diff --git a/.mailmap b/.mailmap
index eb7b5fc..247a3de 100644
--- a/.mailmap
+++ b/.mailmap
@@ -27,6 +27,7 @@
 Benoit Sigoure <tsunanet@gmail.com> <tsuna@lrde.epita.fr>
 Bernt Hansen <bernt@norang.ca> <bernt@alumni.uwaterloo.ca>
 Brandon Casey <drafnel@gmail.com> <casey@nrlssc.navy.mil>
+Brandon Williams <bwilliams.eng@gmail.com> <bmwill@google.com>
 brian m. carlson <sandals@crustytoothpaste.net>
 brian m. carlson <sandals@crustytoothpaste.net> <sandals@crustytoothpaste.ath.cx>
 Bryan Larsen <bryan@larsen.st> <bryan.larsen@gmail.com>
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 8a5e53b..ea78e22 100644
--- a/Documentation/RelNotes/2.21.0.txt
+++ b/Documentation/RelNotes/2.21.0.txt
@@ -24,6 +24,33 @@
    object into account (e.g. a tag object would want to go under
    refs/tags/).
 
+ * "git checkout [<tree-ish>] path..." learned to report the number of
+   paths that have been checked out of the index or the tree-ish,
+   which gives it the same degree of noisy-ness as the case in which
+   the command checks out a branch.
+
+ * "git quiltimport" learned "--keep-non-patch" option.
+
+ * "git worktree remove" and "git worktree move" refused to work when
+   there is a submodule involved.  This has been loosened to ignore
+   uninitialized submodules.
+
+ * "git cherry-pick -m1" was forbidden when picking a non-merge
+   commit, even though there _is_ parent number 1 for such a commit.
+   This was done to avoid mistakes back when "cherry-pick" was about
+   picking a single commit, but is no longer useful with "cherry-pick"
+   that can pick a range of commits.  Now the "-m$num" option is
+   allowed when picking any commit, as long as $num names an existing
+   parent of the commit.
+
+ * Update "git multimail" from the upstream.
+
+ * "git p4" update.
+
+ * The "--format=<placeholder>" option of for-each-ref, branch and tag
+   learned to show a few more traits of objects that can be learned by
+   the object_info API.
+
 
 Performance, Internal Implementation, Development Support etc.
 
@@ -33,6 +60,23 @@
  * More codepaths become aware of working with in-core repository
    instance other than the default "the_repository".
 
+ * The "strncat()" function is now among the banned functions.
+
+ * Portability updates for the HPE NonStop platform.
+
+ * Earlier we added "-Wformat-security" to developer builds, assuming
+   that "-Wall" (which includes "-Wformat" which in turn is required
+   to use "-Wformat-security") is always in effect.  This is not true
+   when config.mak.autogen is in use, unfortunately.  This has been
+   fixed by unconditionally adding "-Wall" to developer builds.
+
+ * The loose object cache used to optimize existence look-up has been
+   updated.
+
+ * Flaky tests can now be repeatedly run under load with the
+   "--stress" option.
+   (merge fb7d1e3ac8 sg/stress-test later to maint).
+
 
 Fixes since v2.20
 -----------------
@@ -63,4 +107,82 @@
    which has been corrected.
    (merge 02818a98d7 mk/http-backend-kill-children-before-exit later to maint).
 
+ * "git rev-list --exclude-promisor-objects" had to take an object
+   that does not exist locally (and is lazily available) from the
+   command line without barfing, but the code dereferenced NULL.
+   (merge 4cf67869b2 md/list-lazy-objects-fix later to maint).
+
+ * The traversal over tree objects has learned to honor
+   ":(attr:label)" pathspec match, which has been implemented only for
+   enumerating paths on the filesystem.
+   (merge 5a0b97b34c nd/attr-pathspec-in-tree-walk later to maint).
+
+ * BSD port updates.
+   (merge 4e3ecbd439 cb/openbsd-allows-reading-directory later to maint).
+   (merge b6bdc2a0f5 cb/t5004-empty-tar-archive-fix later to maint).
+   (merge 82cbc8cde2 cb/test-lint-cp-a later to maint).
+
+ * Lines that begin with a certain keyword that come over the wire, as
+   well as lines that consist only of one of these keywords, ought to
+   be painted in color for easier eyeballing, but the latter was
+   broken ever since the feature was introduced in 2.19, which has
+   been corrected.
+   (merge 1f67290450 hn/highlight-sideband-keywords later to maint).
+
+ * "git log -G<regex>" looked for a hunk in the "git log -p" patch
+   output that contained a string that matches the given pattern.
+   Optimize this code to ignore binary files, which by default will
+   not show any hunk that would match any pattern (unless textconv or
+   the --text option is in effect, that is).
+   (merge e0e7cb8080 tb/log-G-binary later to maint).
+
+ * "git submodule update" ought to use a single job unless asked, but
+   by mistake used multiple jobs, which has been fixed.
+   (merge e3a9d1aca9 sb/submodule-fetchjobs-default-to-one later to maint).
+
+ * "git stripspace" should be usable outside a git repository, but
+   under the "-s" or "-c" mode, it didn't.
+   (merge 957da75802 jn/stripspace-wo-repository later to maint).
+
+ * Some of the documentation pages formatted incorrectly with
+   Asciidoctor, which have been fixed.
+   (merge b62eb1d2f4 ma/asciidoctor later to maint).
+
+ * The core.worktree setting in a submodule repository should not be
+   pointing at a directory when the submodule loses its working tree
+   (e.g. getting deinit'ed), but the code did not properly maintain
+   this invariant.
+
+ * With zsh, "git cmd path<TAB>" was completed to "git cmd path name"
+   when the completed path has a special character like SP in it,
+   without any attempt to keep "path name" a single filename.  This
+   has been fixed to complete it to "git cmd path\ name" just like
+   Bash completion does.
+
+ * The test suite tried to see if it is run under bash, but the check
+   itself failed under some other implementations of shell (notably
+   under NetBSD).  This has been corrected.
+   (merge 54ea72f09c sg/test-bash-version-fix later to maint).
+
+ * "git gc" and "git repack" did not close the open packfiles that
+   they found unneeded before removing them, which didn't work on a
+   platform incapable of removing an open file.  This has been
+   corrected.
+   (merge 5bdece0d70 js/gc-repack-close-before-remove 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).
+   (merge a8f5a59067 en/directory-renames-nothanks-doc-update later to maint).
+   (merge ec36c42a63 nd/indentation-fix later to maint).
+   (merge f116ee21cd do/gitweb-strict-export-conf-doc later to maint).
+   (merge 112ea42663 fd/gitweb-snapshot-conf-doc-fix later to maint).
+   (merge 1cadad6f65 tb/use-common-win32-pathfuncs-on-cygwin later to maint).
+   (merge 57e9dcaa65 km/rebase-doc-typofix later to maint).
+   (merge b8b4cb27e6 ds/gc-doc-typofix later to maint).
+   (merge 3b3357626e nd/style-opening-brace later to maint).
+   (merge b4583d5595 es/doc-worktree-guessremote-config later to maint).
+   (merge cce99cd8c6 ds/commit-graph-assert-missing-parents later to maint).
+   (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).
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/config/worktree.txt b/Documentation/config/worktree.txt
index b853798..048e349 100644
--- a/Documentation/config/worktree.txt
+++ b/Documentation/config/worktree.txt
@@ -1,6 +1,6 @@
 worktree.guessRemote::
-	With `add`, if no branch argument, and neither of `-b` nor
-	`-B` nor `--detach` are given, the command defaults to
+	If no branch is specified and neither `-b` nor `-B` nor
+	`--detach` is used, then `git worktree add` defaults to
 	creating a new branch from HEAD.  If `worktree.guessRemote` is
 	set to true, `worktree add` tries to find a remote-tracking
 	branch whose name uniquely matches the new branch name.  If
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 0378cd5..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
@@ -524,6 +535,8 @@
 came into being: use the feature iteratively to feed the interesting
 block in the preimage back into `-S`, and keep going until you get the
 very first version of the block.
++
+Binary files are searched as well.
 
 -G<regex>::
 	Look for differences whose patch text contains added/removed
@@ -543,6 +556,9 @@
 -S"regexec\(regexp" --pickaxe-regex` will not (because the number of
 occurrences of that string did not change).
 +
+Unless `--text` is supplied patches of binary files without a textconv
+filter will be ignored.
++
 See the 'pickaxe' entry in linkgit:gitdiffcore[7] for more
 information.
 
diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
index 7401333..9a2e9cd 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-column.txt b/Documentation/git-column.txt
index 763afab..f58e9c4 100644
--- a/Documentation/git-column.txt
+++ b/Documentation/git-column.txt
@@ -47,7 +47,7 @@
 	The number of spaces between columns. One space by default.
 
 EXAMPLES
-------
+--------
 
 Format data by columns:
 ------------
diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index 901faef..774cecc 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -128,13 +128,18 @@
 
 objectsize::
 	The size of the object (the same as 'git cat-file -s' reports).
-
+	Append `:disk` to get the size, in bytes, that the object takes up on
+	disk. See the note about on-disk sizes in the `CAVEATS` section below.
 objectname::
 	The object name (aka SHA-1).
 	For a non-ambiguous abbreviation of the object name append `:short`.
 	For an abbreviation of the object name with desired length append
 	`:short=<length>`, where the minimum length is MINIMUM_ABBREV. The
 	length may be exceeded to ensure unique object names.
+deltabase::
+	This expands to the object name of the delta base for the
+	given object, if it is stored as a delta.  Otherwise it
+	expands to the null object name (all zeroes).
 
 upstream::
 	The name of a local ref which can be considered ``upstream''
@@ -361,6 +366,20 @@
 git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
 ------------
 
+CAVEATS
+-------
+
+Note that the sizes of objects on disk are reported accurately, but care
+should be taken in drawing conclusions about which refs or objects are
+responsible for disk usage. The size of a packed non-delta object may be
+much larger than the size of objects which delta against it, but the
+choice of which object is the base and which is the delta is arbitrary
+and is subject to change during a repack.
+
+Note also that multiple copies of an object may be present in the object
+database; in this case, it is undefined which copy's size or delta base
+will be reported.
+
 SEE ALSO
 --------
 linkgit:git-show-ref[1]
diff --git a/Documentation/git-gc.txt b/Documentation/git-gc.txt
index c20ee6c..a744249 100644
--- a/Documentation/git-gc.txt
+++ b/Documentation/git-gc.txt
@@ -137,7 +137,7 @@
 it within all non-bare repos or it can be set to a boolean value.
 This defaults to true.
 
-The optional configuration variable `gc.commitGraph` determines if
+The optional configuration variable `gc.writeCommitGraph` determines if
 'git gc' should run 'git commit-graph write'. This can be set to a
 boolean value. This defaults to false.
 
diff --git a/Documentation/git-init.txt b/Documentation/git-init.txt
index 3c5a67f..057076c 100644
--- a/Documentation/git-init.txt
+++ b/Documentation/git-init.txt
@@ -38,8 +38,6 @@
 OPTIONS
 -------
 
---
-
 -q::
 --quiet::
 
@@ -111,8 +109,6 @@
 If you provide a 'directory', the command is run inside it. If this directory
 does not exist, it will be created.
 
---
-
 TEMPLATE DIRECTORY
 ------------------
 
diff --git a/Documentation/git-quiltimport.txt b/Documentation/git-quiltimport.txt
index 8cf952b..70562dc 100644
--- a/Documentation/git-quiltimport.txt
+++ b/Documentation/git-quiltimport.txt
@@ -10,7 +10,7 @@
 --------
 [verse]
 'git quiltimport' [--dry-run | -n] [--author <author>] [--patches <dir>]
-		[--series <file>]
+		[--series <file>] [--keep-non-patch]
 
 
 DESCRIPTION
@@ -56,6 +56,9 @@
 or the value of the `$QUILT_SERIES` environment
 variable.
 
+--keep-non-patch::
+	Pass `-b` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index dff17b3..4dd5853 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
@@ -501,6 +507,11 @@
 	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
 --------------------
 
@@ -570,8 +581,9 @@
 Directory rename detection
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-The merge and interactive backends work fine with
-directory rename detection.  The am backend sometimes does not.
+Directory rename heuristics are enabled in the merge and interactive
+backends.  Due to the lack of accurate tree information, directory
+rename detection is disabled in the am backend.
 
 include::merge-strategies.txt[]
 
@@ -979,7 +991,7 @@
 
 At this time, the `merge` command will *always* use the `recursive`
 merge strategy for regular merges, and `octopus` for octopus merges,
-strategy, with no way to choose a different one. To work around
+with no way to choose a different one. To work around
 this, an `exec` command can be used to call `git merge` explicitly,
 using the fact that the labels are worktree-local refs (the ref
 `refs/rewritten/onto` would correspond to the label `onto`, for example).
diff --git a/Documentation/git-show-ref.txt b/Documentation/git-show-ref.txt
index d28e615..ab4d271 100644
--- a/Documentation/git-show-ref.txt
+++ b/Documentation/git-show-ref.txt
@@ -37,8 +37,8 @@
 
 	Show the HEAD reference, even if it would normally be filtered out.
 
---tags::
 --heads::
+--tags::
 
 	Limit to "refs/heads" and "refs/tags", respectively.  These options
 	are not mutually exclusive; when given both, references stored in
diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index d9f422d..861d821 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt
@@ -197,31 +197,33 @@
 Ignored files are not listed, unless `--ignored` option is in effect,
 in which case `XY` are `!!`.
 
-    X          Y     Meaning
-    -------------------------------------------------
-	     [AMD]   not updated
-    M        [ MD]   updated in index
-    A        [ MD]   added to index
-    D                deleted from index
-    R        [ MD]   renamed in index
-    C        [ MD]   copied in index
-    [MARC]           index and work tree matches
-    [ MARC]     M    work tree changed since index
-    [ MARC]     D    deleted in work tree
-    [ D]        R    renamed in work tree
-    [ D]        C    copied in work tree
-    -------------------------------------------------
-    D           D    unmerged, both deleted
-    A           U    unmerged, added by us
-    U           D    unmerged, deleted by them
-    U           A    unmerged, added by them
-    D           U    unmerged, deleted by us
-    A           A    unmerged, both added
-    U           U    unmerged, both modified
-    -------------------------------------------------
-    ?           ?    untracked
-    !           !    ignored
-    -------------------------------------------------
+....
+X          Y     Meaning
+-------------------------------------------------
+	 [AMD]   not updated
+M        [ MD]   updated in index
+A        [ MD]   added to index
+D                deleted from index
+R        [ MD]   renamed in index
+C        [ MD]   copied in index
+[MARC]           index and work tree matches
+[ MARC]     M    work tree changed since index
+[ MARC]     D    deleted in work tree
+[ D]        R    renamed in work tree
+[ D]        C    copied in work tree
+-------------------------------------------------
+D           D    unmerged, both deleted
+A           U    unmerged, added by us
+U           D    unmerged, deleted by them
+U           A    unmerged, added by them
+D           U    unmerged, deleted by us
+A           A    unmerged, both added
+U           U    unmerged, both modified
+-------------------------------------------------
+?           ?    untracked
+!           !    ignored
+-------------------------------------------------
+....
 
 Submodules have more state and instead report
 		M    the submodule has a different HEAD than
@@ -281,14 +283,16 @@
 If `--branch` is given, a series of header lines are printed with
 information about the current branch.
 
-    Line                                     Notes
-    ------------------------------------------------------------
-    # branch.oid <commit> | (initial)        Current commit.
-    # branch.head <branch> | (detached)      Current branch.
-    # branch.upstream <upstream_branch>      If upstream is set.
-    # branch.ab +<ahead> -<behind>           If upstream is set and
-					     the commit is present.
-    ------------------------------------------------------------
+....
+Line                                     Notes
+------------------------------------------------------------
+# branch.oid <commit> | (initial)        Current commit.
+# branch.head <branch> | (detached)      Current branch.
+# branch.upstream <upstream_branch>      If upstream is set.
+# branch.ab +<ahead> -<behind>           If upstream is set and
+					 the commit is present.
+------------------------------------------------------------
+....
 
 ### Changed Tracked Entries
 
@@ -306,56 +310,60 @@
 
     2 <XY> <sub> <mH> <mI> <mW> <hH> <hI> <X><score> <path><sep><origPath>
 
-    Field       Meaning
-    --------------------------------------------------------
-    <XY>        A 2 character field containing the staged and
-		unstaged XY values described in the short format,
-		with unchanged indicated by a "." rather than
-		a space.
-    <sub>       A 4 character field describing the submodule state.
-		"N..." when the entry is not a submodule.
-		"S<c><m><u>" when the entry is a submodule.
-		<c> is "C" if the commit changed; otherwise ".".
-		<m> is "M" if it has tracked changes; otherwise ".".
-		<u> is "U" if there are untracked changes; otherwise ".".
-    <mH>        The octal file mode in HEAD.
-    <mI>        The octal file mode in the index.
-    <mW>        The octal file mode in the worktree.
-    <hH>        The object name in HEAD.
-    <hI>        The object name in the index.
-    <X><score>  The rename or copy score (denoting the percentage
-		of similarity between the source and target of the
-		move or copy). For example "R100" or "C75".
-    <path>      The pathname.  In a renamed/copied entry, this
-		is the target path.
-    <sep>       When the `-z` option is used, the 2 pathnames are separated
-		with a NUL (ASCII 0x00) byte; otherwise, a tab (ASCII 0x09)
-		byte separates them.
-    <origPath>  The pathname in the commit at HEAD or in the index.
-		This is only present in a renamed/copied entry, and
-		tells where the renamed/copied contents came from.
-    --------------------------------------------------------
+....
+Field       Meaning
+--------------------------------------------------------
+<XY>        A 2 character field containing the staged and
+	    unstaged XY values described in the short format,
+	    with unchanged indicated by a "." rather than
+	    a space.
+<sub>       A 4 character field describing the submodule state.
+	    "N..." when the entry is not a submodule.
+	    "S<c><m><u>" when the entry is a submodule.
+	    <c> is "C" if the commit changed; otherwise ".".
+	    <m> is "M" if it has tracked changes; otherwise ".".
+	    <u> is "U" if there are untracked changes; otherwise ".".
+<mH>        The octal file mode in HEAD.
+<mI>        The octal file mode in the index.
+<mW>        The octal file mode in the worktree.
+<hH>        The object name in HEAD.
+<hI>        The object name in the index.
+<X><score>  The rename or copy score (denoting the percentage
+	    of similarity between the source and target of the
+	    move or copy). For example "R100" or "C75".
+<path>      The pathname.  In a renamed/copied entry, this
+	    is the target path.
+<sep>       When the `-z` option is used, the 2 pathnames are separated
+	    with a NUL (ASCII 0x00) byte; otherwise, a tab (ASCII 0x09)
+	    byte separates them.
+<origPath>  The pathname in the commit at HEAD or in the index.
+	    This is only present in a renamed/copied entry, and
+	    tells where the renamed/copied contents came from.
+--------------------------------------------------------
+....
 
 Unmerged entries have the following format; the first character is
 a "u" to distinguish from ordinary changed entries.
 
     u <xy> <sub> <m1> <m2> <m3> <mW> <h1> <h2> <h3> <path>
 
-    Field       Meaning
-    --------------------------------------------------------
-    <XY>        A 2 character field describing the conflict type
-		as described in the short format.
-    <sub>       A 4 character field describing the submodule state
-		as described above.
-    <m1>        The octal file mode in stage 1.
-    <m2>        The octal file mode in stage 2.
-    <m3>        The octal file mode in stage 3.
-    <mW>        The octal file mode in the worktree.
-    <h1>        The object name in stage 1.
-    <h2>        The object name in stage 2.
-    <h3>        The object name in stage 3.
-    <path>      The pathname.
-    --------------------------------------------------------
+....
+Field       Meaning
+--------------------------------------------------------
+<XY>        A 2 character field describing the conflict type
+	    as described in the short format.
+<sub>       A 4 character field describing the submodule state
+	    as described above.
+<m1>        The octal file mode in stage 1.
+<m2>        The octal file mode in stage 2.
+<m3>        The octal file mode in stage 3.
+<mW>        The octal file mode in the worktree.
+<h1>        The object name in stage 1.
+<h2>        The object name in stage 2.
+<h3>        The object name in stage 3.
+<path>      The pathname.
+--------------------------------------------------------
+....
 
 ### Other Items
 
diff --git a/Documentation/gitdiffcore.txt b/Documentation/gitdiffcore.txt
index c0a60f3..c970d9f 100644
--- a/Documentation/gitdiffcore.txt
+++ b/Documentation/gitdiffcore.txt
@@ -242,7 +242,8 @@
 regular expression.  This means that it will detect in-file (or what
 rename-detection considers the same file) moves, which is noise.  The
 implementation runs diff twice and greps, and this can be quite
-expensive.
+expensive.  To speed things up binary files without textconv filters
+will be ignored.
 
 When `-S` or `-G` are used without `--pickaxe-all`, only filepairs
 that match their respective criterion are kept in the output.  When
diff --git a/Documentation/gitweb.conf.txt b/Documentation/gitweb.conf.txt
index c0a326e..92535db 100644
--- a/Documentation/gitweb.conf.txt
+++ b/Documentation/gitweb.conf.txt
@@ -207,8 +207,8 @@
 
 $strict_export::
 	Only allow viewing of repositories also shown on the overview page.
-	This for example makes `$gitweb_export_ok` file decide if repository is
-	available and not only if it is shown.  If `$gitweb_list` points to
+	This for example makes `$export_ok` file decide if repository is
+	available and not only if it is shown.  If `$projects_list` points to
 	file with list of project, only those repositories listed would be
 	available for gitweb.  Can be set during building gitweb via
 	`GITWEB_STRICT_EXPORT`.  By default this variable is not set, which
@@ -684,7 +684,7 @@
 a definitive list.  By default only "tgz" is offered.
 +
 This feature can be configured on a per-repository basis via
-repository's `gitweb.blame` configuration variable, which contains
+repository's `gitweb.snapshot` configuration variable, which contains
 a comma separated list of formats or "none" to disable snapshots.
 Unknown values are ignored.
 
diff --git a/Documentation/glossary-content.txt b/Documentation/glossary-content.txt
index 0d2aa48..023ca95 100644
--- a/Documentation/glossary-content.txt
+++ b/Documentation/glossary-content.txt
@@ -404,6 +404,8 @@
 - "`!ATTR`" requires that the attribute `ATTR` be
   unspecified.
 +
+Note that when matching against a tree object, attributes are still
+obtained from working tree, not from the given tree object.
 
 exclude;;
 	After a path matches any non-exclude pathspec, it will be run
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index bab5f50..98b538b 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -13,8 +13,6 @@
 Note that these are applied before commit
 ordering and formatting options, such as `--reverse`.
 
