Sync with 'maint'
diff --git a/.gitignore b/.gitignore
index b1020b8..833ef3b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -114,6 +114,7 @@
 /git-read-tree
 /git-rebase
 /git-rebase--am
+/git-rebase--helper
 /git-rebase--interactive
 /git-rebase--merge
 /git-receive-pack
diff --git a/.mailmap b/.mailmap
index c44cf67..ab85e0d 100644
--- a/.mailmap
+++ b/.mailmap
@@ -178,6 +178,7 @@
 Pascal Obry <pascal@obry.net> <pascal.obry@gmail.com>
 Pascal Obry <pascal@obry.net> <pascal.obry@wanadoo.fr>
 Pat Notz <patnotz@gmail.com> <pknotz@sandia.gov>
+Patrick Steinhardt <ps@pks.im> <patrick.steinhardt@elego.de>
 Paul Mackerras <paulus@samba.org> <paulus@dorrigo.(none)>
 Paul Mackerras <paulus@samba.org> <paulus@pogo.(none)>
 Peter Baumann <waste.manager@gmx.de> <Peter.B.Baumann@stud.informatik.uni-erlangen.de>
diff --git a/Documentation/RelNotes/2.13.0.txt b/Documentation/RelNotes/2.13.0.txt
new file mode 100644
index 0000000..adf6e44
--- /dev/null
+++ b/Documentation/RelNotes/2.13.0.txt
@@ -0,0 +1,390 @@
+Git 2.13 Release Notes
+======================
+
+Backward compatibility notes.
+
+ * Use of an empty string as a pathspec element that is used for
+   'everything matches' is still warned and Git asks users to use a
+   more explicit '.' for that instead.  The hope is that existing
+   users will not mind this change, and eventually the warning can be
+   turned into a hard error, upgrading the deprecation into removal of
+   this (mis)feature.  That is not scheduled to happen in the upcoming
+   release (yet).
+
+ * The historical argument order "git merge <msg> HEAD <commit>..."
+   has been deprecated for quite some time, and will be removed in a
+   future release.
+
+ * The default location "~/.git-credential-cache/socket" for the
+   socket used to communicate with the credential-cache daemon has
+   been moved to "~/.cache/git/credential/socket".
+
+
+Updates since v2.12
+-------------------
+
+UI, Workflows & Features
+
+ * "git describe" and "git name-rev" have been taught to take more
+   than one refname patterns to restrict the set of refs to base their
+   naming output on, and also learned to take negative patterns to
+   name refs not to be used for naming via their "--exclude" option.
+
+ * Deletion of a branch "foo/bar" could remove .git/refs/heads/foo
+   once there no longer is any other branch whose name begins with
+   "foo/", but we didn't do so so far.  Now we do.
+
+ * When "git merge" detects a path that is renamed in one history
+   while the other history deleted (or modified) it, it now reports
+   both paths to help the user understand what is going on in the two
+   histories being merged.
+
+ * The <url> part in "http.<url>.<variable>" configuration variable
+   can now be spelled with '*' that serves as wildcard.
+   E.g. "http.https://*.example.com.proxy" can be used to specify the
+   proxy used for https://a.example.com, https://b.example.com, etc.,
+   i.e. any host in the example.com domain.
+
+ * "git tag" did not leave useful message when adding a new entry to
+   reflog; this was left unnoticed for a long time because refs/tags/*
+   doesn't keep reflog by default.
+
+ * The "negative" pathspec feature was somewhat more cumbersome to use
+   than necessary in that its short-hand used "!" which needed to be
+   escaped from shells, and it required "exclude from what?" specified.
+
+ * The command line options for ssh invocation needs to be tweaked for
+   some implementations of SSH (e.g. PuTTY plink wants "-P <port>"
+   while OpenSSH wants "-p <port>" to specify port to connect to), and
+   the variant was guessed when GIT_SSH environment variable is used
+   to specify it.  The logic to guess now applies to the command
+   specified by the newer GIT_SSH_COMMAND and also core.sshcommand
+   configuration variable, and comes with an escape hatch for users to
+   deal with misdetected cases.
+
+ * The "--git-path", "--git-common-dir", and "--shared-index-path"
+   options of "git rev-parse" did not produce usable output.  They are
+   now updated to show the path to the correct file, relative to where
+   the caller is.
+
+ * "git diff -W" has been taught to handle the case where a new
+   function is added at the end of the file better.
+
+ * "git update-ref -d" and other operations to delete references did
+   not leave any entry in HEAD's reflog when the reference being
+   deleted was the current branch.  This is not a problem in practice
+   because you do not want to delete the branch you are currently on,
+   but caused renaming of the current branch to something else not to
+   be logged in a useful way.
+
+ * "Cc:" on the trailer part does not have to conform to RFC strictly,
+   unlike in the e-mail header.  "git send-email" has been updated to
+   ignore anything after '>' when picking addresses, to allow non-address
+   cruft like " # stable 4.4" after the address.
+
+ * When "git submodule init" decides that the submodule in the working
+   tree is its upstream, it now gives a warning as it is not a very
+   common setup.
+   (merge d1b3b81aab sb/submodule-init-url-selection later to maint).
+
+ * "git stash save" takes a pathspec so that the local changes can be
+   stashed away only partially.
+   (merge 9e140909f6 tg/stash-push later to maint).
+
+ * Documentation for "git ls-files" did not refer to core.quotePath.
+
+ * The experimental "split index" feature has gained a few
+   configuration variables to make it easier to use.
+
+ * From a working tree of a repository, a new option of "rev-parse"
+   lets you ask if the repository is used as a submodule of another
+   project, and where the root level of the working tree of that
+   project (i.e. your superproject) is.
+
+ * The pathspec mechanism learned to further limit the paths that
+   match the pattern to those that have specified attributes attached
+   via the gitattributes mechanism.
+
+ * Our source code has used the SHA1_HEADER cpp macro after "#include"
+   in the C code to switch among the SHA-1 implementations. Instead,
+   list the exact header file names and switch among implementations
+   using "#ifdef BLK_SHA1/#include "block-sha1/sha1.h"/.../#endif";
+   this helps some IDE tools.
+
+ * The start-up sequence of "git" needs to figure out some configured
+   settings before it finds and set itself up in the location of the
+   repository and was quite messy due to its "chicken-and-egg" nature.
+   The code has been restructured.
+
+ * The command line prompt (in contrib/) learned a new 'tag' style
+   that can be specified with GIT_PS1_DESCRIBE_STYLE, to describe a
+   detached HEAD with "git describe --tags".
+
+ * The configuration file learned a new "includeIf.<condition>.path"
+   that includes the contents of the given path only when the
+   condition holds.  This allows you to say "include this work-related
+   bit only in the repositories under my ~/work/ directory".
+
+ * Recent update to "rebase -i" started showing a message that is not
+   a warning with "warning:" prefix by mistake.  This has been fixed.
+
+ * Recently we started passing the "--push-options" through the
+   external remote helper interface; now the "smart HTTP" remote
+   helper understands what to do with the passed information.
+
+ * "git describe --dirty" dies when it cannot be determined if the
+   state in the working tree matches that of HEAD (e.g. broken
+   repository or broken submodule).  The command learned a new option
+   "git describe --broken" to give "$name-broken" (where $name is the
+   description of HEAD) in such a case.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The code to list branches in "git branch" has been consolidated
+   with the more generic ref-filter API.
+
+ * Resource usage while enumerating refs from alternate object store
+   has been optimized to help receiving end of "push" that hosts a
+   repository with many "forks".
+
+ * The gitattributes machinery is being taught to work better in a
+   multi-threaded environment.
+
+ * "git rebase -i" starts using the recently updated "sequencer" code.
+
+ * Code and design clean-up for the refs API.
+
+ * The preload-index code has been taught not to bother with the index
+   entries that are paths that are not checked out by "sparse checkout".
+
+ * Some warning() messages from "git clean" were updated to show the
+   errno from failed system calls.
+
+ * The "parse_config_key()" API function has been cleaned up.
+   (merge ad8c7cdadd jk/parse-config-key-cleanup later to maint).
+
+ * A test that creates a confusing branch whose name is HEAD has been
+   corrected not to do so.
+
+ * The code that parses header fields in the commit object has been
+   updated for (micro)performance and code hygiene.
+
+ * An helper function to make it easier to append the result from
+   real_path() to a strbuf has been added.
+   (merge 33ad9ddd0b rs/strbuf-add-real-path later to maint).
+
+ * Reduce authentication round-trip over HTTP when the server supports
+   just a single authentication method.  This also improves the
+   behaviour when Git is misconfigured to enable http.emptyAuth
+   against a server that does not authenticate without a username
+   (i.e. not using Kerberos etc., which makes http.emptyAuth
+   pointless).
+
+ * Windows port wants to use OpenSSL's implementation of SHA-1
+   routines, so let them.
+
+ * The t/perf performance test suite was not prepared to test not so
+   old versions of Git, but now it covers versions of Git that are not
+   so ancient.
+   (merge 28e1fb5466 jt/perf-updates later to maint).
+
+ * Add 32-bit Linux variant to the set of platforms to be tested with
+   Travis CI.
+
+ * "git branch --list" takes the "--abbrev" and "--no-abbrev" options
+   to control the output of the object name in its "-v"(erbose)
+   output, but a recent update started ignoring them; fix it before
+   the breakage reaches to any released version.
+
+ * Picking two versions of Git and running tests to make sure the
+   older one and the newer one interoperate happily has now become
+   possible.
+   (merge bd4d9d993c jk/interop-test later to maint).
+
+ * "uchar [40]" to "struct object_id" conversion continues.
+
+ * "git tag --contains" used to (ab)use the object bits to keep track
+   of the state of object reachability without clearing them after
+   use; this has been cleaned up and made to use the newer commit-slab
+   facility.
+
+ * The "debug" helper used in the test framework learned to run
+   a command under "gdb" interactively.
+   (merge 59210dd56c sg/test-with-stdin later to maint).
+
+ * The "detect attempt to create collisions" variant of SHA-1
+   implementation by Marc Stevens (CWI) and Dan Shumow (Microsoft)
+   has been integrated and made the default.
+
+ * The test framework learned to detect unterminated here documents.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.12
+-----------------
+
+Unless otherwise noted, all the fixes since v2.12 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git repack --depth=<n>" for a long time busted the specified depth
+   when reusing delta from existing packs.  This has been corrected.
+   (merge 42b766d765 jk/delta-chain-limit later to maint).
+
+ * The code to parse the command line "git grep <patterns>... <rev>
+   [[--] <pathspec>...]" has been cleaned up, and a handful of bugs
+   have been fixed (e.g. we used to check "--" if it is a rev).
+
+ * "git ls-remote" and "git archive --remote" are designed to work
+   without being in a directory under Git's control.  However, recent
+   updates revealed that we randomly look into a directory called
+   .git/ without actually doing necessary set-up when working in a
+   repository.  Stop doing so.
+
+ * "git show-branch" expected there were only very short branch names
+   in the repository and used a fixed-length buffer to hold them
+   without checking for overflow.
+
+ * A caller of tempfile API that uses stdio interface to write to
+   files may ignore errors while writing, which is detected when
+   tempfile is closed (with a call to ferror()).  By that time, the
+   original errno that may have told us what went wrong is likely to
+   be long gone and was overwritten by an irrelevant value.
+   close_tempfile() now resets errno to EIO to make errno at least
+   predictable.
+
+ * "git remote rm X", when a branch has remote X configured as the
+   value of its branch.*.remote, tried to remove branch.*.remote and
+   branch.*.merge and failed if either is unset.
+
+ * A "gc.log" file left by a backgrounded "gc --auto" disables further
+   automatic gc; it has been taught to run at least once a day (by
+   default) by ignoring a stale "gc.log" file that is too old.
+
+ * The code to parse "git -c VAR=VAL cmd" and set configuration
+   variable for the duration of cmd had two small bugs, which have
+   been fixed.
+
+ * user.email that consists of only cruft chars should consistently
+   error out, but didn't.
+   (merge 94425552f3 jk/ident-empty later to maint).
+
+ * "git upload-pack", which is a counter-part of "git fetch", did not
+   report a request for a ref that was not advertised as invalid.
+   This is generally not a problem (because "git fetch" will stop
+   before making such a request), but is the right thing to do.
+
+ * A leak in a codepath to read from a packed object in (rare) cases
+   has been plugged.
+
+ * When a redirected http transport gets an error during the
+   redirected request, we ignored the error we got from the server,
+   and ended up giving a not-so-useful error message.
+
+ * The patch subcommand of "git add -i" was meant to have paths
+   selection prompt just like other subcommand, unlike "git add -p"
+   directly jumps to hunk selection.  Recently, this was broken and
+   "add -i" lost the paths selection dialog, but it now has been
+   fixed.
+
+ * Git v2.12 was shipped with an embarrassing breakage where various
+   operations that verify paths given from the user stopped dying when
+   seeing an issue, and instead later triggering segfault.
+
+ * There is no need for Python only to give a few messages to the
+   standard error stream, but we somehow did.
+
+ * The code to parse "git log -L..." command line was buggy when there
+   are many ranges specified with -L; overrun of the allocated buffer
+   has been fixed.
+
+ * The command-line parsing of "git log -L" copied internal data
+   structures using incorrect size on ILP32 systems.
+
+ * "git diff --quiet" relies on the size field in diff_filespec to be
+   correctly populated, but diff_populate_filespec() helper function
+   made an incorrect short-cut when asked only to populate the size
+   field for paths that need to go through convert_to_git() (e.g. CRLF
+   conversion).
+
+ * A few tests were run conditionally under (rare) conditions where
+   they cannot be run (like running cvs tests under 'root' account).
+   (merge c6507484a2 ab/cond-skip-tests later to maint).
+
+ * "git branch @" created refs/heads/@ as a branch, and in general the
+   code that handled @{-1} and @{upstream} was a bit too loose in
+   disambiguating.
+   (merge fd4692ff70 jk/interpret-branch-name later to maint).
+
+ * "git fetch" that requests a commit by object name, when the other
+   side does not allow such an request, failed without much
+   explanation.
+   (merge d56583ded6 mm/fetch-show-error-message-on-unadvertised-object later to maint).
+
+ * "git filter-branch --prune-empty" drops a single-parent commit that
+   becomes a no-op, but did not drop a root commit whose tree is empty.
+   (merge 32da7467eb dp/filter-branch-prune-empty later to maint).
+
+ * Recent versions of Git treats http alternates (used in dumb http
+   transport) just like HTTP redirects and requires the client to
+   enable following it, due to security concerns.  But we forgot to
+   give a warning when we decide not to honor the alternates.
+   (merge 5cae73d5d2 ew/http-alternates-as-redirects-warning later to maint).
+
+ * "git push" had a handful of codepaths that could lead to a deadlock
+   when unexpected error happened, which has been fixed.
+
+ * "Dumb http" transport used to misparse a nonsense http-alternates
+   response, which has been fixed.
+
+ * "git add -p <pathspec>" unnecessarily expanded the pathspec to a
+   list of individual files that matches the pathspec by running "git
+   ls-files <pathspec>", before feeding it to "git diff-index" to see
+   which paths have changes, because historically the pathspec
+   language supported by "diff-index" was weaker.  These days they are
+   equivalent and there is no reason to internally expand it.  This
+   helps both performance and avoids command line argument limit on
+   some platforms.
+   (merge 7288e12cce jk/add-i-use-pathspecs later to maint).
+
+ * "git status --porcelain" is supposed to give a stable output, but a
+   few strings were left as translatable by mistake.
+
+ * "git revert -m 0 $merge_commit" complained that reverting a merge
+   needs to say relative to which parent the reversion needs to
+   happen, as if "-m 0" weren't given.  The correct diagnosis is that
+   "-m 0" does not refer to the first parent ("-m 1" does).  This has
+   been fixed.
+
+ * Code to read submodule.<name>.ignore config did not state the
+   variable name correctly when giving an error message diagnosing
+   misconfiguration.
+
+ * Fix for NO_PTHREADS build.
+   (merge 7b91929ba0 jk/execv-dashed-external later to maint).
+
+ * Fix for potential segv introduced in v2.11.0 and later (also
+   v2.10.2) to "git log --pickaxe-regex -S".
+   (merge f53c5de29c js/regexec-buf later to maint).
+
+ * A few unterminated here documents in tests were fixed, which in
+   turn revealed incorrect expectations the tests make. These tests
+   have been updated.
+   (merge b42ca35e5c st/verify-tag later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge dfa3ad3238 rs/blame-code-cleanup later to maint).
+   (merge ffddfc6328 jk/rev-parse-cleanup later to maint).
+   (merge f20754802a jk/pack-name-cleanups later to maint).
+   (merge d4aae459cd sb/wt-status-cleanup later to maint).
+   (merge e94eac49e6 rs/http-push-cleanup later to maint).
+   (merge ba6746c08f rs/path-name-safety-cleanup later to maint).
