involving moved and copied files' '
+	test_when_finished cleanup_git &&
+	(
+		cd "$cli" &&
+		: >file_to_move &&
+		p4 add file_to_move &&
+		p4 submit -d "change1" &&
+		p4 edit file_to_move &&
+		echo change >>file_to_move &&
+		p4 submit -d "change2" &&
+		p4 opened
+	) &&
+	git p4 clone --dest="$git" //depot &&
+	(
+		cd "$git" &&
+		git config git-p4.detectCopies true &&
+		git config git-p4.detectRenames true &&
+		git config git-p4.skipSubmitEdit true &&
+		mkdir moved &&
+		cp file_to_move copy_of_file &&
+		git add copy_of_file &&
+		git mv file_to_move moved/ &&
+		git commit -m "rename a file" &&
+		git p4 submit -M --shelve --origin HEAD^ &&
+		: >new_file &&
+		git add new_file &&
+		git commit --amend &&
+		git show --stat HEAD &&
+		change=$(last_shelve) &&
+		git p4 submit -M --update-shelve $change --commit HEAD
+	) &&
+	(
+		cd "$cli" &&
+		change=$(last_shelve) &&
+		echo change=$change &&
+		p4 unshelve -s $change &&
+		p4 submit -d "Testing update-shelve" &&
+		test_path_is_file copy_of_file &&
+		test_path_is_file moved/file_to_move &&
+		test_path_is_missing file_to_move &&
+		test_path_is_file new_file &&
+		echo "unshelved and submitted change $change" &&
+		p4 changes moved/file_to_move | grep "Testing update-shelve" &&
+		p4 changes copy_of_file | grep "Testing update-shelve"
 	)
 '
 
diff --git a/t/t9903-bash-prompt.sh b/t/t9903-bash-prompt.sh
index 81a5179..5cadedb 100755
--- a/t/t9903-bash-prompt.sh
+++ b/t/t9903-bash-prompt.sh
@@ -180,7 +180,7 @@
 '
 
 test_expect_success 'prompt - rebase merge' '
-	printf " (b2|REBASE-m 1/3)" >expected &&
+	printf " (b2|REBASE-i 1/3)" >expected &&
 	git checkout b2 &&
 	test_when_finished "git checkout master" &&
 	test_must_fail git rebase --merge b1 b2 &&
diff --git a/t/test-lib.sh b/t/test-lib.sh
index a1abb11..9876b4b 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1154,7 +1154,7 @@
 	error "You haven't built things yet, have you?"
 }
 
-if ! test -x "$GIT_BUILD_DIR"/t/helper/test-tool
+if ! test -x "$GIT_BUILD_DIR"/t/helper/test-tool$X
 then
 	echo >&2 'You need to build test-tool:'
 	echo >&2 'Run "make t/helper/test-tool" in the source (toplevel) directory'
diff --git a/transport-helper.c b/transport-helper.c
index 6cf3bb3..1f52c95 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -679,10 +679,15 @@
 	if (data->transport_options.update_shallow)
 		set_helper_option(transport, "update-shallow", "true");
 
-	if (data->transport_options.filter_options.choice)
-		set_helper_option(
-			transport, "filter",
-			data->transport_options.filter_options.filter_spec);
+	if (data->transport_options.filter_options.choice) {
+		struct strbuf expanded_filter_spec = STRBUF_INIT;
+		expand_list_objects_filter_spec(
+			&data->transport_options.filter_options,
+			&expanded_filter_spec);
+		set_helper_option(transport, "filter",
+				  expanded_filter_spec.buf);
+		strbuf_release(&expanded_filter_spec);
+	}
 
 	if (data->transport_options.negotiation_tips)
 		warning("Ignoring --negotiation-tip because the protocol does not support it.");
diff --git a/transport.c b/transport.c
index 9967815..e078812 100644
--- a/transport.c
+++ b/transport.c
@@ -273,7 +273,8 @@
 
 	packet_reader_init(&reader, data->fd[0], NULL, 0,
 			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
+			   PACKET_READ_GENTLE_ON_EOF |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
 