---
-
 -<number>::
 -n <number>::
 --max-count=<number>::
@@ -308,8 +306,6 @@
 	`<header>` text will be printed with each progress update.
 endif::git-rev-list[]
 
---
-
 History Simplification
 ~~~~~~~~~~~~~~~~~~~~~~
 
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/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/Makefile b/Makefile
index 1a44c81..6e8d017 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).
@@ -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)"
diff --git a/apply.c b/apply.c
index 01793d6..3703bfc 100644
--- a/apply.c
+++ b/apply.c
@@ -3352,7 +3352,8 @@
 
 	costate.refresh_cache = 1;
 	costate.istate = istate;
-	if (checkout_entry(ce, &costate, NULL) || lstat(ce->name, st))
+	if (checkout_entry(ce, &costate, NULL, NULL) ||
+	    lstat(ce->name, st))
 		return error(_("cannot checkout %s"), ce->name);
 	return 0;
 }
diff --git a/archive-tar.c b/archive-tar.c
index a58e1a8..4aabd56 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -142,7 +142,7 @@
  * string and appends it to a struct strbuf.
  */
 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
-                                     const char *value, unsigned int valuelen)
+				     const char *value, unsigned int valuelen)
 {
 	int len, tmp;
 
diff --git a/archive.c b/archive.c
index 180d97c..1f98324 100644
--- a/archive.c
+++ b/archive.c
@@ -36,8 +36,8 @@
 }
 
 static void format_subst(const struct commit *commit,
-                         const char *src, size_t len,
-                         struct strbuf *buf)
+			 const char *src, size_t len,
+			 struct strbuf *buf)
 {
 	char *to_free = NULL;
 	struct strbuf fmt = STRBUF_INIT;
@@ -285,7 +285,8 @@
 		git_attr_set_direction(GIT_ATTR_INDEX);
 	}
 
-	err = read_tree_recursive(args->tree, "", 0, 0, &args->pathspec,
+	err = read_tree_recursive(args->repo, args->tree, "",
+				  0, 0, &args->pathspec,
 				  queue_or_write_archive_entry,
 				  &context);
 	if (err == READ_TREE_RECURSIVE)
@@ -346,7 +347,8 @@
 	ctx.args = args;
 	parse_pathspec(&ctx.pathspec, 0, 0, "", paths);
 	ctx.pathspec.recursive = 1;
-	ret = read_tree_recursive(args->tree, "", 0, 0, &ctx.pathspec,
+	ret = read_tree_recursive(args->repo, args->tree, "",
+				  0, 0, &ctx.pathspec,
 				  reject_entry, &ctx);
 	clear_pathspec(&ctx.pathspec);
 	return ret != 0;
diff --git a/banned.h b/banned.h
index 28f5937..447af24 100644
--- a/banned.h
+++ b/banned.h
@@ -16,6 +16,8 @@
 #define strcat(x,y) BANNED(strcat)
 #undef strncpy
 #define strncpy(x,y,n) BANNED(strncpy)
+#undef strncat
+#define strncat(x,y,n) BANNED(strncat)
 
 #undef sprintf
 #undef vsprintf
diff --git a/bisect.c b/bisect.c
index 4c1b80b..6bf5211 100644
--- a/bisect.c
+++ b/bisect.c
@@ -558,7 +558,8 @@
  * is increased by one between each call, but that should not matter
  * for this application.
  */
-static unsigned get_prn(unsigned count) {
+static unsigned get_prn(unsigned count)
+{
 	count = count * 1103515245 + 12345;
 	return (count/65536) % PRN_MODULO;
 }
diff --git a/builtin/add.c b/builtin/add.c
index f65c172..d461ba0 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -176,7 +176,7 @@
 			die(_("pathspec '%s' did not match any files"),
 			    pathspec->items[i].match);
 	}
-        free(seen);
+	free(seen);
 }
 
 int run_add_interactive(const char *revision, const char *patch_mode,
@@ -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/checkout-index.c b/builtin/checkout-index.c
index eb74774..a2a726a 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -67,7 +67,8 @@
 			continue;
 		did_checkout = 1;
 		if (checkout_entry(ce, &state,
-		    to_tempfile ? topath[ce_stage(ce)] : NULL) < 0)
+				   to_tempfile ? topath[ce_stage(ce)] : NULL,
+				   NULL) < 0)
 			errs++;
 	}
 
@@ -111,7 +112,8 @@
 				write_tempfile_record(last_ce->name, prefix);
 		}
 		if (checkout_entry(ce, &state,
-		    to_tempfile ? topath[ce_stage(ce)] : NULL) < 0)
+				   to_tempfile ? topath[ce_stage(ce)] : NULL,
+				   NULL) < 0)
 			errs++;
 		last_ce = ce;
 	}
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 08b0ac4..6fadf41 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -44,6 +44,7 @@
 	int ignore_skipworktree;
 	int ignore_other_worktrees;
 	int show_progress;
+	int count_checkout_paths;
 	/*
 	 * If new checkout options are added, skip_merge_working_tree
 	 * should be updated accordingly.
@@ -115,7 +116,8 @@
 
 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
 {
-	read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
+	read_tree_recursive(the_repository, tree, "", 0, 0,
+			    pathspec, update_some, NULL);
 
 	/* update the index with the given tree's info
 	 * for all args, expanding wildcards, and exit
@@ -165,12 +167,13 @@
 }
 
 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
-			  const struct checkout *state)
+			  const struct checkout *state, int *nr_checkouts)
 {
 	while (pos < active_nr &&
 	       !strcmp(active_cache[pos]->name, ce->name)) {
 		if (ce_stage(active_cache[pos]) == stage)
-			return checkout_entry(active_cache[pos], state, NULL);
+			return checkout_entry(active_cache[pos], state,
+					      NULL, nr_checkouts);
 		pos++;
 	}
 	if (stage == 2)
@@ -179,7 +182,7 @@
 		return error(_("path '%s' does not have their version"), ce->name);
 }
 
-static int checkout_merged(int pos, const struct checkout *state)
+static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
 {
 	struct cache_entry *ce = active_cache[pos];
 	const char *path = ce->name;
@@ -242,7 +245,7 @@
 	ce = make_transient_cache_entry(mode, &oid, path, 2);
 	if (!ce)
 		die(_("make_cache_entry failed for path '%s'"), path);
-	status = checkout_entry(ce, state, NULL);
+	status = checkout_entry(ce, state, NULL, nr_checkouts);
 	discard_cache_entry(ce);
 	return status;
 }
@@ -257,6 +260,7 @@
 	struct commit *head;
 	int errs = 0;
 	struct lock_file lock_file = LOCK_INIT;
+	int nr_checkouts = 0;
 
 	if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 		die(_("'%s' cannot be used with updating paths"), "--track");
@@ -371,17 +375,36 @@
 		struct cache_entry *ce = active_cache[pos];
 		if (ce->ce_flags & CE_MATCHED) {
 			if (!ce_stage(ce)) {
-				errs |= checkout_entry(ce, &state, NULL);
+				errs |= checkout_entry(ce, &state,
+						       NULL, &nr_checkouts);
 				continue;
 			}
 			if (opts->writeout_stage)
-				errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
+				errs |= checkout_stage(opts->writeout_stage,
+						       ce, pos,
+						       &state, &nr_checkouts);
 			else if (opts->merge)
-				errs |= checkout_merged(pos, &state);
+				errs |= checkout_merged(pos, &state,
+							&nr_checkouts);
 			pos = skip_same_name(ce, pos) - 1;
 		}
 	}
-	errs |= finish_delayed_checkout(&state);
+	errs |= finish_delayed_checkout(&state, &nr_checkouts);
+
+	if (opts->count_checkout_paths) {
+		if (opts->source_tree)
+			fprintf_ln(stderr, Q_("Checked out %d path out of %s",
+					      "Checked out %d paths out of %s",
+					      nr_checkouts),
+				   nr_checkouts,
+				   find_unique_abbrev(&opts->source_tree->object.oid,
+						      DEFAULT_ABBREV));
+		else
+			fprintf_ln(stderr, Q_("Checked out %d path out of the index",
+					      "Checked out %d paths out of the index",
+					      nr_checkouts),
+				   nr_checkouts);
+	}
 
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
@@ -1065,6 +1088,7 @@
 		has_dash_dash = 1; /* case (3) or (1) */
 	else if (dash_dash_pos >= 2)
 		die(_("only one reference expected, %d given."), dash_dash_pos);
+	opts->count_checkout_paths = !opts->quiet && !has_dash_dash;
 
 	if (!strcmp(arg, "-"))
 		arg = "@{-1}";
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 84385ef..98d65bc 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -164,7 +164,8 @@
 	usage_with_options(builtin_config_usage, builtin_config_options);
 }
 
-static void check_argc(int argc, int min, int max) {
+static void check_argc(int argc, int min, int max)
+{
 	if (argc >= min && argc <= max)
 		return;
 	if (min == max)
@@ -598,7 +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/difftool.c b/builtin/difftool.c
index 544b0e8..71318c2 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -323,7 +323,7 @@
 	int ret;
 
 	ce = make_transient_cache_entry(mode, oid, path, 0);
-	ret = checkout_entry(ce, state, NULL);
+	ret = checkout_entry(ce, state, NULL, NULL);
 
 	discard_cache_entry(ce);
 	return ret;
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 63e69a5..f6a5134 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;
 
@@ -219,9 +220,11 @@
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_GENTLE_ON_EOF);
 
-	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 +234,7 @@
 	}
 
 	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..c316c03 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -763,9 +763,6 @@
 			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 +776,6 @@
 		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 +788,6 @@
 		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 +883,8 @@
 				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 = "";
@@ -1478,7 +1471,8 @@
 	 */
 	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 +1640,8 @@
 		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/gc.c b/builtin/gc.c
index 871a56f..020f725 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -317,7 +317,7 @@
 
 static void add_repack_incremental_option(void)
 {
-       argv_array_push(&repack, "--no-write-bitmap-index");
+	argv_array_push(&repack, "--no-write-bitmap-index");
 }
 
 static int need_to_gc(void)
@@ -659,8 +659,10 @@
 
 	report_garbage = report_pack_garbage;
 	reprepare_packed_git(the_repository);
-	if (pack_garbage.nr > 0)
+	if (pack_garbage.nr > 0) {
+		close_all_packs(the_repository->objects);
 		clean_pack_garbage();
+	}
 
 	if (gc_write_commit_graph)
 		write_commit_graph_reachable(get_object_directory(), 0,
diff --git a/builtin/grep.c b/builtin/grep.c
index bad9c0a..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;
 }
 
@@ -553,7 +556,8 @@
 
 		if (match != all_entries_interesting) {
 			strbuf_addstr(&name, base->buf + tn_len);
-			match = tree_entry_interesting(&entry, &name,
+			match = tree_entry_interesting(repo->index,
+						       &entry, &name,
 						       0, pathspec);
 			strbuf_setlen(&name, name_base_len);
 
@@ -566,7 +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;
@@ -574,10 +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);
@@ -585,7 +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 9deff32..a479642 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -641,8 +641,9 @@
 					diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 					name,
 					diff_get_color_opt(&rev.diffopt, DIFF_RESET));
-			read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
-					show_tree_object, rev.diffopt.file);
+			read_tree_recursive(the_repository, (struct tree *)o, "",
+					    0, 0, &match_all, show_tree_object,
+					    rev.diffopt.file);
 			rev.shown_one = 1;
 			break;
 		case OBJ_COMMIT:
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index c70a9c7..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,
@@ -441,7 +443,7 @@
 			       PATHSPEC_PREFER_CWD, prefix, matchbuf);
 	} else
 		memset(&pathspec, 0, sizeof(pathspec));
-	if (read_tree(tree, 1, &pathspec, istate))
+	if (read_tree(the_repository, tree, 1, &pathspec, istate))
 		die("unable to read tree entries %s", tree_name);
 
 	for (i = 0; i < istate->cache_nr; i++) {
diff --git a/builtin/ls-tree.c b/builtin/ls-tree.c
index 7d581d6..7cad3f2 100644
--- a/builtin/ls-tree.c
+++ b/builtin/ls-tree.c
@@ -185,5 +185,6 @@
 	tree = parse_tree_indirect(&oid);
 	if (!tree)
 		die("not a tree object");
-	return !!read_tree_recursive(tree, "", 0, 0, &pathspec, show_tree, NULL);
+	return !!read_tree_recursive(the_repository, tree, "", 0, 0,
+				     &pathspec, show_tree, NULL);
 }
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 70f6fc9..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;
@@ -346,7 +346,7 @@
 
 	setup_traverse_info(&info, base);
 	info.fn = threeway_callback;
-	traverse_trees(3, t, &info);
+	traverse_trees(&the_index, 3, t, &info);
 }
 
 static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 24bba81..0a70d04 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);
@@ -3084,14 +3084,16 @@
 static void get_object_list(int ac, const char **av)
 {
 	struct rev_info revs;
+	struct setup_revision_opt s_r_opt = {
+		.allow_exclude_promisor_objects = 1,
+	};
 	char line[1000];
 	int flags = 0;
 	int save_warning;
 
 	repo_init_revisions(the_repository, &revs, NULL);
 	save_commit_buffer = 0;
-	revs.allow_exclude_promisor_objects_opt = 1;
-	setup_revisions(ac, av, &revs, NULL);
+	setup_revisions(ac, av, &revs, &s_r_opt);
 
 	/* make sure shallows are read */
 	is_repository_shallow(the_repository);
diff --git a/builtin/prune.c b/builtin/prune.c
index e42653b..1ec9ddd 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -120,7 +120,6 @@
 	save_commit_buffer = 0;
 	read_replace_refs = 0;
 	ref_paranoia = 1;
-	revs.allow_exclude_promisor_objects_opt = 1;
 	repo_init_revisions(the_repository, &revs, prefix);
 
 	argc = parse_options(argc, argv, prefix, options, prune_usage, 0);
diff --git a/builtin/push.c b/builtin/push.c
index ee1e842..021dd3b 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -143,7 +143,9 @@
 	return remote->url_nr;
 }
 
-static NORETURN int die_push_simple(struct branch *branch, struct remote *remote) {
+static NORETURN int die_push_simple(struct branch *branch,
+				    struct remote *remote)
+{
 	/*
 	 * There's no point in using shorten_unambiguous_ref here,
 	 * as the ambiguity would be on the remote side, not what
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..774264b 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)
@@ -415,6 +416,8 @@
 			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;
@@ -530,6 +533,7 @@
 
 #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 +541,7 @@
 {
 	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 +641,10 @@
 			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 +683,11 @@
 		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 +760,23 @@
 	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 +857,7 @@
 	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 +935,9 @@
 		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 +955,9 @@
 				   "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;
@@ -1216,6 +1254,9 @@
 		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--)
@@ -1241,7 +1282,7 @@
 		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;
@@ -1251,6 +1292,11 @@
 			die(_("error: 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 "
@@ -1466,7 +1512,8 @@
 					    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 +1587,8 @@
 	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/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/repack.c b/builtin/repack.c
index 2a1c7b2..67f8978 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -419,6 +419,8 @@
 	if (!names.nr && !po_args.quiet)
 		printf_ln(_("Nothing new to pack."));
 
+	close_all_packs(the_repository->objects);
+
 	/*
 	 * Ok we have prepared all new packfiles.
 	 * First see if there are packs of the same name and if so
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 2880ed3..51e9e12 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -361,6 +361,9 @@
 {
 	struct rev_info revs;
 	struct rev_list_info info;
+	struct setup_revision_opt s_r_opt = {
+		.allow_exclude_promisor_objects = 1,
+	};
 	int i;
 	int bisect_list = 0;
 	int bisect_show_vars = 0;
@@ -374,7 +377,6 @@
 	git_config(git_default_config, NULL);
 	repo_init_revisions(the_repository, &revs, prefix);
 	revs.abbrev = DEFAULT_ABBREV;
-	revs.allow_exclude_promisor_objects_opt = 1;
 	revs.commit_format = CMIT_FMT_UNSPECIFIED;
 	revs.do_not_die_on_missing_tree = 1;
 
@@ -406,7 +408,7 @@
 		}
 	}
 
-	argc = setup_revisions(argc, argv, &revs, NULL);
+	argc = setup_revisions(argc, argv, &revs, &s_r_opt);
 
 	memset(&info, 0, sizeof(info));
 	info.revs = &revs;
diff --git a/builtin/stripspace.c b/builtin/stripspace.c
index bdf0328..be33eb8 100644
--- a/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@ -30,6 +30,7 @@
 {
 	struct strbuf buf = STRBUF_INIT;
 	enum stripspace_mode mode = STRIP_DEFAULT;
+	int nongit;
 
 	const struct option options[] = {
 		OPT_CMDMODE('s', "strip-comments", &mode,
@@ -46,7 +47,7 @@
 		usage_with_options(stripspace_usage, options);
 
 	if (mode == STRIP_COMMENTS || mode == COMMENT_LINES) {
-		setup_git_directory_gently(NULL);
+		setup_git_directory_gently(&nongit);
 		git_config(git_default_config, NULL);
 	}
 
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index b45514b..0e140f1 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1131,6 +1131,8 @@
 		if (!(flags & OPT_QUIET))
 			printf(format, displaypath);
 
+		submodule_unset_core_worktree(sub);
+
 		strbuf_release(&sb_rm);
 	}
 
@@ -1552,7 +1554,7 @@
 #define SUBMODULE_UPDATE_CLONE_INIT {0, MODULE_LIST_INIT, 0, \
 	SUBMODULE_UPDATE_STRATEGY_INIT, 0, 0, -1, STRING_LIST_INIT_DUP, 0, \
 	NULL, NULL, NULL, \
-	NULL, 0, 0, 0, NULL, 0, 0, 0}
+	NULL, 0, 0, 0, NULL, 0, 0, 1}
 
 
 static void next_submodule_warn_missing(struct submodule_update_clone *suc,
@@ -2046,7 +2048,7 @@
 	struct repository subrepo;
 
 	if (argc != 2)
-		BUG("submodule--helper connect-gitdir-workingtree <name> <path>");
+		BUG("submodule--helper ensure-core-worktree <path>");
 
 	path = argv[1];
 
@@ -2054,7 +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/builtin/worktree.c b/builtin/worktree.c
index 5e84026..3f9907f 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -9,6 +9,7 @@
 #include "refs.h"
 #include "run-command.h"
 #include "sigchain.h"
+#include "submodule.h"
 #include "refs.h"
 #include "utf8.h"
 #include "worktree.h"
@@ -724,20 +725,36 @@
 static void validate_no_submodules(const struct worktree *wt)
 {
 	struct index_state istate = { NULL };
+	struct strbuf path = STRBUF_INIT;
 	int i, found_submodules = 0;
 
-	if (read_index_from(&istate, worktree_git_path(wt, "index"),
-			    get_worktree_git_dir(wt)) > 0) {
+	if (is_directory(worktree_git_path(wt, "modules"))) {
+		/*
+		 * There could be false positives, e.g. the "modules"
+		 * directory exists but is empty. But it's a rare case and
+		 * this simpler check is probably good enough for now.
+		 */
+		found_submodules = 1;
+	} else if (read_index_from(&istate, worktree_git_path(wt, "index"),
+				   get_worktree_git_dir(wt)) > 0) {
 		for (i = 0; i < istate.cache_nr; i++) {
 			struct cache_entry *ce = istate.cache[i];
+			int err;
 
-			if (S_ISGITLINK(ce->ce_mode)) {
-				found_submodules = 1;
-				break;
-			}
+			if (!S_ISGITLINK(ce->ce_mode))
+				continue;
+
+			strbuf_reset(&path);
+			strbuf_addf(&path, "%s/%s", wt->path, ce->name);
+			if (!is_submodule_populated_gently(path.buf, &err))
+				continue;
+
+			found_submodules = 1;
+			break;
 		}
 	}
 	discard_index(&istate);
+	strbuf_release(&path);
 
 	if (found_submodules)
 		die(_("working trees containing submodules cannot be moved or removed"));
diff --git a/cache-tree.c b/cache-tree.c
index 190c6e5..c4b8a1f 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -448,7 +448,7 @@
 }
 
 static void write_one(struct strbuf *buffer, struct cache_tree *it,
-                      const char *path, int pathlen)
+		      const char *path, int pathlen)
 {
 	int i;
 
@@ -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 ca36b44..009e8b3 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];
@@ -1028,16 +1038,12 @@
 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 +1053,13 @@
 
 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 +1084,7 @@
 
 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)
@@ -1365,9 +1377,9 @@
 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
@@ -1375,10 +1387,13 @@
  *
  *   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
@@ -1539,9 +1554,9 @@
 #define CHECKOUT_INIT { NULL, "" }
 
 #define TEMPORARY_FILENAME_LENGTH 25
-extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
+extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath, int *nr_checkouts);
 extern void enable_delayed_checkout(struct checkout *state);
-extern int finish_delayed_checkout(struct checkout *state);
+extern int finish_delayed_checkout(struct checkout *state, int *nr_checkouts);
 
 struct cache_def {
 	struct strbuf path;
diff --git a/commit-graph.c b/commit-graph.c
index 99163c2..3f9c03a 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -23,18 +23,12 @@
 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
 #define GRAPH_CHUNKID_LARGEEDGES 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_PARENT_MISSING 0x7fffffff
 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
 #define GRAPH_PARENT_NONE 0x70000000
 
@@ -44,13 +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));
@@ -125,15 +124,15 @@
 	}
 
 	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);
+		      hash_version, oid_version());
 		goto cleanup_fail;
 	}
 
 	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;
@@ -149,7 +148,7 @@
 
 		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;
@@ -493,7 +492,9 @@
 					      commit_to_sha1);
 
 			if (edge_value < 0)
-				edge_value = GRAPH_PARENT_MISSING;
+				BUG("missing parent %s for commit %s",
+				    oid_to_hex(&parent->item->object.oid),
+				    oid_to_hex(&(*list)->object.oid));
 		}
 
 		hashwrite_be32(f, edge_value);
@@ -511,7 +512,9 @@
 					      nr_commits,
 					      commit_to_sha1);
 			if (edge_value < 0)
-				edge_value = GRAPH_PARENT_MISSING;
+				BUG("missing parent %s for commit %s",
+				    oid_to_hex(&parent->item->object.oid),
+				    oid_to_hex(&(*list)->object.oid));
 		}
 
 		hashwrite_be32(f, edge_value);
@@ -564,7 +567,9 @@
 						  commit_to_sha1);
 
 			if (edge_value < 0)
-				edge_value = GRAPH_PARENT_MISSING;
+				BUG("missing parent %s for commit %s",
+				    oid_to_hex(&parent->item->object.oid),
+				    oid_to_hex(&(*list)->object.oid));
 			else if (!parent->next)
 				edge_value |= GRAPH_LAST_EDGE;
 
@@ -638,26 +643,29 @@
 
 static void close_reachable(struct packed_oid_list *oids, int report_progress)
 {
-	int i;
+	int i, j;
 	struct commit *commit;
 	struct progress *progress = NULL;
-	int j = 0;
 
 	if (report_progress)
 		progress = start_delayed_progress(
-			_("Annotating commits in commit graph"), 0);
+			_("Loading known commits in commit graph"), j = 0);
 	for (i = 0; i < oids->nr; i++) {
 		display_progress(progress, ++j);
 		commit = lookup_commit(the_repository, &oids->list[i]);
 		if (commit)
 			commit->object.flags |= UNINTERESTING;
 	}
+	stop_progress(&progress);
 
 	/*
 	 * As this loop runs, oids->nr may grow, but not more
 	 * than the number of missing commits in the reachable
 	 * closure.
 	 */
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Expanding reachable commits in commit graph"), j = 0);
 	for (i = 0; i < oids->nr; i++) {
 		display_progress(progress, ++j);
 		commit = lookup_commit(the_repository, &oids->list[i]);
@@ -665,7 +673,11 @@
 		if (commit && !parse_commit(commit))