+   (merge d41626ff9e rs/shortlog-cleanup later to maint).
+   (merge dce96c41f9 rs/update-hook-optim later to maint).
+   (merge 37e61153e2 jk/quote-env-path-list-component later to maint).
+   (merge a4dded0189 sb/submodule-update-initial-runs-custom-script later to maint).
+   (merge 70471ed9bb sb/t3600-rephrase later to maint).
+   (merge e7e183d6ee km/config-grammofix later to maint).
diff --git a/Documentation/config.txt b/Documentation/config.txt
index e43d147..1df1965 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -79,18 +79,69 @@
 Includes
 ~~~~~~~~
 
-You can include one config file from another by setting the special
+You can include a config file from another by setting the special
 `include.path` variable to the name of the file to be included. The
 variable takes a pathname as its value, and is subject to tilde
-expansion.
+expansion. `include.path` can be given multiple times.
 
-The
-included file is expanded immediately, as if its contents had been
+The included file is expanded immediately, as if its contents had been
 found at the location of the include directive. If the value of the
-`include.path` variable is a relative path, the path is considered to be
-relative to the configuration file in which the include directive was
-found.  See below for examples.
+`include.path` variable is a relative path, the path is considered to
+be relative to the configuration file in which the include directive
+was found.  See below for examples.
 
+Conditional includes
+~~~~~~~~~~~~~~~~~~~~
+
+You can include a config file from another conditionally by setting a
+`includeIf.<condition>.path` variable to the name of the file to be
+included. The variable's value is treated the same way as
+`include.path`. `includeIf.<condition>.path` can be given multiple times.
+
+The condition starts with a keyword followed by a colon and some data
+whose format and meaning depends on the keyword. Supported keywords
+are:
+
+`gitdir`::
+
+	The data that follows the keyword `gitdir:` is used as a glob
+	pattern. If the location of the .git directory matches the
+	pattern, the include condition is met.
++
+The .git location may be auto-discovered, or come from `$GIT_DIR`
+environment variable. If the repository is auto discovered via a .git
+file (e.g. from submodules, or a linked worktree), the .git location
+would be the final location where the .git directory is, not where the
+.git file is.
++
+The pattern can contain standard globbing wildcards and two additional
+ones, `**/` and `/**`, that can match multiple path components. Please
+refer to linkgit:gitignore[5] for details. For convenience:
+
+ * If the pattern starts with `~/`, `~` will be substituted with the
+   content of the environment variable `HOME`.
+
+ * If the pattern starts with `./`, it is replaced with the directory
+   containing the current config file.
+
+ * If the pattern does not start with either `~/`, `./` or `/`, `**/`
+   will be automatically prepended. For example, the pattern `foo/bar`
+   becomes `**/foo/bar` and would match `/any/path/to/foo/bar`.
+
+ * If the pattern ends with `/`, `**` will be automatically added. For
+   example, the pattern `foo/` becomes `foo/**`. In other words, it
+   matches "foo" and everything inside, recursively.
+
+`gitdir/i`::
+	This is the same as `gitdir` except that matching is done
+	case-insensitively (e.g. on case-insensitive file sytems)
+
+A few more notes on matching via `gitdir` and `gitdir/i`:
+
+ * Symlinks in `$GIT_DIR` are not resolved before matching.
+
+ * Note that "../" is not special and will match literally, which is
+   unlikely what you want.
 
 Example
 ~~~~~~~
@@ -119,6 +170,17 @@
 		path = foo ; expand "foo" relative to the current file
 		path = ~/foo ; expand "foo" in your `$HOME` directory
 
+	; include if $GIT_DIR is /path/to/foo/.git
+	[includeIf "gitdir:/path/to/foo/.git"]
+		path = /path/to/foo.inc
+
+	; include for all repositories inside /path/to/group
+	[includeIf "gitdir:/path/to/group/"]
+		path = /path/to/foo.inc
+
+	; include for all repositories inside $HOME/to/group
+	[includeIf "gitdir:~/to/group/"]
+		path = /path/to/foo.inc
 
 Values
 ~~~~~~
@@ -334,6 +396,10 @@
 	crawlers and some backup systems).
 	See linkgit:git-update-index[1]. True by default.
 
+core.splitIndex::
+	If true, the split-index feature of the index will be used.
+	See linkgit:git-update-index[1]. False by default.
+
 core.untrackedCache::
 	Determines what to do about the untracked cache feature of the
 	index. It will be kept, if this variable is unset or set to
@@ -350,16 +416,19 @@
 	all fields, including the sub-second part of mtime and ctime.
 
 core.quotePath::
-	The commands that output paths (e.g. 'ls-files',
-	'diff'), when not given the `-z` option, will quote
-	"unusual" characters in the pathname by enclosing the
-	pathname in a double-quote pair and with backslashes the
-	same way strings in C source code are quoted.  If this
-	variable is set to false, the bytes higher than 0x80 are
-	not quoted but output as verbatim.  Note that double
-	quote, backslash and control characters are always
-	quoted without `-z` regardless of the setting of this
-	variable.
+	Commands that output paths (e.g. 'ls-files', 'diff'), will
+	quote "unusual" characters in the pathname by enclosing the
+	pathname in double-quotes and escaping those characters with
+	backslashes in the same way C escapes control characters (e.g.
+	`\t` for TAB, `\n` for LF, `\\` for backslash) or bytes with
+	values larger than 0x80 (e.g. octal `\302\265` for "micro" in
+	UTF-8).  If this variable is set to false, bytes higher than
+	0x80 are not considered "unusual" any more. Double-quotes,
+	backslash and control characters are always escaped regardless
+	of the setting of this variable.  A simple space character is
+	not considered "unusual".  Many commands can output pathnames
+	completely verbatim using the `-z` option. The default value
+	is true.
 
 core.eol::
 	Sets the line ending type to use in the working directory for
@@ -1925,7 +1994,10 @@
   must match exactly between the config key and the URL.
 
 . Host/domain name (e.g., `example.com` in `https://example.com/`).
-  This field must match exactly between the config key and the URL.
+  This field must match between the config key and the URL. It is
+  possible to specify a `*` as part of the host name to match all subdomains
+  at this level. `https://*.example.com/` for example would match
+  `https://foo.example.com/`, but not `https://foo.bar.example.com/`.
 
 . Port number (e.g., `8080` in `http://example.com:8080/`).
   This field must match exactly between the config key and the URL.
@@ -1960,6 +2032,17 @@
 matched against are those given directly to Git commands.  This means any URLs
 visited as a result of a redirection do not participate in matching.
 
+ssh.variant::
+	Depending on the value of the environment variables `GIT_SSH` or
+	`GIT_SSH_COMMAND`, or the config setting `core.sshCommand`, Git
+	auto-detects whether to adjust its command-line parameters for use
+	with plink or tortoiseplink, as opposed to the default (OpenSSH).
++
+The config variable `ssh.variant` can be set to override this auto-detection;
+valid values are `ssh`, `plink`, `putty` or `tortoiseplink`. Any other value
+will be treated as normal ssh. This setting can be overridden via the
+environment variable `GIT_SSH_VARIANT`.
+
 i18n.commitEncoding::
 	Character encoding the commit messages are stored in; Git itself
 	does not care per se, but this information is necessary e.g. when
@@ -2835,6 +2918,31 @@
 	The default set of branches for linkgit:git-show-branch[1].
 	See linkgit:git-show-branch[1].
 
+splitIndex.maxPercentChange::
+	When the split index feature is used, this specifies the
+	percent of entries the split index can contain compared to the
+	total number of entries in both the split index and the shared
+	index before a new shared index is written.
+	The value should be between 0 and 100. If the value is 0 then
+	a new shared index is always written, if it is 100 a new
+	shared index is never written.
+	By default the value is 20, so a new shared index is written
+	if the number of entries in the split index would be greater
+	than 20 percent of the total number of entries.
+	See linkgit:git-update-index[1].
+
+splitIndex.sharedIndexExpire::
+	When the split index feature is used, shared index files that
+	were not modified since the time this variable specifies will
+	be removed when a new shared index file is created. The value
+	"now" expires all entries immediately, and "never" suppresses
+	expiration altogether.
+	The default value is "2.weeks.ago".
+	Note that a shared index file is considered modified (for the
+	purpose of expiration) each time a new split-index file is
+	either created based on it or read from it.
+	See linkgit:git-update-index[1].
+
 status.relativePaths::
 	By default, linkgit:git-status[1] shows paths relative to the
 	current directory. Setting this variable to `false` shows paths
diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt
index cf52626..706916c 100644
--- a/Documentation/diff-format.txt
+++ b/Documentation/diff-format.txt
@@ -78,9 +78,10 @@
 :100644 100644 5be4a4...... 000000...... M file.c
 ------------------------------------------------
 
-When `-z` option is not used, TAB, LF, and backslash characters
-in pathnames are represented as `\t`, `\n`, and `\\`,
-respectively.
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
 
 diff format for merges
 ----------------------
diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt
index d2a7ff5..231105c 100644
--- a/Documentation/diff-generate-patch.txt
+++ b/Documentation/diff-generate-patch.txt
@@ -53,10 +53,9 @@
 The <mode> is included if the file mode does not change; otherwise,
 separate lines indicate the old and the new mode.
 
-3.  TAB, LF, double quote and backslash characters in pathnames
-    are represented as `\t`, `\n`, `\"` and `\\`, respectively.
-    If there is need for such substitution then the whole
-    pathname is put in double quotes.
+3.  Pathnames with "unusual" characters are quoted as explained for
+    the configuration variable `core.quotePath` (see
+    linkgit:git-config[1]).
 
 4.  All the `file1` files in the output refer to files before the
     commit, and all the `file2` files refer to files after the commit.
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index d91ddbd..89cc0f4 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -192,10 +192,9 @@
 	given, do not munge pathnames and use NULs as output field terminators.
 endif::git-log[]
 +
-Without this option, each pathname output will have TAB, LF, double quotes,
-and backslash characters replaced with `\t`, `\n`, `\"`, and `\\`,
-respectively, and the pathname will be enclosed in double quotes if
-any of those replacements occurred.
+Without this option, pathnames with "unusual" characters are quoted as
+explained for the configuration variable `core.quotePath` (see
+linkgit:git-config[1]).
 
 --name-only::
 	Show only names of changed files.
diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
index 8ddb207..631cbd8 100644
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -108,10 +108,9 @@
 	When `--numstat` has been given, do not munge pathnames,
 	but use a NUL-terminated machine-readable format.
 +
-Without this option, each pathname output will have TAB, LF, double quotes,
-and backslash characters replaced with `\t`, `\n`, `\"`, and `\\`,
-respectively, and the pathname will be enclosed in double quotes if
-any of those replacements occurred.
+Without this option, pathnames with "unusual" characters are quoted as
+explained for the configuration variable `core.quotePath` (see
+linkgit:git-config[1]).
 
 -p<n>::
 	Remove <n> leading slashes from traditional diff paths. The
diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index 28d46cc..c203e8c 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -12,7 +12,7 @@
 	[--list] [-v [--abbrev=<length> | --no-abbrev]]
 	[--column[=<options>] | --no-column]
 	[(--merged | --no-merged | --contains) [<commit>]] [--sort=<key>]
-	[--points-at <object>] [<pattern>...]
+	[--points-at <object>] [--format=<format>] [<pattern>...]
 'git branch' [--set-upstream | --track | --no-track] [-l] [-f] <branchname> [<start-point>]
 'git branch' (--set-upstream-to=<upstream> | -u <upstream>) [<branchname>]
 'git branch' --unset-upstream [<branchname>]
@@ -142,8 +142,13 @@
 	List both remote-tracking branches and local branches.
 
 --list::
-	Activate the list mode. `git branch <pattern>` would try to create a branch,
-	use `git branch --list <pattern>` to list matching branches.
+	List branches.  With optional `<pattern>...`, e.g. `git
+	branch --list 'maint-*'`, list only the branches that match
+	the pattern(s).
++
+This should not be confused with `git branch -l <branchname>`,
+which creates a branch named `<branchname>` with a reflog.
+See `--create-reflog` above for details.
 
 -v::
 -vv::
@@ -253,6 +258,11 @@
 --points-at <object>::
 	Only list branches of the given object.
 
+--format <format>::
+	A string that interpolates `%(fieldname)` from the object
+	pointed at by a ref being shown.  The format is the same as
+	that of linkgit:git-for-each-ref[1].
+
 Examples
 --------
 
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 8e2c066..d6399c0 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -256,6 +256,13 @@
 	out anyway. In other words, the ref can be held by more than one
 	worktree.
 
+--[no-]recurse-submodules::
+	Using --recurse-submodules will update the content of all initialized
+	submodules according to the commit recorded in the superproject. If
+	local modifications in a submodule would be overwritten the checkout
+	will fail unless `-f` is used. If nothing (or --no-recurse-submodules)
+	is used, the work trees of submodules will not be updated.
+
 <branch>::
 	Branch to checkout; if it refers to a branch (i.e., a name that,
 	when prepended with "refs/heads/", is a valid ref), then that
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 2763edb..ed0f5b9 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -117,9 +117,12 @@
 
 -z::
 --null::
-	When showing `short` or `porcelain` status output, terminate
-	entries in the status output with NUL, instead of LF. If no
-	format is given, implies the `--porcelain` output format.
+	When showing `short` or `porcelain` status output, print the
+	filename verbatim and terminate the entries with NUL, instead of LF.
+	If no format is given, implies the `--porcelain` output format.
+	Without the `-z` option, filenames with "unusual" characters are
+	quoted as explained for the configuration variable `core.quotePath`
+	(see linkgit:git-config[1]).
 
 -F <file>::
 --file=<file>::
diff --git a/Documentation/git-credential-cache.txt b/Documentation/git-credential-cache.txt
index 96208f8..2b85826 100644
--- a/Documentation/git-credential-cache.txt
+++ b/Documentation/git-credential-cache.txt
@@ -33,10 +33,13 @@
 --socket <path>::
 
 	Use `<path>` to contact a running cache daemon (or start a new
-	cache daemon if one is not started). Defaults to
-	`~/.git-credential-cache/socket`. If your home directory is on a
-	network-mounted filesystem, you may need to change this to a
-	local filesystem. You must specify an absolute path.
+	cache daemon if one is not started).
+	Defaults to `$XDG_CACHE_HOME/git/credential/socket` unless
+	`~/.git-credential-cache/` exists in which case
+	`~/.git-credential-cache/socket` is used instead.
+	If your home directory is on a network-mounted filesystem, you
+	may need to change this to a local filesystem. You must specify
+	an absolute path.
 
 CONTROLLING THE DAEMON
 ----------------------
diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt
index e4ac448..26f19d3 100644
--- a/Documentation/git-describe.txt
+++ b/Documentation/git-describe.txt
@@ -30,9 +30,14 @@
 	Commit-ish object names to describe.  Defaults to HEAD if omitted.
 
 --dirty[=<mark>]::
-	Describe the working tree.
-	It means describe HEAD and appends <mark> (`-dirty` by
-	default) if the working tree is dirty.
+--broken[=<mark>]::
+	Describe the state of the working tree.  When the working
+	tree matches HEAD, the output is the same as "git describe
+	HEAD".  If the working tree has local modification "-dirty"
+	is appended to it.  If a repository is corrupt and Git
+	cannot determine if there is local modification, Git will
+	error out, unless `--broken' is given, which appends
+	the suffix "-broken" instead.
 
 --all::
 	Instead of using only the annotated tags, use any ref
@@ -83,7 +88,20 @@
 --match <pattern>::
 	Only consider tags matching the given `glob(7)` pattern,
 	excluding the "refs/tags/" prefix.  This can be used to avoid
-	leaking private tags from the repository.
+	leaking private tags from the repository. If given multiple times, a
+	list of patterns will be accumulated, and tags matching any of the
+	patterns will be considered. Use `--no-match` to clear and reset the
+	list of patterns.
+
+--exclude <pattern>::
+	Do not consider tags matching the given `glob(7)` pattern, excluding
+	the "refs/tags/" prefix. This can be used to narrow the tag space and
+	find only tags matching some meaningful criteria. If given multiple
+	times, a list of patterns will be accumulated and tags matching any
+	of the patterns will be excluded. When combined with --match a tag will
+	be considered when it matches at least one --match pattern and does not
+	match any of the --exclude patterns. Use `--no-exclude` to clear and
+	reset the list of patterns.
 
 --always::
 	Show uniquely abbreviated commit object as fallback.
diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index abe13f3..111e1be 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -95,11 +95,20 @@
 	The name of the ref (the part after $GIT_DIR/).
 	For a non-ambiguous short name of the ref append `:short`.
 	The option core.warnAmbiguousRefs is used to select the strict
-	abbreviation mode. If `strip=<N>` is appended, strips `<N>`
-	slash-separated path components from the front of the refname
-	(e.g., `%(refname:strip=2)` turns `refs/tags/foo` into `foo`.
-	`<N>` must be a positive integer.  If a displayed ref has fewer
-	components than `<N>`, the command aborts with an error.