 	data->version = discover_version(&reader);
 	switch (data->version) {
diff --git a/tree-diff.c b/tree-diff.c
index 34ee3b1..e6d306f 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -239,7 +239,7 @@
 						DIFF_STATUS_ADDED;
 
 			if (tpi_valid) {
-				oid_i = tp[i].entry.oid;
+				oid_i = &tp[i].entry.oid;
 				mode_i = tp[i].entry.mode;
 			}
 			else {
@@ -280,7 +280,7 @@
 			/* same rule as in emitthis */
 			int tpi_valid = tp && !(tp[i].entry.mode & S_IFXMIN_NEQ);
 
-			parents_oid[i] = tpi_valid ? tp[i].entry.oid : NULL;
+			parents_oid[i] = tpi_valid ? &tp[i].entry.oid : NULL;
 		}
 
 		strbuf_add(base, path, pathlen);
@@ -492,7 +492,7 @@
 						continue;
 
 					/* diff(t,pi) != ø */
-					if (!oideq(t.entry.oid, tp[i].entry.oid) ||
+					if (!oideq(&t.entry.oid, &tp[i].entry.oid) ||
 					    (t.entry.mode != tp[i].entry.mode))
 						continue;
 
diff --git a/tree-walk.c b/tree-walk.c
index fb7959b..1e4bbc8 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -48,7 +48,8 @@
 	/* Initialize the descriptor entry */
 	desc->entry.path = path;
 	desc->entry.mode = canon_mode(mode);
-	desc->entry.oid  = (const struct object_id *)(path + len);
+	desc->entry.pathlen = len - 1;
+	hashcpy(desc->entry.oid.hash, (const unsigned char *)path + len);
 
 	return 0;
 }
@@ -107,7 +108,7 @@
 static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
 {
 	const void *buf = desc->buffer;
-	const unsigned char *end = desc->entry.oid->hash + the_hash_algo->rawsz;
+	const unsigned char *end = (const unsigned char *)desc->entry.path + desc->entry.pathlen + 1 + the_hash_algo->rawsz;
 	unsigned long size = desc->size;
 	unsigned long len = end - (const unsigned char *)buf;
 
@@ -175,9 +176,11 @@
 		pathlen--;
 	info->pathlen = pathlen ? pathlen + 1 : 0;
 	info->name.path = base;
-	info->name.oid = (void *)(base + pathlen + 1);
-	if (pathlen)
+	info->name.pathlen = pathlen;
+	if (pathlen) {
+		hashcpy(info->name.oid.hash, (const unsigned char *)base + pathlen + 1);
 		info->prev = &dummy;
+	}
 }
 
 char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
@@ -502,10 +505,10 @@
 	int namelen = strlen(name);
 	while (t->size) {
 		const char *entry;
-		const struct object_id *oid;
+		struct object_id oid;
 		int entrylen, cmp;
 
-		oid = tree_entry_extract(t, &entry, mode);
+		oidcpy(&oid, tree_entry_extract(t, &entry, mode));
 		entrylen = tree_entry_len(&t->entry);
 		update_tree_entry(t);
 		if (entrylen > namelen)
@@ -516,7 +519,7 @@
 		if (cmp < 0)
 			break;
 		if (entrylen == namelen) {
-			oidcpy(result, oid);
+			oidcpy(result, &oid);
 			return 0;
 		}
 		if (name[entrylen] != '/')
@@ -524,10 +527,10 @@
 		if (!S_ISDIR(*mode))
 			break;
 		if (++entrylen == namelen) {
-			oidcpy(result, oid);
+			oidcpy(result, &oid);
 			return 0;
 		}
-		return get_tree_entry(oid, name + entrylen, result, mode);
+		return get_tree_entry(&oid, name + entrylen, result, mode);
 	}
 	return -1;
 }
diff --git a/tree-walk.h b/tree-walk.h
index de6b951..8225171 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -1,12 +1,12 @@
 #ifndef TREE_WALK_H
 #define TREE_WALK_H
 