 			add_missing_parents(oids, commit);
 	}
+	stop_progress(&progress);
 
+	if (report_progress)
+		progress = start_delayed_progress(
+			_("Clearing commit marks in commit graph"), j = 0);
 	for (i = 0; i < oids->nr; i++) {
 		display_progress(progress, ++j);
 		commit = lookup_commit(the_repository, &oids->list[i]);
@@ -761,6 +773,7 @@
 	int num_extra_edges;
 	struct commit_list *parent;
 	struct progress *progress = NULL;
+	const unsigned hashsz = the_hash_algo->rawsz;
 
 	if (!commit_graph_compatible(the_repository))
 		return;
@@ -861,7 +874,7 @@
 			count_distinct++;
 	}
 
-	if (count_distinct >= GRAPH_PARENT_MISSING)
+	if (count_distinct >= GRAPH_EDGE_LAST_MASK)
 		die(_("the commit graph format cannot write %d commits"), count_distinct);
 
 	commits.nr = 0;
@@ -888,7 +901,7 @@
 	}
 	num_chunks = num_extra_edges ? 4 : 3;
 
-	if (commits.nr >= GRAPH_PARENT_MISSING)
+	if (commits.nr >= GRAPH_EDGE_LAST_MASK)
 		die(_("too many commits to write graph"));
 
 	compute_generation_numbers(&commits, report_progress);
@@ -906,7 +919,7 @@
 	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 */
 
@@ -921,8 +934,8 @@
 
 	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++) {
@@ -935,8 +948,8 @@
 	}
 
 	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_oids(f, hashsz, commits.list, commits.nr);
+	write_graph_chunk_data(f, hashsz, commits.list, commits.nr);
 	write_graph_chunk_large_edges(f, commits.list, commits.nr);
 
 	close_commit_graph(the_repository);
diff --git a/compat/cygwin.c b/compat/cygwin.c
deleted file mode 100644
index b9862d6..0000000
--- a/compat/cygwin.c
+++ /dev/null
@@ -1,19 +0,0 @@
-#include "../git-compat-util.h"
-#include "../cache.h"
-
-int cygwin_offset_1st_component(const char *path)
-{
-	const char *pos = path;
-	/* unc paths */
-	if (is_dir_sep(pos[0]) && is_dir_sep(pos[1])) {
-		/* skip server name */
-		pos = strchr(pos + 2, '/');
-		if (!pos)
-			return 0; /* Error: malformed unc path */
-
-		do {
-			pos++;
-		} while (*pos && pos[0] != '/');
-	}
-	return pos + is_dir_sep(*pos) - path;
-}
diff --git a/compat/cygwin.h b/compat/cygwin.h
deleted file mode 100644
index 8e52de4..0000000
--- a/compat/cygwin.h
+++ /dev/null
@@ -1,2 +0,0 @@
-int cygwin_offset_1st_component(const char *path);
-#define offset_1st_component cygwin_offset_1st_component
diff --git a/compat/mingw.c b/compat/mingw.c
index 34b3880..b459e1a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -350,7 +350,7 @@
 		return 0;
 
 	/* We cannot use basename(), as it would remove trailing slashes */
-	mingw_skip_dos_drive_prefix((char **)&path);
+	win32_skip_dos_drive_prefix((char **)&path);
 	if (!*path)
 		return 0;
 
@@ -2275,33 +2275,6 @@
 	return -1;
 }
 
-int mingw_skip_dos_drive_prefix(char **path)
-{
-	int ret = has_dos_drive_prefix(*path);
-	*path += ret;
-	return ret;
-}
-
-int mingw_offset_1st_component(const char *path)
-{
-	char *pos = (char *)path;
-
-	/* unc paths */
-	if (!skip_dos_drive_prefix(&pos) &&
-			is_dir_sep(pos[0]) && is_dir_sep(pos[1])) {
-		/* skip server name */
-		pos = strpbrk(pos + 2, "\\/");
-		if (!pos)
-			return 0; /* Error: malformed unc path */
-
-		do {
-			pos++;
-		} while (*pos && !is_dir_sep(*pos));
-	}
-
-	return pos + is_dir_sep(*pos) - path;
-}
-
 int xutftowcsn(wchar_t *wcs, const char *utfs, size_t wcslen, int utflen)
 {
 	int upos = 0, wpos = 0;
diff --git a/compat/mingw.h b/compat/mingw.h
index 8c24dda..30d9fb3 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -443,32 +443,12 @@
  * git specific compatibility
  */
 
-#define has_dos_drive_prefix(path) \
-	(isalpha(*(path)) && (path)[1] == ':' ? 2 : 0)
-int mingw_skip_dos_drive_prefix(char **path);
-#define skip_dos_drive_prefix mingw_skip_dos_drive_prefix
-static inline int mingw_is_dir_sep(int c)
-{
-	return c == '/' || c == '\\';
-}
-#define is_dir_sep mingw_is_dir_sep
-static inline char *mingw_find_last_dir_sep(const char *path)
-{
-	char *ret = NULL;
-	for (; *path; ++path)
-		if (is_dir_sep(*path))
-			ret = (char *)path;
-	return ret;
-}
 static inline void convert_slashes(char *path)
 {
 	for (; *path; path++)
 		if (*path == '\\')
 			*path = '/';
 }
-#define find_last_dir_sep mingw_find_last_dir_sep
-int mingw_offset_1st_component(const char *path);
-#define offset_1st_component mingw_offset_1st_component
 #define PATH_SEP ';'
 extern char *mingw_query_user_email(void);
 #define query_user_email mingw_query_user_email
diff --git a/compat/regex/regcomp.c b/compat/regex/regcomp.c
index 51cd60b..c0d8388 100644
--- a/compat/regex/regcomp.c
+++ b/compat/regex/regcomp.c
@@ -17,6 +17,14 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#if defined __TANDEM
+ /* This is currently duplicated from git-compat-utils.h */
+# ifdef NO_INTPTR_T
+ typedef long intptr_t;
+ typedef unsigned long uintptr_t;
+# endif
+#endif
+
 static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
 					  size_t length, reg_syntax_t syntax);
 static void re_compile_fastmap_iter (regex_t *bufp,
diff --git a/compat/win32/path-utils.c b/compat/win32/path-utils.c
new file mode 100644
index 0000000..d9d3641
--- /dev/null
+++ b/compat/win32/path-utils.c
@@ -0,0 +1,28 @@
+#include "../../git-compat-util.h"
+
+int win32_skip_dos_drive_prefix(char **path)
+{
+	int ret = has_dos_drive_prefix(*path);
+	*path += ret;
+	return ret;
+}
+
+int win32_offset_1st_component(const char *path)
+{
+	char *pos = (char *)path;
+
+	/* unc paths */
+	if (!skip_dos_drive_prefix(&pos) &&
+			is_dir_sep(pos[0]) && is_dir_sep(pos[1])) {
+		/* skip server name */
+		pos = strpbrk(pos + 2, "\\/");
+		if (!pos)
+			return 0; /* Error: malformed unc path */
+
+		do {
+			pos++;
+		} while (*pos && !is_dir_sep(*pos));
+	}
+
+	return pos + is_dir_sep(*pos) - path;
+}
diff --git a/compat/win32/path-utils.h b/compat/win32/path-utils.h
new file mode 100644
index 0000000..0f70d43
--- /dev/null
+++ b/compat/win32/path-utils.h
@@ -0,0 +1,20 @@
+#define has_dos_drive_prefix(path) \
+	(isalpha(*(path)) && (path)[1] == ':' ? 2 : 0)
+int win32_skip_dos_drive_prefix(char **path);
+#define skip_dos_drive_prefix win32_skip_dos_drive_prefix
+static inline int win32_is_dir_sep(int c)
+{
+	return c == '/' || c == '\\';
+}
+#define is_dir_sep win32_is_dir_sep
+static inline char *win32_find_last_dir_sep(const char *path)
+{
+	char *ret = NULL;
+	for (; *path; ++path)
+		if (is_dir_sep(*path))
+			ret = (char *)path;
+	return ret;
+}
+#define find_last_dir_sep win32_find_last_dir_sep
+int win32_offset_1st_component(const char *path);
+#define offset_1st_component win32_offset_1st_component
diff --git a/config.mak.dev b/config.mak.dev
index bbeeff4..7354fe1 100644
--- a/config.mak.dev
+++ b/config.mak.dev
@@ -6,6 +6,7 @@
 # don't warn for each N_ use
 CFLAGS += -DUSE_PARENS_AROUND_GETTEXT_N=0
 endif
+CFLAGS += -Wall
 CFLAGS += -Wdeclaration-after-statement
 CFLAGS += -Wformat-security
 CFLAGS += -Wno-format-zero-length
diff --git a/config.mak.uname b/config.mak.uname
index 3ee7da0..7b36a1d 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -187,7 +187,7 @@
 	UNRELIABLE_FSTAT = UnfortunatelyYes
 	OBJECT_CREATION_USES_RENAMES = UnfortunatelyNeedsTo
 	MMAP_PREVENTS_DELETE = UnfortunatelyYes
-	COMPAT_OBJS += compat/cygwin.o
+	COMPAT_OBJS += compat/win32/path-utils.o
 	FREAD_READS_DIRECTORIES = UnfortunatelyYes
 endif
 ifeq ($(uname_S),FreeBSD)
@@ -233,6 +233,7 @@
 	HAVE_BSD_SYSCTL = YesPlease
 	HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
 	PROCFS_EXECUTABLE_PATH = /proc/curproc/file
+	FREAD_READS_DIRECTORIES = UnfortunatelyYes
 endif
 ifeq ($(uname_S),MirBSD)
 	NO_STRCASESTR = YesPlease
@@ -441,26 +442,43 @@
 	# INLINE='' would just replace one set of warnings with another and
 	# still not compile in c89 mode, due to non-const array initializations.
 	CC = cc -c99
+	# Build down-rev compatible objects that don't use our new getopt_long.
+	ifeq ($(uname_R).$(uname_V),J06.21)
+		CC += -WRVU=J06.20
+	endif
+	ifeq ($(uname_R).$(uname_V),L17.02)
+		CC += -WRVU=L16.05
+	endif
 	# Disable all optimization, seems to result in bad code, with -O or -O2
 	# or even -O1 (default), /usr/local/libexec/git-core/git-pack-objects
 	# abends on "git push". Needs more investigation.
-	CFLAGS = -g -O0
+	CFLAGS = -g -O0 -Winline
 	# We'd want it to be here.
 	prefix = /usr/local
-	# Our's are in ${prefix}/bin (perl might also be in /usr/bin/perl).
-	PERL_PATH = ${prefix}/bin/perl
-	PYTHON_PATH = ${prefix}/bin/python
-
+	# perl and python must be in /usr/bin on NonStop - supplied by HPE
+	# with operating system in that managed directory.
+	PERL_PATH = /usr/bin/perl
+	PYTHON_PATH = /usr/bin/python
+	# The current /usr/coreutils/rm at lowest support level does not work
+	# with the git test structure. Long paths as in
+	# 'trash directory...' cause rm to terminate prematurely without fully
+	# removing the directory at OS releases J06.21 and L17.02.
+	# Default to the older rm until those two releases are deprecated.
+	RM = /bin/rm -f
 	# As detected by './configure'.
 	# Missdetected, hence commented out, see below.
 	#NO_CURL = YesPlease
 	# Added manually, see above.
+	NEEDS_SSL_WITH_CURL = YesPlease
+	NEEDS_CRYPTO_WITH_SSL = YesPlease
+	HAVE_DEV_TTY = YesPlease
 	HAVE_LIBCHARSET_H = YesPlease
 	HAVE_STRINGS_H = YesPlease
 	NEEDS_LIBICONV = YesPlease
 	NEEDS_LIBINTL_BEFORE_LIBICONV = YesPlease
 	NO_SYS_SELECT_H = UnfortunatelyYes
 	NO_D_TYPE_IN_DIRENT = YesPlease
+	NO_GETTEXT = YesPlease
 	NO_HSTRERROR = YesPlease
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
@@ -470,7 +488,7 @@
 	NO_MKDTEMP = YesPlease
 	# Currently libiconv-1.9.1.
 	OLD_ICONV = UnfortunatelyYes
-	NO_REGEX = YesPlease
+	NO_REGEX = NeedsStartEnd
 	NO_PTHREADS = UnfortunatelyYes
 
 	# Not detected (nor checked for) by './configure'.
@@ -527,6 +545,7 @@
 	COMPAT_CFLAGS += -DNOGDI -Icompat -Icompat/win32
 	COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
 	COMPAT_OBJS += compat/mingw.o compat/winansi.o \
+		compat/win32/path-utils.o \
 		compat/win32/pthread.o compat/win32/syslog.o \
 		compat/win32/dirent.o
 	BASIC_CFLAGS += -DWIN32 -DPROTECT_NTFS_DEFAULT=1
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/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 9e8ec95..499e56f 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -438,7 +438,7 @@
 # Callers must take care of providing only paths that match the current path
 # to be completed and adding any prefix path components, if necessary.
 # 1: List of newline-separated matching paths, complete with all prefix
-#    path componens.
+#    path components.
 __gitcomp_file_direct ()
 {
 	local IFS=$'\n'
@@ -855,7 +855,7 @@
 
 __git_complete_revlist_file ()
 {
-	local pfx ls ref cur_="$cur"
+	local dequoted_word pfx ls ref cur_="$cur"
 	case "$cur_" in
 	*..?*:*)
 		return
@@ -863,14 +863,18 @@
 	?*:*)
 		ref="${cur_%%:*}"
 		cur_="${cur_#*:}"
-		case "$cur_" in
+
+		__git_dequote "$cur_"
+
+		case "$dequoted_word" in
 		?*/*)
-			pfx="${cur_%/*}"
-			cur_="${cur_##*/}"
+			pfx="${dequoted_word%/*}"
+			cur_="${dequoted_word##*/}"
 			ls="$ref:$pfx"
 			pfx="$pfx/"
 			;;
 		*)
+			cur_="$dequoted_word"
 			ls="$ref"
 			;;
 		esac
@@ -880,21 +884,10 @@
 		*)   pfx="$ref:$pfx" ;;
 		esac
 
-		__gitcomp_nl "$(__git ls-tree "$ls" \
-				| sed '/^100... blob /{
-				           s,^.*	,,
-				           s,$, ,
-				       }
-				       /^120000 blob /{
-				           s,^.*	,,
-				           s,$, ,
-				       }
-				       /^040000 tree /{
-				           s,^.*	,,
-				           s,$,/,
-				       }
-				       s/^.*	//')" \
-			"$pfx" "$cur_" ""
+		__gitcomp_file "$(__git ls-tree "$ls" \
+				| sed 's/^.*	//
+				       s/$//')" \
+			"$pfx" "$cur_"
 		;;
 	*...*)
 		pfx="${cur_%...*}..."
@@ -2993,7 +2986,7 @@
 
 		local IFS=$'\n'
 		compset -P '*[=:]'
-		compadd -Q -f -- ${=1} && _ret=0
+		compadd -f -- ${=1} && _ret=0
 	}
 
 	__gitcomp_file ()
@@ -3002,7 +2995,7 @@
 
 		local IFS=$'\n'
 		compset -P '*[=:]'
-		compadd -Q -p "${2-}" -f -- ${=1} && _ret=0
+		compadd -p "${2-}" -f -- ${=1} && _ret=0
 	}
 
 	_git ()
diff --git a/contrib/completion/git-completion.zsh b/contrib/completion/git-completion.zsh
index 049d6b8..886bf95 100644
--- a/contrib/completion/git-completion.zsh
+++ b/contrib/completion/git-completion.zsh
@@ -99,7 +99,7 @@
 
 	local IFS=$'\n'
 	compset -P '*[=:]'
-	compadd -Q -f -- ${=1} && _ret=0
+	compadd -f -- ${=1} && _ret=0
 }
 
 __gitcomp_file ()
@@ -108,7 +108,7 @@
 
 	local IFS=$'\n'
 	compset -P '*[=:]'
-	compadd -Q -p "${2-}" -f -- ${=1} && _ret=0
+	compadd -p "${2-}" -f -- ${=1} && _ret=0
 }
 
 __git_zsh_bash_func ()
diff --git a/contrib/hooks/multimail/CHANGES b/contrib/hooks/multimail/CHANGES
index 2076cf9..35791fd 100644
--- a/contrib/hooks/multimail/CHANGES
+++ b/contrib/hooks/multimail/CHANGES
@@ -1,3 +1,59 @@
+Release 1.5.0
+=============
+
+Backward-incompatible change
+----------------------------
+
+The name of classes for environment was misnamed as `*Environement`.
+It is now `*Environment`.
+
+New features
+------------
+
+* A Thread-Index header is now added to each email sent (except for
+  combined emails where it would not make sense), so that MS Outlook
+  properly groups messages by threads even though they have a
+  different subject line. Unfortunately, even adding this header the
+  threading still seems to be unreliable, but it is unclear whether
+  this is an issue on our side or on MS Outlook's side (see discussion
+  here: https://github.com/git-multimail/git-multimail/pull/194).
+
+* A new variable multimailhook.ExcludeMergeRevisions was added to send
+  notification emails only for non-merge commits.
+
+* For gitolite environment, it is now possible to specify the mail map
+  in a separate file in addition to gitolite.conf, using the variable
+  multimailhook.MailaddressMap.
+
+Internal changes
+----------------
+
+* The testsuite now uses GIT_PRINT_SHA1_ELLIPSIS where needed for
+  compatibility with recent Git versions. Only tests are affected.
+
+* We don't try to install pyflakes in the continuous integration job
+  for old Python versions where it's no longer available.
+
+* Stop using the deprecated cgi.escape in Python 3.
+
+* New flake8 warnings have been fixed.
+
+* Python 3.6 is now tested against on Travis-CI.
+
+* A bunch of lgtm.com warnings have been fixed.
+
+Bug fixes
+---------
+
+* SMTPMailer logs in only once now. It used to re-login for each email
+  sent which triggered errors for some SMTP servers.
+
+* migrate-mailhook-config was broken by internal refactoring, it
+  should now work again.
+
+This version was tested with Python 2.6 to 3.7. It was tested with Git
+1.7.10.406.gdc801, 2.15.1 and 2.20.1.98.gecbdaf0.
+
 Release 1.4.0
 =============
 
diff --git a/contrib/hooks/multimail/CONTRIBUTING.rst b/contrib/hooks/multimail/CONTRIBUTING.rst
index da65570..de20a54 100644
--- a/contrib/hooks/multimail/CONTRIBUTING.rst
+++ b/contrib/hooks/multimail/CONTRIBUTING.rst
@@ -4,9 +4,8 @@
 git-multimail is an open-source project, built by volunteers. We would
 welcome your help!
 
-The current maintainers are Matthieu Moy
-<matthieu.moy@grenoble-inp.fr> and Michael Haggerty
-<mhagger@alum.mit.edu>.
+The current maintainers are `Matthieu Moy <http://matthieu-moy.fr>`__ and
+`Michael Haggerty <https://github.com/mhagger>`__.
 
 Please note that although a copy of git-multimail is distributed in
 the "contrib" section of the main Git project, development takes place
@@ -33,6 +32,29 @@
 Please CC emails regarding git-multimail to the maintainers so that we
 don't overlook them.
 
+Help needed: testers/maintainer for specific environments/OS
+------------------------------------------------------------
+
+The current maintainer uses and tests git-multimail on Linux with the
+Generic environment. More testers, or better contributors are needed
+to test git-multimail on other real-life setups:
+
+* Mac OS X, Windows: git-multimail is currently not supported on these
+  platforms. But since we have no external dependencies and try to
+  write code as portable as possible, it is possible that
+  git-multimail already runs there and if not, it is likely that it
+  could be ported easily.
+
+  Patches to improve support for Windows and OS X are welcome.
+  Ideally, there would be a sub-maintainer for each OS who would test
+  at least once before each release (around twice a year).
+
+* Gerrit, Stash, Gitolite environments: although the testsuite
+  contains tests for these environments, a tester/maintainer for each
+  environment would be welcome to test and report failure (or success)
+  on real-life environments periodically (here also, feedback before
+  each release would be highly appreciated).
+
 
 .. _`git-multimail repository on GitHub`: https://github.com/git-multimail/git-multimail
 .. _`Git mailing list`: git@vger.kernel.org
diff --git a/contrib/hooks/multimail/README.Git b/contrib/hooks/multimail/README.Git
index 161b023..0444442 100644
--- a/contrib/hooks/multimail/README.Git
+++ b/contrib/hooks/multimail/README.Git
@@ -6,10 +6,10 @@
     https://github.com/git-multimail/git-multimail
 
 The version in this directory was obtained from the upstream project
-on August 17 2016 and consists of the "git-multimail" subdirectory from
+on January 07 2019 and consists of the "git-multimail" subdirectory from
 revision
 
-    07b1cb6bfd7be156c62e1afa17cae13b850a869f refs/tags/1.4.0
+    04e80e6c40be465cc62b6c246f0fcb8fd2cfd454 refs/tags/1.5.0
 
 Please see the README file in this directory for information about how
 to report bugs or contribute to git-multimail.
diff --git a/contrib/hooks/multimail/README b/contrib/hooks/multimail/README.rst
similarity index 95%
rename from contrib/hooks/multimail/README
rename to contrib/hooks/multimail/README.rst
index 5105373..7c0fc4a 100644
--- a/contrib/hooks/multimail/README
+++ b/contrib/hooks/multimail/README.rst
@@ -1,4 +1,4 @@
-git-multimail version 1.4.0
+git-multimail version 1.5.0
 ===========================
 
 .. image:: https://travis-ci.org/git-multimail/git-multimail.svg?branch=master
@@ -20,8 +20,8 @@
 
 Please note: although, as a convenience, git-multimail may be
 distributed along with the main Git project, development of
-git-multimail takes place in its own, separate project.  See section
-"Getting involved" below for more information.
+git-multimail takes place in its own, separate project.  Please, read
+`<CONTRIBUTING.rst>`__ for more information.
 
 
 By default, for each push received by the repository, git-multimail:
@@ -89,6 +89,10 @@
   the multimailhook.mailer configuration variable below for how to
   configure git-multimail to send emails via an SMTP server.
 
+* git-multimail is currently tested only on Linux. It may or may not
+  work on other platforms such as Windows and Mac OS. See
+  `<CONTRIBUTING.rst>`__ to improve the situation.
+
 
 Invocation
 ----------
@@ -369,7 +373,7 @@
         unset, then the value of multimailhook.from is used.
 
       multimailhook.smtpServerTimeout
-        Timeout in seconds.
+        Timeout in seconds. Default is 10.
 
       multimailhook.smtpEncryption
         Set the security type. Allowed values: ``none``, ``ssl``, ``tls`` (starttls).
@@ -419,8 +423,20 @@
     If config values are unset, the value of the From: header is
     determined as follows:
 
-    1. (gitolite environment only) Parse gitolite.conf, looking for a
-       block of comments that looks like this::
+    1. (gitolite environment only)
+       1.a) If ``multimailhook.MailaddressMap`` is set, and is a path
+       to an existing file (if relative, it is considered relative to
+       the place where ``gitolite.conf`` is located), then this file
+       should contain lines like::
+
+           username Firstname Lastname <email@example.com>
+
+       git-multimail will then look for a line where ``$GL_USER``
+       matches the ``username`` part, and use the rest of the line for
+       the ``From:`` header.
+
+       1.b) Parse gitolite.conf, looking for a block of comments that
+       looks like this::
 
            # BEGIN USER EMAILS
            # username Firstname Lastname <email@example.com>
@@ -436,6 +452,11 @@
 
     3. Use the value of multimailhook.envelopeSender.
 
+multimailhook.MailaddressMap
+    (gitolite environment only)
+    File to look for a ``From:`` address based on the user doing the
+    push. Defaults to unset. See ``multimailhook.from`` for details.
+
 multimailhook.administrator
     The name and/or email address of the administrator of the Git
     repository; used in FOOTER_TEMPLATE.  Default is
@@ -484,6 +505,11 @@
     mailbombing, for example on an initial push.  To disable commit
     emails limit, set this option to 0.  The default is 500.
 
+multimailhook.excludeMergeRevisions
+    When sending out revision emails, do not consider merge commits (the
+    functional equivalent of `rev-list --no-merges`).
+    The default is `false` (send merge commit emails).
+
 multimailhook.emailStrictUTF8
     If this boolean option is set to `true`, then the main part of the
     email body is forced to be valid UTF-8.  Any characters that are
diff --git a/contrib/hooks/multimail/doc/gitolite.rst b/contrib/hooks/multimail/doc/gitolite.rst
index 00aedd9..5054833 100644
--- a/contrib/hooks/multimail/doc/gitolite.rst
+++ b/contrib/hooks/multimail/doc/gitolite.rst
@@ -46,6 +46,15 @@
       config multimailhook.mailingList = # Where emails should be sent
       config multimailhook.from = # From address to use
 
+Note that by default, gitolite forbids ``<`` and ``>`` in variable
+values (for security/paranoia reasons, see
+`compensating for UNSAFE_PATT
+<http://gitolite.com/gitolite/git-config/index.html#compensating-for-unsafe95patt>`__
+in gitolite's documentation for explanations and a way to disable
+this). As a consequence, you will not be able to use ``First Last
+<First.Last@example.com>`` as recipient email, but specifying
+``First.Last@example.com`` alone works.
+
 Obviously, you can customize all parameters on a per-repository basis by
 adding these ``config multimailhook.*`` lines in the section
 corresponding to a repository or set of repositories.
diff --git a/contrib/hooks/multimail/git_multimail.py b/contrib/hooks/multimail/git_multimail.py
index 73fdda6..8823399 100755
--- a/contrib/hooks/multimail/git_multimail.py
+++ b/contrib/hooks/multimail/git_multimail.py
@@ -1,6 +1,6 @@
 #! /usr/bin/env python
 
-__version__ = '1.4.0'
+__version__ = '1.5.0'
 
 # Copyright (c) 2015-2016 Matthieu Moy and others
 # Copyright (c) 2012-2014 Michael Haggerty and others
@@ -64,7 +64,9 @@
     # Python < 2.6 do not have ssl, but that's OK if we don't use it.
     pass
 import time
-import cgi
+
+import uuid
+import base64
 
 PYTHON3 = sys.version_info >= (3, 0)
 
@@ -73,7 +75,7 @@
         for element in iterable:
             if not element:
                 return False
-            return True
+        return True
 
 
 def is_ascii(s):
@@ -108,6 +110,12 @@
             return out.decode(sys.getdefaultencoding())
         except UnicodeEncodeError:
             return out.decode(ENCODING)
+
+    import html
+
+    def html_escape(s):