+	abbreviation mode. If `lstrip=<N>` (`rstrip=<N>`) is appended, strips `<N>`
+	slash-separated path components from the front (back) of the refname
+	(e.g. `%(refname:lstrip=2)` turns `refs/tags/foo` into `foo` and
+	`%(refname:rstrip=2)` turns `refs/tags/foo` into `refs`).
+	If `<N>` is a negative number, strip as many path components as
+	necessary from the specified end to leave `-<N>` path components
+	(e.g. `%(refname:lstrip=-2)` turns
+	`refs/tags/foo` into `tags/foo` and `%(refname:rstrip=-1)`
+	turns `refs/tags/foo` into `refs`). When the ref does not have
+	enough components, the result becomes an empty string if
+	stripping with positive <N>, or it becomes the full refname if
+	stripping with negative <N>.  Neither is an error.
++
+`strip` can be used as a synomym to `lstrip`.
 
 objecttype::
 	The type of the object (`blob`, `tree`, `commit`, `tag`).
@@ -110,21 +119,31 @@
 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.
 
 upstream::
 	The name of a local ref which can be considered ``upstream''
-	from the displayed ref. Respects `:short` in the same way as
-	`refname` above.  Additionally respects `:track` to show
-	"[ahead N, behind M]" and `:trackshort` to show the terse
-	version: ">" (ahead), "<" (behind), "<>" (ahead and behind),
-	or "=" (in sync).  Has no effect if the ref does not have
-	tracking information associated with it.
+	from the displayed ref. Respects `:short`, `:lstrip` and
+	`:rstrip` in the same way as `refname` above.  Additionally
+	respects `:track` to show "[ahead N, behind M]" and
+	`:trackshort` to show the terse version: ">" (ahead), "<"
+	(behind), "<>" (ahead and behind), or "=" (in sync). `:track`
+	also prints "[gone]" whenever unknown upstream ref is
+	encountered. Append `:track,nobracket` to show tracking
+	information without brackets (i.e "ahead N, behind M").  Has
+	no effect if the ref does not have tracking information
+	associated with it.  All the options apart from `nobracket`
+	are mutually exclusive, but if used together the last option
+	is selected.
 
 push::
-	The name of a local ref which represents the `@{push}` location
-	for the displayed ref. Respects `:short`, `:track`, and
-	`:trackshort` options as `upstream` does. Produces an empty
-	string if no `@{push}` ref is configured.
+	The name of a local ref which represents the `@{push}`
+	location for the displayed ref. Respects `:short`, `:lstrip`,
+	`:rstrip`, `:track`, and `:trackshort` options as `upstream`
+	does. Produces an empty string if no `@{push}` ref is
+	configured.
 
 HEAD::
 	'*' if HEAD matches current ref (the checked out branch), ' '
@@ -149,6 +168,25 @@
 	quoted, but if nested then only the topmost level performs
 	quoting.
 
+if::
+	Used as %(if)...%(then)...%(end) or
+	%(if)...%(then)...%(else)...%(end).  If there is an atom with
+	value or string literal after the %(if) then everything after
+	the %(then) is printed, else if the %(else) atom is used, then
+	everything after %(else) is printed. We ignore space when
+	evaluating the string before %(then), this is useful when we
+	use the %(HEAD) atom which prints either "*" or " " and we
+	want to apply the 'if' condition only on the 'HEAD' ref.
+	Append ":equals=<string>" or ":notequals=<string>" to compare
+	the value between the %(if:...) and %(then) atoms with the
+	given string.
+
+symref::
+	The ref which the given symbolic ref refers to. If not a
+	symbolic ref, nothing is printed. Respects the `:short`,
+	`:lstrip` and `:rstrip` options in the same way as `refname`
+	above.
+
 In addition to the above, for commit and tag objects, the header
 field names (`tree`, `parent`, `object`, `type`, and `tag`) can
 be used to specify the value in the header field.
@@ -186,6 +224,14 @@
 the date by adding `:` followed by date format name (see the
 values the `--date` option to linkgit:git-rev-list[1] takes).
 
+Some atoms like %(align) and %(if) always require a matching %(end).
+We call them "opening atoms" and sometimes denote them as %($open).
+
+When a scripting language specific quoting is in effect, everything
+between a top-level opening atom and its matching %(end) is evaluated
+according to the semantics of the opening atom and only its result
+from the top-level is quoted.
+
 
 EXAMPLES
 --------
@@ -273,6 +319,22 @@
 eval "$eval"
 ------------
 
+
+An example to show the usage of %(if)...%(then)...%(else)...%(end).
+This prefixes the current branch with a star.
+
+------------
+git for-each-ref --format="%(if)%(HEAD)%(then)* %(else)  %(end)%(refname:short)" refs/heads/
+------------
+
+
+An example to show the usage of %(if)...%(then)...%(end).
+This prints the authorname, if present.
+
+------------
+git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
+------------
+
 SEE ALSO
 --------
 linkgit:git-show-ref[1]
diff --git a/Documentation/git-ls-files.txt b/Documentation/git-ls-files.txt
index 446209e..1cab703 100644
--- a/Documentation/git-ls-files.txt
+++ b/Documentation/git-ls-files.txt
@@ -77,7 +77,8 @@
 	succeed.
 
 -z::
-	\0 line termination on output.
+	\0 line termination on output and do not quote filenames.
+	See OUTPUT below for more information.
 
 -x <pattern>::
 --exclude=<pattern>::
@@ -196,9 +197,10 @@
 the user (or the porcelain) to see what should eventually be recorded at the
 path. (see linkgit:git-read-tree[1] for more information on state)
 
-When `-z` option is not used, TAB, LF, and backslash characters
-in pathnames are represented as `\t`, `\n`, and `\\`,
-respectively.
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
 
 
 Exclude Patterns
diff --git a/Documentation/git-ls-tree.txt b/Documentation/git-ls-tree.txt
index dbc91f9..9dee7be 100644
--- a/Documentation/git-ls-tree.txt
+++ b/Documentation/git-ls-tree.txt
@@ -53,7 +53,8 @@
 	Show object size of blob (file) entries.
 
 -z::
-	\0 line termination on output.
+	\0 line termination on output and do not quote filenames.
+	See OUTPUT FORMAT below for more information.
 
 --name-only::
 --name-status::
@@ -82,8 +83,6 @@
 -------------
         <mode> SP <type> SP <object> TAB <file>
 
-Unless the `-z` option is used, TAB, LF, and backslash characters
-in pathnames are represented as `\t`, `\n`, and `\\`, respectively.
 This output format is compatible with what `--index-info --stdin` of
 'git update-index' expects.
 
@@ -95,6 +94,11 @@
 with minimum width of 7 characters.  Object size is given only for blobs
 (file) entries; for other entries `-` character is used in place of size.
 
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Documentation/git-name-rev.txt b/Documentation/git-name-rev.txt
index ca28fb8..e8e68f5 100644
--- a/Documentation/git-name-rev.txt
+++ b/Documentation/git-name-rev.txt
@@ -26,7 +26,18 @@
 
 --refs=<pattern>::
 	Only use refs whose names match a given shell pattern.  The pattern
-	can be one of branch name, tag name or fully qualified ref name.
+	can be one of branch name, tag name or fully qualified ref name. If
+	given multiple times, use refs whose names match any of the given shell
+	patterns. Use `--no-refs` to clear any previous ref patterns given.
+
+--exclude=<pattern>::
+	Do not use any ref whose name matches a given shell pattern. The
+	pattern can be one of branch name, tag name or fully qualified ref
+	name. If given multiple times, a ref will be excluded when it matches
+	any of the given patterns. When used together with --refs, a ref will
+	be used as a match only when it matches at least one --refs pattern and
+	does not match any --exclude patterns. Use `--no-exclude` to clear the
+	list of exclude patterns.
 
 --all::
 	List all commits reachable from all refs
diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index fa1d557..ed9d63e 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt
@@ -115,6 +115,12 @@
 	directories the index file and index output file are
 	located in.
 
+--[no-]recurse-submodules::
+	Using --recurse-submodules will update the content of all initialized
+	submodules according to the commit recorded in the superproject by
+	calling read-tree recursively, also setting the submodules HEAD to be
+	detached at that commit.
+
 --no-sparse-checkout::
 	Disable sparse checkout support even if `core.sparseCheckout`
 	is true.
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index 7241e96..c40c470 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -217,6 +217,10 @@
 is not detected to lie in a Git repository or work tree
 print a message to stderr and exit with nonzero status.
 
+--absolute-git-dir::
+	Like `--git-dir`, but its output is always the canonicalized
+	absolute path.
+
 --git-common-dir::
 	Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
 
@@ -257,6 +261,12 @@
 --show-toplevel::
 	Show the absolute path of the top-level directory.
 
+--show-superproject-working-tree
+	Show the absolute path of the root of the superproject's
+	working tree (if exists) that uses the current repository as
+	its submodule.  Outputs nothing if the current repository is
+	not used as a submodule by any project.
+
 --shared-index-path::
 	Show the path to the shared index file in split index mode, or
 	empty if not in split-index mode.
diff --git a/Documentation/git-send-pack.txt b/Documentation/git-send-pack.txt
index a831dd0..966abb0 100644
--- a/Documentation/git-send-pack.txt
+++ b/Documentation/git-send-pack.txt
@@ -81,6 +81,12 @@
 	will also fail if the actual call to `gpg --sign` fails.  See
 	linkgit:git-receive-pack[1] for the details on the receiving end.
 
+--push-option=<string>::
+	Pass the specified string as a push option for consumption by
+	hooks on the server side.  If the server doesn't support push
+	options, error out.  See linkgit:git-push[1] and
+	linkgit:githooks[5] for details.
+
 <host>::
 	A remote host to house the repository.  When this
 	part is specified, 'git-receive-pack' is invoked via
diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
index 2e9e344..70191d0 100644
--- a/Documentation/git-stash.txt
+++ b/Documentation/git-stash.txt
@@ -13,8 +13,11 @@
 'git stash' drop [-q|--quiet] [<stash>]
 'git stash' ( pop | apply ) [--index] [-q|--quiet] [<stash>]
 'git stash' branch <branchname> [<stash>]
-'git stash' [save [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
-	     [-u|--include-untracked] [-a|--all] [<message>]]
+'git stash' save [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
+	     [-u|--include-untracked] [-a|--all] [<message>]
+'git stash' [push [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
+	     [-u|--include-untracked] [-a|--all] [-m|--message <message>]]
+	     [--] [<pathspec>...]]
 'git stash' clear
 'git stash' create [<message>]
 'git stash' store [-m|--message <message>] [-q|--quiet] <commit>
@@ -46,14 +49,24 @@
 -------
 
 save [-p|--patch] [-k|--[no-]keep-index] [-u|--include-untracked] [-a|--all] [-q|--quiet] [<message>]::
+push [-p|--patch] [-k|--[no-]keep-index] [-u|--include-untracked] [-a|--all] [-q|--quiet] [-m|--message <message>] [--] [<pathspec>...]::
 
 	Save your local modifications to a new 'stash' and roll them
 	back to HEAD (in the working tree and in the index).
 	The <message> part is optional and gives
-	the description along with the stashed state.  For quickly making
-	a snapshot, you can omit _both_ "save" and <message>, but giving
-	only <message> does not trigger this action to prevent a misspelled
-	subcommand from making an unwanted stash.
+	the description along with the stashed state.
++
+For quickly making a snapshot, you can omit "push".  In this mode,
+non-option arguments are not allowed to prevent a misspelled
+subcommand from making an unwanted stash.  The two exceptions to this
+are `stash -p` which acts as alias for `stash push -p` and pathspecs,
+which are allowed after a double hyphen `--` for disambiguation.
++
+When pathspec is given to 'git stash push', the new stash records the
+modified states only for the files that match the pathspec.  The index
+entries and working tree files are then rolled back to the state in
+HEAD only for these files, too, leaving files that do not match the
+pathspec intact.
 +
 If the `--keep-index` option is used, all changes already added to the
 index are left intact.
diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index 725065e..ba87365 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt
@@ -322,10 +322,9 @@
 without any quoting and lines are terminated with a NUL (ASCII 0x00)
 byte.
 
-Otherwise, all pathnames will be "C-quoted" if they contain any tab,
-linefeed, double quote, or backslash characters. In C-quoting, these
-characters will be replaced with the corresponding C-style escape
-sequences and the resulting pathname will be double quoted.
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).
 
 
 CONFIGURATION
diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8acc72e..e05d0cd 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -73,13 +73,17 @@
 +
 <repository> is the URL of the new submodule's origin repository.
 This may be either an absolute URL, or (if it begins with ./
-or ../), the location relative to the superproject's origin
+or ../), the location relative to the superproject's default remote
 repository (Please note that to specify a repository 'foo.git'
 which is located right next to a superproject 'bar.git', you'll
 have to use '../foo.git' instead of './foo.git' - as one might expect
 when following the rules for relative URLs - because the evaluation
 of relative URLs in Git is identical to that of relative directories).
-If the superproject doesn't have an origin configured
++
+The default remote is the remote of the remote tracking branch
+of the current branch. If no such remote tracking branch exists or
+the HEAD is detached, "origin" is assumed to be the default remote.
+If the superproject doesn't have a default remote configured
 the superproject is its own authoritative upstream and the current
 working directory is used instead.
 +
@@ -118,18 +122,24 @@
 
 init [--] [<path>...]::
 	Initialize the submodules recorded in the index (which were
-	added and committed elsewhere) by copying submodule
-	names and urls from .gitmodules to .git/config.
-	Optional <path> arguments limit which submodules will be initialized.
-	It will also copy the value of `submodule.$name.update` into
-	.git/config.
-	The key used in .git/config is `submodule.$name.url`.
-	This command does not alter existing information in .git/config.
-	You can then customize the submodule clone URLs in .git/config
-	for your local setup and proceed to `git submodule update`;
-	you can also just use `git submodule update --init` without
-	the explicit 'init' step if you do not intend to customize
-	any submodule locations.
+	added and committed elsewhere) by setting `submodule.$name.url`
+	in .git/config. It uses the same setting from .gitmodules as
+	a template. If the URL is relative, it will be resolved using
+	the default remote. If there is no default remote, the current
+	repository will be assumed to be upstream.
++
+Optional <path> arguments limit which submodules will be initialized.
+If no path is specified, all submodules are initialized.
++
+When present, it will also copy the value of `submodule.$name.update`.
+This command does not alter existing information in .git/config.
+You can then customize the submodule clone URLs in .git/config
+for your local setup and proceed to `git submodule update`;
+you can also just use `git submodule update --init` without
+the explicit 'init' step if you do not intend to customize
+any submodule locations.
++
+See the add subcommand for the defintion of default remote.
 
 deinit [-f|--force] (--all|[--] <path>...)::
 	Unregister the given submodules, i.e. remove the whole
diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index 7386c93..1579abf 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -163,14 +163,16 @@
 
 --split-index::
 --no-split-index::
-	Enable or disable split index mode. If enabled, the index is
-	split into two files, $GIT_DIR/index and $GIT_DIR/sharedindex.<SHA-1>.
-	Changes are accumulated in $GIT_DIR/index while the shared
-	index file contains all index entries stays unchanged. If
-	split-index mode is already enabled and `--split-index` is
-	given again, all changes in $GIT_DIR/index are pushed back to
-	the shared index file. This mode is designed for very large
-	indexes that take a significant amount of time to read or write.
+	Enable or disable split index mode. If split-index mode is
+	already enabled and `--split-index` is given again, all
+	changes in $GIT_DIR/index are pushed back to the shared index
+	file.
++
+These options take effect whatever the value of the `core.splitIndex`
+configuration variable (see linkgit:git-config[1]). But a warning is
+emitted when the change goes against the configured value, as the
+configured value will take effect next time the index is read and this
+will remove the intended effect of the option.
 
 --untracked-cache::
 --no-untracked-cache::
@@ -388,6 +390,31 @@
 different from assume-unchanged bit's. Skip-worktree also takes
 precedence over assume-unchanged bit when both are set.
 
+Split index
+-----------
+
+This mode is designed for repositories with very large indexes, and
+aims at reducing the time it takes to repeatedly write these indexes.
+
+In this mode, the index is split into two files, $GIT_DIR/index and
+$GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in
+$GIT_DIR/index, the split index, while the shared index file contains
+all index entries and stays unchanged.
+
+All changes in the split index are pushed back to the shared index
+file when the number of entries in the split index reaches a level
+specified by the splitIndex.maxPercentChange config variable (see
+linkgit:git-config[1]).
+
+Each time a new shared index file is created, the old shared index
+files are deleted if their modification time is older than what is
+specified by the splitIndex.sharedIndexExpire config variable (see
+linkgit:git-config[1]).
+
+To avoid deleting a shared index file that is still used, its
+modification time is updated to the current time everytime a new split
+index based on the shared index file is either created or read from.