-struct index_state;
-struct strbuf;
+#include "cache.h"
 
 struct name_entry {
-	const struct object_id *oid;
+	struct object_id oid;
 	const char *path;
+	int pathlen;
 	unsigned int mode;
 };
 
@@ -20,12 +20,12 @@
 {
 	*pathp = desc->entry.path;
 	*modep = desc->entry.mode;
-	return desc->entry.oid;
+	return &desc->entry.oid;
 }
 
 static inline int tree_entry_len(const struct name_entry *ne)
 {
-	return (const char *)ne->oid - ne->path - 1;
+	return ne->pathlen;
 }
 
 /*
diff --git a/tree.c b/tree.c
index 0b5c84d..9f0457c 100644
--- a/tree.c
+++ b/tree.c
@@ -86,7 +86,7 @@
 				continue;
 		}
 
-		switch (fn(entry.oid, base,
+		switch (fn(&entry.oid, base,
 			   entry.path, entry.mode, stage, context)) {
 		case 0:
 			continue;
@@ -97,19 +97,19 @@
 		}
 
 		if (S_ISDIR(entry.mode))
-			oidcpy(&oid, entry.oid);
+			oidcpy(&oid, &entry.oid);
 		else if (S_ISGITLINK(entry.mode)) {
 			struct commit *commit;
 
-			commit = lookup_commit(r, entry.oid);
+			commit = lookup_commit(r, &entry.oid);
 			if (!commit)
 				die("Commit %s in submodule path %s%s not found",
-				    oid_to_hex(entry.oid),
+				    oid_to_hex(&entry.oid),
 				    base->buf, entry.path);
 
 			if (parse_commit(commit))
 				die("Invalid commit %s in submodule path %s%s",
-				    oid_to_hex(entry.oid),
+				    oid_to_hex(&entry.oid),
 				    base->buf, entry.path);
 
 			oidcpy(&oid, get_commit_tree_oid(commit));
diff --git a/unpack-trees.c b/unpack-trees.c
index 94265a7..01c2175 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -679,7 +679,7 @@
 
 static inline int are_same_oid(struct name_entry *name_j, struct name_entry *name_k)
 {
-	return name_j->oid && name_k->oid && oideq(name_j->oid, name_k->oid);
+	return !is_null_oid(&name_j->oid) && !is_null_oid(&name_k->oid) && oideq(&name_j->oid, &name_k->oid);
 }
 
 static int all_trees_same_as_cache_tree(int n, unsigned long dirmask,
@@ -857,7 +857,7 @@
 		else {
 			const struct object_id *oid = NULL;
 			if (dirmask & 1)
-				oid = names[i].oid;
+				oid = &names[i].oid;
 			buf[nr_buf++] = fill_tree_descriptor(t + i, oid);
 		}
 	}
@@ -981,7 +981,7 @@
 	ce->ce_mode = create_ce_mode(n->mode);
 	ce->ce_flags = create_ce_flags(stage);
 	ce->ce_namelen = len;
-	oidcpy(&ce->oid, n->oid);
+	oidcpy(&ce->oid, &n->oid);
 	make_traverse_path(ce->name, info, n);
 
 	return ce;
diff --git a/upload-pack.c b/upload-pack.c
index 5e81f1f..d098ef5 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -43,7 +43,6 @@
 
 static timestamp_t oldest_have;
 
-static int deepen_relative;
 static int multi_ack;
 static int no_done;
 static int use_thin_pack, use_ofs_delta, use_include_tag;
@@ -71,6 +70,8 @@
 static int allow_ref_in_want;
 static struct list_objects_filter_options filter_options;
 