+        return html.escape(s)
+
 else:
     def is_string(s):
         try:
@@ -130,6 +138,10 @@
     def next(it):
         return it.next()
 
+    import cgi
+
+    def html_escape(s):
+        return cgi.escape(s, True)
 
 try:
     from email.charset import Charset
@@ -190,6 +202,7 @@
 Message-ID: %(msgid)s
 From: %(fromaddr)s
 Reply-To: %(reply_to)s
+Thread-Index: %(thread_index)s
 X-Git-Host: %(fqdn)s
 X-Git-Repo: %(repo_shortname)s
 X-Git-Refname: %(refname)s
@@ -322,6 +335,7 @@
 Reply-To: %(reply_to)s
 In-Reply-To: %(reply_to_msgid)s
 References: %(reply_to_msgid)s
+Thread-Index: %(thread_index)s
 X-Git-Host: %(fqdn)s
 X-Git-Repo: %(repo_shortname)s
 X-Git-Refname: %(refname)s
@@ -763,6 +777,9 @@
     def __eq__(self, other):
         return isinstance(other, GitObject) and self.sha1 == other.sha1
 
+    def __ne__(self, other):
+        return not self == other
+
     def __hash__(self):
         return hash(self.sha1)
 
@@ -852,7 +869,7 @@
         if html_escape_val:
             for k in values:
                 if is_string(values[k]):
-                    values[k] = cgi.escape(values[k], True)
+                    values[k] = html_escape(values[k])
         for line in template.splitlines(True):
             yield line % values
 
@@ -909,7 +926,7 @@
 
         raise NotImplementedError()
 
-    def generate_email_body(self):
+    def generate_email_body(self, push):
         """Generate the main part of the email body, a line at a time.
 
         The text in the body might be truncated after a specified
@@ -936,7 +953,7 @@
             yield "<pre style='margin:0'>\n"
 
             for line in lines:
-                yield cgi.escape(line)
+                yield html_escape(line)
 
             yield '</pre>\n'
         else:
@@ -1011,7 +1028,7 @@
                     fgcolor = '404040'
 
                 # Chop the trailing LF, we don't want it inside <pre>.
-                line = cgi.escape(line[:-1])
+                line = html_escape(line[:-1])
 
                 if bgcolor or fgcolor:
                     style = 'display:block; white-space:pre;'
@@ -1060,6 +1077,10 @@
         self.author = read_git_output(['log', '--no-walk', '--format=%aN <%aE>', self.rev.sha1])
         self.recipients = self.environment.get_revision_recipients(self)
 
+        # -s is short for --no-patch, but -s works on older git's (e.g. 1.7)
+        self.parents = read_git_lines(['show', '-s', '--format=%P',
+                                      self.rev.sha1])[0].split()
+
         self.cc_recipients = ''
         if self.environment.get_scancommitforcc():
             self.cc_recipients = ', '.join(to.strip() for to in self._cc_recipients())
@@ -1090,6 +1111,7 @@
             oneline = oneline[:max_subject_length - 6] + ' [...]'
 
         values['rev'] = self.rev.sha1
+        values['parents'] = ' '.join(self.parents)
         values['rev_short'] = self.rev.short
         values['change_type'] = self.change_type
         values['refname'] = self.refname
@@ -1097,6 +1119,7 @@
         values['short_refname'] = self.reference_change.short_refname
         values['refname_type'] = self.reference_change.refname_type
         values['reply_to_msgid'] = self.reference_change.msgid
+        values['thread_index'] = self.reference_change.thread_index
         values['num'] = self.num
         values['tot'] = self.tot
         values['recipients'] = self.recipients
@@ -1244,6 +1267,23 @@
             old=old, new=new, rev=rev,
             )
 
+    @staticmethod
+    def make_thread_index():
+        """Return a string appropriate for the Thread-Index header,
+        needed by MS Outlook to get threading right.
+
+        The format is (base64-encoded):
+        - 1 byte must be 1
+        - 5 bytes encode a date (hardcoded here)
+        - 16 bytes for a globally unique identifier
+
+        FIXME: Unfortunately, even with the Thread-Index field, MS
+        Outlook doesn't seem to do the threading reliably (see
+        https://github.com/git-multimail/git-multimail/pull/194).
+        """
+        thread_index = b'\x01\x00\x00\x12\x34\x56' + uuid.uuid4().bytes
+        return base64.standard_b64encode(thread_index).decode('ascii')
+
     def __init__(self, environment, refname, short_refname, old, new, rev):
         Change.__init__(self, environment)
         self.change_type = {
@@ -1257,6 +1297,7 @@
         self.new = new
         self.rev = rev
         self.msgid = make_msgid()
+        self.thread_index = self.make_thread_index()
         self.diffopts = environment.diffopts
         self.graphopts = environment.graphopts
         self.logopts = environment.logopts
@@ -1276,6 +1317,7 @@
         values['refname'] = self.refname
         values['short_refname'] = self.short_refname
         values['msgid'] = self.msgid
+        values['thread_index'] = self.thread_index
         values['recipients'] = self.recipients
         values['oldrev'] = str(self.old)
         values['oldrev_short'] = self.old.short
@@ -1941,6 +1983,9 @@
     def __init__(self, environment):
         self.environment = environment
 
+    def close(self):
+        pass
+
     def send(self, lines, to_addrs):
         """Send an email consisting of lines.
 
@@ -2054,6 +2099,7 @@
         self.username = smtpuser
         self.password = smtppass
         self.smtpcacerts = smtpcacerts
+        self.loggedin = False
         try:
             def call(klass, server, timeout):
                 try:
@@ -2130,20 +2176,30 @@
                 % (self.smtpserver, sys.exc_info()[1]))
             sys.exit(1)
 
-    def __del__(self):
+    def close(self):
         if hasattr(self, 'smtp'):
             self.smtp.quit()
             del self.smtp
 
+    def __del__(self):
+        self.close()
+
     def send(self, lines, to_addrs):
         try:
             if self.username or self.password:
-                self.smtp.login(self.username, self.password)
+                if not self.loggedin:
+                    self.smtp.login(self.username, self.password)
+                    self.loggedin = True
             msg = ''.join(lines)
             # turn comma-separated list into Python list if needed.
             if is_string(to_addrs):
                 to_addrs = [email for (name, email) in getaddresses([to_addrs])]
             self.smtp.sendmail(self.envelopesender, to_addrs, msg)
+        except socket.timeout:
+            self.environment.get_logger().error(
+                '*** Error sending email ***\n'
+                '*** SMTP server timed out (timeout is %s)\n'
+                % self.smtpservertimeout)
         except smtplib.SMTPResponseException:
             err = sys.exc_info()[1]
             self.environment.get_logger().error(
@@ -2171,7 +2227,8 @@
 
     SEPARATOR = '=' * 75 + '\n'
 
-    def __init__(self, f):
+    def __init__(self, f, environment=None):
+        super(OutputMailer, self).__init__(environment=environment)
         self.f = f
 
     def send(self, lines, to_addrs):
@@ -2382,6 +2439,7 @@
         self.html_in_footer = False
         self.commitBrowseURL = None
         self.maxcommitemails = 500
+        self.excludemergerevisions = False
         self.diffopts = ['--stat', '--summary', '--find-copies-harder']
         self.graphopts = ['--oneline', '--decorate']
         self.logopts = []
@@ -2621,6 +2679,8 @@
 
         self.commitBrowseURL = config.get('commitBrowseURL')
 
+        self.excludemergerevisions = config.get('excludeMergeRevisions')
+
         maxcommitemails = config.get('maxcommitemails')
         if maxcommitemails is not None:
             try:
@@ -3152,7 +3212,10 @@
         return self.osenv.get('GL_USER', 'unknown user')
 
 
-class GitoliteEnvironmentLowPrecMixin(Environment):
+class GitoliteEnvironmentLowPrecMixin(
+        ConfigEnvironmentMixin,
+        Environment):
+
     def get_repo_shortname(self):
         # The gitolite environment variable $GL_REPO is a pretty good
         # repo_shortname (though it's probably not as good as a value
@@ -3162,6 +3225,16 @@
             super(GitoliteEnvironmentLowPrecMixin, self).get_repo_shortname()
             )
 
+    @staticmethod
+    def _compile_regex(re_template):
+        return (
+            re.compile(re_template % x)
+            for x in (
+                r'BEGIN\s+USER\s+EMAILS',
+                r'([^\s]+)\s+(.*)',
+                r'END\s+USER\s+EMAILS',
+                ))
+
     def get_fromaddr(self, change=None):
         GL_USER = self.osenv.get('GL_USER')
         if GL_USER is not None:
@@ -3174,18 +3247,42 @@
             GL_CONF = self.osenv.get(
                 'GL_CONF',
                 os.path.join(GL_ADMINDIR, 'conf', 'gitolite.conf'))
+
+            mailaddress_map = self.config.get('MailaddressMap')
+            # If relative, consider relative to GL_CONF:
+            if mailaddress_map:
+                mailaddress_map = os.path.join(os.path.dirname(GL_CONF),
+                                               mailaddress_map)
+                if os.path.isfile(mailaddress_map):
+                    f = open(mailaddress_map, 'rU')
+                    try:
+                        # Leading '#' is optional
+                        re_begin, re_user, re_end = self._compile_regex(
+                            r'^(?:\s*#)?\s*%s\s*$')
+                        for l in f:
+                            l = l.rstrip('\n')
+                            if re_begin.match(l) or re_end.match(l):
+                                continue  # Ignore these lines
+                            m = re_user.match(l)
+                            if m:
+                                if m.group(1) == GL_USER:
+                                    return m.group(2)
+                                else:
+                                    continue  # Not this user, but not an error
+                            raise ConfigurationException(
+                                "Syntax error in mail address map.\n"
+                                "Check file {}.\n"
+                                "Line: {}".format(mailaddress_map, l))
+
+                    finally:
+                        f.close()
+
             if os.path.isfile(GL_CONF):
                 f = open(GL_CONF, 'rU')
                 try:
                     in_user_emails_section = False
-                    re_template = r'^\s*#\s*%s\s*$'
-                    re_begin, re_user, re_end = (
-                        re.compile(re_template % x)
-                        for x in (
-                            r'BEGIN\s+USER\s+EMAILS',
-                            re.escape(GL_USER) + r'\s+(.*)',
-                            r'END\s+USER\s+EMAILS',
-                            ))
+                    re_begin, re_user, re_end = self._compile_regex(
+                        r'^\s*#\s*%s\s*$')
                     for l in f:
                         l = l.rstrip('\n')
                         if not in_user_emails_section:
@@ -3195,8 +3292,8 @@
                         if re_end.match(l):
                             break
                         m = re_user.match(l)
-                        if m:
-                            return m.group(1)
+                        if m and m.group(1) == GL_USER:
+                            return m.group(2)
                 finally:
                     f.close()
         return super(GitoliteEnvironmentLowPrecMixin, self).get_fromaddr(change)
@@ -3228,7 +3325,7 @@
         self.__repo = repo
 
     def get_pusher(self):
-        return re.match('(.*?)\s*<', self.__user).group(1)
+        return re.match(r'(.*?)\s*<', self.__user).group(1)
 
     def get_pusher_email(self):
         return self.__user
@@ -3262,7 +3359,7 @@
             if self.__submitter.find('<') != -1:
                 # Submitter has a configured email, we transformed
                 # __submitter into an RFC 2822 string already.
-                return re.match('(.*?)\s*<', self.__submitter).group(1)
+                return re.match(r'(.*?)\s*<', self.__submitter).group(1)
             else:
                 # Submitter has no configured email, it's just his name.
                 return self.__submitter
@@ -3615,6 +3712,9 @@
 
             for (num, sha1) in enumerate(sha1s):
                 rev = Revision(change, GitObject(sha1), num=num + 1, tot=len(sha1s))
+                if len(rev.parents) > 1 and change.environment.excludemergerevisions:
+                    # skipping a merge commit
+                    continue
                 if not rev.recipients and rev.cc_recipients:
                     change.environment.log_msg('*** Replacing Cc: with To:')
                     rev.recipients = rev.cc_recipients
@@ -3664,11 +3764,14 @@
         changes.append(
             ReferenceChange.create(environment, oldrev, newrev, refname)
             )
-    if changes:
-        push = Push(environment, changes)
+    if not changes:
+        mailer.close()
+        return
+    push = Push(environment, changes)
+    try:
         push.send_emails(mailer, body_filter=environment.filter_body)
-    if hasattr(mailer, '__del__'):
-        mailer.__del__()
+    finally:
+        mailer.close()
 
 
 def run_as_update_hook(environment, mailer, refname, oldrev, newrev, force_send=False):
@@ -3687,10 +3790,14 @@
             refname,
             ),
         ]
+    if not changes:
+        mailer.close()
+        return
     push = Push(environment, changes, force_send)
-    push.send_emails(mailer, body_filter=environment.filter_body)
-    if hasattr(mailer, '__del__'):
-        mailer.__del__()
+    try:
+        push.send_emails(mailer, body_filter=environment.filter_body)
+    finally:
+        mailer.close()
 
 
 def check_ref_filter(environment):
@@ -3860,7 +3967,7 @@
         low_prec_mixin = known_env['lowprec']
         environment_mixins.append(low_prec_mixin)
     environment_mixins.append(Environment)
-    klass_name = env_name.capitalize() + 'Environement'
+    klass_name = env_name.capitalize() + 'Environment'
     environment_klass = type(
         klass_name,
         tuple(environment_mixins),
@@ -4057,21 +4164,21 @@
                 environment, 'git_multimail.error', environment.error_log_file, logging.ERROR)
             self.loggers.append(error_log_file)
 
-    def info(self, msg):
+    def info(self, msg, *args, **kwargs):
         for l in self.loggers:
-            l.info(msg)
+            l.info(msg, *args, **kwargs)
 
-    def debug(self, msg):
+    def debug(self, msg, *args, **kwargs):
         for l in self.loggers:
-            l.debug(msg)
+            l.debug(msg, *args, **kwargs)
 
-    def warning(self, msg):
+    def warning(self, msg, *args, **kwargs):
         for l in self.loggers:
-            l.warning(msg)
+            l.warning(msg, *args, **kwargs)
 
-    def error(self, msg):
+    def error(self, msg, *args, **kwargs):
         for l in self.loggers:
-            l.error(msg)
+            l.error(msg, *args, **kwargs)
 
 
 def main(args):
@@ -4189,7 +4296,7 @@
             show_env(environment, sys.stderr)
 
         if options.stdout or environment.stdout:
-            mailer = OutputMailer(sys.stdout)
+            mailer = OutputMailer(sys.stdout, environment)
         else:
             mailer = choose_mailer(config, environment)
 
@@ -4234,5 +4341,6 @@
             sys.stderr.write(msg)
         sys.exit(1)
 
+
 if __name__ == '__main__':
     main(sys.argv[1:])
diff --git a/contrib/hooks/multimail/migrate-mailhook-config b/contrib/hooks/multimail/migrate-mailhook-config
index 992657b..241ba22 100755
--- a/contrib/hooks/multimail/migrate-mailhook-config
+++ b/contrib/hooks/multimail/migrate-mailhook-config
@@ -110,11 +110,12 @@
 
     try:
         read_output(
-            ['git', 'config']
-            + local_option
-            + ['--get-regexp', '^%s\.' % (section,)]
+            ['git', 'config'] +
+            local_option +
+            ['--get-regexp', '^%s\.' % (section,)]
             )
-    except CommandError, e:
+    except CommandError:
+        t, e, traceback = sys.exc_info()
         if e.retcode == 1:
             # This means that no settings were found.
             return True
@@ -188,7 +189,9 @@
             sys.stderr.write(
                 '...copying "%s.%s" to "%s.%s"\n' % (old.section, name, new.section, name)
                 )
-            new.set_recipients(name, old.get_recipients(name))
+            old_recipients = old.get_all(name, default=None)
+            old_recipients = ', '.join(o.strip() for o in old_recipients)
+            new.set_recipients(name, old_recipients)
 
     if strict:
         sys.stderr.write(
diff --git a/contrib/hooks/multimail/post-receive.example b/contrib/hooks/multimail/post-receive.example
index 1ea113d..b9bb118 100755
--- a/contrib/hooks/multimail/post-receive.example
+++ b/contrib/hooks/multimail/post-receive.example
@@ -30,7 +30,6 @@
 """
 
 import sys
-import os
 
 # If necessary, add the path to the directory containing
 # git_multimail.py to the Python path as follows.  (This is not
@@ -86,6 +85,7 @@
 
 # Use Python's smtplib to send emails.  Both arguments are required.
 #mailer = git_multimail.SMTPMailer(
+#    environment=environment,
 #    envelopesender='git-repo@example.com',
 #    # The smtpserver argument can also include a port number; e.g.,
 #    #     smtpserver='mail.example.com:25'
diff --git a/convert.c b/convert.c
index e084822..0d89ae7 100644
--- a/convert.c
+++ b/convert.c
@@ -705,7 +705,7 @@
 }
 
 static int apply_single_file_filter(const char *path, const char *src, size_t len, int fd,
-                        struct strbuf *dst, const char *cmd)
+				    struct strbuf *dst, const char *cmd)
 {
 	/*
 	 * Create a pipeline to have the command filter the buffer's
@@ -778,7 +778,8 @@
 
 static void handle_filter_error(const struct strbuf *filter_status,
 				struct cmd2process *entry,
-				const unsigned int wanted_capability) {
+				const unsigned int wanted_capability)
+{
 	if (!strcmp(filter_status->buf, "error"))
 		; /* The filter signaled a problem with the file. */
 	else if (!strcmp(filter_status->buf, "abort") && wanted_capability) {
@@ -1091,7 +1092,7 @@
 }
 
 static int ident_to_git(const char *path, const char *src, size_t len,
-                        struct strbuf *buf, int ident)
+			struct strbuf *buf, int ident)
 {
 	char *dst, *dollar;
 
@@ -1135,7 +1136,7 @@
 }
 
 static int ident_to_worktree(const char *path, const char *src, size_t len,
-                             struct strbuf *buf, int ident)
+			     struct strbuf *buf, int ident)
 {
 	struct object_id oid;
 	char *to_free = NULL, *dollar, *spc;
diff --git a/credential-cache--daemon.c b/credential-cache--daemon.c
index 4dfbc8c..ec1271f 100644
--- a/credential-cache--daemon.c
+++ b/credential-cache--daemon.c
@@ -91,7 +91,8 @@
 }
 
 static int read_request(FILE *fh, struct credential *c,
-			struct strbuf *action, int *timeout) {
+			struct strbuf *action, int *timeout)
+{
 	static struct strbuf item = STRBUF_INIT;
 	const char *p;
 
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 15556c1..e8c3e80 100644
--- a/diff.c
+++ b/diff.c
@@ -291,7 +291,7 @@
 		return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 }
 
-static int parse_color_moved_ws(const char *arg)
+static unsigned parse_color_moved_ws(const char *arg)
 {
 	int ret = 0;
 	struct string_list l = STRING_LIST_INIT_DUP;
@@ -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;
@@ -312,15 +314,19 @@
 			ret |= XDF_IGNORE_WHITESPACE;
 		else if (!strcmp(sb.buf, "allow-indentation-change"))
 			ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
-		else
-			error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
+		else {
+			ret |= COLOR_MOVED_WS_ERROR;
+			error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
+		}
 
 		strbuf_release(&sb);
 	}
 
 	if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
-	    (ret & XDF_WHITESPACE_FLAGS))
-		die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
+	    (ret & XDF_WHITESPACE_FLAGS)) {
+		error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
+		ret |= COLOR_MOVED_WS_ERROR;
+	}
 
 	string_list_clear(&l, 0);
 
@@ -341,8 +347,8 @@
 		return 0;
 	}
 	if (!strcmp(var, "diff.colormovedws")) {
-		int cm = parse_color_moved_ws(value);
-		if (cm < 0)
+		unsigned cm = parse_color_moved_ws(value);
+		if (cm & COLOR_MOVED_WS_ERROR)
 			return -1;
 		diff_color_moved_ws_default = cm;
 		return 0;
@@ -489,7 +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;
@@ -750,6 +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}
@@ -780,44 +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;
 }
@@ -829,51 +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,
@@ -939,6 +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;
@@ -1017,8 +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++;
 		}
@@ -1038,14 +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++) {
@@ -1053,11 +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 */
@@ -1067,7 +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++) {
@@ -1075,6 +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:
@@ -1090,7 +1148,7 @@
 			free(key);
 			break;
 		default:
-			flipped_block = 1;
+			flipped_block = 0;
 		}
 
 		if (!match) {
@@ -1101,13 +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)
@@ -1130,21 +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);
 
@@ -1488,7 +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);
@@ -1637,7 +1704,8 @@
 	strbuf_release(&msgbuf);
 }
 
-static struct diff_tempfile *claim_diff_tempfile(void) {
+static struct diff_tempfile *claim_diff_tempfile(void)
+{
 	int i;
 	for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 		if (!diff_temp[i].name)
@@ -3476,7 +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;
@@ -3519,12 +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,
@@ -4819,7 +4890,8 @@
 	return 0;
 }
 
-static void enable_patch_output(int *fmt) {
+static void enable_patch_output(int *fmt)
+{
 	*fmt &= ~DIFF_FORMAT_NO_OUTPUT;
 	*fmt |= DIFF_FORMAT_PATCH;
 }
@@ -5034,10 +5106,15 @@
 	else if (skip_prefix(arg, "--color-moved=", &arg)) {
 		int cm = parse_color_moved(arg);
 		if (cm < 0)
-			die("bad --color-moved argument: %s", arg);
+			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)) {
-		options->color_moved_ws_handling = parse_color_moved_ws(arg);
+		unsigned cm = parse_color_moved_ws(arg);
+		if (cm & COLOR_MOVED_WS_ERROR)
+			return -1;
+		options->color_moved_ws_handling = cm;
 	} else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
 		options->use_color = 1;
 		options->word_diff = DIFF_WORDS_COLOR;
diff --git a/diff.h b/diff.h
index 412138b..b512d04 100644
--- a/diff.h
+++ b/diff.h
@@ -225,7 +225,8 @@
 
 	/* XDF_WHITESPACE_FLAGS regarding block detection are set at 2, 3, 4 */
 	#define COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE (1<<5)
-	int color_moved_ws_handling;
+	#define COLOR_MOVED_WS_ERROR (1<<0)
+	unsigned color_moved_ws_handling;
 
 	struct repository *repo;
 };