+
 Untracked cache
 ---------------
 
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 88c39d3..ecc1bb4 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -1027,6 +1027,12 @@
 personal `.ssh/config` file.  Please consult your ssh documentation
 for further details.
 
+`GIT_SSH_VARIANT`::
+	If this environment variable is set, it overrides Git's autodetection
+	whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH,
+	plink or tortoiseplink. This variable overrides the config setting
+	`ssh.variant` that serves the same purpose.
+
 `GIT_ASKPASS`::
 	If this environment variable is set, then Git commands which need to
 	acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index e0b66c1..a53d093 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -21,9 +21,11 @@
 	pattern	attr1 attr2 ...
 
 That is, a pattern followed by an attributes list,
-separated by whitespaces.  When the pattern matches the
-path in question, the attributes listed on the line are given to
-the path.
+separated by whitespaces. Leading and trailing whitespaces are
+ignored. Lines that begin with '#' are ignored. Patterns
+that begin with a double quote are quoted in C style.
+When the pattern matches the path in question, the attributes
+listed on the line are given to the path.
 
 Each attribute can be in one of these states for a given path:
 
@@ -86,7 +88,7 @@
 Attributes for all users on a system should be placed in the
 `$(prefix)/etc/gitattributes` file.
 
-Sometimes you would need to override an setting of an attribute
+Sometimes you would need to override a setting of an attribute
 for a path to `Unspecified` state.  This can be done by listing
 the name of the attribute prefixed with an exclamation point `!`.
 
diff --git a/Documentation/glossary-content.txt b/Documentation/glossary-content.txt
index 8ad29e6..6e991c2 100644
--- a/Documentation/glossary-content.txt
+++ b/Documentation/glossary-content.txt
@@ -384,10 +384,33 @@
 +
 Glob magic is incompatible with literal magic.
 
+attr;;
+After `attr:` comes a space separated list of "attribute
+requirements", all of which must be met in order for the
+path to be considered a match; this is in addition to the
+usual non-magic pathspec pattern matching.
+See linkgit:gitattributes[5].
++
+Each of the attribute requirements for the path takes one of
+these forms:
+
+- "`ATTR`" requires that the attribute `ATTR` be set.
+
+- "`-ATTR`" requires that the attribute `ATTR` be unset.
+
+- "`ATTR=VALUE`" requires that the attribute `ATTR` be
+  set to the string `VALUE`.
+
+- "`!ATTR`" requires that the attribute `ATTR` be
+  unspecified.
++
+
 exclude;;
 	After a path matches any non-exclude pathspec, it will be run
-	through all exclude pathspec (magic signature: `!`). If it
-	matches, the path is ignored.
+	through all exclude pathspec (magic signature: `!` or its
+	synonym `^`). If it matches, the path is ignored.  When there
+	is no non-exclude pathspec, the exclusion is applied to the
+	result set as if invoked without any pathspec.
 --
 
 [[def_parent]]parent::
diff --git a/Documentation/technical/api-gitattributes.txt b/Documentation/technical/api-gitattributes.txt
index 2602668..e7cbb7c 100644
--- a/Documentation/technical/api-gitattributes.txt
+++ b/Documentation/technical/api-gitattributes.txt
@@ -16,10 +16,15 @@
 	of no interest to the calling programs.  The name of the
 	attribute can be retrieved by calling `git_attr_name()`.
 
-`struct git_attr_check`::
+`struct attr_check_item`::
 
-	This structure represents a set of attributes to check in a call
-	to `git_check_attr()` function, and receives the results.
+	This structure represents one attribute and its value.
+
+`struct attr_check`::
+
+	This structure represents a collection of `attr_check_item`.
+	It is passed to `git_check_attr()` function, specifying the
+	attributes to check, and receives their values.
 
 
 Attribute Values
@@ -27,7 +32,7 @@
 
 An attribute for a path can be in one of four states: Set, Unset,
 Unspecified or set to a string, and `.value` member of `struct
-git_attr_check` records it.  There are three macros to check these:
+attr_check_item` records it.  There are three macros to check these:
 
 `ATTR_TRUE()`::
 
@@ -48,49 +53,51 @@
 Querying Specific Attributes
 ----------------------------
 
-* Prepare an array of `struct git_attr_check` to define the list of
-  attributes you would want to check.  To populate this array, you would
-  need to define necessary attributes by calling `git_attr()` function.
+* Prepare `struct attr_check` using attr_check_initl()
+  function, enumerating the names of attributes whose values you are
+  interested in, terminated with a NULL pointer.  Alternatively, an
+  empty `struct attr_check` can be prepared by calling
+  `attr_check_alloc()` function and then attributes you want to
+  ask about can be added to it with `attr_check_append()`
+  function.
 
 * Call `git_check_attr()` to check the attributes for the path.
 
-* Inspect `git_attr_check` structure to see how each of the attribute in
-  the array is defined for the path.
+* Inspect `attr_check` structure to see how each of the
+  attribute in the array is defined for the path.
 
 
 Example
 -------
 
-To see how attributes "crlf" and "indent" are set for different paths.
+To see how attributes "crlf" and "ident" are set for different paths.
 
-. Prepare an array of `struct git_attr_check` with two elements (because
-  we are checking two attributes).  Initialize their `attr` member with
-  pointers to `struct git_attr` obtained by calling `git_attr()`:
+. Prepare a `struct attr_check` with two elements (because
+  we are checking two attributes):
 
 ------------
-static struct git_attr_check check[2];
+static struct attr_check *check;
 static void setup_check(void)
 {
-	if (check[0].attr)
+	if (check)
 		return; /* already done */
-	check[0].attr = git_attr("crlf");
-	check[1].attr = git_attr("ident");
+	check = attr_check_initl("crlf", "ident", NULL);
 }
 ------------
 
-. Call `git_check_attr()` with the prepared array of `struct git_attr_check`:
+. Call `git_check_attr()` with the prepared `struct attr_check`:
 
 ------------
 	const char *path;
 
 	setup_check();
-	git_check_attr(path, ARRAY_SIZE(check), check);
+	git_check_attr(path, check);
 ------------
 
-. Act on `.value` member of the result, left in `check[]`:
+. Act on `.value` member of the result, left in `check->items[]`:
 
 ------------
-	const char *value = check[0].value;
+	const char *value = check->items[0].value;
 
 	if (ATTR_TRUE(value)) {
 		The attribute is Set, by listing only the name of the
@@ -109,20 +116,39 @@
 	}
 ------------
 
+To see how attributes in argv[] are set for different paths, only
+the first step in the above would be different.
+
+------------
+static struct attr_check *check;
+static void setup_check(const char **argv)
+{
+	check = attr_check_alloc();
+	while (*argv) {
+		struct git_attr *attr = git_attr(*argv);
+		attr_check_append(check, attr);
+		argv++;
+	}
+}
+------------
+
 
 Querying All Attributes
 -----------------------
 
 To get the values of all attributes associated with a file:
 
-* Call `git_all_attrs()`, which returns an array of `git_attr_check`
-  structures.
+* Prepare an empty `attr_check` structure by calling
+  `attr_check_alloc()`.
 
-* Iterate over the `git_attr_check` array to examine the attribute
-  names and values.  The name of the attribute described by a
-  `git_attr_check` object can be retrieved via
-  `git_attr_name(check[i].attr)`.  (Please note that no items will be
-  returned for unset attributes, so `ATTR_UNSET()` will return false
-  for all returned `git_array_check` objects.)
+* Call `git_all_attrs()`, which populates the `attr_check`
+  with the attributes attached to the path.
 
-* Free the `git_array_check` array.
+* Iterate over the `attr_check.items[]` array to examine
+  the attribute names and values.  The name of the attribute
+  described by a  `attr_check.items[]` object can be retrieved via
+  `git_attr_name(check->items[i].attr)`.  (Please note that no items
+  will be returned for unset attributes, so `ATTR_UNSET()` will return
+  false for all returned `attr_check.items[]` objects.)
+
+* Free the `attr_check` struct by calling `attr_check_free()`.
diff --git a/Documentation/technical/api-hashmap.txt b/Documentation/technical/api-hashmap.txt
index a3f020c..ccc634b 100644
--- a/Documentation/technical/api-hashmap.txt
+++ b/Documentation/technical/api-hashmap.txt
@@ -21,6 +21,9 @@
 `cmpfn` stores the comparison function specified in `hashmap_init()`. In
 advanced scenarios, it may be useful to change this, e.g. to switch between
 case-sensitive and case-insensitive lookup.
++
+When `disallow_rehash` is set, automatic rehashes are prevented during inserts
+and deletes.
 
 `struct hashmap_entry`::
 
@@ -57,6 +60,7 @@
 `unsigned int strihash(const char *buf)`::
 `unsigned int memhash(const void *buf, size_t len)`::
 `unsigned int memihash(const void *buf, size_t len)`::
+`unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len)`::
 
 	Ready-to-use hash functions for strings, using the FNV-1 algorithm (see
 	http://www.isthe.com/chongo/tech/comp/fnv).
@@ -65,6 +69,9 @@
 `memihash` operate on arbitrary-length memory.
 +
 `strihash` and `memihash` are case insensitive versions.
++
+`memihash_cont` is a variant of `memihash` that allows a computation to be
+continued with another chunk of data.
 
 `unsigned int sha1hash(const unsigned char *sha1)`::
 
@@ -184,6 +191,21 @@
 +
 Returns the removed entry, or NULL if not found.
 
+`void hashmap_disallow_rehash(struct hashmap *map, unsigned value)`::
+
+	Disallow/allow automatic rehashing of the hashmap during inserts
+	and deletes.
++
+This is useful if the caller knows that the hashmap will be accessed
+by multiple threads.
++
+The caller is still responsible for any necessary locking; this simply
+prevents unexpected rehashing.  The caller is also responsible for properly
+sizing the initial hashmap to ensure good performance.
++
+A call to allow rehashing does not force a rehash; that might happen
+with the next insert or delete.
+
 `void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter)`::
 `void *hashmap_iter_next(struct hashmap_iter *iter)`::
 `void *hashmap_iter_first(struct hashmap *map, struct hashmap_iter *iter)`::
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 27bd701..36768b4 100644
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -168,6 +168,11 @@
 	Introduce an option with string argument.
 	The string argument is put into `str_var`.
 
+`OPT_STRING_LIST(short, long, &struct string_list, arg_str, description)`::
+	Introduce an option with string argument.
+	The string argument is stored as an element in `string_list`.
+	Use of `--no-option` will clear the list of preceding values.
+
 `OPT_INTEGER(short, long, &int_var, description)`::
 	Introduce an option with integer argument.
 	The integer is put into `int_var`.
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index e83f591..817d1cf 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.12.2
+DEF_VER=v2.12.GIT
 
 LF='
 '
diff --git a/Makefile b/Makefile
index d5454ca..9f8b35a 100644
--- a/Makefile
+++ b/Makefile
@@ -140,6 +140,13 @@
 # Define PPC_SHA1 environment variable when running make to make use of
 # a bundled SHA1 routine optimized for PowerPC.
 #
+# Define DC_SHA1 to unconditionally enable the collision-detecting sha1
+# algorithm. This is slower, but may detect attempted collision attacks.
+# Takes priority over other *_SHA1 knobs.
+#
+# Define OPENSSL_SHA1 environment variable when running make to link
+# with the SHA1 routine from openssl library.
+#
 # Define SHA1_MAX_BLOCK_SIZE to limit the amount of data that will be hashed
 # in one call to the platform's SHA1_Update(). e.g. APPLE_COMMON_CRYPTO
 # wants 'SHA1_MAX_BLOCK_SIZE=1024L*1024L*1024L' defined.
@@ -614,6 +621,7 @@
 TEST_PROGRAMS_NEED_X += test-genrandom
 TEST_PROGRAMS_NEED_X += test-hashmap
 TEST_PROGRAMS_NEED_X += test-index-version
+TEST_PROGRAMS_NEED_X += test-lazy-init-name-hash
 TEST_PROGRAMS_NEED_X += test-line-buffer
 TEST_PROGRAMS_NEED_X += test-match-trees
 TEST_PROGRAMS_NEED_X += test-mergesort
@@ -779,6 +787,7 @@
 LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
 LIB_OBJS += object.o
+LIB_OBJS += oidset.o
 LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-bitmap-write.o
 LIB_OBJS += pack-check.o
@@ -930,6 +939,7 @@
 BUILTIN_OBJS += builtin/pull.o
 BUILTIN_OBJS += builtin/push.o
 BUILTIN_OBJS += builtin/read-tree.o
+BUILTIN_OBJS += builtin/rebase--helper.o
 BUILTIN_OBJS += builtin/receive-pack.o
 BUILTIN_OBJS += builtin/reflog.o
 BUILTIN_OBJS += builtin/remote.o
@@ -1381,20 +1391,27 @@
 	SHA1_MAX_BLOCK_SIZE = 1024L*1024L*1024L
 endif
 
+ifdef OPENSSL_SHA1
+	EXTLIBS += $(LIB_4_CRYPTO)
+	BASIC_CFLAGS += -DSHA1_OPENSSL
+else
 ifdef BLK_SHA1
-	SHA1_HEADER = "block-sha1/sha1.h"
 	LIB_OBJS += block-sha1/sha1.o
+	BASIC_CFLAGS += -DSHA1_BLK
 else
 ifdef PPC_SHA1
-	SHA1_HEADER = "ppc/sha1.h"
 	LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o
+	BASIC_CFLAGS += -DSHA1_PPC
 else
 ifdef APPLE_COMMON_CRYPTO
 	COMPAT_CFLAGS += -DCOMMON_DIGEST_FOR_OPENSSL
-	SHA1_HEADER = <CommonCrypto/CommonDigest.h>
+	BASIC_CFLAGS += -DSHA1_APPLE
 else
-	SHA1_HEADER = <openssl/sha.h>
-	EXTLIBS += $(LIB_4_CRYPTO)
+	DC_SHA1 := YesPlease
+	LIB_OBJS += sha1dc/sha1.o
+	LIB_OBJS += sha1dc/ubc_check.o
+	BASIC_CFLAGS += -DSHA1_DC
+endif
 endif
 endif
 endif
@@ -1586,7 +1603,6 @@
 
 # Shell quote (do not use $(call) to accommodate ancient setups);
 
-SHA1_HEADER_SQ = $(subst ','\'',$(SHA1_HEADER))
 ETC_GITCONFIG_SQ = $(subst ','\'',$(ETC_GITCONFIG))
 ETC_GITATTRIBUTES_SQ = $(subst ','\'',$(ETC_GITATTRIBUTES))
 
@@ -1619,8 +1635,7 @@
 # from the dependency list, that would make each entry appear twice.
 LIBS = $(filter-out %.o, $(GITLIBS)) $(EXTLIBS)
 
-BASIC_CFLAGS += -DSHA1_HEADER='$(SHA1_HEADER_SQ)' \
-	$(COMPAT_CFLAGS)
+BASIC_CFLAGS += $(COMPAT_CFLAGS)
 LIB_OBJS += $(COMPAT_OBJS)
 
 # Quote for C
@@ -2223,6 +2238,7 @@
 	@echo NO_PYTHON=\''$(subst ','\'',$(subst ','\'',$(NO_PYTHON)))'\' >>$@+
 	@echo NO_UNIX_SOCKETS=\''$(subst ','\'',$(subst ','\'',$(NO_UNIX_SOCKETS)))'\' >>$@+
 	@echo PAGER_ENV=\''$(subst ','\'',$(subst ','\'',$(PAGER_ENV)))'\' >>$@+
+	@echo DC_SHA1=\''$(subst ','\'',$(subst ','\'',$(DC_SHA1)))'\' >>$@+
 ifdef TEST_OUTPUT_DIRECTORY
 	@echo TEST_OUTPUT_DIRECTORY=\''$(subst ','\'',$(subst ','\'',$(TEST_OUTPUT_DIRECTORY)))'\' >>$@+
 endif
diff --git a/RelNotes b/RelNotes
index a04927d..125bf78 120000
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/2.12.3.txt
\ No newline at end of file
+Documentation/RelNotes/2.13.0.txt
\ No newline at end of file
diff --git a/abspath.c b/abspath.c
index b02e068..7f1cfe9 100644
--- a/abspath.c
+++ b/abspath.c
@@ -246,29 +246,21 @@
 	return strbuf_detach(&sb, NULL);
 }
 
-/*
- * Unlike prefix_path, this should be used if the named file does
- * not have to interact with index entry; i.e. name of a random file
- * on the filesystem.