+static int allow_sideband_all;
+
 static void reset_timeout(void)
 {
 	alarm(timeout);
@@ -140,14 +141,17 @@
 	if (use_include_tag)
 		argv_array_push(&pack_objects.args, "--include-tag");
 	if (filter_options.filter_spec) {
+		struct strbuf expanded_filter_spec = STRBUF_INIT;
+		expand_list_objects_filter_spec(&filter_options,
+						&expanded_filter_spec);
 		if (pack_objects.use_shell) {
 			struct strbuf buf = STRBUF_INIT;
-			sq_quote_buf(&buf, filter_options.filter_spec);
+			sq_quote_buf(&buf, expanded_filter_spec.buf);
 			argv_array_pushf(&pack_objects.args, "--filter=%s", buf.buf);
 			strbuf_release(&buf);
 		} else {
 			argv_array_pushf(&pack_objects.args, "--filter=%s",
-					 filter_options.filter_spec);
+					 expanded_filter_spec.buf);
 		}
 	}
 
@@ -354,7 +358,8 @@
 					    min_generation);
 }
 
-static int get_common_commits(struct object_array *have_obj,
+static int get_common_commits(struct packet_reader *reader,
+			      struct object_array *have_obj,
 			      struct object_array *want_obj)
 {
 	struct object_id oid;
@@ -366,12 +371,11 @@
 	save_commit_buffer = 0;
 
 	for (;;) {
-		char *line = packet_read_line(0, NULL);
 		const char *arg;
 
 		reset_timeout();
 
-		if (!line) {
+		if (packet_reader_read(reader) != PACKET_READ_NORMAL) {
 			if (multi_ack == 2 && got_common
 			    && !got_other && ok_to_give_up(have_obj, want_obj)) {
 				sent_ready = 1;
@@ -390,7 +394,7 @@
 			got_other = 0;
 			continue;
 		}
-		if (skip_prefix(line, "have ", &arg)) {
+		if (skip_prefix(reader->line, "have ", &arg)) {
 			switch (got_oid(arg, &oid, have_obj)) {
 			case -1: /* they have what we do not */
 				got_other = 1;
@@ -416,7 +420,7 @@
 			}
 			continue;
 		}
-		if (!strcmp(line, "done")) {
+		if (!strcmp(reader->line, "done")) {
 			if (have_obj->nr > 0) {
 				if (multi_ack)
 					packet_write_fmt(1, "ACK %s\n", last_hex);
@@ -425,7 +429,7 @@
 			packet_write_fmt(1, "NAK\n");
 			return -1;
 		}
-		die("git upload-pack: expected SHA1 list, got '%s'", line);
+		die("git upload-pack: expected SHA1 list, got '%s'", reader->line);
 	}
 }
 
@@ -613,13 +617,14 @@
 	}
 }
 
-static void send_shallow(struct commit_list *result)
+static void send_shallow(struct packet_writer *writer,
+			 struct commit_list *result)
 {
 	while (result) {
 		struct object *object = &result->item->object;
 		if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
-			packet_write_fmt(1, "shallow %s",
-					 oid_to_hex(&object->oid));
+			packet_writer_write(writer, "shallow %s",
+					    oid_to_hex(&object->oid));
 			register_shallow(the_repository, &object->oid);
 			shallow_nr++;
 		}
@@ -627,7 +632,8 @@
 	}
 }
 
-static void send_unshallow(const struct object_array *shallows,
+static void send_unshallow(struct packet_writer *writer,
+			   const struct object_array *shallows,
 			   struct object_array *want_obj)
 {
 	int i;
@@ -636,8 +642,8 @@
 		struct object *object = shallows->objects[i].item;
 		if (object->flags & NOT_SHALLOW) {
 			struct commit_list *parents;
-			packet_write_fmt(1, "unshallow %s",
-					 oid_to_hex(&object->oid));
+			packet_writer_write(writer, "unshallow %s",
+					    oid_to_hex(&object->oid));
 			object->flags &= ~CLIENT_SHALLOW;
 			/*
 			 * We want to _register_ "object" as shallow, but we
@@ -662,7 +668,9 @@
 	}
 }
 