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index ad939d2..a9c6d60 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -154,6 +154,12 @@
 	if (textconv_one == textconv_two && diff_unmodified_pair(p))
 		return 0;
 
+	if ((o->pickaxe_opts & DIFF_PICKAXE_KIND_G) &&
+	    !o->flags.text &&
+	    ((!textconv_one && diff_filespec_is_binary(o->repo, p->one)) ||
+	     (!textconv_two && diff_filespec_is_binary(o->repo, p->two))))
+		return 0;
+
 	mf1.size = fill_textconv(o->repo, textconv_one, p->one, &mf1.ptr);
 	mf2.size = fill_textconv(o->repo, textconv_two, p->two, &mf2.ptr);
 
diff --git a/dir.c b/dir.c
index ab6477d..2128448 100644
--- a/dir.c
+++ b/dir.c
@@ -276,44 +276,6 @@
 #define DO_MATCH_DIRECTORY (1<<1)
 #define DO_MATCH_SUBMODULE (1<<2)
 
-static int match_attrs(const struct index_state *istate,
-		       const char *name, int namelen,
-		       const struct pathspec_item *item)
-{
-	int i;
-	char *to_free = NULL;
-
-	if (name[namelen])
-		name = to_free = xmemdupz(name, namelen);
-
-	git_check_attr(istate, name, item->attr_check);
-
-	free(to_free);
-
-	for (i = 0; i < item->attr_match_nr; i++) {
-		const char *value;
-		int matched;
-		enum attr_match_mode match_mode;
-
-		value = item->attr_check->items[i].value;
-		match_mode = item->attr_match[i].match_mode;
-
-		if (ATTR_TRUE(value))
-			matched = (match_mode == MATCH_SET);
-		else if (ATTR_FALSE(value))
-			matched = (match_mode == MATCH_UNSET);
-		else if (ATTR_UNSET(value))
-			matched = (match_mode == MATCH_UNSPECIFIED);
-		else
-			matched = (match_mode == MATCH_VALUE &&
-				   !strcmp(item->attr_match[i].value, value));
-		if (!matched)
-			return 0;
-	}
-
-	return 1;
-}
-
 /*
  * Does 'match' match the given name?
  * A match is found if
@@ -367,7 +329,8 @@
 	    strncmp(item->match, name - prefix, item->prefix))
 		return 0;
 
-	if (item->attr_match_nr && !match_attrs(istate, name, namelen, item))
+	if (item->attr_match_nr &&
+	    !match_pathspec_attrs(istate, name, namelen, item))
 		return 0;
 
 	/* If the match was just the prefix, we matched */
diff --git a/entry.c b/entry.c
index 0a3c451..6fd72b3 100644
--- a/entry.c
+++ b/entry.c
@@ -161,7 +161,7 @@
 	return !available;
 }
 
-int finish_delayed_checkout(struct checkout *state)
+int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 {
 	int errs = 0;
 	unsigned delayed_object_count;
@@ -226,7 +226,7 @@
 				ce = index_file_exists(state->istate, path->string,
 						       strlen(path->string), 0);
 				if (ce) {
-					errs |= checkout_entry(ce, state, NULL);
+					errs |= checkout_entry(ce, state, NULL, nr_checkouts);
 					filtered_bytes += ce->ce_stat_data.sd_size;
 					display_throughput(progress, filtered_bytes);
 				} else
@@ -435,8 +435,8 @@
  * its name is returned in topath[], which must be able to hold at
  * least TEMPORARY_FILENAME_LENGTH bytes long.
  */
-int checkout_entry(struct cache_entry *ce,
-		   const struct checkout *state, char *topath)
+int checkout_entry(struct cache_entry *ce, const struct checkout *state,
+		   char *topath, int *nr_checkouts)
 {
 	static struct strbuf path = STRBUF_INIT;
 	struct stat st;
@@ -506,5 +506,7 @@
 		return 0;
 
 	create_directories(path.buf, path.len, state);
+	if (nr_checkouts)
+		(*nr_checkouts)++;
 	return write_entry(ce, path.buf, state, 0);
 }
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..577faa6 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1007,6 +1007,8 @@
 			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)
@@ -1232,6 +1234,8 @@
 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 +1245,7 @@
 			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 +1258,7 @@
 				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 +1268,11 @@
 	    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,
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/git-compat-util.h b/git-compat-util.h
index 09b0102..29a1990 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -193,10 +193,11 @@
 #endif
 
 #if defined(__CYGWIN__)
-#include "compat/cygwin.h"
+#include "compat/win32/path-utils.h"
 #endif
 #if defined(__MINGW32__)
 /* pull in Windows compatibility stuff */
+#include "compat/win32/path-utils.h"
 #include "compat/mingw.h"
 #elif defined(_MSC_VER)
 #include "compat/msvc.h"
@@ -397,6 +398,19 @@
 #define query_user_email() NULL
 #endif
 
+#ifdef __TANDEM
+#include <floss.h(floss_execl,floss_execlp,floss_execv,floss_execvp)>
+#include <floss.h(floss_getpwuid)>
+#ifndef NSIG
+/*
+ * NonStop NSE and NSX do not provide NSIG. SIGGUARDIAN(99) is the highest
+ * known, by detective work using kill -l as a list is all signals
+ * instead of signal.h where it should be.
+ */
+# define NSIG 100
+#endif
+#endif
+
 #if defined(__HP_cc) && (__HP_cc >= 61000)
 #define NORETURN __attribute__((noreturn))
 #define NORETURN_PTR
@@ -721,7 +735,7 @@
 #ifdef NO_MEMMEM
 #define memmem gitmemmem
 void *gitmemmem(const void *haystack, size_t haystacklen,
-                const void *needle, size_t needlelen);
+		const void *needle, size_t needlelen);
 #endif
 
 #ifdef OVERRIDE_STRDUP
diff --git a/git-legacy-rebase.sh b/git-legacy-rebase.sh
index b4c7dbf..3bb0682 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 () {
@@ -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 () {
@@ -163,7 +170,8 @@
 		"$allow_empty_message" "$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 () {
@@ -255,6 +263,11 @@
 		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 "$interactive_rebase" && interactive_rebase=implied
+		;;
 	--interactive)
 		interactive_rebase=explicit
 		;;
@@ -378,6 +391,12 @@
 	--gpg-sign=*)
 		gpg_sign_opt="-S${1#--gpg-sign=}"
 		;;
+	--reschedule-failed-exec)
+		reschedule_failed_exec=--reschedule-failed-exec
+		;;
+	--no-reschedule-failed-exec)
+		reschedule_failed_exec=
+		;;
 	--)
 		shift
 		break
@@ -534,6 +553,9 @@
 	#       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'")"
+
+	test -n "$reschedule_failed_exec" &&
+		die "$(gettext "error: cannot combine '--preserve-merges' with '--reschedule-failed-exec'")"
 fi
 
 if test -n "$rebase_merges"
diff --git a/git-p4.py b/git-p4.py
index 1998c3e..3e12774 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -332,6 +332,8 @@
             die_bad_access("p4 error: {0}".format(data))
         else:
             die_bad_access("unknown error")
+    elif code == "info":
+        return
     else:
         die_bad_access("unknown error code {0}".format(code))
 
diff --git a/git-quiltimport.sh b/git-quiltimport.sh
index 6d3a88d..e3d3909 100755
--- a/git-quiltimport.sh
+++ b/git-quiltimport.sh
@@ -8,6 +8,7 @@
 author=       author name and email address for patches without any
 patches=      path to the quilt patches
 series=       path to the quilt series file
+keep-non-patch Pass -b to git mailinfo
 "
 SUBDIRECTORY_ON=Yes
 . git-sh-setup
@@ -32,6 +33,9 @@
 		shift
 		QUILT_SERIES="$1"
 		;;
+	--keep-non-patch)
+		MAILINFO_OPT="-b"
+		;;
 	--)
 		shift
 		break;;
@@ -98,7 +102,7 @@
 		continue
 	fi
 	echo $patch_name
-	git mailinfo "$tmp_msg" "$tmp_patch" \
+	git mailinfo $MAILINFO_OPT "$tmp_msg" "$tmp_patch" \
 		<"$QUILT_PATCHES/$patch_name" >"$tmp_info" || exit 3
 	test -s "$tmp_patch" || {
 		echo "Patch is empty.  Was it split wrong?"
diff --git a/git-rebase--common.sh b/git-rebase--common.sh
index 7e39d22..a8a4460 100644
--- a/git-rebase--common.sh
+++ b/git-rebase--common.sh
@@ -19,6 +19,7 @@
 		"$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.c b/git.c
index 4d53a3d..0ce0e13 100644
--- a/git.c
+++ b/git.c
@@ -98,7 +98,8 @@
 	return 0;
 }
 
-static void commit_pager_choice(void) {
+static void commit_pager_choice(void)
+{
 	switch (use_pager) {
 	case 0:
 		setenv("GIT_PAGER", "cat", 1);
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/imap-send.c b/imap-send.c
index b4eb886..18ca6ba 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -1471,7 +1471,8 @@
 }
 
 static int curl_append_msgs_to_imap(struct imap_server_conf *server,
-				    struct strbuf* all_msgs, int total) {
+				    struct strbuf* all_msgs, int total)
+{
 	int ofs = 0;
 	int n = 0;
 	struct buffer msgbuf = { STRBUF_INIT, 0 };
diff --git a/list-objects.c b/list-objects.c
index cf7f25b..a2296a8 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -114,7 +114,8 @@
 
 	while (tree_entry(&desc, &entry)) {
 		if (match != all_entries_interesting) {
-			match = tree_entry_interesting(&entry, base, 0,
+			match = tree_entry_interesting(ctx->revs->repo->index,
+						       &entry, base, 0,
 						       &ctx->revs->diffopt.pathspec);
 			if (match == all_entries_not_interesting)
 				break;
@@ -123,15 +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/ls-refs.c b/ls-refs.c
index a06f12e..9c9a7c6 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.
@@ -40,6 +41,9 @@
 	const char *refname_nons = strip_namespace(refname);
 	struct strbuf refline = STRBUF_INIT;
 
+	if (ref_is_hidden(refname_nons, refname))
+		return 0;
+
 	if (!ref_match(&data->prefixes, refname))
 		return 0;
 
@@ -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/merge-recursive.c b/merge-recursive.c
index ecf8db0..59ba4b4 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -469,7 +469,8 @@
 {
 	struct pathspec match_all;
 	memset(&match_all, 0, sizeof(match_all));
-	read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o);
+	read_tree_recursive(the_repository, tree, "", 0, 0,
+			    &match_all, save_files_dirs, o);
 }
 
 static int get_tree_entry_if_blob(const struct object_id *tree,
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 60758ef..e16aa38 100644
--- a/object-store.h
+++ b/object-store.h
@@ -20,7 +20,7 @@
 	 * Be sure to call odb_load_loose_cache() before using.
 	 */
 	char loose_objects_subdir_seen[256];
-	struct oid_array loose_objects_cache;
+	struct oid_array loose_objects_cache[256];
 
 	/*
 	 * Path to the alternative object store. If this is a relative path,
@@ -48,11 +48,14 @@
 void add_to_alternates_memory(const char *dir);
 
 /*
- * Populate an odb's loose object cache for one particular subdirectory (i.e.,
- * the one that corresponds to the first byte of objects you're interested in,
- * from 0 to 255 inclusive).
+ * Populate and return the loose object cache array corresponding to the
+ * given object ID.
  */
-void odb_load_loose_cache(struct object_directory *odb, int subdir_nr);
+struct oid_array *odb_loose_cache(struct object_directory *odb,
+				  const struct object_id *oid);
+
+/* Empty the loose object cache for the specified object directory. */
+void odb_clear_loose_cache(struct object_directory *odb);
 
 struct packed_git {
 	struct packed_git *next;
diff --git a/object.c b/object.c
index 79d6360..a5c5cf8 100644
--- a/object.c
+++ b/object.c
@@ -485,7 +485,7 @@
 static void free_object_directory(struct object_directory *odb)
 {
 	free(odb->path);
-	oid_array_clear(&odb->loose_objects_cache);
+	odb_clear_loose_cache(odb);
 	free(odb);
 }
 
diff --git a/packfile.c b/packfile.c
index 8c6b47c..ac6bb64 100644
--- a/packfile.c
+++ b/packfile.c
@@ -994,11 +994,8 @@
 {
 	struct object_directory *odb;
 
-	for (odb = r->objects->odb; odb; odb = odb->next) {
-		oid_array_clear(&odb->loose_objects_cache);
-		memset(&odb->loose_objects_subdir_seen, 0,
-		       sizeof(odb->loose_objects_subdir_seen));
-	}
+	for (odb = r->objects->odb; odb; odb = odb->next)
+		odb_clear_loose_cache(odb);
 
 	r->objects->approximate_object_count_valid = 0;
 	r->objects->packed_git_initialized = 0;
@@ -2100,7 +2097,7 @@
 			 */
 			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/parse-options.c b/parse-options.c
index 01c2acb..9f84bac 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -236,7 +236,7 @@
 }
 
 static int parse_long_opt(struct parse_opt_ctx_t *p, const char *arg,
-                          const struct option *options)
+			  const struct option *options)
 {
 	const struct option *all_opts = options;
 	const char *arg_end = strchrnul(arg, '=');
diff --git a/parse-options.h b/parse-options.h
index 81380c2..14fe324 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -175,11 +175,11 @@
  * Returns the number of arguments left in argv[].
  */
 extern int parse_options(int argc, const char **argv, const char *prefix,
-                         const struct option *options,
-                         const char * const usagestr[], int flags);
+			 const struct option *options,
+			 const char * const usagestr[], int flags);
 
 extern NORETURN void usage_with_options(const char * const *usagestr,
-                                        const struct option *options);
+					const struct option *options);
 
 extern NORETURN void usage_msg_opt(const char *msg,
 				   const char * const *usagestr,
diff --git a/pathspec.c b/pathspec.c
index 6f00599..e85298f 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -659,3 +659,41 @@
 	FREE_AND_NULL(pathspec->items);
 	pathspec->nr = 0;
 }
+
+int match_pathspec_attrs(const struct index_state *istate,
+			 const char *name, int namelen,
+			 const struct pathspec_item *item)
+{
+	int i;
+	char *to_free = NULL;
+
+	if (name[namelen])
+		name = to_free = xmemdupz(name, namelen);
+
+	git_check_attr(istate, name, item->attr_check);
+
+	free(to_free);
+
+	for (i = 0; i < item->attr_match_nr; i++) {
+		const char *value;
+		int matched;
+		enum attr_match_mode match_mode;
+
+		value = item->attr_check->items[i].value;
+		match_mode = item->attr_match[i].match_mode;
+
+		if (ATTR_TRUE(value))
+			matched = (match_mode == MATCH_SET);
+		else if (ATTR_FALSE(value))
+			matched = (match_mode == MATCH_UNSET);
+		else if (ATTR_UNSET(value))
+			matched = (match_mode == MATCH_UNSPECIFIED);
+		else
+			matched = (match_mode == MATCH_VALUE &&
+				   !strcmp(item->attr_match[i].value, value));
+		if (!matched)
+			return 0;
+	}
+
+	return 1;
+}
diff --git a/pathspec.h b/pathspec.h
index a6525a6..1c18a2c 100644
--- a/pathspec.h
+++ b/pathspec.h
@@ -80,13 +80,13 @@
  * Any arguments used are copied. It is safe for the caller to modify
  * or free 'prefix' and 'args' after calling this function.
  */
-extern void parse_pathspec(struct pathspec *pathspec,
-			   unsigned magic_mask,
-			   unsigned flags,
-			   const char *prefix,
-			   const char **args);
-extern void copy_pathspec(struct pathspec *dst, const struct pathspec *src);
-extern void clear_pathspec(struct pathspec *);
+void parse_pathspec(struct pathspec *pathspec,
+		    unsigned magic_mask,
+		    unsigned flags,
+		    const char *prefix,
+		    const char **args);
+void copy_pathspec(struct pathspec *dst, const struct pathspec *src);
+void clear_pathspec(struct pathspec *);
 
 static inline int ps_strncmp(const struct pathspec_item *item,
 			     const char *s1, const char *s2, size_t n)
@@ -106,10 +106,13 @@
 		return strcmp(s1, s2);
 }
 
-extern void add_pathspec_matches_against_index(const struct pathspec *pathspec,
-					       const struct index_state *istate,
-					       char *seen);
-extern char *find_pathspecs_matching_against_index(const struct pathspec *pathspec,
-						   const struct index_state *istate);
+void add_pathspec_matches_against_index(const struct pathspec *pathspec,
+					const struct index_state *istate,
+					char *seen);
+char *find_pathspecs_matching_against_index(const struct pathspec *pathspec,
+					    const struct index_state *istate);
+int match_pathspec_attrs(const struct index_state *istate,
+			 const char *name, int namelen,
+			 const struct pathspec_item *item);
 
 #endif /* PATHSPEC_H */
diff --git a/quote.c b/quote.c
index c95dd2c..7f2aa6f 100644
--- a/quote.c
+++ b/quote.c
@@ -234,7 +234,7 @@
  *     Return value is the same as in (1).
  */
 static size_t quote_c_style_counted(const char *name, ssize_t maxlen,
-                                    struct strbuf *sb, FILE *fp, int no_dq)
+				    struct strbuf *sb, FILE *fp, int no_dq)
 {
 #undef EMIT
 #define EMIT(c)                                 \
diff --git a/read-cache.c b/read-cache.c
index 48c1797..bfff271 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3495,71 +3495,71 @@
 
 static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset)
 {
-       const char *index = NULL;
-       uint32_t extsize, ext_version;
-       struct index_entry_offset_table *ieot;
-       int i, nr;
+	const char *index = NULL;
+	uint32_t extsize, ext_version;
+	struct index_entry_offset_table *ieot;
+	int i, nr;
 
-       /* find the IEOT extension */
-       if (!offset)
-	       return NULL;
-       while (offset <= mmap_size - the_hash_algo->rawsz - 8) {
-	       extsize = get_be32(mmap + offset + 4);
-	       if (CACHE_EXT((mmap + offset)) == CACHE_EXT_INDEXENTRYOFFSETTABLE) {
-		       index = mmap + offset + 4 + 4;
-		       break;
-	       }
-	       offset += 8;
-	       offset += extsize;
-       }
-       if (!index)
-	       return NULL;
+	/* find the IEOT extension */
+	if (!offset)
+		return NULL;
+	while (offset <= mmap_size - the_hash_algo->rawsz - 8) {
+		extsize = get_be32(mmap + offset + 4);
+		if (CACHE_EXT((mmap + offset)) == CACHE_EXT_INDEXENTRYOFFSETTABLE) {
+			index = mmap + offset + 4 + 4;
+			break;
+		}
+		offset += 8;
+		offset += extsize;
+	}
+	if (!index)
+		return NULL;
 
-       /* validate the version is IEOT_VERSION */
-       ext_version = get_be32(index);
-       if (ext_version != IEOT_VERSION) {
-	       error("invalid IEOT version %d", ext_version);
-	       return NULL;
-       }
-       index += sizeof(uint32_t);
+	/* validate the version is IEOT_VERSION */
+	ext_version = get_be32(index);
+	if (ext_version != IEOT_VERSION) {
+		error("invalid IEOT version %d", ext_version);
+		return NULL;
+	}
+	index += sizeof(uint32_t);
 
-       /* extension size - version bytes / bytes per entry */
-       nr = (extsize - sizeof(uint32_t)) / (sizeof(uint32_t) + sizeof(uint32_t));
-       if (!nr) {
-	       error("invalid number of IEOT entries %d", nr);
-	       return NULL;
-       }
-       ieot = xmalloc(sizeof(struct index_entry_offset_table)
-	       + (nr * sizeof(struct index_entry_offset)));
-       ieot->nr = nr;
-       for (i = 0; i < nr; i++) {
-	       ieot->entries[i].offset = get_be32(index);
-	       index += sizeof(uint32_t);
-	       ieot->entries[i].nr = get_be32(index);
-	       index += sizeof(uint32_t);
-       }
+	/* extension size - version bytes / bytes per entry */
+	nr = (extsize - sizeof(uint32_t)) / (sizeof(uint32_t) + sizeof(uint32_t));
+	if (!nr) {
+		error("invalid number of IEOT entries %d", nr);
+		return NULL;
+	}
+	ieot = xmalloc(sizeof(struct index_entry_offset_table)
+		       + (nr * sizeof(struct index_entry_offset)));
+	ieot->nr = nr;
+	for (i = 0; i < nr; i++) {
+		ieot->entries[i].offset = get_be32(index);
+		index += sizeof(uint32_t);
+		ieot->entries[i].nr = get_be32(index);
+		index += sizeof(uint32_t);
+	}
 
-       return ieot;
+	return ieot;
 }
 
 static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot)
 {
-       uint32_t buffer;
-       int i;
+	uint32_t buffer;
+	int i;
 
-       /* version */
-       put_be32(&buffer, IEOT_VERSION);
-       strbuf_add(sb, &buffer, sizeof(uint32_t));
+	/* version */
+	put_be32(&buffer, IEOT_VERSION);
+	strbuf_add(sb, &buffer, sizeof(uint32_t));
 
-       /* ieot */
-       for (i = 0; i < ieot->nr; i++) {
+	/* ieot */
+	for (i = 0; i < ieot->nr; i++) {
 
-	       /* offset */
-	       put_be32(&buffer, ieot->entries[i].offset);
-	       strbuf_add(sb, &buffer, sizeof(uint32_t));
+		/* offset */
+		put_be32(&buffer, ieot->entries[i].offset);
+		strbuf_add(sb, &buffer, sizeof(uint32_t));
 
-	       /* count */
-	       put_be32(&buffer, ieot->entries[i].nr);
-	       strbuf_add(sb, &buffer, sizeof(uint32_t));
-       }
+		/* count */
+		put_be32(&buffer, ieot->entries[i].nr);
+		strbuf_add(sb, &buffer, sizeof(uint32_t));
+	}
 }
diff --git a/ref-filter.c b/ref-filter.c
index 61d75d5..422a9c9 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -231,12 +231,30 @@
 static int objectsize_atom_parser(const struct ref_format *format, struct used_atom *atom,
 				  const char *arg, struct strbuf *err)
 {
+	if (!arg) {
+		if (*atom->name == '*')
+			oi_deref.info.sizep = &oi_deref.size;
+		else
+			oi.info.sizep = &oi.size;
+	} else if (!strcmp(arg, "disk")) {
+		if (*atom->name == '*')
+			oi_deref.info.disk_sizep = &oi_deref.disk_size;
+		else
+			oi.info.disk_sizep = &oi.disk_size;
+	} else
+		return strbuf_addf_ret(err, -1, _("unrecognized %%(objectsize) argument: %s"), arg);
+	return 0;
+}
+
+static int deltabase_atom_parser(const struct ref_format *format, struct used_atom *atom,
+				 const char *arg, struct strbuf *err)
+{
 	if (arg)
-		return strbuf_addf_ret(err, -1, _("%%(objectsize) does not take arguments"));
+		return strbuf_addf_ret(err, -1, _("%%(deltabase) does not take arguments"));
 	if (*atom->name == '*')
-		oi_deref.info.sizep = &oi_deref.size;
+		oi_deref.info.delta_base_sha1 = oi_deref.delta_base_oid.hash;
 	else
-		oi.info.sizep = &oi.size;
+		oi.info.delta_base_sha1 = oi.delta_base_oid.hash;
 	return 0;
 }
 
@@ -431,6 +449,7 @@
 	{ "objecttype", SOURCE_OTHER, FIELD_STR, objecttype_atom_parser },
 	{ "objectsize", SOURCE_OTHER, FIELD_ULONG, objectsize_atom_parser },
 	{ "objectname", SOURCE_OTHER, FIELD_STR, objectname_atom_parser },
+	{ "deltabase", SOURCE_OTHER, FIELD_STR, deltabase_atom_parser },
 	{ "tree", SOURCE_OBJ },
 	{ "parent", SOURCE_OBJ },
 	{ "numparent", SOURCE_OBJ, FIELD_ULONG },
@@ -880,10 +899,14 @@
 			name++;
 		if (!strcmp(name, "objecttype"))
 			v->s = xstrdup(type_name(oi->type));
-		else if (!strcmp(name, "objectsize")) {
+		else if (!strcmp(name, "objectsize:disk")) {
+			v->value = oi->disk_size;
+			v->s = xstrfmt("%"PRIuMAX, (uintmax_t)oi->disk_size);
+		} else if (!strcmp(name, "objectsize")) {
 			v->value = oi->size;
 			v->s = xstrfmt("%"PRIuMAX , (uintmax_t)oi->size);
-		}
+		} else if (!strcmp(name, "deltabase"))
+			v->s = xstrdup(oid_to_hex(&oi->delta_base_oid));
 		else if (deref)
 			grab_objectname(name, &oi->oid, v, &used_atom[i]);
 	}
@@ -1482,6 +1505,8 @@
 				     OBJECT_INFO_LOOKUP_REPLACE))
 		return strbuf_addf_ret(err, -1, _("missing object %s for %s"),
 				       oid_to_hex(&oi->oid), ref->refname);
+	if (oi->info.disk_sizep && oi->disk_size < 0)
+		BUG("Object size is less than zero.");
 
 	if (oi->info.contentp) {
 		*obj = parse_object_buffer(the_repository, &oi->oid, oi->type, oi->size, oi->content, &eaten);
diff --git a/remote-curl.c b/remote-curl.c
index 1220dff..6ff9c66 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -380,7 +380,6 @@
 	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) {
@@ -546,14 +545,30 @@
 }
 #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;
 }
 
@@ -617,7 +632,8 @@
 	return err;
 }
 
-static curl_off_t xcurl_off_t(size_t len) {
+static curl_off_t xcurl_off_t(size_t len)
+{
 	uintmax_t size = len;
 	if (size > maximum_signed_value_of_type(curl_off_t))
 		die("cannot handle pushes this big");
@@ -633,6 +649,7 @@
 	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
@@ -765,7 +782,10 @@
 
 	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;
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 13e0519..119947c 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 */
@@ -1463,6 +1463,7 @@