- */
-const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
+char *prefix_filename(const char *pfx, const char *arg)
 {
-	static struct strbuf path = STRBUF_INIT;
-#ifndef GIT_WINDOWS_NATIVE
-	if (!pfx_len || is_absolute_path(arg))
-		return arg;
-	strbuf_reset(&path);
-	strbuf_add(&path, pfx, pfx_len);
-	strbuf_addstr(&path, arg);
-#else
-	/* don't add prefix to absolute paths, but still replace '\' by '/' */
-	strbuf_reset(&path);
-	if (is_absolute_path(arg))
+	struct strbuf path = STRBUF_INIT;
+	size_t pfx_len = pfx ? strlen(pfx) : 0;
+
+	if (!pfx_len)
+		; /* nothing to prefix */
+	else if (is_absolute_path(arg))
 		pfx_len = 0;
-	else if (pfx_len)
+	else
 		strbuf_add(&path, pfx, pfx_len);
+
 	strbuf_addstr(&path, arg);
+#ifdef GIT_WINDOWS_NATIVE
 	convert_slashes(path.buf + pfx_len);
 #endif
-	return path.buf;
+	return strbuf_detach(&path, NULL);
 }
diff --git a/apply.c b/apply.c
index 0e2caea..e6dbab2 100644
--- a/apply.c
+++ b/apply.c
@@ -2046,7 +2046,7 @@
 	char *old_name = *name;
 	if (!old_name)
 		return;
-	*name = xstrdup(prefix_filename(state->prefix, state->prefix_length, *name));
+	*name = prefix_filename(state->prefix, *name);
 	free(old_name);
 }
 
@@ -4805,6 +4805,7 @@
 
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
+		char *to_free = NULL;
 		int fd;
 
 		if (!strcmp(arg, "-")) {
@@ -4814,21 +4815,21 @@
 			errs |= res;
 			read_stdin = 0;
 			continue;
-		} else if (0 < state->prefix_length)
-			arg = prefix_filename(state->prefix,
-					      state->prefix_length,
-					      arg);
+		} else
+			arg = to_free = prefix_filename(state->prefix, arg);
 
 		fd = open(arg, O_RDONLY);
 		if (fd < 0) {
 			error(_("can't open patch '%s': %s"), arg, strerror(errno));
 			res = -128;
+			free(to_free);
 			goto end;
 		}
 		read_stdin = 0;
 		set_default_whitespace_mode(state);
 		res = apply_patch(state, fd, arg, options);
 		close(fd);
+		free(to_free);
 		if (res < 0)
 			goto end;
 		errs |= res;
diff --git a/archive.c b/archive.c
index 01751e5..60b8891 100644
--- a/archive.c
+++ b/archive.c
@@ -87,19 +87,6 @@
 	return buffer;
 }
 
-static void setup_archive_check(struct git_attr_check *check)
-{
-	static struct git_attr *attr_export_ignore;
-	static struct git_attr *attr_export_subst;
-
-	if (!attr_export_ignore) {
-		attr_export_ignore = git_attr("export-ignore");
-		attr_export_subst = git_attr("export-subst");
-	}
-	check[0].attr = attr_export_ignore;
-	check[1].attr = attr_export_subst;
-}
-
 struct directory {
 	struct directory *up;
 	struct object_id oid;
@@ -120,10 +107,10 @@
 		void *context)
 {
 	static struct strbuf path = STRBUF_INIT;
+	static struct attr_check *check;
 	struct archiver_context *c = context;
 	struct archiver_args *args = c->args;
 	write_archive_entry_fn_t write_entry = c->write_entry;
-	struct git_attr_check check[2];
 	const char *path_without_prefix;
 	int err;
 
@@ -137,11 +124,12 @@
 		strbuf_addch(&path, '/');
 	path_without_prefix = path.buf + args->baselen;
 
-	setup_archive_check(check);
-	if (!git_check_attr(path_without_prefix, ARRAY_SIZE(check), check)) {
-		if (ATTR_TRUE(check[0].value))
+	if (!check)
+		check = attr_check_initl("export-ignore", "export-subst", NULL);
+	if (!git_check_attr(path_without_prefix, check)) {
+		if (ATTR_TRUE(check->items[0].value))
 			return 0;
-		args->convert = ATTR_TRUE(check[1].value);
+		args->convert = ATTR_TRUE(check->items[1].value);
 	}
 
 	if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
diff --git a/attr.c b/attr.c
index 1fcf042..7e21344 100644
--- a/attr.c
+++ b/attr.c
@@ -13,6 +13,8 @@
 #include "attr.h"
 #include "dir.h"
 #include "utf8.h"
+#include "quote.h"
+#include "thread-utils.h"
 
 const char git_attr__true[] = "(builtin)true";
 const char git_attr__false[] = "\0(builtin)false";
@@ -22,99 +24,234 @@
 #define ATTR__UNSET NULL
 #define ATTR__UNKNOWN git_attr__unknown
 
-/* This is a randomly chosen prime. */
-#define HASHSIZE 257
-
 #ifndef DEBUG_ATTR
 #define DEBUG_ATTR 0
 #endif
 
 struct git_attr {
-	struct git_attr *next;
-	unsigned h;
-	int attr_nr;
-	int maybe_macro;
-	int maybe_real;
-	char name[FLEX_ARRAY];
+	int attr_nr; /* unique attribute number */
+	char name[FLEX_ARRAY]; /* attribute name */
 };
-static int attr_nr;
-static int cannot_trust_maybe_real;
 
-static struct git_attr_check *check_all_attr;
-static struct git_attr *(git_attr_hash[HASHSIZE]);
-
-char *git_attr_name(struct git_attr *attr)
+const char *git_attr_name(const struct git_attr *attr)
 {
 	return attr->name;
 }
 
-static unsigned hash_name(const char *name, int namelen)
-{
-	unsigned val = 0, c;
+struct attr_hashmap {
+	struct hashmap map;
+#ifndef NO_PTHREADS
+	pthread_mutex_t mutex;
+#endif
+};
 
-	while (namelen--) {
-		c = *name++;
-		val = ((val << 7) | (val >> 22)) ^ c;
-	}
-	return val;
+static inline void hashmap_lock(struct attr_hashmap *map)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_lock(&map->mutex);
+#endif
 }
 
-static int invalid_attr_name(const char *name, int namelen)
+static inline void hashmap_unlock(struct attr_hashmap *map)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_unlock(&map->mutex);
+#endif
+}
+
+/*
+ * The global dictionary of all interned attributes.  This
+ * is a singleton object which is shared between threads.
+ * Access to this dictionary must be surrounded with a mutex.
+ */
+static struct attr_hashmap g_attr_hashmap;
+
+/* The container for objects stored in "struct attr_hashmap" */
+struct attr_hash_entry {
+	struct hashmap_entry ent; /* must be the first member! */
+	const char *key; /* the key; memory should be owned by value */
+	size_t keylen; /* length of the key */
+	void *value; /* the stored value */
+};
+
+/* attr_hashmap comparison function */
+static int attr_hash_entry_cmp(const struct attr_hash_entry *a,
+			       const struct attr_hash_entry *b,
+			       void *unused)
+{
+	return (a->keylen != b->keylen) || strncmp(a->key, b->key, a->keylen);
+}
+
+/* Initialize an 'attr_hashmap' object */
+static void attr_hashmap_init(struct attr_hashmap *map)
+{
+	hashmap_init(&map->map, (hashmap_cmp_fn) attr_hash_entry_cmp, 0);
+}
+
+/*
+ * Retrieve the 'value' stored in a hashmap given the provided 'key'.
+ * If there is no matching entry, return NULL.
+ */
+static void *attr_hashmap_get(struct attr_hashmap *map,
+			      const char *key, size_t keylen)
+{
+	struct attr_hash_entry k;
+	struct attr_hash_entry *e;
+
+	if (!map->map.tablesize)
+		attr_hashmap_init(map);
+
+	hashmap_entry_init(&k, memhash(key, keylen));
+	k.key = key;
+	k.keylen = keylen;
+	e = hashmap_get(&map->map, &k, NULL);
+
+	return e ? e->value : NULL;
+}
+
+/* Add 'value' to a hashmap based on the provided 'key'. */
+static void attr_hashmap_add(struct attr_hashmap *map,
+			     const char *key, size_t keylen,
+			     void *value)
+{
+	struct attr_hash_entry *e;
+
+	if (!map->map.tablesize)
+		attr_hashmap_init(map);
+
+	e = xmalloc(sizeof(struct attr_hash_entry));
+	hashmap_entry_init(e, memhash(key, keylen));
+	e->key = key;
+	e->keylen = keylen;
+	e->value = value;
+
+	hashmap_add(&map->map, e);
+}
+
+struct all_attrs_item {
+	const struct git_attr *attr;
+	const char *value;
+	/*
+	 * If 'macro' is non-NULL, indicates that 'attr' is a macro based on
+	 * the current attribute stack and contains a pointer to the match_attr
+	 * definition of the macro
+	 */
+	const struct match_attr *macro;
+};
+
+/*
+ * Reallocate and reinitialize the array of all attributes (which is used in
+ * the attribute collection process) in 'check' based on the global dictionary
+ * of attributes.
+ */
+static void all_attrs_init(struct attr_hashmap *map, struct attr_check *check)
+{
+	int i;
+
+	hashmap_lock(map);
+
+	if (map->map.size < check->all_attrs_nr)
+		die("BUG: interned attributes shouldn't be deleted");
+
+	/*
+	 * If the number of attributes in the global dictionary has increased
+	 * (or this attr_check instance doesn't have an initialized all_attrs
+	 * field), reallocate the provided attr_check instance's all_attrs
+	 * field and fill each entry with its corresponding git_attr.
+	 */
+	if (map->map.size != check->all_attrs_nr) {
+		struct attr_hash_entry *e;
+		struct hashmap_iter iter;
+		hashmap_iter_init(&map->map, &iter);
+
+		REALLOC_ARRAY(check->all_attrs, map->map.size);
+		check->all_attrs_nr = map->map.size;
+
+		while ((e = hashmap_iter_next(&iter))) {
+			const struct git_attr *a = e->value;
+			check->all_attrs[a->attr_nr].attr = a;
+		}
+	}
+
+	hashmap_unlock(map);
+
+	/*
+	 * Re-initialize every entry in check->all_attrs.
+	 * This re-initialization can live outside of the locked region since
+	 * the attribute dictionary is no longer being accessed.
+	 */
+	for (i = 0; i < check->all_attrs_nr; i++) {
+		check->all_attrs[i].value = ATTR__UNKNOWN;
+		check->all_attrs[i].macro = NULL;
+	}
+}
+
+static int attr_name_valid(const char *name, size_t namelen)
 {
 	/*
 	 * Attribute name cannot begin with '-' and must consist of
 	 * characters from [-A-Za-z0-9_.].
 	 */
 	if (namelen <= 0 || *name == '-')
-		return -1;
+		return 0;
 	while (namelen--) {
 		char ch = *name++;
 		if (! (ch == '-' || ch == '.' || ch == '_' ||
 		       ('0' <= ch && ch <= '9') ||
 		       ('a' <= ch && ch <= 'z') ||
 		       ('A' <= ch && ch <= 'Z')) )
-			return -1;
+			return 0;
 	}
-	return 0;
+	return 1;
 }
 
-static struct git_attr *git_attr_internal(const char *name, int len)
+static void report_invalid_attr(const char *name, size_t len,
+				const char *src, int lineno)
 {
-	unsigned hval = hash_name(name, len);
-	unsigned pos = hval % HASHSIZE;
+	struct strbuf err = STRBUF_INIT;
+	strbuf_addf(&err, _("%.*s is not a valid attribute name"),
+		    (int) len, name);
+	fprintf(stderr, "%s: %s:%d\n", err.buf, src, lineno);
+	strbuf_release(&err);
+}
+
+/*
+ * Given a 'name', lookup and return the corresponding attribute in the global
+ * dictionary.  If no entry is found, create a new attribute and store it in
+ * the dictionary.
+ */
+static const struct git_attr *git_attr_internal(const char *name, int namelen)
+{
 	struct git_attr *a;
 
-	for (a = git_attr_hash[pos]; a; a = a->next) {
-		if (a->h == hval &&
-		    !memcmp(a->name, name, len) && !a->name[len])
-			return a;
-	}
-
-	if (invalid_attr_name(name, len))
+	if (!attr_name_valid(name, namelen))
 		return NULL;
 
-	FLEX_ALLOC_MEM(a, name, name, len);
-	a->h = hval;
-	a->next = git_attr_hash[pos];
-	a->attr_nr = attr_nr++;
-	a->maybe_macro = 0;
-	a->maybe_real = 0;
-	git_attr_hash[pos] = a;
+	hashmap_lock(&g_attr_hashmap);
 
-	REALLOC_ARRAY(check_all_attr, attr_nr);
-	check_all_attr[a->attr_nr].attr = a;
-	check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
+	a = attr_hashmap_get(&g_attr_hashmap, name, namelen);
+
+	if (!a) {
+		FLEX_ALLOC_MEM(a, name, name, namelen);
+		a->attr_nr = g_attr_hashmap.map.size;
+
+		attr_hashmap_add(&g_attr_hashmap, a->name, namelen, a);
+		assert(a->attr_nr == (g_attr_hashmap.map.size - 1));
+	}
+
+	hashmap_unlock(&g_attr_hashmap);
+
 	return a;
 }
 
-struct git_attr *git_attr(const char *name)
+const struct git_attr *git_attr(const char *name)
 {
 	return git_attr_internal(name, strlen(name));
 }
 
 /* What does a matched pattern decide? */
 struct attr_state {
-	struct git_attr *attr;
+	const struct git_attr *attr;
 	const char *setto;
 };
 
@@ -131,9 +268,8 @@
  * If is_macro is true, then u.attr is a pointer to the git_attr being
  * defined.
  *
- * If is_macro is false, then u.pattern points at the filename pattern
- * to which the rule applies.  (The memory pointed to is part of the
- * memory block allocated for the match_attr instance.)
+ * If is_macro is false, then u.pat is the filename pattern to which the
+ * rule applies.
  *
  * In either case, num_attr is the number of attributes affected by
  * this rule, and state is an array listing them.  The attributes are
@@ -142,7 +278,7 @@
 struct match_attr {
 	union {
 		struct pattern pat;
-		struct git_attr *attr;
+		const struct git_attr *attr;
 	} u;
 	char is_macro;
 	unsigned num_attr;
@@ -177,13 +313,17 @@
 			cp++;
 			len--;
 		}
-		if (invalid_attr_name(cp, len)) {
-			fprintf(stderr,
-				"%.*s is not a valid attribute name: %s:%d\n",
-				len, cp, src, lineno);
+		if (!attr_name_valid(cp, len)) {
+			report_invalid_attr(cp, len, src, lineno);
 			return NULL;
 		}
 	} else {
+		/*
+		 * As this function is always called twice, once with
+		 * e == NULL in the first pass and then e != NULL in
+		 * the second pass, no need for attr_name_valid()
+		 * check here.
+		 */
 		if (*cp == '-' || *cp == '!') {
 			e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 			cp++;
@@ -207,41 +347,47 @@
 	const char *cp, *name, *states;
 	struct match_attr *res = NULL;
 	int is_macro;
+	struct strbuf pattern = STRBUF_INIT;
 
 	cp = line + strspn(line, blank);
 	if (!*cp || *cp == '#')
 		return NULL;
 	name = cp;
-	namelen = strcspn(name, blank);
+
+	if (*cp == '"' && !unquote_c_style(&pattern, name, &states)) {
+		name = pattern.buf;
+		namelen = pattern.len;
+	} else {
+		namelen = strcspn(name, blank);
+		states = name + namelen;
+	}
+
 	if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 	    starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
 		if (!macro_ok) {
 			fprintf(stderr, "%s not allowed: %s:%d\n",
 				name, src, lineno);
-			return NULL;
+			goto fail_return;
 		}
 		is_macro = 1;
 		name += strlen(ATTRIBUTE_MACRO_PREFIX);
 		name += strspn(name, blank);
 		namelen = strcspn(name, blank);
-		if (invalid_attr_name(name, namelen)) {
-			fprintf(stderr,
-				"%.*s is not a valid attribute name: %s:%d\n",
-				namelen, name, src, lineno);
-			return NULL;
+		if (!attr_name_valid(name, namelen)) {
+			report_invalid_attr(name, namelen, src, lineno);
+			goto fail_return;
 		}
 	}
 	else
 		is_macro = 0;
 
-	states = name + namelen;
 	states += strspn(states, blank);
 
 	/* First pass to count the attr_states */
 	for (cp = states, num_attr = 0; *cp; num_attr++) {
 		cp = parse_attr(src, lineno, cp, NULL);
 		if (!cp)
-			return NULL;
+			goto fail_return;
 	}
 
 	res = xcalloc(1,
@@ -250,7 +396,6 @@
 		      (is_macro ? 0 : namelen + 1));
 	if (is_macro) {
 		res->u.attr = git_attr_internal(name, namelen);
-		res->u.attr->maybe_macro = 1;
 	} else {
 		char *p = (char *)&(res->state[num_attr]);
 		memcpy(p, name, namelen);
@@ -262,7 +407,7 @@
 		if (res->u.pat.flags & EXC_FLAG_NEGATIVE) {
 			warning(_("Negative patterns are ignored in git attributes\n"
 				  "Use '\\!' for literal leading exclamation."));
-			return NULL;
+			goto fail_return;
 		}
 	}
 	res->is_macro = is_macro;
@@ -271,13 +416,15 @@
 	/* Second pass to fill the attr_states */
 	for (cp = states, i = 0; *cp; i++) {
 		cp = parse_attr(src, lineno, cp, &(res->state[i]));
-		if (!is_macro)
-			res->state[i].attr->maybe_real = 1;
-		if (res->state[i].attr->maybe_macro)
-			cannot_trust_maybe_real = 1;
 	}
 
+	strbuf_release(&pattern);
 	return res;
+
+fail_return:
+	strbuf_release(&pattern);
+	free(res);
+	return NULL;
 }
 
 /*
@@ -295,19 +442,19 @@
  * directory (again, reading the file from top to bottom) down to the
  * current directory, and then scan the list backwards to find the first match.