-static void deepen(int depth, int deepen_relative,
+static int check_ref(const char *refname_full, const struct object_id *oid,
+		     int flag, void *cb_data);
+static void deepen(struct packet_writer *writer, int depth, int deepen_relative,
 		   struct object_array *shallows, struct object_array *want_obj)
 {
 	if (depth == INFINITE_DEPTH && !is_repository_shallow(the_repository)) {
@@ -676,11 +684,18 @@
 		struct object_array reachable_shallows = OBJECT_ARRAY_INIT;
 		struct commit_list *result;
 
+		/*
+		 * Checking for reachable shallows requires that our refs be
+		 * marked with OUR_REF.
+		 */
+		head_ref_namespaced(check_ref, NULL);
+		for_each_namespaced_ref(check_ref, NULL);
+
 		get_reachable_list(shallows, &reachable_shallows);
 		result = get_shallow_commits(&reachable_shallows,
 					     depth + 1,
 					     SHALLOW, NOT_SHALLOW);
-		send_shallow(result);
+		send_shallow(writer, result);
 		free_commit_list(result);
 		object_array_clear(&reachable_shallows);
 	} else {
@@ -688,14 +703,15 @@
 
 		result = get_shallow_commits(want_obj, depth,
 					     SHALLOW, NOT_SHALLOW);
-		send_shallow(result);
+		send_shallow(writer, result);
 		free_commit_list(result);
 	}
 
-	send_unshallow(shallows, want_obj);
+	send_unshallow(writer, shallows, want_obj);
 }
 
-static void deepen_by_rev_list(int ac, const char **av,
+static void deepen_by_rev_list(struct packet_writer *writer, int ac,
+			       const char **av,
 			       struct object_array *shallows,
 			       struct object_array *want_obj)
 {
@@ -703,15 +719,17 @@
 
 	close_commit_graph(the_repository);
 	result = get_shallow_commits_by_rev_list(ac, av, SHALLOW, NOT_SHALLOW);
-	send_shallow(result);
+	send_shallow(writer, result);
 	free_commit_list(result);
-	send_unshallow(shallows, want_obj);
+	send_unshallow(writer, shallows, want_obj);
 }
 
 /* Returns 1 if a shallow list is sent or 0 otherwise */
-static int send_shallow_list(int depth, int deepen_rev_list,
+static int send_shallow_list(struct packet_writer *writer,
+			     int depth, int deepen_rev_list,
 			     timestamp_t deepen_since,
 			     struct string_list *deepen_not,
+			     int deepen_relative,
 			     struct object_array *shallows,
 			     struct object_array *want_obj)
 {
@@ -720,7 +738,7 @@
 	if (depth > 0 && deepen_rev_list)
 		die("git upload-pack: deepen and deepen-since (or deepen-not) cannot be used together");
 	if (depth > 0) {
-		deepen(depth, deepen_relative, shallows, want_obj);
+		deepen(writer, depth, deepen_relative, shallows, want_obj);
 		ret = 1;
 	} else if (deepen_rev_list) {
 		struct argv_array av = ARGV_ARRAY_INIT;
@@ -741,7 +759,7 @@
 			struct object *o = want_obj->objects[i].item;
 			argv_array_push(&av, oid_to_hex(&o->oid));
 		}
-		deepen_by_rev_list(av.argc, av.argv, shallows, want_obj);
+		deepen_by_rev_list(writer, av.argc, av.argv, shallows, want_obj);
 		argv_array_clear(&av);
 		ret = 1;
 	} else {
@@ -826,7 +844,7 @@
 	return 0;
 }
 
-static void receive_needs(struct object_array *want_obj)
+static void receive_needs(struct packet_reader *reader, struct object_array *want_obj)
 {
 	struct object_array shallows = OBJECT_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
@@ -834,39 +852,41 @@
 	int has_non_tip = 0;
 	timestamp_t deepen_since = 0;
 	int deepen_rev_list = 0;
+	int deepen_relative = 0;
+	struct packet_writer writer;
 
 	shallow_nr = 0;
+	packet_writer_init(&writer, 1);
 	for (;;) {
 		struct object *o;
 		const char *features;
 		struct object_id oid_buf;
-		char *line = packet_read_line(0, NULL);
 		const char *arg;
 
 		reset_timeout();
-		if (!line)
+		if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 			break;
 