 	revs->abbrev = DEFAULT_ABBREV;
 	revs->ignore_merges = 1;
 	revs->simplify_history = 1;
+	revs->pruning.repo = r;
 	revs->pruning.flags.recursive = 1;
 	revs->pruning.flags.quick = 1;
 	revs->pruning.add_remove = file_add_remove;
@@ -1495,8 +1496,8 @@
 }
 
 static void add_pending_commit_list(struct rev_info *revs,
-                                    struct commit_list *commit_list,
-                                    unsigned int flags)
+				    struct commit_list *commit_list,
+				    unsigned int flags)
 {
 	while (commit_list) {
 		struct object *object = &commit_list->item->object;
@@ -1729,6 +1730,8 @@
 	if (!cant_be_filename)
 		verify_non_filename(revs->prefix, arg);
 	object = get_reference(revs, arg, &oid, flags ^ local_flags);
+	if (!object)
+		return revs->ignore_missing ? 0 : -1;
 	add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
 	add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
 	free(oc.path);
@@ -1791,7 +1794,8 @@
 }
 
 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
-			       int *unkc, const char **unkv)
+			       int *unkc, const char **unkv,
+			       const struct setup_revision_opt* opt)
 {
 	const char *arg = argv[0];
 	const char *optarg;
@@ -2151,7 +2155,7 @@
 		revs->limited = 1;
 	} else if (!strcmp(arg, "--ignore-missing")) {
 		revs->ignore_missing = 1;
-	} else if (revs->allow_exclude_promisor_objects_opt &&
+	} else if (opt && opt->allow_exclude_promisor_objects &&
 		   !strcmp(arg, "--exclude-promisor-objects")) {
 		if (fetch_if_missing)
 			BUG("exclude_promisor_objects can only be used when fetch_if_missing is 0");
@@ -2173,7 +2177,7 @@
 			const char * const usagestr[])
 {
 	int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
-				    &ctx->cpidx, ctx->out);
+				    &ctx->cpidx, ctx->out, NULL);
 	if (n <= 0) {
 		error("unknown option `%s'", ctx->argv[0]);
 		usage_with_options(usagestr, options);
@@ -2391,7 +2395,8 @@
 				continue;
 			}
 
-			opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
+			opts = handle_revision_opt(revs, argc - i, argv + i,
+						   &left, argv, opt);
 			if (opts > 0) {
 				i += opts - 1;
 				continue;
diff --git a/revision.h b/revision.h
index 7987bfc..52e5a88 100644
--- a/revision.h
+++ b/revision.h
@@ -161,7 +161,6 @@
 			do_not_die_on_missing_tree:1,
 
 			/* for internal use only */
-			allow_exclude_promisor_objects_opt:1,
 			exclude_promisor_objects:1;
 
 	/* Diff flags */
@@ -297,7 +296,8 @@
 	const char *def;
 	void (*tweak)(struct rev_info *, struct setup_revision_opt *);
 	const char *submodule;	/* TODO: drop this and use rev_info->repo */
-	int assume_dashdash;
+	unsigned int	assume_dashdash:1,
+			allow_exclude_promisor_objects:1;
 	unsigned revarg_opt;
 };
 
diff --git a/sequencer.c b/sequencer.c
index b68bca0..213815d 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -158,6 +158,7 @@
 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)
 {
@@ -1689,7 +1690,8 @@
 	return res;
 }
 
-static void flush_rewritten_pending(void) {
+static void flush_rewritten_pending(void)
+{
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id newoid;
 	FILE *out;
@@ -1714,7 +1716,8 @@
 }
 
 static void record_in_rewritten(struct object_id *oid,
-		enum todo_command next_command) {
+		enum todo_command next_command)
+{
 	FILE *out = fopen_or_warn(rebase_path_rewritten_pending(), "a");
 
 	if (!out)
@@ -1788,9 +1791,13 @@
 			return error(_("commit %s does not have parent %d"),
 				oid_to_hex(&commit->object.oid), opts->mainline);
 		parent = p->item;
-	} else if (0 < opts->mainline)
-		return error(_("mainline was specified but commit %s is not a merge."),
-			oid_to_hex(&commit->object.oid));
+	} else if (1 < opts->mainline)
+		/*
+		 *  Non-first parent explicitly specified as mainline for
+		 *  non-merge commit
+		 */
+		return error(_("commit %s does not have parent %d"),
+			     oid_to_hex(&commit->object.oid), opts->mainline);
 	else
 		parent = commit->parents->item;
 
@@ -2388,6 +2395,9 @@
 			opts->signoff = 1;
 		}
 
+		if (file_exists(rebase_path_reschedule_failed_exec()))
+			opts->reschedule_failed_exec = 1;
+
 		read_strategy_opts(opts, &buf);
 		strbuf_release(&buf);
 
@@ -2469,6 +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;
 }
@@ -3626,9 +3638,10 @@
 			*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)) {
diff --git a/sequencer.h b/sequencer.h
index 9d83f0f..5d7bc04 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -40,6 +40,7 @@
 	int allow_empty_message;
 	int keep_redundant_commits;
 	int verbose;
+	int reschedule_failed_exec;
 
 	int mainline;
 
diff --git a/setup.c b/setup.c
index 1be5037..12bf25a 100644
--- a/setup.c
+++ b/setup.c
@@ -831,16 +831,6 @@
 	return NULL;
 }
 
-static const char *setup_nongit(const char *cwd, int *nongit_ok)
-{
-	if (!nongit_ok)
-		die(_("not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
-	if (chdir(cwd))
-		die_errno(_("cannot come back to cwd"));
-	*nongit_ok = 1;
-	return NULL;
-}
-
 static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 {
 	struct stat buf;
@@ -1054,7 +1044,7 @@
 {
 	static struct strbuf cwd = STRBUF_INIT;
 	struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
-	const char *prefix;
+	const char *prefix = NULL;
 	struct repository_format repo_fmt;
 
 	/*
@@ -1079,9 +1069,6 @@
 	strbuf_addbuf(&dir, &cwd);
 
 	switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
-	case GIT_DIR_NONE:
-		prefix = NULL;
-		break;
 	case GIT_DIR_EXPLICIT:
 		prefix = setup_explicit_git_dir(gitdir.buf, &cwd, &repo_fmt, nongit_ok);
 		break;
@@ -1097,29 +1084,51 @@
 		prefix = setup_bare_git_dir(&cwd, dir.len, &repo_fmt, nongit_ok);
 		break;
 	case GIT_DIR_HIT_CEILING:
-		prefix = setup_nongit(cwd.buf, nongit_ok);
+		if (!nongit_ok)
+			die(_("not a git repository (or any of the parent directories): %s"),
+			    DEFAULT_GIT_DIR_ENVIRONMENT);
+		*nongit_ok = 1;
 		break;
 	case GIT_DIR_HIT_MOUNT_POINT:
-		if (nongit_ok) {
-			*nongit_ok = 1;
-			strbuf_release(&cwd);
-			strbuf_release(&dir);
-			return NULL;
-		}
-		die(_("not a git repository (or any parent up to mount point %s)\n"
-		      "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
-		    dir.buf);
+		if (!nongit_ok)
+			die(_("not a git repository (or any parent up to mount point %s)\n"
+			      "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
+			    dir.buf);
+		*nongit_ok = 1;
+		break;
+	case GIT_DIR_NONE:
+		/*
+		 * As a safeguard against setup_git_directory_gently_1 returning
+		 * this value, fallthrough to BUG. Otherwise it is possible to
+		 * set startup_info->have_repository to 1 when we did nothing to
+		 * find a repository.
+		 */
 	default:
 		BUG("unhandled setup_git_directory_1() result");
 	}
 
-	if (prefix)
-		setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
-	else
+	/*
+	 * At this point, nongit_ok is stable. If it is non-NULL and points
+	 * to a non-zero value, then this means that we haven't found a
+	 * repository and that the caller expects startup_info to reflect
+	 * this.
+	 *
+	 * Regardless of the state of nongit_ok, startup_info->prefix and
+	 * the GIT_PREFIX environment variable must always match. For details
+	 * see Documentation/config/alias.txt.
+	 */
+	if (nongit_ok && *nongit_ok) {
+		startup_info->have_repository = 0;
+		startup_info->prefix = NULL;
 		setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
-
-	startup_info->have_repository = !nongit_ok || !*nongit_ok;
-	startup_info->prefix = prefix;
+	} else {
+		startup_info->have_repository = 1;
+		startup_info->prefix = prefix;
+		if (prefix)
+			setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
+		else
+			setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
+	}
 
 	/*
 	 * Not all paths through the setup code will call 'set_git_dir()' (which
@@ -1132,7 +1141,10 @@
 	 * the user has set GIT_DIR.  It may be beneficial to disallow bogus
 	 * GIT_DIR values at some point in the future.
 	 */
-	if (startup_info->have_repository || getenv(GIT_DIR_ENVIRONMENT)) {
+	if (/* GIT_DIR_EXPLICIT, GIT_DIR_DISCOVERED, GIT_DIR_BARE */
+	    startup_info->have_repository ||
+	    /* GIT_DIR_EXPLICIT */
+	    getenv(GIT_DIR_ENVIRONMENT)) {
 		if (!the_repository->gitdir) {
 			const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
 			if (!gitdir)
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 5a272f7..10f9e99 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
@@ -924,7 +992,6 @@
 static int quick_has_loose(struct repository *r,
 			   const unsigned char *sha1)
 {
-	int subdir_nr = sha1[0];
 	struct object_id oid;
 	struct object_directory *odb;
 
@@ -932,8 +999,7 @@
 
 	prepare_alt_odb(r);
 	for (odb = r->objects->odb; odb; odb = odb->next) {
-		odb_load_loose_cache(odb, subdir_nr);
-		if (oid_array_lookup(&odb->loose_objects_cache, &oid) >= 0)
+		if (oid_array_lookup(odb_loose_cache(odb, &oid), &oid) >= 0)
 			return 1;
 	}
 	return 0;
@@ -962,6 +1028,7 @@
 			if (!*size) {
 				/* mmap() is forbidden on empty files */
 				error(_("object file %s is empty"), path);
+				close(fd);
 				return NULL;
 			}
 			map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
@@ -2152,8 +2219,10 @@
 	return 0;
 }
 
-void odb_load_loose_cache(struct object_directory *odb, int subdir_nr)
+struct oid_array *odb_loose_cache(struct object_directory *odb,
+				  const struct object_id *oid)
 {
+	int subdir_nr = oid->hash[0];
 	struct strbuf buf = STRBUF_INIT;
 
 	if (subdir_nr < 0 ||
@@ -2161,15 +2230,26 @@
 		BUG("subdir_nr out of range");
 
 	if (odb->loose_objects_subdir_seen[subdir_nr])
-		return;
+		return &odb->loose_objects_cache[subdir_nr];
 
 	strbuf_addstr(&buf, odb->path);
 	for_each_file_in_obj_subdir(subdir_nr, &buf,
 				    append_loose_object,
 				    NULL, NULL,
-				    &odb->loose_objects_cache);
+				    &odb->loose_objects_cache[subdir_nr]);
 	odb->loose_objects_subdir_seen[subdir_nr] = 1;
 	strbuf_release(&buf);
+	return &odb->loose_objects_cache[subdir_nr];
+}
+
+void odb_clear_loose_cache(struct object_directory *odb)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(odb->loose_objects_cache); i++)
+		oid_array_clear(&odb->loose_objects_cache[i]);
+	memset(&odb->loose_objects_subdir_seen, 0,
+	       sizeof(odb->loose_objects_subdir_seen));
 }
 
 static int check_stream_sha1(git_zstream *stream,
diff --git a/sha1-name.c b/sha1-name.c
index b245028..a656481 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -87,21 +87,21 @@
 
 static void find_short_object_filename(struct disambiguate_state *ds)
 {
-	int subdir_nr = ds->bin_pfx.hash[0];
 	struct object_directory *odb;
 
 	for (odb = the_repository->objects->odb;
 	     odb && !ds->ambiguous;
 	     odb = odb->next) {
 		int pos;
+		struct oid_array *loose_objects;
 
-		odb_load_loose_cache(odb, subdir_nr);
-		pos = oid_array_lookup(&odb->loose_objects_cache, &ds->bin_pfx);
+		loose_objects = odb_loose_cache(odb, &ds->bin_pfx);
+		pos = oid_array_lookup(loose_objects, &ds->bin_pfx);
 		if (pos < 0)
 			pos = -1 - pos;
-		while (!ds->ambiguous && pos < odb->loose_objects_cache.nr) {
+		while (!ds->ambiguous && pos < loose_objects->nr) {
 			const struct object_id *oid;
-			oid = odb->loose_objects_cache.oid + pos;
+			oid = loose_objects->oid + pos;
 			if (!match_sha(ds->len, ds->bin_pfx.hash, oid->hash))
 				break;
 			update_candidates(ds, oid);
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 368647a..7c3d33d 100644
--- a/sideband.c
+++ b/sideband.c
@@ -87,7 +87,7 @@
 		struct keyword_entry *p = keywords + i;
 		int len = strlen(p->keyword);
 
-		if (n <= len)
+		if (n < len)
 			continue;
 		/*
 		 * Match case insensitively, so we colorize output from existing
@@ -95,7 +95,8 @@
 		 * messages. We only highlight the word precisely, so
 		 * "successful" stays uncolored.
 		 */
-		if (!strncasecmp(p->keyword, src, len) && !isalnum(src[len])) {
+		if (!strncasecmp(p->keyword, src, len) &&
+		    (len == n || !isalnum(src[len]))) {
 			strbuf_addstr(dest, p->color);
 			strbuf_add(dest, src, len);
 			strbuf_addstr(dest, GIT_COLOR_RESET);
diff --git a/string-list.c b/string-list.c
index 1f6063f..a917955 100644
--- a/string-list.c
+++ b/string-list.c
@@ -155,7 +155,8 @@
 	return *item->string != '\0';
 }
 
-void string_list_remove_empty_items(struct string_list *list, int free_util) {
+void string_list_remove_empty_items(struct string_list *list, int free_util)
+{
 	filter_string_list(list, free_util, item_is_not_empty, NULL);
 }
 
diff --git a/submodule.c b/submodule.c
index 6415cc5..7b5cea8 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;
@@ -495,6 +494,12 @@
 			 DEFAULT_GIT_DIR_ENVIRONMENT);
 }
 
+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);
+}
+
 /* 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
@@ -1136,11 +1141,11 @@
 	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 +1162,9 @@
 	 * 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 +1178,14 @@
 		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 +1229,16 @@
 	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 +1265,126 @@
 	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 +1395,12 @@
 			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 +1409,66 @@
 			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 +1476,66 @@
 			       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 +1566,8 @@
 	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 +1576,7 @@
 
 	argv_array_clear(&spf.args);
 out:
-	string_list_clear(&changed_submodule_names, 1);
+	free_submodules_oids(&spf.changed_submodule_names);
 	return spf.result;
 }
 
@@ -1561,6 +1755,18 @@
 	return ret;
 }
 
+void submodule_unset_core_worktree(const struct submodule *sub)
+{
+	char *config_path = xstrfmt("%s/modules/%s/config",
+				    get_git_common_dir(), sub->name);
+
+	if (git_config_set_in_file_gently(config_path, "core.worktree", NULL))
+		warning(_("Could not unset core.worktree setting in submodule '%s'"),
+			  sub->path);
+
+	free(config_path);
+}
+
 static const char *get_super_prefix_or_empty(void)
 {
 	const char *s = get_super_prefix();
@@ -1726,6 +1932,8 @@
 
 			if (is_empty_dir(path))
 				rmdir_or_warn(path);
+
+			submodule_unset_core_worktree(sub);
 		}
 	}
 out:
diff --git a/submodule.h b/submodule.h
index a680214..9e18e9b 100644
--- a/submodule.h
+++ b/submodule.h
@@ -131,6 +131,8 @@
 			const char *new_head,
 			unsigned flags);
 
+void submodule_unset_core_worktree(const struct submodule *sub);
+
 /*
  * Prepare the "env_array" parameter of a "struct child_process" for executing
  * a submodule by clearing any repo-specific environment variables, but
diff --git a/symlinks.c b/symlinks.c
index 5261e8c..69d458a 100644
--- a/symlinks.c
+++ b/symlinks.c
@@ -221,7 +221,7 @@
  */
 int check_leading_path(const char *name, int len)
 {
-    return threaded_check_leading_path(&default_cache, name, len);
+	return threaded_check_leading_path(&default_cache, name, len);
 }
 
 /*
diff --git a/t/README b/t/README
index 28711cc..11ce767 100644
--- a/t/README
+++ b/t/README
@@ -186,6 +186,22 @@
 	this feature by setting the GIT_TEST_CHAIN_LINT environment
 	variable to "1" or "0", respectively.
 
+--stress::
+--stress=<N>::
+	Run the test script repeatedly in multiple parallel jobs until
+	one of them fails.  Useful for reproducing rare failures in
+	flaky tests.  The number of parallel jobs is, in order of
+	precedence: <N>, or the value of the GIT_TEST_STRESS_LOAD
+	environment variable, or twice the number of available
+	processors (as shown by the 'getconf' utility),	or 8.
+	Implies `--verbose -x --immediate` to get the most information
+	about the failure.  Note that the verbose output of each test
+	job is saved to 't/test-results/$TEST_NAME.stress-<nr>.out',
+	and only the output of the failed test job is shown on the
+	terminal.  The names of the trash directories get a
+	'.stress-<nr>' suffix, and the trash directory of the failed
+	test job is renamed to end with a '.stress-failed' suffix.
+
 You can also set the GIT_TEST_INSTALLED environment variable to
 the bindir of an existing git installation to test that installation.
 You still need to have built this git sandbox, from which various
@@ -425,7 +441,8 @@
  - Creates an empty test directory with an empty .git/objects database
    and chdir(2) into it.  This directory is 't/trash
    directory.$test_name_without_dotsh', with t/ subject to change by
-   the --root option documented above.
+   the --root option documented above, and a '.stress-<N>' suffix
+   appended by the --stress option.
 
  - Defines standard test helper functions for your scripts to
    use.  These functions are designed to make all scripts behave
diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
index b45bdac..8037eef 100755
--- a/t/check-non-portable-shell.pl
+++ b/t/check-non-portable-shell.pl
@@ -35,6 +35,7 @@
 		chomp;
 	}
 
+	/\bcp\s+-a/ and err 'cp -a is not portable';
 	/\bsed\s+-i/ and err 'sed -i is not portable';
 	/\becho\s+-[neE]/ and err 'echo with option is not portable (use printf)';
 	/^\s*declare\s+/ and err 'arrays/declare not portable';
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-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-sigchain.c b/t/helper/test-sigchain.c
index 77ac5bc..d013bcc 100644
--- a/t/helper/test-sigchain.c
+++ b/t/helper/test-sigchain.c
@@ -14,7 +14,8 @@
 X(three)
 #undef X
 
-int cmd__sigchain(int argc, const char **argv) {
+int cmd__sigchain(int argc, const char **argv)
+{
 	sigchain_push(SIGTERM, one);
 	sigchain_push(SIGTERM, two);
 	sigchain_push(SIGTERM, three);
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-git-daemon.sh b/t/lib-git-daemon.sh
index f98de95..79db3b7 100644
--- a/t/lib-git-daemon.sh
+++ b/t/lib-git-daemon.sh
@@ -28,7 +28,7 @@
 	test_skip_or_die $GIT_TEST_GIT_DAEMON "file system does not support FIFOs"
 fi
 
-LIB_GIT_DAEMON_PORT=${LIB_GIT_DAEMON_PORT-${this_test#t}}
+test_set_port LIB_GIT_DAEMON_PORT
 
 GIT_DAEMON_PID=
 GIT_DAEMON_DOCUMENT_ROOT_PATH="$PWD"/repo
@@ -54,19 +54,11 @@
 		"$@" "$GIT_DAEMON_DOCUMENT_ROOT_PATH" \
 		>&3 2>git_daemon_output &
 	GIT_DAEMON_PID=$!
-	>daemon.log
 	{
 		read -r line <&7
-		printf "%s\n" "$line"
-		printf >&4 "%s\n" "$line"
-		(
-			while read -r line <&7
-			do
-				printf "%s\n" "$line"
-				printf >&4 "%s\n" "$line"
-			done
-		) &
-	} 7<git_daemon_output >>"$TRASH_DIRECTORY/daemon.log" &&
+		printf "%s\n" "$line" >&4
+		cat <&7 >&4 &
+	} 7<git_daemon_output &&
 
 	# Check expected output
 	if test x"$(expr "$line" : "\[[0-9]*\] \(.*\)")" != x"Ready to rumble"
diff --git a/t/lib-git-p4.sh b/t/lib-git-p4.sh
index c275994..b3be3ba 100644
--- a/t/lib-git-p4.sh
+++ b/t/lib-git-p4.sh
@@ -53,14 +53,7 @@
 	(cd / && "$PYTHON_PATH" -c 'import time; print(int(time.time()))')
 }
 
-# Try to pick a unique port: guess a large number, then hope
-# no more than one of each test is running.
-#
-# This does not handle the case where somebody else is running the
-# same tests and has chosen the same ports.
-testid=${this_test#t}
-git_p4_test_start=9800
-P4DPORT=$((10669 + ($testid - $git_p4_test_start)))
+test_set_port P4DPORT
 
 P4PORT=localhost:$P4DPORT
 P4CLIENT=client
diff --git a/t/lib-git-svn.sh b/t/lib-git-svn.sh
index a8130f9..f3b478c 100644
--- a/t/lib-git-svn.sh
+++ b/t/lib-git-svn.sh
@@ -13,6 +13,7 @@
 GIT_DIR=$PWD/.git
 GIT_SVN_DIR=$GIT_DIR/svn/refs/remotes/git-svn
 SVN_TREE=$GIT_SVN_DIR/svn-tree
+test_set_port SVNSERVE_PORT
 
 svn >/dev/null 2>&1
 if test $? -ne 1
@@ -119,7 +120,6 @@
 }
 
 start_svnserve () {
-	SVNSERVE_PORT=${SVNSERVE_PORT-${this_test#t}}
 	svnserve --listen-port $SVNSERVE_PORT \
 		 --root "$rawsvnrepo" \
 		 --listen-once \
diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh
index a8729f8..e465116 100644
--- a/t/lib-httpd.sh
+++ b/t/lib-httpd.sh
@@ -82,7 +82,7 @@
 esac
 
 LIB_HTTPD_PATH=${LIB_HTTPD_PATH-"$DEFAULT_HTTPD_PATH"}
-LIB_HTTPD_PORT=${LIB_HTTPD_PORT-${this_test#t}}
+test_set_port LIB_HTTPD_PORT
 
 TEST_PATH="$TEST_DIRECTORY"/lib-httpd
 HTTPD_ROOT_PATH="$PWD"/httpd
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 581c010..cc4b875 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -115,6 +115,7 @@
 	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/lib-submodule-update.sh b/t/lib-submodule-update.sh
index 0163917..5b56b23 100755
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -235,7 +235,7 @@
 	then
 		mkdir -p submodule_update/.git/modules/sub1/modules &&
 		cp -r submodule_update_repo/.git/modules/sub1/modules/sub2 submodule_update/.git/modules/sub1/modules/sub2
-		GIT_WORK_TREE=. git -C submodule_update/.git/modules/sub1/modules/sub2 config --unset core.worktree
+		# core.worktree is unset for sub2 as it is not checked out
 	fi &&
 	# indicate we are interested in the submodule:
 	git -C submodule_update config submodule.sub1.url "bogus" &&
@@ -709,7 +709,8 @@
 			git branch -t remove_sub1 origin/remove_sub1 &&
 			$command remove_sub1 &&
 			test_superproject_content origin/remove_sub1 &&
-			! test -e sub1
+			! test -e sub1 &&
+			test_must_fail git config -f .git/modules/sub1/config core.worktree
 		)
 	'
 	# ... absorbing a .git directory along the way.
diff --git a/t/t0015-hash.sh b/t/t0015-hash.sh
new file mode 100755
index 0000000..291e906
--- /dev/null
+++ b/t/t0015-hash.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+test_description='test basic hash implementation'
+. ./test-lib.sh
+
+
+test_expect_success 'test basic SHA-1 hash values' '
+	test-tool sha1 </dev/null >actual &&
+	grep da39a3ee5e6b4b0d3255bfef95601890afd80709 actual &&
+	printf "a" | test-tool sha1 >actual &&
+	grep 86f7e437faa5a7fce15d1ddcb9eaeaea377667b8 actual &&
+	printf "abc" | test-tool sha1 >actual &&
+	grep a9993e364706816aba3e25717850c26c9cd0d89d actual &&
+	printf "message digest" | test-tool sha1 >actual &&
+	grep c12252ceda8be8994d5fa0290a47231c1d16aae3 actual &&
+	printf "abcdefghijklmnopqrstuvwxyz" | test-tool sha1 >actual &&
+	grep 32d10c7b8cf96570ca04ce37f2a19d84240d3a89 actual &&
+	perl -e "$| = 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/t0027-auto-crlf.sh b/t/t0027-auto-crlf.sh
index beb5927..3587e45 100755
--- a/t/t0027-auto-crlf.sh
+++ b/t/t0027-auto-crlf.sh
@@ -293,9 +293,9 @@
 	do
 		rm crlf_false_attr__$f.txt &&
 		if test -z "$ceol"; then
-			git checkout crlf_false_attr__$f.txt
+			git checkout -- crlf_false_attr__$f.txt
 		else
-			git -c core.eol=$ceol checkout crlf_false_attr__$f.txt
+			git -c core.eol=$ceol checkout -- crlf_false_attr__$f.txt
 		fi
 	done
 
diff --git a/t/t0030-stripspace.sh b/t/t0030-stripspace.sh
index 5ce47e8..0c24a0f 100755
--- a/t/t0030-stripspace.sh
+++ b/t/t0030-stripspace.sh
@@ -430,9 +430,15 @@
 test_expect_success '-c with comment char defined in .git/config' '
 	test_config core.commentchar = &&
 	printf "= foo\n" >expect &&
-	printf "foo" | (
-		mkdir sub && cd sub && git stripspace -c
-	) >actual &&
+	rm -fr sub &&
+	mkdir sub &&
+	printf "foo" | git -C sub stripspace -c >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '-c outside git repository' '
+	printf "# foo\n" >expect &&
+	printf "foo" | nongit git stripspace -c >actual &&
 	test_cmp expect actual
 '
 