  * This is exactly the same as what is_excluded() does in dir.c to deal with
- * .gitignore
+ * .gitignore file and info/excludes file as a fallback.
  */
 
-static struct attr_stack {
+struct attr_stack {
 	struct attr_stack *prev;
 	char *origin;
 	size_t originlen;
 	unsigned num_matches;
 	unsigned alloc;
 	struct match_attr **attrs;
-} *attr_stack;
+};
 
-static void free_attr_elem(struct attr_stack *e)
+static void attr_stack_free(struct attr_stack *e)
 {
 	int i;
 	free(e->origin);
@@ -330,6 +477,190 @@
 	free(e);
 }
 
+static void drop_attr_stack(struct attr_stack **stack)
+{
+	while (*stack) {
+		struct attr_stack *elem = *stack;
+		*stack = elem->prev;
+		attr_stack_free(elem);
+	}
+}
+
+/* List of all attr_check structs; access should be surrounded by mutex */
+static struct check_vector {
+	size_t nr;
+	size_t alloc;
+	struct attr_check **checks;
+#ifndef NO_PTHREADS
+	pthread_mutex_t mutex;
+#endif
+} check_vector;
+
+static inline void vector_lock(void)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_lock(&check_vector.mutex);
+#endif
+}
+
+static inline void vector_unlock(void)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_unlock(&check_vector.mutex);
+#endif
+}
+
+static void check_vector_add(struct attr_check *c)
+{
+	vector_lock();
+
+	ALLOC_GROW(check_vector.checks,
+		   check_vector.nr + 1,
+		   check_vector.alloc);
+	check_vector.checks[check_vector.nr++] = c;
+
+	vector_unlock();
+}
+
+static void check_vector_remove(struct attr_check *check)
+{
+	int i;
+
+	vector_lock();
+
+	/* Find entry */
+	for (i = 0; i < check_vector.nr; i++)
+		if (check_vector.checks[i] == check)
+			break;
+
+	if (i >= check_vector.nr)
+		die("BUG: no entry found");
+
+	/* shift entries over */
+	for (; i < check_vector.nr - 1; i++)
+		check_vector.checks[i] = check_vector.checks[i + 1];
+
+	check_vector.nr--;
+
+	vector_unlock();
+}
+
+/* Iterate through all attr_check instances and drop their stacks */
+static void drop_all_attr_stacks(void)
+{
+	int i;
+
+	vector_lock();
+
+	for (i = 0; i < check_vector.nr; i++) {
+		drop_attr_stack(&check_vector.checks[i]->stack);
+	}
+
+	vector_unlock();
+}
+
+struct attr_check *attr_check_alloc(void)
+{
+	struct attr_check *c = xcalloc(1, sizeof(struct attr_check));
+
+	/* save pointer to the check struct */
+	check_vector_add(c);
+
+	return c;
+}
+
+struct attr_check *attr_check_initl(const char *one, ...)
+{
+	struct attr_check *check;
+	int cnt;
+	va_list params;
+	const char *param;
+
+	va_start(params, one);
+	for (cnt = 1; (param = va_arg(params, const char *)) != NULL; cnt++)
+		;
+	va_end(params);
+
+	check = attr_check_alloc();
+	check->nr = cnt;
+	check->alloc = cnt;
+	check->items = xcalloc(cnt, sizeof(struct attr_check_item));
+
+	check->items[0].attr = git_attr(one);
+	va_start(params, one);
+	for (cnt = 1; cnt < check->nr; cnt++) {
+		const struct git_attr *attr;
+		param = va_arg(params, const char *);
+		if (!param)
+			die("BUG: counted %d != ended at %d",
+			    check->nr, cnt);
+		attr = git_attr(param);
+		if (!attr)
+			die("BUG: %s: not a valid attribute name", param);
+		check->items[cnt].attr = attr;
+	}
+	va_end(params);
+	return check;
+}
+
+struct attr_check *attr_check_dup(const struct attr_check *check)
+{
+	struct attr_check *ret;
+
+	if (!check)
+		return NULL;
+
+	ret = attr_check_alloc();
+
+	ret->nr = check->nr;
+	ret->alloc = check->alloc;
+	ALLOC_ARRAY(ret->items, ret->nr);
+	COPY_ARRAY(ret->items, check->items, ret->nr);
+
+	return ret;
+}
+
+struct attr_check_item *attr_check_append(struct attr_check *check,
+					  const struct git_attr *attr)
+{
+	struct attr_check_item *item;
+
+	ALLOC_GROW(check->items, check->nr + 1, check->alloc);
+	item = &check->items[check->nr++];
+	item->attr = attr;
+	return item;
+}
+
+void attr_check_reset(struct attr_check *check)
+{
+	check->nr = 0;
+}
+
+void attr_check_clear(struct attr_check *check)
+{
+	free(check->items);
+	check->items = NULL;
+	check->alloc = 0;
+	check->nr = 0;
+
+	free(check->all_attrs);
+	check->all_attrs = NULL;
+	check->all_attrs_nr = 0;
+
+	drop_attr_stack(&check->stack);
+}
+
+void attr_check_free(struct attr_check *check)
+{
+	if (check) {
+		/* Remove check from the check vector */
+		check_vector_remove(check);
+
+		attr_check_clear(check);
+		free(check);
+	}
+}
+
 static const char *builtin_attr[] = {
 	"[attr]binary -diff -merge -text",
 	NULL,
@@ -362,9 +693,31 @@
 	return res;
 }
 
+/*
+ * Callers into the attribute system assume there is a single, system-wide
+ * global state where attributes are read from and when the state is flipped by
+ * calling git_attr_set_direction(), the stack frames that have been
+ * constructed need to be discarded so so that subsequent calls into the
+ * attribute system will lazily read from the right place.  Since changing
+ * direction causes a global paradigm shift, it should not ever be called while
+ * another thread could potentially be calling into the attribute system.
+ */
 static enum git_attr_direction direction;
 static struct index_state *use_index;
 
+void git_attr_set_direction(enum git_attr_direction new_direction,
+			    struct index_state *istate)
+{
+	if (is_bare_repository() && new_direction != GIT_ATTR_INDEX)
+		die("BUG: non-INDEX attr direction in a bare repo");
+
+	if (new_direction != direction)
+		drop_all_attr_stacks();
+
+	direction = new_direction;
+	use_index = istate;
+}
+
 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 {
 	FILE *fp = fopen(path, "r");
@@ -402,8 +755,8 @@
 	for (sp = buf; *sp; ) {
 		char *ep;
 		int more;
-		for (ep = sp; *ep && *ep != '\n'; ep++)
-			;
+
+		ep = strchrnul(sp, '\n');
 		more = (*ep == '\n');
 		*ep = '\0';
 		handle_attr_line(res, sp, path, ++lineno, macro_ok);
@@ -415,25 +768,28 @@
 
 static struct attr_stack *read_attr(const char *path, int macro_ok)
 {
-	struct attr_stack *res;
+	struct attr_stack *res = NULL;
 
-	if (direction == GIT_ATTR_CHECKOUT) {
+	if (direction == GIT_ATTR_INDEX) {
 		res = read_attr_from_index(path, macro_ok);
-		if (!res)
-			res = read_attr_from_file(path, macro_ok);
-	}
-	else if (direction == GIT_ATTR_CHECKIN) {
-		res = read_attr_from_file(path, macro_ok);
-		if (!res)
-			/*
-			 * There is no checked out .gitattributes file there, but
-			 * we might have it in the index.  We allow operation in a
-			 * sparsely checked out work tree, so read from it.
-			 */
+	} else if (!is_bare_repository()) {
+		if (direction == GIT_ATTR_CHECKOUT) {
 			res = read_attr_from_index(path, macro_ok);
+			if (!res)
+				res = read_attr_from_file(path, macro_ok);
+		} else if (direction == GIT_ATTR_CHECKIN) {
+			res = read_attr_from_file(path, macro_ok);
+			if (!res)
+				/*
+				 * There is no checked out .gitattributes file
+				 * there, but we might have it in the index.
+				 * We allow operation in a sparsely checked out
+				 * work tree, so read from it.
+				 */
+				res = read_attr_from_index(path, macro_ok);
+		}
 	}
-	else
-		res = read_attr_from_index(path, macro_ok);
+
 	if (!res)
 		res = xcalloc(1, sizeof(*res));
 	return res;
@@ -464,16 +820,7 @@
 #define debug_push(a) do { ; } while (0)
 #define debug_pop(a) do { ; } while (0)
 #define debug_set(a,b,c,d) do { ; } while (0)
-#endif
-
-static void drop_attr_stack(void)
-{
-	while (attr_stack) {
-		struct attr_stack *elem = attr_stack;
-		attr_stack = elem->prev;
-		free_attr_elem(elem);
-	}
-}
+#endif /* DEBUG_ATTR */
 
 static const char *git_etc_gitattributes(void)
 {
@@ -483,6 +830,14 @@
 	return system_wide;
 }
 
+static const char *get_home_gitattributes(void)
+{
+	if (!git_attributes_file)
+		git_attributes_file = xdg_config_home("attributes");
+
+	return git_attributes_file;
+}
+
 static int git_attr_system(void)
 {
 	return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
@@ -490,64 +845,60 @@
 
 static GIT_PATH_FUNC(git_path_info_attributes, INFOATTRIBUTES_FILE)
 
-static void bootstrap_attr_stack(void)
+static void push_stack(struct attr_stack **attr_stack_p,
+		       struct attr_stack *elem, char *origin, size_t originlen)
 {
-	struct attr_stack *elem;
-
-	if (attr_stack)
-		return;
-
-	elem = read_attr_from_array(builtin_attr);
-	elem->origin = NULL;
-	elem->prev = attr_stack;
-	attr_stack = elem;
-
-	if (git_attr_system()) {
-		elem = read_attr_from_file(git_etc_gitattributes(), 1);
-		if (elem) {
-			elem->origin = NULL;
-			elem->prev = attr_stack;
-			attr_stack = elem;
-		}
+	if (elem) {
+		elem->origin = origin;
+		if (origin)
+			elem->originlen = originlen;
+		elem->prev = *attr_stack_p;
+		*attr_stack_p = elem;
 	}
-
-	if (!git_attributes_file)
-		git_attributes_file = xdg_config_home("attributes");
-	if (git_attributes_file) {
-		elem = read_attr_from_file(git_attributes_file, 1);
-		if (elem) {
-			elem->origin = NULL;
-			elem->prev = attr_stack;
-			attr_stack = elem;
-		}
-	}
-
-	if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
-		elem = read_attr(GITATTRIBUTES_FILE, 1);
-		elem->origin = xstrdup("");
-		elem->originlen = 0;
-		elem->prev = attr_stack;
-		attr_stack = elem;
-		debug_push(elem);
-	}
-
-	if (startup_info->have_repository)
-		elem = read_attr_from_file(git_path_info_attributes(), 1);
-	else
-		elem = NULL;
-
-	if (!elem)
-		elem = xcalloc(1, sizeof(*elem));
-	elem->origin = NULL;
-	elem->prev = attr_stack;
-	attr_stack = elem;
 }
 
-static void prepare_attr_stack(const char *path, int dirlen)
+static void bootstrap_attr_stack(struct attr_stack **stack)
 {
-	struct attr_stack *elem, *info;
-	int len;
-	const char *cp;
+	struct attr_stack *e;
+
+	if (*stack)
+		return;
+
+	/* builtin frame */
+	e = read_attr_from_array(builtin_attr);
+	push_stack(stack, e, NULL, 0);
+
+	/* system-wide frame */
+	if (git_attr_system()) {
+		e = read_attr_from_file(git_etc_gitattributes(), 1);
+		push_stack(stack, e, NULL, 0);
+	}
+
+	/* home directory */
+	if (get_home_gitattributes()) {
+		e = read_attr_from_file(get_home_gitattributes(), 1);
+		push_stack(stack, e, NULL, 0);
+	}
+
+	/* root directory */
+	e = read_attr(GITATTRIBUTES_FILE, 1);
+	push_stack(stack, e, xstrdup(""), 0);
+
+	/* info frame */
+	if (startup_info->have_repository)
+		e = read_attr_from_file(git_path_info_attributes(), 1);
+	else
+		e = NULL;
+	if (!e)
+		e = xcalloc(1, sizeof(struct attr_stack));
+	push_stack(stack, e, NULL, 0);
+}
+
+static void prepare_attr_stack(const char *path, int dirlen,
+			       struct attr_stack **stack)
+{
+	struct attr_stack *info;
+	struct strbuf pathbuf = STRBUF_INIT;
 
 	/*
 	 * At the bottom of the attribute stack is the built-in
@@ -564,13 +915,13 @@
 	 * .gitattributes in deeper directories to shallower ones,
 	 * and finally use the built-in set as the default.
 	 */
-	bootstrap_attr_stack();
+	bootstrap_attr_stack(stack);
 
 	/*
 	 * Pop the "info" one that is always at the top of the stack.
 	 */
-	info = attr_stack;
-	attr_stack = info->prev;
+	info = *stack;
+	*stack = info->prev;
 
 	/*
 	 * Pop the ones from directories that are not the prefix of
@@ -578,59 +929,63 @@
 	 * the root one (whose origin is an empty string "") or the builtin
 	 * one (whose origin is NULL) without popping it.
 	 */
-	while (attr_stack->origin) {
-		int namelen = strlen(attr_stack->origin);
+	while ((*stack)->origin) {
+		int namelen = (*stack)->originlen;
+		struct attr_stack *elem;
 
-		elem = attr_stack;
+		elem = *stack;
 		if (namelen <= dirlen &&
 		    !strncmp(elem->origin, path, namelen) &&
 		    (!namelen || path[namelen] == '/'))
 			break;
 
 		debug_pop(elem);
-		attr_stack = elem->prev;
-		free_attr_elem(elem);
+		*stack = elem->prev;
+		attr_stack_free(elem);
 	}
 
 	/*
-	 * Read from parent directories and push them down
+	 * bootstrap_attr_stack() should have added, and the
+	 * above loop should have stopped before popping, the
+	 * root element whose attr_stack->origin is set to an
+	 * empty string.
 	 */
-	if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
-		/*
-		 * bootstrap_attr_stack() should have added, and the
-		 * above loop should have stopped before popping, the
-		 * root element whose attr_stack->origin is set to an
-		 * empty string.
-		 */
-		struct strbuf pathbuf = STRBUF_INIT;
+	assert((*stack)->origin);
 
-		assert(attr_stack->origin);
-		while (1) {
-			len = strlen(attr_stack->origin);
-			if (dirlen <= len)
-				break;
-			cp = memchr(path + len + 1, '/', dirlen - len - 1);
-			if (!cp)
-				cp = path + dirlen;
-			strbuf_add(&pathbuf, path, cp - path);
+	strbuf_addstr(&pathbuf, (*stack)->origin);
+	/* Build up to the directory 'path' is in */
+	while (pathbuf.len < dirlen) {
+		size_t len = pathbuf.len;
+		struct attr_stack *next;
+		char *origin;
+
+		/* Skip path-separator */
+		if (len < dirlen && is_dir_sep(path[len]))
+			len++;
+		/* Find the end of the next component */
+		while (len < dirlen && !is_dir_sep(path[len]))
+			len++;
+
+		if (pathbuf.len > 0)
 			strbuf_addch(&pathbuf, '/');
-			strbuf_addstr(&pathbuf, GITATTRIBUTES_FILE);
-			elem = read_attr(pathbuf.buf, 0);
-			strbuf_setlen(&pathbuf, cp - path);
-			elem->origin = strbuf_detach(&pathbuf, &elem->originlen);
-			elem->prev = attr_stack;
-			attr_stack = elem;
-			debug_push(elem);
-		}
+		strbuf_add(&pathbuf, path + pathbuf.len, (len - pathbuf.len));
+		strbuf_addf(&pathbuf, "/%s", GITATTRIBUTES_FILE);
 
-		strbuf_release(&pathbuf);
+		next = read_attr(pathbuf.buf, 0);
+
+		/* reset the pathbuf to not include "/.gitattributes" */
+		strbuf_setlen(&pathbuf, len);
+
+		origin = xstrdup(pathbuf.buf);
+		push_stack(stack, next, origin, len);
 	}
 
 	/*
 	 * Finally push the "info" one at the top of the stack.