-		if (process_shallow(line, &shallows))
+		if (process_shallow(reader->line, &shallows))
 			continue;
-		if (process_deepen(line, &depth))
+		if (process_deepen(reader->line, &depth))
 			continue;
-		if (process_deepen_since(line, &deepen_since, &deepen_rev_list))
+		if (process_deepen_since(reader->line, &deepen_since, &deepen_rev_list))
 			continue;
-		if (process_deepen_not(line, &deepen_not, &deepen_rev_list))
+		if (process_deepen_not(reader->line, &deepen_not, &deepen_rev_list))
 			continue;
 
-		if (skip_prefix(line, "filter ", &arg)) {
+		if (skip_prefix(reader->line, "filter ", &arg)) {
 			if (!filter_capability_requested)
 				die("git upload-pack: filtering capability not negotiated");
 			parse_list_objects_filter(&filter_options, arg);
 			continue;
 		}
 
-		if (!skip_prefix(line, "want ", &arg) ||
+		if (!skip_prefix(reader->line, "want ", &arg) ||
 		    parse_oid_hex(arg, &oid_buf, &features))
 			die("git upload-pack: protocol error, "
-			    "expected to get object ID, not '%s'", line);
+			    "expected to get object ID, not '%s'", reader->line);
 
 		if (parse_feature_request(features, "deepen-relative"))
 			deepen_relative = 1;
@@ -893,9 +913,9 @@
 
 		o = parse_object(the_repository, &oid_buf);
 		if (!o) {
-			packet_write_fmt(1,
-					 "ERR upload-pack: not our ref %s",
-					 oid_to_hex(&oid_buf));
+			packet_writer_error(&writer,
+					    "upload-pack: not our ref %s",
+					    oid_to_hex(&oid_buf));
 			die("git upload-pack: not our ref %s",
 			    oid_to_hex(&oid_buf));
 		}
@@ -924,8 +944,9 @@
 	if (depth == 0 && !deepen_rev_list && shallows.nr == 0)
 		return;
 
-	if (send_shallow_list(depth, deepen_rev_list, deepen_since,
-			      &deepen_not, &shallows, want_obj))
+	if (send_shallow_list(&writer, depth, deepen_rev_list, deepen_since,
+			      &deepen_not, deepen_relative, &shallows,
+			      want_obj))
 		packet_flush(1);
 	object_array_clear(&shallows);
 }
@@ -1041,6 +1062,8 @@
 		allow_filter = git_config_bool(var, value);
 	} else if (!strcmp("uploadpack.allowrefinwant", var)) {
 		allow_ref_in_want = git_config_bool(var, value);
+	} else if (!strcmp("uploadpack.allowsidebandall", var)) {
+		allow_sideband_all = git_config_bool(var, value);
 	}
 
 	if (current_config_scope() != CONFIG_SCOPE_REPO) {
@@ -1055,6 +1078,7 @@
 {
 	struct string_list symref = STRING_LIST_INIT_DUP;
 	struct object_array want_obj = OBJECT_ARRAY_INIT;
+	struct packet_reader reader;
 
 	stateless_rpc = options->stateless_rpc;
 	timeout = options->timeout;
@@ -1078,10 +1102,14 @@
 	if (options->advertise_refs)
 		return;
 
-	receive_needs(&want_obj);
+	packet_reader_init(&reader, 0, NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+
+	receive_needs(&reader, &want_obj);
 	if (want_obj.nr) {
 		struct object_array have_obj = OBJECT_ARRAY_INIT;
-		get_common_commits(&have_obj, &want_obj);
+		get_common_commits(&reader, &have_obj, &want_obj);
 		create_pack_file(&have_obj, &want_obj);
 	}
 }
@@ -1098,6 +1126,8 @@
 	int deepen_rev_list;
 	int deepen_relative;
 