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 96bf6d6..99a614b 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -31,7 +31,15 @@
 	test_must_be_empty err
 '
 
-test_expect_success 'run_command is restricted to PATH' '
+
+test_lazy_prereq RUNS_COMMANDS_FROM_PWD '
+	write_script runs-commands-from-pwd <<-\EOF &&
+	true
+	EOF
+	runs-commands-from-pwd >/dev/null 2>&1
+'
+
+test_expect_success !RUNS_COMMANDS_FROM_PWD 'run_command is restricted to PATH' '
 	write_script should-not-run <<-\EOF &&
 	echo yikes
 	EOF
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index ba3887f..bce0278 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -349,7 +349,7 @@
 	grep $(git -C repo rev-parse bar) out  # sanity check that some walking was done
 '
 
-test_expect_success 'rev-list accepts missing and promised objects on command line' '
+test_expect_success 'rev-list dies for missing objects on cmd line' '
 	rm -rf repo &&
 	test_create_repo repo &&
 	test_commit -C repo foo &&
@@ -366,7 +366,19 @@
 
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
-	git -C repo rev-list --exclude-promisor-objects --objects "$COMMIT" "$TREE" "$BLOB"
+
+	for OBJ in "$COMMIT" "$TREE" "$BLOB"; do
+		test_must_fail git -C repo rev-list --objects \
+			--exclude-promisor-objects "$OBJ" &&
+		test_must_fail git -C repo rev-list --objects-edge-aggressive \
+			--exclude-promisor-objects "$OBJ" &&
+
+		# Do not die or crash when --ignore-missing is passed.
+		git -C repo rev-list --ignore-missing --objects \
+			--exclude-promisor-objects "$OBJ" &&
+		git -C repo rev-list --ignore-missing --objects-edge-aggressive \
+			--exclude-promisor-objects "$OBJ"
+	done
 '
 
 test_expect_success 'gc repacks promisor objects separately from non-promisor objects' '
@@ -480,7 +492,6 @@
 	! grep "$TREE_HASH" out
 '
 
-LIB_HTTPD_PORT=12345  # default port, 410, cannot be used as non-root
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/t/t2028-worktree-move.sh b/t/t2028-worktree-move.sh
index 33c0337..939d18d 100755
--- a/t/t2028-worktree-move.sh
+++ b/t/t2028-worktree-move.sh
@@ -112,6 +112,26 @@
 	git worktree move --force --force flump ploof
 '
 
+test_expect_success 'move a repo with uninitialized submodule' '
+	git init withsub &&
+	(
+		cd withsub &&
+		test_commit initial &&
+		git submodule add "$PWD"/.git sub &&
+		git commit -m withsub &&
+		git worktree add second HEAD &&
+		git worktree move second third
+	)
+'
+
+test_expect_success 'not move a repo with initialized submodule' '
+	(
+		cd withsub &&
+		git -C third submodule update &&
+		test_must_fail git worktree move third forth
+	)
+'
+
 test_expect_success 'remove main worktree' '
 	test_must_fail git worktree remove .
 '
@@ -185,4 +205,21 @@
 	)
 '
 
+test_expect_success 'remove a repo with uninitialized submodule' '
+	(
+		cd withsub &&
+		git worktree add to-remove HEAD &&
+		git worktree remove to-remove
+	)
+'
+
+test_expect_success 'not remove a repo with initialized submodule' '
+	(
+		cd withsub &&
+		git worktree add to-remove HEAD &&
+		git -C to-remove submodule update &&
+		test_must_fail git worktree remove to-remove
+	)
+'
+
 test_done
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/t3502-cherry-pick-merge.sh b/t/t3502-cherry-pick-merge.sh
index b160271..8b635a1 100755
--- a/t/t3502-cherry-pick-merge.sh
+++ b/t/t3502-cherry-pick-merge.sh
@@ -40,12 +40,12 @@
 	test_expect_code 129 git cherry-pick -m 0 b
 '
 
-test_expect_success 'cherry-pick a non-merge with -m should fail' '
+test_expect_success 'cherry-pick explicit first parent of a non-merge' '
 
 	git reset --hard &&
 	git checkout a^0 &&
-	test_expect_code 128 git cherry-pick -m 1 b &&
-	git diff --exit-code a --
+	git cherry-pick -m 1 b &&
+	git diff --exit-code c --
 
 '
 
@@ -84,12 +84,12 @@
 
 '
 
-test_expect_success 'revert a non-merge with -m should fail' '
+test_expect_success 'revert explicit first parent of a non-merge' '
 
 	git reset --hard &&
 	git checkout c^0 &&
-	test_must_fail git revert -m 1 b &&
-	git diff --exit-code c
+	git revert -m 1 b &&
+	git diff --exit-code a --
 
 '
 
diff --git a/t/t3506-cherry-pick-ff.sh b/t/t3506-cherry-pick-ff.sh
index fb889ac..127dd00 100755
--- a/t/t3506-cherry-pick-ff.sh
+++ b/t/t3506-cherry-pick-ff.sh
@@ -64,10 +64,10 @@
 	git checkout -b new A
 '
 
-test_expect_success 'cherry-pick a non-merge with --ff and -m should fail' '
+test_expect_success 'cherry-pick explicit first parent of a non-merge with --ff' '
 	git reset --hard A -- &&
-	test_must_fail git cherry-pick --ff -m 1 B &&
-	git diff --exit-code A --
+	git cherry-pick --ff -m 1 B &&
+	git diff --exit-code C --
 '
 
 test_expect_success 'cherry pick a merge with --ff but without -m should fail' '
diff --git a/t/t3510-cherry-pick-sequence.sh b/t/t3510-cherry-pick-sequence.sh
index c84eeef..941d502 100755
--- a/t/t3510-cherry-pick-sequence.sh
+++ b/t/t3510-cherry-pick-sequence.sh
@@ -61,7 +61,11 @@
 
 test_expect_success 'cherry-pick persists opts correctly' '
 	pristine_detach initial &&
-	test_expect_code 128 git cherry-pick -s -m 1 --strategy=recursive -X patience -X ours initial..anotherpick &&
+	# to make sure that the session to cherry-pick a sequence
+	# gets interrupted, use a high-enough number that is larger
+	# than the number of parents of any commit we have created
+	mainline=4 &&
+	test_expect_code 128 git cherry-pick -s -m $mainline --strategy=recursive -X patience -X ours initial..anotherpick &&
 	test_path_is_dir .git/sequencer &&
 	test_path_is_file .git/sequencer/head &&
 	test_path_is_file .git/sequencer/todo &&
@@ -69,7 +73,7 @@
 	echo "true" >expect &&
 	git config --file=.git/sequencer/opts --get-all options.signoff >actual &&
 	test_cmp expect actual &&
-	echo "1" >expect &&
+	echo "$mainline" >expect &&
 	git config --file=.git/sequencer/opts --get-all options.mainline >actual &&
 	test_cmp expect actual &&
 	echo "recursive" >expect &&
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index a9fb226..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>
@@ -1885,11 +1888,30 @@
 		<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
 '
 
+test_expect_success 'bogus settings in move detection erroring out' '
+	test_must_fail git diff --color-moved=bogus 2>err &&
+	test_i18ngrep "must be one of" err &&
+	test_i18ngrep bogus err &&
+
+	test_must_fail git -c diff.colormoved=bogus diff 2>err &&
+	test_i18ngrep "must be one of" err &&
+	test_i18ngrep "from command-line config" err &&
+
+	test_must_fail git diff --color-moved-ws=bogus 2>err &&
+	test_i18ngrep "possible values" err &&
+	test_i18ngrep bogus err &&
+
+	test_must_fail git -c diff.colormovedws=bogus diff 2>err &&
+	test_i18ngrep "possible values" err &&
+	test_i18ngrep "from command-line config" err
+'
+
 test_expect_success 'compare whitespace delta incompatible with other space options' '
 	test_must_fail git diff \
 		--color-moved-ws=allow-indentation-change,ignore-all-space \
@@ -1897,4 +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/t4209-log-pickaxe.sh b/t/t4209-log-pickaxe.sh
index 844df76..5d06f5f 100755
--- a/t/t4209-log-pickaxe.sh
+++ b/t/t4209-log-pickaxe.sh
@@ -106,4 +106,39 @@
 	rm .gitattributes
 '
 
+test_expect_success 'setup log -[GS] binary & --text' '
+	git checkout --orphan GS-binary-and-text &&
+	git read-tree --empty &&
+	printf "a\na\0a\n" >data.bin &&
+	git add data.bin &&
+	git commit -m "create binary file" data.bin &&
+	printf "a\na\0a\n" >>data.bin &&
+	git commit -m "modify binary file" data.bin &&
+	git rm data.bin &&
+	git commit -m "delete binary file" data.bin &&
+	git log >full-log
+'
+
+test_expect_success 'log -G ignores binary files' '
+	git log -Ga >log &&
+	test_must_be_empty log
+'
+
+test_expect_success 'log -G looks into binary files with -a' '
+	git log -a -Ga >log &&
+	test_cmp log full-log
+'
+
+test_expect_success 'log -G looks into binary files with textconv filter' '
+	test_when_finished "rm .gitattributes" &&
+	echo "* diff=bin" >.gitattributes &&
+	git -c diff.bin.textconv=cat log -Ga >log &&
+	test_cmp log full-log
+'
+
+test_expect_success 'log -S looks into binary files' '
+	git log -Sa >log &&
+	test_cmp log full-log
+'
+
 test_done
diff --git a/t/t5004-archive-corner-cases.sh b/t/t5004-archive-corner-cases.sh
index ced4435..271eb5a 100755
--- a/t/t5004-archive-corner-cases.sh
+++ b/t/t5004-archive-corner-cases.sh
@@ -3,8 +3,12 @@
 test_description='test corner cases of git-archive'
 . ./test-lib.sh
 
-test_expect_success 'create commit with empty tree' '
-	git commit --allow-empty -m foo
+# the 10knuls.tar file is used to test for an empty git generated tar
+# without having to invoke tar because an otherwise valid empty GNU tar
+# will be considered broken by {Open,Net}BSD tar
+test_expect_success 'create commit with empty tree and fake empty tar' '
+	git commit --allow-empty -m foo &&
+	perl -e "print \"\\0\" x 10240" >10knuls.tar
 '
 
 # Make a dir and clean it up afterwards
@@ -47,7 +51,6 @@
 
 test_expect_success 'tar archive of empty tree is empty' '
 	git archive --format=tar HEAD: >empty.tar &&
-	perl -e "print \"\\0\" x 10240" >10knuls.tar &&
 	test_cmp_bin 10knuls.tar empty.tar
 '
 
@@ -106,16 +109,12 @@
 
 test_expect_success 'archive empty subtree with no pathspec' '
 	git archive --format=tar $root_tree >subtree-all.tar &&
-	make_dir extract &&
-	"$TAR" xf subtree-all.tar -C extract &&
-	check_dir extract
+	test_cmp_bin 10knuls.tar subtree-all.tar
 '
 
 test_expect_success 'archive empty subtree by direct pathspec' '
 	git archive --format=tar $root_tree -- sub >subtree-path.tar &&
-	make_dir extract &&
-	"$TAR" xf subtree-path.tar -C extract &&
-	check_dir extract
+	test_cmp_bin 10knuls.tar subtree-path.tar
 '
 
 ZIPINFO=zipinfo
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/t5409-colorize-remote-messages.sh b/t/t5409-colorize-remote-messages.sh
index f81b681..2a8c449 100755
--- a/t/t5409-colorize-remote-messages.sh
+++ b/t/t5409-colorize-remote-messages.sh
@@ -17,6 +17,7 @@
 	echo " " "error: leading space"
 	echo "    "
 	echo Err
+	echo SUCCESS
 	exit 0
 	EOF
 	echo 1 >file &&
@@ -35,6 +36,7 @@
 	grep "<BOLD;RED>error<RESET>: error" decoded &&
 	grep "<YELLOW>hint<RESET>:" decoded &&
 	grep "<BOLD;GREEN>success<RESET>:" decoded &&
+	grep "<BOLD;GREEN>SUCCESS<RESET>" decoded &&
 	grep "<BOLD;YELLOW>warning<RESET>:" decoded
 '
 
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 32e722d..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 &&
@@ -260,7 +266,7 @@
 # This test spawns a daemon, so run it only if the user would be OK with
 # testing with git-daemon.
 test_expect_success PIPE,JGIT,GIT_DAEMON 'indicate no refs in standards-compliant empty remote' '
-	JGIT_DAEMON_PORT=${JGIT_DAEMON_PORT-${this_test#t}} &&
+	test_set_port JGIT_DAEMON_PORT &&
 	JGIT_DAEMON_PID= &&
 	git init --bare empty.git &&
 	>empty.git/git-daemon-export-ok &&
diff --git a/t/t5526-fetch-submodules.sh b/t/t5526-fetch-submodules.sh
index 6c2f9b2..63205df 100755
--- a/t/t5526-fetch-submodules.sh
+++ b/t/t5526-fetch-submodules.sh
@@ -524,6 +524,8 @@
 	git config fetch.recurseSubmodules true &&
 	(
 		cd downstream &&
+		GIT_TRACE=$(pwd)/trace.out git fetch &&
+		grep "1 tasks" trace.out &&
 		GIT_TRACE=$(pwd)/trace.out git fetch --jobs 7 &&
 		grep "7 tasks" trace.out &&
 		git config submodule.fetchJobs 8 &&
@@ -600,4 +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 $F
+	)
+'
+
 test_done
diff --git a/t/t5570-git-daemon.sh b/t/t5570-git-daemon.sh
index 7466aad..58ee787 100755
--- a/t/t5570-git-daemon.sh
+++ b/t/t5570-git-daemon.sh
@@ -183,19 +183,6 @@
 		git ls-remote "$GIT_DAEMON_URL/escape.git"
 '
 
-test_expect_success 'daemon log records all attributes' '
-	cat >expect <<-\EOF &&
-	Extended attribute "host": localhost
-	Extended attribute "protocol": version=1
-	EOF
-	>daemon.log &&
-	GIT_OVERRIDE_VIRTUAL_HOST=localhost \
-		git -c protocol.version=1 \
-			ls-remote "$GIT_DAEMON_URL/interp.git" &&
-	grep -i extended.attribute daemon.log | cut -d" " -f2- >actual &&
-	test_cmp expect actual
-'
-
 test_expect_success FAKENC 'hostname interpolation works after LF-stripping' '
 	{
 		printf "git-upload-pack /interp.git\n\0host=localhost" | packetize
diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
new file mode 100755
index 0000000..cd9283e
--- /dev/null
+++ b/t/t5581-http-curl-verbose.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='test GIT_CURL_VERBOSE'
+. ./test-lib.sh
+. "$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/t5601-clone.sh b/t/t5601-clone.sh
index 8bbc706..d6948cb 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -487,7 +487,7 @@
 	expect_ssh "$@"
 }
 
-test_expect_success !MINGW 'clone c:temp is ssl' '
+test_expect_success !MINGW,!CYGWIN 'clone c:temp is ssl' '
 	test_clone_url c:temp c temp
 '
 
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 0f2b09e..a738c0c 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
 #
 . "$TEST_DIRECTORY"/lib-httpd.sh
diff --git a/t/t6135-pathspec-with-attrs.sh b/t/t6135-pathspec-with-attrs.sh
index e436a73..457cc16 100755
--- a/t/t6135-pathspec-with-attrs.sh
+++ b/t/t6135-pathspec-with-attrs.sh
@@ -31,7 +31,7 @@
 	mkdir sub &&
 	while read path
 	do
-		: >$path &&
+		echo content >$path &&
 		git add $path || return 1
 	done <expect &&
 	git commit -m "initial commit" &&
@@ -48,6 +48,10 @@
 	test_must_be_empty actual
 '
 
+test_expect_success 'pathspec with labels and non existent .gitattributes (2)' '
+	test_must_fail git grep content HEAD -- ":(attr:label)"
+'
+
 test_expect_success 'setup .gitattributes' '
 	cat <<-\EOF >.gitattributes &&
 	fileA labelA
@@ -74,6 +78,15 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'check specific set attr (2)' '
+	cat <<-\EOF >expect &&
+	HEAD:fileSetLabel
+	HEAD:sub/fileSetLabel
+	EOF
+	git grep -l content HEAD ":(attr:label)" >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'check specific unset attr' '
 	cat <<-\EOF >expect &&
 	fileUnsetLabel
@@ -83,6 +96,15 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'check specific unset attr (2)' '
+	cat <<-\EOF >expect &&
+	HEAD:fileUnsetLabel
+	HEAD:sub/fileUnsetLabel
+	EOF
+	git grep -l content HEAD ":(attr:-label)" >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'check specific value attr' '
 	cat <<-\EOF >expect &&
 	fileValue
@@ -94,6 +116,16 @@
 	test_must_be_empty actual
 '
 
+test_expect_success 'check specific value attr (2)' '
+	cat <<-\EOF >expect &&
+	HEAD:fileValue
+	HEAD:sub/fileValue
+	EOF
+	git grep -l content HEAD ":(attr:label=foo)" >actual &&
+	test_cmp expect actual &&
+	test_must_fail git grep -l content HEAD ":(attr:label=bar)"
+'
+
 test_expect_success 'check unspecified attr' '
 	cat <<-\EOF >expect &&
 	.gitattributes
@@ -118,6 +150,30 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'check unspecified attr (2)' '
+	cat <<-\EOF >expect &&
+	HEAD:.gitattributes
+	HEAD:fileA
+	HEAD:fileAB
+	HEAD:fileAC
+	HEAD:fileB
+	HEAD:fileBC
+	HEAD:fileC
+	HEAD:fileNoLabel
+	HEAD:fileWrongLabel
+	HEAD:sub/fileA
+	HEAD:sub/fileAB
+	HEAD:sub/fileAC
+	HEAD:sub/fileB
+	HEAD:sub/fileBC
+	HEAD:sub/fileC
+	HEAD:sub/fileNoLabel
+	HEAD:sub/fileWrongLabel
+	EOF
+	git grep -l ^ HEAD ":(attr:!label)" >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'check multiple unspecified attr' '
 	cat <<-\EOF >expect &&
 	.gitattributes
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 97bfbee..0ffd630 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -83,6 +83,8 @@
 test_atom head push:strip=-1 master
 test_atom head objecttype commit
 test_atom head objectsize 171
+test_atom head objectsize:disk 138
+test_atom head deltabase 0000000000000000000000000000000000000000
 test_atom head objectname $(git rev-parse refs/heads/master)
 test_atom head objectname:short $(git rev-parse --short refs/heads/master)
 test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
@@ -124,6 +126,10 @@
 test_atom tag push ''
 test_atom tag objecttype tag
 test_atom tag objectsize 154
+test_atom tag objectsize:disk 138
+test_atom tag '*objectsize:disk' 138
+test_atom tag deltabase 0000000000000000000000000000000000000000
+test_atom tag '*deltabase' 0000000000000000000000000000000000000000
 test_atom tag objectname $(git rev-parse refs/tags/testtag)
 test_atom tag objectname:short $(git rev-parse --short refs/tags/testtag)
 test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 76a7cb0..aba2d4d 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -984,6 +984,11 @@
 	rmdir init
 '
 
+test_expect_success 'submodule deinit should unset core.worktree' '
+	test_path_is_file .git/modules/example/config &&
+	test_must_fail git config -f .git/modules/example/config core.worktree
+'
+
 test_expect_success 'submodule deinit from subdirectory' '
 	git submodule update --init &&
 	git config submodule.example.foo bar &&
diff --git a/t/t7412-submodule-absorbgitdirs.sh b/t/t7412-submodule-absorbgitdirs.sh
index ce74c12..1cfa150 100755
--- a/t/t7412-submodule-absorbgitdirs.sh
+++ b/t/t7412-submodule-absorbgitdirs.sh
@@ -75,7 +75,12 @@
 	GIT_WORK_TREE=../../../nested git -C sub1/.git/modules/nested config \
 		core.worktree "../../../nested" &&
 	# make sure this re-setup is correct
-	git status --ignore-submodules=none
+	git status --ignore-submodules=none &&
+
+	# also make sure this old setup does not regress
+	git submodule update --init --recursive >out 2>err &&
+	test_must_be_empty out &&
+	test_must_be_empty err
 '
 
 test_expect_success 'absorb the git dir in a nested submodule' '
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 6558eee..3a2c632 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1516,8 +1516,8 @@
 
 test_expect_success '<ref>: completes paths' '
 	test_completion "git show mytag:f" <<-\EOF
-	file1 Z
-	file2 Z
+	file1Z
+	file2Z
 	EOF
 '
 
@@ -1526,7 +1526,7 @@
 	git add "name with spaces" &&
 	git commit -m spaces &&
 	test_completion "git show HEAD:nam" <<-\EOF
-	name with spaces Z
+	name with spacesZ
 	EOF
 '
 
@@ -1535,8 +1535,8 @@
 	git add "name with \${meta}" &&
 	git commit -m meta &&
 	test_completion "git show HEAD:nam" <<-\EOF
-	name with ${meta} Z
-	name with spaces Z
+	name with ${meta}Z
+	name with spacesZ
 	EOF
 '
 
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 6b3bbf9..92cf8f8 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1263,3 +1263,42 @@
 	fi &&
 	eval "printf '%s' \"\${$var}\""
 }
+
+# Choose a port number based on the test script's number and store it in
+# the given variable name, unless that variable already contains a number.
+test_set_port () {
+	local var=$1 port
+
+	if test $# -ne 1 || test -z "$var"
+	then
+		BUG "test_set_port requires a variable name"
+	fi
+
+	eval port=\$$var
+	case "$port" in
+	"")
+		# No port is set in the given env var, use the test
+		# number as port number instead.
+		# Remove not only the leading 't', but all leading zeros
+		# as well, so the arithmetic below won't (mis)interpret
+		# a test number like '0123' as an octal value.
+		port=${this_test#${this_test%%[1-9]*}}
+		if test "${port:-0}" -lt 1024
+		then
+			# root-only port, use a larger one instead.
+			port=$(($port + 10000))
+		fi
+		;;
+	*[^0-9]*|0*)
+		error >&7 "invalid port number: $port"
+		;;
+	*)
+		# The user has specified the port.
+		;;
+	esac
+
+	# Make sure that parallel '--stress' test jobs get different
+	# ports.
+	port=$(($port + ${GIT_TEST_STRESS_JOB_NR:-0}))
+	eval $var=$port
+}
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 0f1faa2..a1abb11 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -71,19 +71,222 @@
 	exit 1
 fi
 
+# Parse options while taking care to leave $@ intact, so we will still
+# have all the original command line options when executing the test
+# script again for '--tee' and '--verbose-log' below.
+store_arg_to=
+prev_opt=
+for opt
+do
+	if test -n "$store_arg_to"
+	then
+		eval $store_arg_to=\$opt
+		store_arg_to=
+		prev_opt=
+		continue
+	fi
+
+	case "$opt" in
+	-d|--d|--de|--deb|--debu|--debug)
+		debug=t ;;
+	-i|--i|--im|--imm|--imme|--immed|--immedi|--immedia|--immediat|--immediate)
+		immediate=t ;;
+	-l|--l|--lo|--lon|--long|--long-|--long-t|--long-te|--long-tes|--long-test|--long-tests)
+		GIT_TEST_LONG=t; export GIT_TEST_LONG ;;
+	-r)
+		store_arg_to=run_list
+		;;
+	--run=*)
+		run_list=${opt#--*=} ;;
+	-h|--h|--he|--hel|--help)
+		help=t ;;
+	-v|--v|--ve|--ver|--verb|--verbo|--verbos|--verbose)
+		verbose=t ;;
+	--verbose-only=*)
+		verbose_only=${opt#--*=}
+		;;
+	-q|--q|--qu|--qui|--quie|--quiet)
+		# Ignore --quiet under a TAP::Harness. Saying how many tests
+		# passed without the ok/not ok details is always an error.
+		test -z "$HARNESS_ACTIVE" && quiet=t ;;
+	--with-dashes)
+		with_dashes=t ;;
+	--no-color)
+		color= ;;
+	--va|--val|--valg|--valgr|--valgri|--valgrin|--valgrind)
+		valgrind=memcheck
+		tee=t
+		;;
+	--valgrind=*)
+		valgrind=${opt#--*=}
+		tee=t
+		;;
+	--valgrind-only=*)
+		valgrind_only=${opt#--*=}
+		tee=t
+		;;
+	--tee)
+		tee=t ;;
+	--root=*)
+		root=${opt#--*=} ;;
+	--chain-lint)
+		GIT_TEST_CHAIN_LINT=1 ;;
+	--no-chain-lint)
+		GIT_TEST_CHAIN_LINT=0 ;;
+	-x)
+		trace=t ;;
+	-V|--verbose-log)
+		verbose_log=t
+		tee=t
+		;;
+	--stress)
+		stress=t ;;
+	--stress=*)
+		stress=${opt#--*=}
+		case "$stress" in
+		*[^0-9]*|0*|"")
+			echo "error: --stress=<N> requires the number of jobs to run" >&2
+			exit 1
+			;;
+		*)	# Good.
+			;;
+		esac
+		;;
+	*)
+		echo "error: unknown test option '$opt'" >&2; exit 1 ;;
+	esac
+
+	prev_opt=$opt
+done
+if test -n "$store_arg_to"
+then
+	echo "error: $prev_opt requires an argument" >&2
+	exit 1
+fi
+
+if test -n "$valgrind_only"
+then
+	test -z "$valgrind" && valgrind=memcheck
+	test -z "$verbose" && verbose_only="$valgrind_only"
+elif test -n "$valgrind"
+then
+	test -z "$verbose_log" && verbose=t
+fi
+
+if test -n "$stress"
+then
+	verbose=t
+	trace=t
+	immediate=t
+fi
+
+TEST_STRESS_JOB_SFX="${GIT_TEST_STRESS_JOB_NR:+.stress-$GIT_TEST_STRESS_JOB_NR}"
+TEST_NAME="$(basename "$0" .sh)"
+TEST_RESULTS_DIR="$TEST_OUTPUT_DIRECTORY/test-results"
+TEST_RESULTS_BASE="$TEST_RESULTS_DIR/$TEST_NAME$TEST_STRESS_JOB_SFX"
+TRASH_DIRECTORY="trash directory.$TEST_NAME$TEST_STRESS_JOB_SFX"
+test -n "$root" && TRASH_DIRECTORY="$root/$TRASH_DIRECTORY"
+case "$TRASH_DIRECTORY" in
+/*) ;; # absolute path is good
+ *) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$TRASH_DIRECTORY" ;;
+esac
+
+# If --stress was passed, run this test repeatedly in several parallel loops.
+if test "$GIT_TEST_STRESS_STARTED" = "done"
+then
+	: # Don't stress test again.
+elif test -n "$stress"
+then
+	if test "$stress" != t
+	then
+		job_count=$stress
+	elif test -n "$GIT_TEST_STRESS_LOAD"
+	then
+		job_count="$GIT_TEST_STRESS_LOAD"
+	elif job_count=$(getconf _NPROCESSORS_ONLN 2>/dev/null) &&
+	     test -n "$job_count"
+	then
+		job_count=$((2 * $job_count))
+	else
+		job_count=8
+	fi
+
+	mkdir -p "$TEST_RESULTS_DIR"
+	stressfail="$TEST_RESULTS_BASE.stress-failed"
+	rm -f "$stressfail"
+
+	stress_exit=0
+	trap '
+		kill $job_pids 2>/dev/null
+		wait
+		stress_exit=1
+	' TERM INT HUP
+
+	job_pids=
+	job_nr=0
+	while test $job_nr -lt "$job_count"
+	do
+		(
+			GIT_TEST_STRESS_STARTED=done
+			GIT_TEST_STRESS_JOB_NR=$job_nr