 	 */
-	info->prev = attr_stack;
-	attr_stack = info;
+	push_stack(stack, info, NULL, 0);
+
+	strbuf_release(&pathbuf);
 }
 
 static int path_matches(const char *pathname, int pathlen,
@@ -656,16 +1011,16 @@
 			      pattern, prefix, pat->patternlen, pat->flags);
 }
 
-static int macroexpand_one(int attr_nr, int rem);
+static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem);
 
-static int fill_one(const char *what, struct match_attr *a, int rem)
+static int fill_one(const char *what, struct all_attrs_item *all_attrs,
+		    const struct match_attr *a, int rem)
 {
-	struct git_attr_check *check = check_all_attr;
 	int i;
 
-	for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {
-		struct git_attr *attr = a->state[i].attr;
-		const char **n = &(check[attr->attr_nr].value);
+	for (i = a->num_attr - 1; rem > 0 && i >= 0; i--) {
+		const struct git_attr *attr = a->state[i].attr;
+		const char **n = &(all_attrs[attr->attr_nr].value);
 		const char *v = a->state[i].setto;
 
 		if (*n == ATTR__UNKNOWN) {
@@ -674,64 +1029,72 @@
 				  attr, v);
 			*n = v;
 			rem--;
-			rem = macroexpand_one(attr->attr_nr, rem);
+			rem = macroexpand_one(all_attrs, attr->attr_nr, rem);
 		}
 	}
 	return rem;
 }
 
 static int fill(const char *path, int pathlen, int basename_offset,
-		struct attr_stack *stk, int rem)
+		const struct attr_stack *stack,
+		struct all_attrs_item *all_attrs, int rem)
 {
-	int i;
-	const char *base = stk->origin ? stk->origin : "";
+	for (; rem > 0 && stack; stack = stack->prev) {
+		int i;
+		const char *base = stack->origin ? stack->origin : "";
 
-	for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
-		struct match_attr *a = stk->attrs[i];
-		if (a->is_macro)
-			continue;
-		if (path_matches(path, pathlen, basename_offset,
-				 &a->u.pat, base, stk->originlen))
-			rem = fill_one("fill", a, rem);
+		for (i = stack->num_matches - 1; 0 < rem && 0 <= i; i--) {
+			const struct match_attr *a = stack->attrs[i];
+			if (a->is_macro)
+				continue;
+			if (path_matches(path, pathlen, basename_offset,
+					 &a->u.pat, base, stack->originlen))
+				rem = fill_one("fill", all_attrs, a, rem);
+		}
 	}
+
 	return rem;
 }
 
-static int macroexpand_one(int nr, int rem)
+static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem)
 {
-	struct attr_stack *stk;
-	struct match_attr *a = NULL;
-	int i;
+	const struct all_attrs_item *item = &all_attrs[nr];
 
-	if (check_all_attr[nr].value != ATTR__TRUE ||
-	    !check_all_attr[nr].attr->maybe_macro)
+	if (item->macro && item->value == ATTR__TRUE)
+		return fill_one("expand", all_attrs, item->macro, rem);
+	else
 		return rem;
-
-	for (stk = attr_stack; !a && stk; stk = stk->prev)
-		for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
-			struct match_attr *ma = stk->attrs[i];
-			if (!ma->is_macro)
-				continue;
-			if (ma->u.attr->attr_nr == nr)
-				a = ma;
-		}
-
-	if (a)
-		rem = fill_one("expand", a, rem);
-
-	return rem;
 }
 
 /*
- * Collect attributes for path into the array pointed to by
- * check_all_attr. If num is non-zero, only attributes in check[] are
- * collected. Otherwise all attributes are collected.
+ * Marks the attributes which are macros based on the attribute stack.
+ * This prevents having to search through the attribute stack each time
+ * a macro needs to be expanded during the fill stage.
  */
-static void collect_some_attrs(const char *path, int num,
-			       struct git_attr_check *check)
-
+static void determine_macros(struct all_attrs_item *all_attrs,
+			     const struct attr_stack *stack)
 {
-	struct attr_stack *stk;
+	for (; stack; stack = stack->prev) {
+		int i;
+		for (i = stack->num_matches - 1; i >= 0; i--) {
+			const struct match_attr *ma = stack->attrs[i];
+			if (ma->is_macro) {
+				int n = ma->u.attr->attr_nr;
+				if (!all_attrs[n].macro) {
+					all_attrs[n].macro = ma;
+				}
+			}
+		}
+	}
+}
+
+/*
+ * Collect attributes for path into the array pointed to by check->all_attrs.
+ * If check->check_nr is non-zero, only attributes in check[] are collected.
+ * Otherwise all attributes are collected.
+ */
+static void collect_some_attrs(const char *path, struct attr_check *check)
+{
 	int i, pathlen, rem, dirlen;
 	const char *cp, *last_slash = NULL;
 	int basename_offset;
@@ -749,81 +1112,67 @@
 		dirlen = 0;
 	}
 
-	prepare_attr_stack(path, dirlen);
-	for (i = 0; i < attr_nr; i++)
-		check_all_attr[i].value = ATTR__UNKNOWN;
-	if (num && !cannot_trust_maybe_real) {
+	prepare_attr_stack(path, dirlen, &check->stack);
+	all_attrs_init(&g_attr_hashmap, check);
+	determine_macros(check->all_attrs, check->stack);
+
+	if (check->nr) {
 		rem = 0;
-		for (i = 0; i < num; i++) {
-			if (!check[i].attr->maybe_real) {
-				struct git_attr_check *c;
-				c = check_all_attr + check[i].attr->attr_nr;
-				c->value = ATTR__UNSET;
+		for (i = 0; i < check->nr; i++) {
+			int n = check->items[i].attr->attr_nr;
+			struct all_attrs_item *item = &check->all_attrs[n];
+			if (item->macro) {
+				item->value = ATTR__UNSET;
 				rem++;
 			}
 		}
-		if (rem == num)
+		if (rem == check->nr)
 			return;
 	}
 
-	rem = attr_nr;
-	for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
-		rem = fill(path, pathlen, basename_offset, stk, rem);
+	rem = check->all_attrs_nr;
+	fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
 }
 
-int git_check_attr(const char *path, int num, struct git_attr_check *check)
+int git_check_attr(const char *path, struct attr_check *check)
 {
 	int i;
 
-	collect_some_attrs(path, num, check);
+	collect_some_attrs(path, check);
 
-	for (i = 0; i < num; i++) {
-		const char *value = check_all_attr[check[i].attr->attr_nr].value;
+	for (i = 0; i < check->nr; i++) {
+		size_t n = check->items[i].attr->attr_nr;
+		const char *value = check->all_attrs[n].value;
 		if (value == ATTR__UNKNOWN)
 			value = ATTR__UNSET;
-		check[i].value = value;
+		check->items[i].value = value;
 	}
 
 	return 0;
 }
 
-int git_all_attrs(const char *path, int *num, struct git_attr_check **check)
+void git_all_attrs(const char *path, struct attr_check *check)
 {
-	int i, count, j;
+	int i;
 
-	collect_some_attrs(path, 0, NULL);
+	attr_check_reset(check);
+	collect_some_attrs(path, check);
 
-	/* Count the number of attributes that are set. */
-	count = 0;
-	for (i = 0; i < attr_nr; i++) {
-		const char *value = check_all_attr[i].value;
-		if (value != ATTR__UNSET && value != ATTR__UNKNOWN)
-			++count;
+	for (i = 0; i < check->all_attrs_nr; i++) {
+		const char *name = check->all_attrs[i].attr->name;
+		const char *value = check->all_attrs[i].value;
+		struct attr_check_item *item;
+		if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
+			continue;
+		item = attr_check_append(check, git_attr(name));
+		item->value = value;
 	}
-	*num = count;
-	ALLOC_ARRAY(*check, count);
-	j = 0;
-	for (i = 0; i < attr_nr; i++) {
-		const char *value = check_all_attr[i].value;
-		if (value != ATTR__UNSET && value != ATTR__UNKNOWN) {
-			(*check)[j].attr = check_all_attr[i].attr;
-			(*check)[j].value = value;
-			++j;
-		}
-	}
-
-	return 0;
 }
 
-void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
+void attr_start(void)
 {
-	enum git_attr_direction old = direction;
-
-	if (is_bare_repository() && new != GIT_ATTR_INDEX)
-		die("BUG: non-INDEX attr direction in a bare repo");
-
-	direction = new;
-	if (new != old)
-		drop_attr_stack();
-	use_index = istate;
+#ifndef NO_PTHREADS
+	pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
+	pthread_mutex_init(&check_vector.mutex, NULL);
+#endif
 }
diff --git a/attr.h b/attr.h
index 8b08d33..442d464 100644
--- a/attr.h
+++ b/attr.h
@@ -4,11 +4,15 @@
 /* An attribute is a pointer to this opaque structure */
 struct git_attr;
 
+/* opaque structures used internally for attribute collection */
+struct all_attrs_item;
+struct attr_stack;
+
 /*
  * Given a string, return the gitattribute object that
  * corresponds to it.
  */
-struct git_attr *git_attr(const char *);
+const struct git_attr *git_attr(const char *);
 
 /* Internal use */
 extern const char git_attr__true[];
@@ -20,38 +24,58 @@
 #define ATTR_UNSET(v) ((v) == NULL)
 
 /*
- * Send one or more git_attr_check to git_check_attr(), and
+ * Send one or more git_attr_check to git_check_attrs(), and
  * each 'value' member tells what its value is.
  * Unset one is returned as NULL.
  */
-struct git_attr_check {
-	struct git_attr *attr;
+struct attr_check_item {
+	const struct git_attr *attr;
 	const char *value;
 };
 
+struct attr_check {
+	int nr;
+	int alloc;
+	struct attr_check_item *items;
+	int all_attrs_nr;
+	struct all_attrs_item *all_attrs;
+	struct attr_stack *stack;
+};
+
+extern struct attr_check *attr_check_alloc(void);
+extern struct attr_check *attr_check_initl(const char *, ...);
+extern struct attr_check *attr_check_dup(const struct attr_check *check);
+
+extern struct attr_check_item *attr_check_append(struct attr_check *check,
+						 const struct git_attr *attr);
+
+extern void attr_check_reset(struct attr_check *check);
+extern void attr_check_clear(struct attr_check *check);
+extern void attr_check_free(struct attr_check *check);
+
 /*
  * Return the name of the attribute represented by the argument.  The
  * return value is a pointer to a null-delimited string that is part
  * of the internal data structure; it should not be modified or freed.
  */
-char *git_attr_name(struct git_attr *);
+extern const char *git_attr_name(const struct git_attr *);
 
-int git_check_attr(const char *path, int, struct git_attr_check *);
+extern int git_check_attr(const char *path, struct attr_check *check);
 
 /*
- * Retrieve all attributes that apply to the specified path.  *num
- * will be set to the number of attributes on the path; **check will
- * be set to point at a newly-allocated array of git_attr_check
- * objects describing the attributes and their values.  *check must be
- * free()ed by the caller.
+ * Retrieve all attributes that apply to the specified path.
+ * check holds the attributes and their values.
  */
-int git_all_attrs(const char *path, int *num, struct git_attr_check **check);
+extern void git_all_attrs(const char *path, struct attr_check *check);
 
 enum git_attr_direction {
 	GIT_ATTR_CHECKIN,
 	GIT_ATTR_CHECKOUT,
 	GIT_ATTR_INDEX
 };
-void git_attr_set_direction(enum git_attr_direction, struct index_state *);
+void git_attr_set_direction(enum git_attr_direction new_direction,
+			    struct index_state *istate);
+
+extern void attr_start(void);
 
 #endif /* ATTR_H */
diff --git a/branch.c b/branch.c
index b955d4f..5c12036 100644
--- a/branch.c
+++ b/branch.c
@@ -345,7 +345,8 @@
 	    branch, wt->path);
 }
 
-int replace_each_worktree_head_symref(const char *oldref, const char *newref)
+int replace_each_worktree_head_symref(const char *oldref, const char *newref,
+				      const char *logmsg)
 {
 	int ret = 0;
 	struct worktree **worktrees = get_worktrees(0);
@@ -358,7 +359,7 @@
 			continue;
 
 		if (set_worktree_head_symref(get_worktree_git_dir(worktrees[i]),
-					     newref)) {
+					     newref, logmsg)) {
 			ret = -1;
 			error(_("HEAD of working tree %s is not updated"),
 			      worktrees[i]->path);
diff --git a/branch.h b/branch.h
index 3103eb9..b077885 100644
--- a/branch.h
+++ b/branch.h
@@ -71,6 +71,7 @@
  * This will be used when renaming a branch. Returns 0 if successful, non-zero
  * otherwise.
  */
-extern int replace_each_worktree_head_symref(const char *oldref, const char *newref);
+extern int replace_each_worktree_head_symref(const char *oldref, const char *newref,
+					     const char *logmsg);
 
 #endif
diff --git a/builtin.h b/builtin.h
index 67f8051..9e4a898 100644
--- a/builtin.h
+++ b/builtin.h
@@ -103,6 +103,7 @@
 extern int cmd_pull(int argc, const char **argv, const char *prefix);
 extern int cmd_push(int argc, const char **argv, const char *prefix);
 extern int cmd_read_tree(int argc, const char **argv, const char *prefix);
+extern int cmd_rebase__helper(int argc, const char **argv, const char *prefix);
 extern int cmd_receive_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_reflog(int argc, const char **argv, const char *prefix);
 extern int cmd_remote(int argc, const char **argv, const char *prefix);
diff --git a/builtin/am.c b/builtin/am.c
index 31fb605..f7a7a97 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1049,7 +1049,7 @@
 	} else {
 		write_state_text(state, "abort-safety", "");
 		if (!state->rebasing)
-			delete_ref("ORIG_HEAD", NULL, 0);
+			delete_ref(NULL, "ORIG_HEAD", NULL, 0);
 	}
 
 	/*
@@ -2172,7 +2172,7 @@
 				has_curr_head ? &curr_head : NULL, 0,
 				UPDATE_REFS_DIE_ON_ERR);
 	else if (curr_branch)
-		delete_ref(curr_branch, NULL, REF_NODEREF);
+		delete_ref(NULL, curr_branch, NULL, REF_NODEREF);
 
 	free(curr_branch);
 	am_destroy(state);
diff --git a/builtin/branch.c b/builtin/branch.c
index babfd0f..52688f2 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -28,20 +28,21 @@
 	N_("git branch [<options>] [-r] (-d | -D) <branch-name>..."),
 	N_("git branch [<options>] (-m | -M) [<old-branch>] <new-branch>"),
 	N_("git branch [<options>] [-r | -a] [--points-at]"),
+	N_("git branch [<options>] [-r | -a] [--format]"),
 	NULL
 };
 
 static const char *head;
-static unsigned char head_sha1[20];
+static struct object_id head_oid;
 
 static int branch_use_color = -1;
 static char branch_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_RESET,
-	GIT_COLOR_NORMAL,	/* PLAIN */
-	GIT_COLOR_RED,		/* REMOTE */
-	GIT_COLOR_NORMAL,	/* LOCAL */
-	GIT_COLOR_GREEN,	/* CURRENT */
-	GIT_COLOR_BLUE,		/* UPSTREAM */
+	GIT_COLOR_NORMAL,       /* PLAIN */
+	GIT_COLOR_RED,          /* REMOTE */
+	GIT_COLOR_NORMAL,       /* LOCAL */
+	GIT_COLOR_GREEN,        /* CURRENT */
+	GIT_COLOR_BLUE,         /* UPSTREAM */
 };
 enum color_branch {
 	BRANCH_COLOR_RESET = 0,
@@ -117,13 +118,13 @@
 	if (kind == FILTER_REFS_BRANCHES) {
 		struct branch *branch = branch_get(name);
 		const char *upstream = branch_get_upstream(branch, NULL);
-		unsigned char sha1[20];
+		struct object_id oid;
 
 		if (upstream &&
 		    (reference_name = reference_name_to_free =
 		     resolve_refdup(upstream, RESOLVE_REF_READING,
-				    sha1, NULL)) != NULL)
-			reference_rev = lookup_commit_reference(sha1);
+				    oid.hash, NULL)) != NULL)
+			reference_rev = lookup_commit_reference(oid.hash);
 	}
 	if (!reference_rev)
 		reference_rev = head_rev;
@@ -153,10 +154,10 @@
 }
 
 static int check_branch_commit(const char *branchname, const char *refname,
-			       const unsigned char *sha1, struct commit *head_rev,
+			       const struct object_id *oid, struct commit *head_rev,
 			       int kinds, int force)
 {
-	struct commit *rev = lookup_commit_reference(sha1);
+	struct commit *rev = lookup_commit_reference(oid->hash);
 	if (!rev) {
 		error(_("Couldn't look up commit object for '%s'"), refname);
 		return -1;
@@ -183,7 +184,7 @@
 			   int quiet)
 {
 	struct commit *head_rev = NULL;
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *name = NULL;
 	const char *fmt;
 	int i;
@@ -210,7 +211,7 @@
 	}
 
 	if (!force) {
-		head_rev = lookup_commit_reference(head_sha1);
+		head_rev = lookup_commit_reference(head_oid.hash);
 		if (!head_rev)
 			die(_("Couldn't look up commit object for HEAD"));
 	}
@@ -238,7 +239,7 @@
 					RESOLVE_REF_READING
 					| RESOLVE_REF_NO_RECURSE
 					| RESOLVE_REF_ALLOW_BAD_NAME,
-					sha1, &flags);
+					oid.hash, &flags);
 		if (!target) {
 			error(remote_branch
 			      ? _("remote-tracking branch '%s' not found.")