+	struct packet_writer writer;
+
 	unsigned stateless_rpc : 1;
 
 	unsigned use_thin_pack : 1;
@@ -1121,6 +1151,7 @@
 	data->haves = haves;
 	data->shallows = shallows;
 	data->deepen_not = deepen_not;
+	packet_writer_init(&data->writer, 1);
 }
 
 static void upload_pack_data_clear(struct upload_pack_data *data)
@@ -1132,7 +1163,8 @@
 	string_list_clear(&data->deepen_not, 0);
 }
 
-static int parse_want(const char *line, struct object_array *want_obj)
+static int parse_want(struct packet_writer *writer, const char *line,
+		      struct object_array *want_obj)
 {
 	const char *arg;
 	if (skip_prefix(line, "want ", &arg)) {
@@ -1145,9 +1177,9 @@
 
 		o = parse_object(the_repository, &oid);
 		if (!o) {
-			packet_write_fmt(1,
-					 "ERR upload-pack: not our ref %s",
-					 oid_to_hex(&oid));
+			packet_writer_error(writer,
+					    "upload-pack: not our ref %s",
+					    oid_to_hex(&oid));
 			die("git upload-pack: not our ref %s",
 			    oid_to_hex(&oid));
 		}
@@ -1163,7 +1195,8 @@
 	return 0;
 }
 
-static int parse_want_ref(const char *line, struct string_list *wanted_refs,
+static int parse_want_ref(struct packet_writer *writer, const char *line,
+			  struct string_list *wanted_refs,
 			  struct object_array *want_obj)
 {
 	const char *arg;
@@ -1173,7 +1206,7 @@
 		struct object *o;
 
 		if (read_ref(arg, &oid)) {
-			packet_write_fmt(1, "ERR unknown ref %s", arg);
+			packet_writer_error(writer, "unknown ref %s", arg);
 			die("unknown ref %s", arg);
 		}
 
@@ -1216,10 +1249,11 @@
 		const char *p;
 
 		/* process want */
-		if (parse_want(arg, want_obj))
+		if (parse_want(&data->writer, arg, want_obj))
 			continue;
 		if (allow_ref_in_want &&
-		    parse_want_ref(arg, &data->wanted_refs, want_obj))
+		    parse_want_ref(&data->writer, arg, &data->wanted_refs,
+				   want_obj))
 			continue;
 		/* process have line */
 		if (parse_have(arg, &data->haves))
@@ -1268,6 +1302,13 @@
 			continue;
 		}
 
+		if ((git_env_bool("GIT_TEST_SIDEBAND_ALL", 0) ||
+		     allow_sideband_all) &&
+		    !strcmp(arg, "sideband-all")) {
+			data->writer.use_sideband = 1;
+			continue;
+		}
+
 		/* ignore unknown lines maybe? */
 		die("unexpected line: '%s'", arg);
 	}
@@ -1313,26 +1354,26 @@
 	return 0;
 }
 
-static int send_acks(struct oid_array *acks, struct strbuf *response,
+static int send_acks(struct packet_writer *writer, struct oid_array *acks,
 		     const struct object_array *have_obj,
 		     struct object_array *want_obj)
 {
 	int i;
 
-	packet_buf_write(response, "acknowledgments\n");
+	packet_writer_write(writer, "acknowledgments\n");
 
 	/* Send Acks */
 	if (!acks->nr)
-		packet_buf_write(response, "NAK\n");
+		packet_writer_write(writer, "NAK\n");
 
 	for (i = 0; i < acks->nr; i++) {
-		packet_buf_write(response, "ACK %s\n",
-				 oid_to_hex(&acks->oid[i]));
+		packet_writer_write(writer, "ACK %s\n",
+				    oid_to_hex(&acks->oid[i]));
 	}
 
 	if (ok_to_give_up(have_obj, want_obj)) {
 		/* Send Ready */
-		packet_buf_write(response, "ready\n");
+		packet_writer_write(writer, "ready\n");
 		return 1;
 	}
 