+			export GIT_TEST_STRESS_STARTED GIT_TEST_STRESS_JOB_NR
+
+			trap '
+				kill $test_pid 2>/dev/null
+				wait
+				exit 1
+			' TERM INT
+
+			cnt=0
+			while ! test -e "$stressfail"
+			do
+				$TEST_SHELL_PATH "$0" "$@" >"$TEST_RESULTS_BASE.stress-$job_nr.out" 2>&1 &
+				test_pid=$!
+
+				if wait $test_pid
+				then
+					printf "OK   %2d.%d\n" $GIT_TEST_STRESS_JOB_NR $cnt
+				else
+					echo $GIT_TEST_STRESS_JOB_NR >>"$stressfail"
+					printf "FAIL %2d.%d\n" $GIT_TEST_STRESS_JOB_NR $cnt
+				fi
+				cnt=$(($cnt + 1))
+			done
+		) &
+		job_pids="$job_pids $!"
+		job_nr=$(($job_nr + 1))
+	done
+
+	wait
+
+	if test -f "$stressfail"
+	then
+		echo "Log(s) of failed test run(s):"
+		for failed_job_nr in $(sort -n "$stressfail")
+		do
+			echo "Contents of '$TEST_RESULTS_BASE.stress-$failed_job_nr.out':"
+			cat "$TEST_RESULTS_BASE.stress-$failed_job_nr.out"
+		done
+		rm -rf "$TRASH_DIRECTORY.stress-failed"
+		# Move the last one.
+		mv "$TRASH_DIRECTORY.stress-$failed_job_nr" "$TRASH_DIRECTORY.stress-failed"
+	fi
+
+	exit $stress_exit
+fi
+
 # if --tee was passed, write the output not only to the terminal, but
 # additionally to the file test-results/$BASENAME.out, too.
-case "$GIT_TEST_TEE_STARTED, $* " in
-done,*)
-	# do not redirect again
-	;;
-*' --tee '*|*' --va'*|*' -V '*|*' --verbose-log '*)
-	mkdir -p "$TEST_OUTPUT_DIRECTORY/test-results"
-	BASE="$TEST_OUTPUT_DIRECTORY/test-results/$(basename "$0" .sh)"
+if test "$GIT_TEST_TEE_STARTED" = "done"
+then
+	: # do not redirect again
+elif test -n "$tee"
+then
+	mkdir -p "$TEST_RESULTS_DIR"
 
 	# Make this filename available to the sub-process in case it is using
 	# --verbose-log.
-	GIT_TEST_TEE_OUTPUT_FILE=$BASE.out
+	GIT_TEST_TEE_OUTPUT_FILE=$TEST_RESULTS_BASE.out
 	export GIT_TEST_TEE_OUTPUT_FILE
 
 	# Truncate before calling "tee -a" to get rid of the results
@@ -91,11 +294,38 @@
 	>"$GIT_TEST_TEE_OUTPUT_FILE"
 
 	(GIT_TEST_TEE_STARTED=done ${TEST_SHELL_PATH} "$0" "$@" 2>&1;
-	 echo $? >"$BASE.exit") | tee -a "$GIT_TEST_TEE_OUTPUT_FILE"
-	test "$(cat "$BASE.exit")" = 0
+	 echo $? >"$TEST_RESULTS_BASE.exit") | tee -a "$GIT_TEST_TEE_OUTPUT_FILE"
+	test "$(cat "$TEST_RESULTS_BASE.exit")" = 0
 	exit
-	;;
-esac
+fi
+
+if test -n "$trace" && test -n "$test_untraceable"
+then
+	# '-x' tracing requested, but this test script can't be reliably
+	# traced, unless it is run with a Bash version supporting
+	# BASH_XTRACEFD (introduced in Bash v4.1).
+	#
+	# Perform this version check _after_ the test script was
+	# potentially re-executed with $TEST_SHELL_PATH for '--tee' or
+	# '--verbose-log', so the right shell is checked and the
+	# warning is issued only once.
+	if test -n "$BASH_VERSION" && eval '
+	     test ${BASH_VERSINFO[0]} -gt 4 || {
+	       test ${BASH_VERSINFO[0]} -eq 4 &&
+	       test ${BASH_VERSINFO[1]} -ge 1
+	     }
+	   '
+	then
+		: Executed by a Bash version supporting BASH_XTRACEFD.  Good.
+	else
+		echo >&2 "warning: ignoring -x; '$0' is untraceable without BASH_XTRACEFD"
+		trace=
+	fi
+fi
+if test -n "$trace" && test -z "$verbose_log"
+then
+	verbose=t
+fi
 
 # For repeatability, reset the environment to known value.
 # TERM is sanitized below, after saving color control sequences.
@@ -193,7 +423,7 @@
 
 # Add libc MALLOC and MALLOC_PERTURB test
 # only if we are not executing the test with valgrind
-if expr " $GIT_TEST_OPTS " : ".* --valgrind " >/dev/null ||
+if test -n "$valgrind" ||
    test -n "$TEST_NO_MALLOC_CHECK"
 then
 	setup_malloc_check () {
@@ -264,100 +494,6 @@
 	) &&
 	color=t
 
-while test "$#" -ne 0
-do
-	case "$1" in
-	-d|--d|--de|--deb|--debu|--debug)
-		debug=t; shift ;;
-	-i|--i|--im|--imm|--imme|--immed|--immedi|--immedia|--immediat|--immediate)
-		immediate=t; shift ;;
-	-l|--l|--lo|--lon|--long|--long-|--long-t|--long-te|--long-tes|--long-test|--long-tests)
-		GIT_TEST_LONG=t; export GIT_TEST_LONG; shift ;;
-	-r)
-		shift; test "$#" -ne 0 || {
-			echo 'error: -r requires an argument' >&2;
-			exit 1;
-		}
-		run_list=$1; shift ;;
-	--run=*)
-		run_list=${1#--*=}; shift ;;
-	-h|--h|--he|--hel|--help)
-		help=t; shift ;;
-	-v|--v|--ve|--ver|--verb|--verbo|--verbos|--verbose)
-		verbose=t; shift ;;
-	--verbose-only=*)
-		verbose_only=${1#--*=}
-		shift ;;
-	-q|--q|--qu|--qui|--quie|--quiet)
-		# Ignore --quiet under a TAP::Harness. Saying how many tests
-		# passed without the ok/not ok details is always an error.
-		test -z "$HARNESS_ACTIVE" && quiet=t; shift ;;
-	--with-dashes)
-		with_dashes=t; shift ;;
-	--no-color)
-		color=; shift ;;
-	--va|--val|--valg|--valgr|--valgri|--valgrin|--valgrind)
-		valgrind=memcheck
-		shift ;;
-	--valgrind=*)
-		valgrind=${1#--*=}
-		shift ;;
-	--valgrind-only=*)
-		valgrind_only=${1#--*=}
-		shift ;;
-	--tee)
-		shift ;; # was handled already
-	--root=*)
-		root=${1#--*=}
-		shift ;;
-	--chain-lint)
-		GIT_TEST_CHAIN_LINT=1
-		shift ;;
-	--no-chain-lint)
-		GIT_TEST_CHAIN_LINT=0
-		shift ;;
-	-x)
-		# Some test scripts can't be reliably traced  with '-x',
-		# unless the test is run with a Bash version supporting
-		# BASH_XTRACEFD (introduced in Bash v4.1).  Check whether
-		# this test is marked as such, and ignore '-x' if it
-		# isn't executed with a suitable Bash version.
-		if test -z "$test_untraceable" || {
-		     test -n "$BASH_VERSION" && {
-		       test ${BASH_VERSINFO[0]} -gt 4 || {
-			 test ${BASH_VERSINFO[0]} -eq 4 &&
-			 test ${BASH_VERSINFO[1]} -ge 1
-		       }
-		     }
-		   }
-		then
-			trace=t
-		else
-			echo >&2 "warning: ignoring -x; '$0' is untraceable without BASH_XTRACEFD"
-		fi
-		shift ;;
-	-V|--verbose-log)
-		verbose_log=t
-		shift ;;
-	*)
-		echo "error: unknown test option '$1'" >&2; exit 1 ;;
-	esac
-done
-
-if test -n "$valgrind_only"
-then
-	test -z "$valgrind" && valgrind=memcheck
-	test -z "$verbose" && verbose_only="$valgrind_only"
-elif test -n "$valgrind"
-then
-	test -z "$verbose_log" && verbose=t
-fi
-
-if test -n "$trace" && test -z "$verbose_log"
-then
-	verbose=t
-fi
-
 if test -n "$color"
 then
 	# Save the color control sequences now rather than run tput
@@ -476,7 +612,7 @@
 
 GIT_EXIT_OK=
 trap 'die' EXIT
-trap 'exit $?' INT
+trap 'exit $?' INT TERM HUP
 
 # The user-facing functions are loaded from a separate file so that
 # test_perf subshells can have them too
@@ -818,12 +954,9 @@
 
 	if test -z "$HARNESS_ACTIVE"
 	then
-		test_results_dir="$TEST_OUTPUT_DIRECTORY/test-results"
-		mkdir -p "$test_results_dir"
-		base=${0##*/}
-		test_results_path="$test_results_dir/${base%.sh}.counts"
+		mkdir -p "$TEST_RESULTS_DIR"
 
-		cat >"$test_results_path" <<-EOF
+		cat >"$TEST_RESULTS_BASE.counts" <<-EOF
 		total $test_count
 		success $test_success
 		fixed $test_fixed
@@ -1029,12 +1162,6 @@
 fi
 
 # Test repository
-TRASH_DIRECTORY="trash directory.$(basename "$0" .sh)"
-test -n "$root" && TRASH_DIRECTORY="$root/$TRASH_DIRECTORY"
-case "$TRASH_DIRECTORY" in
-/*) ;; # absolute path is good
- *) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$TRASH_DIRECTORY" ;;
-esac
 rm -fr "$TRASH_DIRECTORY" || {
 	GIT_EXIT_OK=t
 	echo >&5 "FATAL: Cannot prepare test area"
diff --git a/transport-helper.c b/transport-helper.c
index bf225c6..6cf3bb3 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -1026,7 +1026,8 @@
 }
 
 
-static int has_attribute(const char *attrs, const char *attr) {
+static int has_attribute(const char *attrs, const char *attr)
+{
 	int len;
 	if (!attrs)
 		return 0;
@@ -1225,9 +1226,8 @@
 		return 0;	/* No space for more. */
 
 	transfer_debug("%s is readable", t->src_name);
-	bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
-	if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
-		errno != EINTR) {
+	bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
+	if (bytes < 0) {
 		error_errno(_("read(%s) failed"), t->src_name);
 		return -1;
 	} else if (bytes == 0) {
@@ -1254,7 +1254,7 @@
 
 	transfer_debug("%s is writable", t->dest_name);
 	bytes = xwrite(t->dest, t->buf, t->bufuse);
-	if (bytes < 0 && errno != EWOULDBLOCK) {
+	if (bytes < 0) {
 		error_errno(_("write(%s) failed"), t->dest_name);
 		return -1;
 	} else if (bytes > 0) {
diff --git a/tree-diff.c b/tree-diff.c
index 0e54324..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);
@@ -299,7 +299,8 @@
 	enum interesting match;
 
 	while (t->size) {
-		match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
+		match = tree_entry_interesting(opt->repo->index, &t->entry,
+					       base, 0, &opt->pathspec);
 		if (match) {
 			if (match == all_entries_not_interesting)
 				t->size = 0;
@@ -491,7 +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 79bafbd..277e3b3 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)
@@ -365,7 +368,8 @@
 	}
 }
 
-static inline int prune_traversal(struct name_entry *e,
+static inline int prune_traversal(struct index_state *istate,
+				  struct name_entry *e,
 				  struct traverse_info *info,
 				  struct strbuf *base,
 				  int still_interesting)
@@ -374,10 +378,13 @@
 		return 2;
 	if (still_interesting < 0)
 		return still_interesting;
-	return tree_entry_interesting(e, base, 0, info->pathspec);
+	return tree_entry_interesting(istate, e, base,
+				      0, info->pathspec);
 }
 
-int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
+int traverse_trees(struct index_state *istate,
+		   int n, struct tree_desc *t,
+		   struct traverse_info *info)
 {
 	int error = 0;
 	struct name_entry *entry = xmalloc(n*sizeof(*entry));
@@ -461,7 +468,7 @@
 		}
 		if (!mask)
 			break;
-		interesting = prune_traversal(e, info, &base, interesting);
+		interesting = prune_traversal(istate, e, info, &base, interesting);
 		if (interesting < 0)
 			break;
 		if (interesting) {
@@ -498,10 +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)
@@ -512,7 +519,7 @@
 		if (cmp < 0)
 			break;
 		if (entrylen == namelen) {
-			oidcpy(result, oid);
+			oidcpy(result, &oid);
 			return 0;
 		}
 		if (name[entrylen] != '/')
@@ -520,10 +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;
 }
@@ -928,7 +935,8 @@
  * Pre-condition: either baselen == base_offset (i.e. empty path)
  * or base[baselen-1] == '/' (i.e. with trailing slash).
  */
-static enum interesting do_match(const struct name_entry *entry,
+static enum interesting do_match(struct index_state *istate,
+				 const struct name_entry *entry,
 				 struct strbuf *base, int base_offset,
 				 const struct pathspec *ps,
 				 int exclude)
@@ -944,7 +952,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	if (!ps->nr) {
 		if (!ps->recursive ||
@@ -976,14 +985,20 @@
 
 			if (!ps->recursive ||
 			    !(ps->magic & PATHSPEC_MAXDEPTH) ||
-			    ps->max_depth == -1)
-				return all_entries_interesting;
+			    ps->max_depth == -1) {
+				if (!item->attr_match_nr)
+					return all_entries_interesting;
+				else
+					goto interesting;
+			}
 
-			return within_depth(base_str + matchlen + 1,
-					    baselen - matchlen - 1,
-					    !!S_ISDIR(entry->mode),
-					    ps->max_depth) ?
-				entry_interesting : entry_not_interesting;
+			if (within_depth(base_str + matchlen + 1,
+					 baselen - matchlen - 1,
+					 !!S_ISDIR(entry->mode),
+					 ps->max_depth))
+				goto interesting;
+			else
+				return entry_not_interesting;
 		}
 
 		/* Either there must be no base, or the base must match. */
@@ -991,12 +1006,12 @@
 			if (match_entry(item, entry, pathlen,
 					match + baselen, matchlen - baselen,
 					&never_interesting))
-				return entry_interesting;
+				goto interesting;
 
 			if (item->nowildcard_len < item->len) {
 				if (!git_fnmatch(item, match + baselen, entry->path,
 						 item->nowildcard_len - baselen))
-					return entry_interesting;
+					goto interesting;
 
 				/*
 				 * Match all directories. We'll try to
@@ -1017,7 +1032,7 @@
 				    !ps_strncmp(item, match + baselen,
 						entry->path,
 						item->nowildcard_len - baselen))
-					return entry_interesting;
+					goto interesting;
 			}
 
 			continue;
@@ -1052,7 +1067,7 @@
 		if (!git_fnmatch(item, match, base->buf + base_offset,
 				 item->nowildcard_len)) {
 			strbuf_setlen(base, base_offset + baselen);
-			return entry_interesting;
+			goto interesting;
 		}
 
 		/*
@@ -1066,7 +1081,7 @@
 		    !ps_strncmp(item, match, base->buf + base_offset,
 				item->nowildcard_len)) {
 			strbuf_setlen(base, base_offset + baselen);
-			return entry_interesting;
+			goto interesting;
 		}
 
 		strbuf_setlen(base, base_offset + baselen);
@@ -1080,6 +1095,38 @@
 		 */
 		if (ps->recursive && S_ISDIR(entry->mode))
 			return entry_interesting;
+		continue;
+interesting:
+		if (item->attr_match_nr) {
+			int ret;
+
+			/*
+			 * Must not return all_entries_not_interesting
+			 * prematurely. We do not know if all entries do not
+			 * match some attributes with current attr API.
+			 */
+			never_interesting = entry_not_interesting;
+
+			/*
+			 * Consider all directories interesting (because some
+			 * of those files inside may match some attributes
+			 * even though the parent dir does not)
+			 *
+			 * FIXME: attributes _can_ match directories and we
+			 * can probably return all_entries_interesting or
+			 * all_entries_not_interesting here if matched.
+			 */
+			if (S_ISDIR(entry->mode))
+				return entry_interesting;
+
+			strbuf_add(base, entry->path, pathlen);
+			ret = match_pathspec_attrs(istate, base->buf + base_offset,
+						   base->len - base_offset, item);
+			strbuf_setlen(base, base_offset + baselen);
+			if (!ret)
+				continue;
+		}
+		return entry_interesting;
 	}
 	return never_interesting; /* No matches */
 }
@@ -1090,12 +1137,13 @@
  * Pre-condition: either baselen == base_offset (i.e. empty path)
  * or base[baselen-1] == '/' (i.e. with trailing slash).
  */
-enum interesting tree_entry_interesting(const struct name_entry *entry,
+enum interesting tree_entry_interesting(struct index_state *istate,
+					const struct name_entry *entry,
 					struct strbuf *base, int base_offset,
 					const struct pathspec *ps)
 {
 	enum interesting positive, negative;
-	positive = do_match(entry, base, base_offset, ps, 0);
+	positive = do_match(istate, entry, base, base_offset, ps, 0);
 
 	/*
 	 * case | entry | positive | negative | result
@@ -1132,7 +1180,7 @@
 	    positive <= entry_not_interesting) /* #1, #2, #11, #12 */
 		return positive;
 
-	negative = do_match(entry, base, base_offset, ps, 1);
+	negative = do_match(istate, entry, base, base_offset, ps, 1);
 
 	/* #8, #18 */
 	if (positive == all_entries_interesting &&
diff --git a/tree-walk.h b/tree-walk.h
index 1968310..a4ad28e 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -1,11 +1,12 @@
 #ifndef TREE_WALK_H
 #define TREE_WALK_H
 
-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;
 };
 
@@ -19,12 +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;
 }
 
 /*
@@ -48,7 +49,7 @@
 
 struct traverse_info;
 typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *);
-int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info);
+int traverse_trees(struct index_state *istate, int n, struct tree_desc *t, struct traverse_info *info);
 
 enum follow_symlinks_result {
 	FOUND = 0, /* This includes out-of-tree links */
@@ -98,8 +99,9 @@
 	all_entries_interesting = 2 /* yes, and all subsequent entries will be */
 };
 
-extern enum interesting tree_entry_interesting(const struct name_entry *,
-					       struct strbuf *, int,
-					       const struct pathspec *ps);
+enum interesting tree_entry_interesting(struct index_state *istate,
+					const struct name_entry *,
+					struct strbuf *, int,
+					const struct pathspec *ps);
 
 #endif
diff --git a/tree.c b/tree.c
index 215d3fd..9f0457c 100644
--- a/tree.c
+++ b/tree.c
@@ -60,7 +60,8 @@
 				  ADD_CACHE_JUST_APPEND);
 }
 
-static int read_tree_1(struct tree *tree, struct strbuf *base,
+static int read_tree_1(struct repository *r,
+		       struct tree *tree, struct strbuf *base,
 		       int stage, const struct pathspec *pathspec,
 		       read_tree_fn_t fn, void *context)
 {
@@ -77,14 +78,15 @@
 
 	while (tree_entry(&desc, &entry)) {
 		if (retval != all_entries_interesting) {
-			retval = tree_entry_interesting(&entry, base, 0, pathspec);
+			retval = tree_entry_interesting(r->index, &entry,
+							base, 0, pathspec);
 			if (retval == all_entries_not_interesting)
 				break;
 			if (retval == entry_not_interesting)
 				continue;
 		}
 
-		switch (fn(entry.oid, base,
+		switch (fn(&entry.oid, base,
 			   entry.path, entry.mode, stage, context)) {
 		case 0:
 			continue;
@@ -95,19 +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(the_repository, 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));
@@ -118,7 +120,7 @@
 		len = tree_entry_len(&entry);
 		strbuf_add(base, entry.path, len);
 		strbuf_addch(base, '/');
-		retval = read_tree_1(lookup_tree(the_repository, &oid),
+		retval = read_tree_1(r, lookup_tree(r, &oid),
 				     base, stage, pathspec,
 				     fn, context);
 		strbuf_setlen(base, oldlen);
@@ -128,7 +130,8 @@
 	return 0;
 }
 
-int read_tree_recursive(struct tree *tree,
+int read_tree_recursive(struct repository *r,
+			struct tree *tree,
 			const char *base, int baselen,
 			int stage, const struct pathspec *pathspec,
 			read_tree_fn_t fn, void *context)
@@ -137,7 +140,7 @@
 	int ret;
 
 	strbuf_add(&sb, base, baselen);
-	ret = read_tree_1(tree, &sb, stage, pathspec, fn, context);
+	ret = read_tree_1(r, tree, &sb, stage, pathspec, fn, context);
 	strbuf_release(&sb);
 	return ret;
 }
@@ -152,8 +155,8 @@
 				  ce2->name, ce2->ce_namelen, ce_stage(ce2));
 }
 
-int read_tree(struct tree *tree, int stage, struct pathspec *match,
-	      struct index_state *istate)
+int read_tree(struct repository *r, struct tree *tree, int stage,
+	      struct pathspec *match, struct index_state *istate)
 {
 	read_tree_fn_t fn = NULL;
 	int i, err;
@@ -181,7 +184,7 @@
 
 	if (!fn)
 		fn = read_one_entry_quick;
-	err = read_tree_recursive(tree, "", 0, stage, match, fn, istate);
+	err = read_tree_recursive(r, tree, "", 0, stage, match, fn, istate);
 	if (fn == read_one_entry || err)
 		return err;
 
diff --git a/tree.h b/tree.h
index d4807dc..9383745 100644
--- a/tree.h
+++ b/tree.h
@@ -3,7 +3,7 @@
 
 #include "object.h"
 
-extern const char *tree_type;
+struct repository;
 struct strbuf;
 
 struct tree {
@@ -12,6 +12,8 @@
 	unsigned long size;
 };
 
+extern const char *tree_type;
+
 struct tree *lookup_tree(struct repository *r, const struct object_id *oid);
 
 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size);
@@ -29,12 +31,14 @@
 #define READ_TREE_RECURSIVE 1
 typedef int (*read_tree_fn_t)(const struct object_id *, struct strbuf *, const char *, unsigned int, int, void *);
 
-extern int read_tree_recursive(struct tree *tree,
-			       const char *base, int baselen,
-			       int stage, const struct pathspec *pathspec,
-			       read_tree_fn_t fn, void *context);
+int read_tree_recursive(struct repository *r,
+			struct tree *tree,
+			const char *base, int baselen,
+			int stage, const struct pathspec *pathspec,
+			read_tree_fn_t fn, void *context);
 
-extern int read_tree(struct tree *tree, int stage, struct pathspec *pathspec,
-		     struct index_state *istate);
+int read_tree(struct repository *r, struct tree *tree,
+	      int stage, struct pathspec *pathspec,
+	      struct index_state *istate);
 
 #endif /* TREE_H */
diff --git a/unpack-trees.c b/unpack-trees.c
index 6d53cbf..01c2175 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -294,7 +294,7 @@
 			repo_read_gitmodules(the_repository);
 		} else if (state && (ce->ce_flags & CE_UPDATE)) {
 			submodule_free(the_repository);
-			checkout_entry(ce, state, NULL);
+			checkout_entry(ce, state, NULL, NULL);
 			repo_read_gitmodules(the_repository);
 		}
 	}
@@ -450,12 +450,12 @@
 			display_progress(progress, ++cnt);
 			ce->ce_flags &= ~CE_UPDATE;
 			if (o->update && !o->dry_run) {
-				errs |= checkout_entry(ce, &state, NULL);
+				errs |= checkout_entry(ce, &state, NULL, NULL);
 			}
 		}
 	}
 	stop_progress(&progress);
-	errs |= finish_delayed_checkout(&state);
+	errs |= finish_delayed_checkout(&state, NULL);
 	if (o->update)
 		git_attr_set_direction(GIT_ATTR_CHECKIN);
 
@@ -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,
@@ -794,6 +794,7 @@
 				    struct name_entry *names,
 				    struct traverse_info *info)
 {
+	struct unpack_trees_options *o = info->data;
 	int i, ret, bottom;
 	int nr_buf = 0;
 	struct tree_desc t[MAX_UNPACK_TREES];
@@ -804,7 +805,6 @@
 
 	nr_entries = all_trees_same_as_cache_tree(n, dirmask, names, info);
 	if (nr_entries > 0) {
-		struct unpack_trees_options *o = info->data;
 		int pos = index_pos_by_traverse_info(names, info);
 
 		if (!o->merge || df_conflicts)
@@ -857,13 +857,13 @@
 		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);
 		}
 	}
 
 	bottom = switch_cache_bottom(&newinfo);
-	ret = traverse_trees(n, t, &newinfo);
+	ret = traverse_trees(o->src_index, n, t, &newinfo);
 	restore_cache_bottom(&newinfo, bottom);
 
 	for (i = 0; i < nr_buf; i++)
@@ -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;
@@ -1550,7 +1550,7 @@
 		}
 
 		trace_performance_enter();
-		ret = traverse_trees(len, t, &info);
+		ret = traverse_trees(o->src_index, len, t, &info);
 		trace_performance_leave("traverse_trees");
 		if (ret < 0)
 			goto return_failed;
diff --git a/upload-pack.c b/upload-pack.c
index 5e81f1f..9df27b5 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;
@@ -662,6 +661,9 @@
 	}
 }
 
+static int check_ref(const char *refname_full, const struct object_id *oid,
+		     int flag, void *cb_data);
+
 static void deepen(int depth, int deepen_relative,
 		   struct object_array *shallows, struct object_array *want_obj)
 {
@@ -676,6 +678,13 @@
 		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,
@@ -712,6 +721,7 @@
 static int send_shallow_list(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)
 {
@@ -834,6 +844,7 @@
 	int has_non_tip = 0;
 	timestamp_t deepen_since = 0;
 	int deepen_rev_list = 0;
+	int deepen_relative = 0;
 
 	shallow_nr = 0;
 	for (;;) {
@@ -925,7 +936,8 @@
 		return;
 
 	if (send_shallow_list(depth, deepen_rev_list, deepen_since,
-			      &deepen_not, &shallows, want_obj))
+			      &deepen_not, deepen_relative, &shallows,
+			      want_obj))
 		packet_flush(1);
 	object_array_clear(&shallows);
 }
@@ -1398,6 +1410,7 @@
 
 	if (!send_shallow_list(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,
diff --git a/url.c b/url.c
index eaf4f07..25576c3 100644
--- a/url.c
+++ b/url.c
@@ -104,7 +104,8 @@
 	strbuf_complete(buf, '/');
 }
 
-void str_end_url_with_slash(const char *url, char **dest) {
+void str_end_url_with_slash(const char *url, char **dest)
+{
 	struct strbuf buf = STRBUF_INIT;
 	end_url_with_slash(&buf, url);
 	free(*dest);
diff --git a/userdiff.c b/userdiff.c
index 97007ab..3a78fbf 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -265,7 +265,8 @@
 	return 0;
 }
 
-struct userdiff_driver *userdiff_find_by_name(const char *name) {
+struct userdiff_driver *userdiff_find_by_name(const char *name)
+{
 	int len = strlen(name);
 	return userdiff_find_by_namelen(name, len);
 }
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;
 		}