@@ -1344,25 +1385,20 @@
 				       struct object_array *want_obj)
 {
 	struct oid_array common = OID_ARRAY_INIT;
-	struct strbuf response = STRBUF_INIT;
 	int ret = 0;
 
 	process_haves(&data->haves, &common, have_obj);
 	if (data->done) {
 		ret = 1;
-	} else if (send_acks(&common, &response, have_obj, want_obj)) {
-		packet_buf_delim(&response);
+	} else if (send_acks(&data->writer, &common, have_obj, want_obj)) {
+		packet_writer_delim(&data->writer);
 		ret = 1;
 	} else {
 		/* Add Flush */
-		packet_buf_flush(&response);
+		packet_writer_flush(&data->writer);
 		ret = 0;
 	}
 
-	/* Send response */
-	write_or_die(1, response.buf, response.len);
-	strbuf_release(&response);
-
 	oid_array_clear(&data->haves);
 	oid_array_clear(&common);
 	return ret;
@@ -1375,15 +1411,15 @@
 	if (!data->wanted_refs.nr)
 		return;
 
-	packet_write_fmt(1, "wanted-refs\n");
+	packet_writer_write(&data->writer, "wanted-refs\n");
 
 	for_each_string_list_item(item, &data->wanted_refs) {
-		packet_write_fmt(1, "%s %s\n",
-				 oid_to_hex(item->util),
-				 item->string);
+		packet_writer_write(&data->writer, "%s %s\n",
+				    oid_to_hex(item->util),
+				    item->string);
 	}
 
-	packet_delim(1);
+	packet_writer_delim(&data->writer);
 }
 
 static void send_shallow_info(struct upload_pack_data *data,
@@ -1394,14 +1430,16 @@
 	    !is_repository_shallow(the_repository))
 		return;
 
-	packet_write_fmt(1, "shallow-info\n");
+	packet_writer_write(&data->writer, "shallow-info\n");
 
-	if (!send_shallow_list(data->depth, data->deepen_rev_list,
+	if (!send_shallow_list(&data->writer, data->depth,
+			       data->deepen_rev_list,
 			       data->deepen_since, &data->deepen_not,
+			       data->deepen_relative,
 			       &data->shallows, want_obj) &&
 	    is_repository_shallow(the_repository))
-		deepen(INFINITE_DEPTH, data->deepen_relative, &data->shallows,
-		       want_obj);
+		deepen(&data->writer, INFINITE_DEPTH, data->deepen_relative,
+		       &data->shallows, want_obj);
 
 	packet_delim(1);
 }
@@ -1463,7 +1501,7 @@
 			send_wanted_ref_info(&data);
 			send_shallow_info(&data, &want_obj);
 
-			packet_write_fmt(1, "packfile\n");
+			packet_writer_write(&data.writer, "packfile\n");
 			create_pack_file(&have_obj, &want_obj);
 			state = FETCH_DONE;
 			break;
@@ -1484,6 +1522,7 @@
 	if (value) {
 		int allow_filter_value;
 		int allow_ref_in_want;
+		int allow_sideband_all_value;
 
 		strbuf_addstr(value, "shallow");
 
@@ -1498,6 +1537,13 @@
 					 &allow_ref_in_want) &&
 		    allow_ref_in_want)
 			strbuf_addstr(value, " ref-in-want");
+
+		if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 0) ||
+		    (!repo_config_get_bool(the_repository,
+					   "uploadpack.allowsidebandall",
+					   &allow_sideband_all_value) &&
+		     allow_sideband_all_value))
+			strbuf_addstr(value, " sideband-all");
 	}
 
 	return 1;
diff --git a/walker.c b/walker.c
index 96990d8..d74ae59 100644
--- a/walker.c
+++ b/walker.c
@@ -50,13 +50,13 @@
 			continue;
 		if (S_ISDIR(entry.mode)) {
 			struct tree *tree = lookup_tree(the_repository,
-							entry.oid);
+							&entry.oid);
 			if (tree)
 				obj = &tree->object;
 		}
 		else {
 			struct blob *blob = lookup_blob(the_repository,
-							entry.oid);
+							&entry.oid);
 			if (blob)
 				obj = &blob->object;
 		}