@@ -248,13 +249,13 @@
 		}
 
 		if (!(flags & (REF_ISSYMREF|REF_ISBROKEN)) &&
-		    check_branch_commit(bname.buf, name, sha1, head_rev, kinds,
+		    check_branch_commit(bname.buf, name, &oid, head_rev, kinds,
 					force)) {
 			ret = 1;
 			goto next;
 		}
 
-		if (delete_ref(name, is_null_sha1(sha1) ? NULL : sha1,
+		if (delete_ref(NULL, name, is_null_oid(&oid) ? NULL : oid.hash,
 			       REF_NODEREF)) {
 			error(remote_branch
 			      ? _("Error deleting remote-tracking branch '%s'")
@@ -270,7 +271,7 @@
 			       bname.buf,
 			       (flags & REF_ISBROKEN) ? "broken"
 			       : (flags & REF_ISSYMREF) ? target
-			       : find_unique_abbrev(sha1, DEFAULT_ABBREV));
+			       : find_unique_abbrev(oid.hash, DEFAULT_ABBREV));
 		}
 		delete_branch_config(bname.buf);
 
@@ -283,195 +284,6 @@
 	return(ret);
 }
 
-static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
-		int show_upstream_ref)
-{
-	int ours, theirs;
-	char *ref = NULL;
-	struct branch *branch = branch_get(branch_name);
-	const char *upstream;
-	struct strbuf fancy = STRBUF_INIT;
-	int upstream_is_gone = 0;
-	int added_decoration = 1;
-
-	if (stat_tracking_info(branch, &ours, &theirs, &upstream) < 0) {
-		if (!upstream)
-			return;
-		upstream_is_gone = 1;
-	}
-
-	if (show_upstream_ref) {
-		ref = shorten_unambiguous_ref(upstream, 0);
-		if (want_color(branch_use_color))
-			strbuf_addf(&fancy, "%s%s%s",
-					branch_get_color(BRANCH_COLOR_UPSTREAM),
-					ref, branch_get_color(BRANCH_COLOR_RESET));
-		else
-			strbuf_addstr(&fancy, ref);
-	}
-
-	if (upstream_is_gone) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: gone]"), fancy.buf);
-		else
-			added_decoration = 0;
-	} else if (!ours && !theirs) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s]"), fancy.buf);
-		else
-			added_decoration = 0;
-	} else if (!ours) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: behind %d]"), fancy.buf, theirs);
-		else
-			strbuf_addf(stat, _("[behind %d]"), theirs);
-
-	} else if (!theirs) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: ahead %d]"), fancy.buf, ours);
-		else
-			strbuf_addf(stat, _("[ahead %d]"), ours);
-	} else {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: ahead %d, behind %d]"),
-				    fancy.buf, ours, theirs);
-		else
-			strbuf_addf(stat, _("[ahead %d, behind %d]"),
-				    ours, theirs);
-	}
-	strbuf_release(&fancy);
-	if (added_decoration)
-		strbuf_addch(stat, ' ');
-	free(ref);
-}
-
-static void add_verbose_info(struct strbuf *out, struct ref_array_item *item,
-			     struct ref_filter *filter, const char *refname)
-{
-	struct strbuf subject = STRBUF_INIT, stat = STRBUF_INIT;
-	const char *sub = _(" **** invalid ref ****");
-	struct commit *commit = item->commit;
-
-	if (!parse_commit(commit)) {
-		pp_commit_easy(CMIT_FMT_ONELINE, commit, &subject);
-		sub = subject.buf;
-	}
-
-	if (item->kind == FILTER_REFS_BRANCHES)
-		fill_tracking_info(&stat, refname, filter->verbose > 1);
-
-	strbuf_addf(out, " %s %s%s",
-		find_unique_abbrev(item->commit->object.oid.hash, filter->abbrev),
-		stat.buf, sub);
-	strbuf_release(&stat);
-	strbuf_release(&subject);
-}
-
-static char *get_head_description(void)
-{
-	struct strbuf desc = STRBUF_INIT;
-	struct wt_status_state state;
-	memset(&state, 0, sizeof(state));
-	wt_status_get_state(&state, 1);
-	if (state.rebase_in_progress ||
-	    state.rebase_interactive_in_progress)
-		strbuf_addf(&desc, _("(no branch, rebasing %s)"),
-			    state.branch);
-	else if (state.bisect_in_progress)
-		strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
-			    state.branch);
-	else if (state.detached_from) {
-		if (state.detached_at)
-			/* TRANSLATORS: make sure this matches
-			   "HEAD detached at " in wt-status.c */
-			strbuf_addf(&desc, _("(HEAD detached at %s)"),
-				state.detached_from);
-		else
-			/* TRANSLATORS: make sure this matches
-			   "HEAD detached from " in wt-status.c */
-			strbuf_addf(&desc, _("(HEAD detached from %s)"),
-				state.detached_from);
-	}
-	else
-		strbuf_addstr(&desc, _("(no branch)"));
-	free(state.branch);
-	free(state.onto);
-	free(state.detached_from);
-	return strbuf_detach(&desc, NULL);
-}
-
-static void format_and_print_ref_item(struct ref_array_item *item, int maxwidth,
-				      struct ref_filter *filter, const char *remote_prefix)
-{
-	char c;
-	int current = 0;
-	int color;
-	struct strbuf out = STRBUF_INIT, name = STRBUF_INIT;
-	const char *prefix_to_show = "";
-	const char *prefix_to_skip = NULL;
-	const char *desc = item->refname;
-	char *to_free = NULL;
-
-	switch (item->kind) {
-	case FILTER_REFS_BRANCHES:
-		prefix_to_skip = "refs/heads/";
-		skip_prefix(desc, prefix_to_skip, &desc);
-		if (!filter->detached && !strcmp(desc, head))
-			current = 1;
-		else
-			color = BRANCH_COLOR_LOCAL;
-		break;
-	case FILTER_REFS_REMOTES:
-		prefix_to_skip = "refs/remotes/";
-		skip_prefix(desc, prefix_to_skip, &desc);
-		color = BRANCH_COLOR_REMOTE;
-		prefix_to_show = remote_prefix;
-		break;
-	case FILTER_REFS_DETACHED_HEAD:
-		desc = to_free = get_head_description();
-		current = 1;
-		break;
-	default:
-		color = BRANCH_COLOR_PLAIN;
-		break;
-	}
-
-	c = ' ';
-	if (current) {
-		c = '*';
-		color = BRANCH_COLOR_CURRENT;
-	}
-
-	strbuf_addf(&name, "%s%s", prefix_to_show, desc);
-	if (filter->verbose) {
-		int utf8_compensation = strlen(name.buf) - utf8_strwidth(name.buf);
-		strbuf_addf(&out, "%c %s%-*s%s", c, branch_get_color(color),
-			    maxwidth + utf8_compensation, name.buf,
-			    branch_get_color(BRANCH_COLOR_RESET));
-	} else
-		strbuf_addf(&out, "%c %s%s%s", c, branch_get_color(color),
-			    name.buf, branch_get_color(BRANCH_COLOR_RESET));
-
-	if (item->symref) {
-		const char *symref = item->symref;
-		if (prefix_to_skip)
-			skip_prefix(symref, prefix_to_skip, &symref);
-		strbuf_addf(&out, " -> %s", symref);
-	}
-	else if (filter->verbose)
-		/* " f7c0c00 [ahead 58, behind 197] vcs-svn: drop obj_pool.h" */
-		add_verbose_info(&out, item, filter, desc);
-	if (column_active(colopts)) {
-		assert(!filter->verbose && "--column and --verbose are incompatible");
-		string_list_append(&output, out.buf);
-	} else {
-		printf("%s\n", out.buf);
-	}
-	strbuf_release(&name);
-	strbuf_release(&out);
-	free(to_free);
-}
-
 static int calc_maxwidth(struct ref_array *refs, int remote_bonus)
 {
 	int i, max = 0;
@@ -482,7 +294,12 @@
 
 		skip_prefix(it->refname, "refs/heads/", &desc);
 		skip_prefix(it->refname, "refs/remotes/", &desc);
-		w = utf8_strwidth(desc);
+		if (it->kind == FILTER_REFS_DETACHED_HEAD) {
+			char *head_desc = get_head_description();
+			w = utf8_strwidth(head_desc);
+			free(head_desc);
+		} else
+			w = utf8_strwidth(desc);
 
 		if (it->kind == FILTER_REFS_REMOTES)
 			w += remote_bonus;
@@ -492,12 +309,84 @@
 	return max;
 }
 
-static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sorting)
+static const char *quote_literal_for_format(const char *s)
+{
+	static struct strbuf buf = STRBUF_INIT;
+
+	strbuf_reset(&buf);
+	while (*s) {
+		const char *ep = strchrnul(s, '%');
+		if (s < ep)
+			strbuf_add(&buf, s, ep - s);
+		if (*ep == '%') {
+			strbuf_addstr(&buf, "%%");
+			s = ep + 1;
+		} else {
+			s = ep;
+		}
+	}
+	return buf.buf;
+}
+
+static char *build_format(struct ref_filter *filter, int maxwidth, const char *remote_prefix)
+{
+	struct strbuf fmt = STRBUF_INIT;
+	struct strbuf local = STRBUF_INIT;
+	struct strbuf remote = STRBUF_INIT;
+
+	strbuf_addf(&fmt, "%%(if)%%(HEAD)%%(then)* %s%%(else)  %%(end)",
+		    branch_get_color(BRANCH_COLOR_CURRENT));
+
+	if (filter->verbose) {
+		struct strbuf obname = STRBUF_INIT;
+
+		if (filter->abbrev < 0)
+			strbuf_addf(&obname, "%%(objectname:short)");
+		else if (!filter->abbrev)
+			strbuf_addf(&obname, "%%(objectname)");
+		else
+			strbuf_addf(&obname, "%%(objectname:short=%d)", filter->abbrev);
+
+		strbuf_addf(&local, "%%(align:%d,left)%%(refname:lstrip=2)%%(end)", maxwidth);
+		strbuf_addf(&local, "%s", branch_get_color(BRANCH_COLOR_RESET));
+		strbuf_addf(&local, " %s ", obname.buf);
+
+		if (filter->verbose > 1)
+			strbuf_addf(&local, "%%(if)%%(upstream)%%(then)[%s%%(upstream:short)%s%%(if)%%(upstream:track)"
+				    "%%(then): %%(upstream:track,nobracket)%%(end)] %%(end)%%(contents:subject)",
+				    branch_get_color(BRANCH_COLOR_UPSTREAM), branch_get_color(BRANCH_COLOR_RESET));
+		else
+			strbuf_addf(&local, "%%(if)%%(upstream:track)%%(then)%%(upstream:track) %%(end)%%(contents:subject)");
+
+		strbuf_addf(&remote, "%s%%(align:%d,left)%s%%(refname:lstrip=2)%%(end)%s"
+			    "%%(if)%%(symref)%%(then) -> %%(symref:short)"
+			    "%%(else) %s %%(contents:subject)%%(end)",
+			    branch_get_color(BRANCH_COLOR_REMOTE), maxwidth, quote_literal_for_format(remote_prefix),
+			    branch_get_color(BRANCH_COLOR_RESET), obname.buf);
+		strbuf_release(&obname);
+	} else {
+		strbuf_addf(&local, "%%(refname:lstrip=2)%s%%(if)%%(symref)%%(then) -> %%(symref:short)%%(end)",
+			    branch_get_color(BRANCH_COLOR_RESET));
+		strbuf_addf(&remote, "%s%s%%(refname:lstrip=2)%s%%(if)%%(symref)%%(then) -> %%(symref:short)%%(end)",
+			    branch_get_color(BRANCH_COLOR_REMOTE), quote_literal_for_format(remote_prefix),
+			    branch_get_color(BRANCH_COLOR_RESET));
+	}
+
+	strbuf_addf(&fmt, "%%(if:notequals=refs/remotes)%%(refname:rstrip=-2)%%(then)%s%%(else)%s%%(end)", local.buf, remote.buf);
+
+	strbuf_release(&local);
+	strbuf_release(&remote);
+	return strbuf_detach(&fmt, NULL);
+}
+
+static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sorting, const char *format)
 {
 	int i;
 	struct ref_array array;
 	int maxwidth = 0;
 	const char *remote_prefix = "";
+	struct strbuf out = STRBUF_INIT;
+	char *to_free = NULL;
 
 	/*
 	 * If we are listing more than just remote branches,
@@ -509,18 +398,32 @@
 
 	memset(&array, 0, sizeof(array));
 
-	verify_ref_format("%(refname)%(symref)");
 	filter_refs(&array, filter, filter->kind | FILTER_REFS_INCLUDE_BROKEN);
 
 	if (filter->verbose)
 		maxwidth = calc_maxwidth(&array, strlen(remote_prefix));
 
+	if (!format)
+		format = to_free = build_format(filter, maxwidth, remote_prefix);
+	verify_ref_format(format);
+
 	ref_array_sort(sorting, &array);
 
-	for (i = 0; i < array.nr; i++)
-		format_and_print_ref_item(array.items[i], maxwidth, filter, remote_prefix);
+	for (i = 0; i < array.nr; i++) {
+		format_ref_array_item(array.items[i], format, 0, &out);
+		if (column_active(colopts)) {
+			assert(!filter->verbose && "--column and --verbose are incompatible");
+			 /* format to a string_list to let print_columns() do its job */
+			string_list_append(&output, out.buf);
+		} else {
+			fwrite(out.buf, 1, out.len, stdout);
+			putchar('\n');
+		}
+		strbuf_release(&out);
+	}
 
 	ref_array_clear(&array);
+	free(to_free);
 }
 
 static void reject_rebase_or_bisect_branch(const char *target)
@@ -582,14 +485,15 @@
 
 	if (rename_ref(oldref.buf, newref.buf, logmsg.buf))
 		die(_("Branch rename failed"));
-	strbuf_release(&logmsg);
 
 	if (recovery)
 		warning(_("Renamed a misnamed branch '%s' away"), oldref.buf + 11);
 
-	if (replace_each_worktree_head_symref(oldref.buf, newref.buf))
+	if (replace_each_worktree_head_symref(oldref.buf, newref.buf, logmsg.buf))
 		die(_("Branch renamed to %s, but HEAD is not updated!"), newname);
 
+	strbuf_release(&logmsg);
+
 	strbuf_addf(&oldsection, "branch.%s", oldref.buf + 11);
 	strbuf_release(&oldref);
 	strbuf_addf(&newsection, "branch.%s", newref.buf + 11);
@@ -641,6 +545,7 @@
 	struct ref_filter filter;
 	int icase = 0;
 	static struct ref_sorting *sorting = NULL, **sorting_tail = &sorting;
+	const char *format = NULL;
 
 	struct option options[] = {
 		OPT_GROUP(N_("Generic options")),
@@ -682,9 +587,12 @@
 			N_("print only branches of the object"), 0, parse_opt_object_name
 		},
 		OPT_BOOL('i', "ignore-case", &icase, N_("sorting and filtering are case insensitive")),
+		OPT_STRING(  0 , "format", &format, N_("format"), N_("format to use for the output")),
 		OPT_END(),
 	};
 
+	setup_ref_filter_porcelain_msg();
+
 	memset(&filter, 0, sizeof(filter));
 	filter.kind = FILTER_REFS_BRANCHES;
 	filter.abbrev = -1;
@@ -696,7 +604,7 @@
 
 	track = git_branch_track;
 
-	head = resolve_refdup("HEAD", 0, head_sha1, NULL);
+	head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
 	if (!head)
 		die(_("Failed to resolve HEAD as a valid ref."));
 	if (!strcmp(head, "HEAD"))
@@ -752,7 +660,7 @@
 		if (!sorting)
 			sorting = ref_default_sorting();
 		sorting->ignore_case = icase;
-		print_ref_list(&filter, sorting);
+		print_ref_list(&filter, sorting, format);
 		print_columns(&output, colopts, NULL);
 		string_list_clear(&output, 0);
 		return 0;
diff --git a/builtin/bundle.c b/builtin/bundle.c
index 4883a43..d0de59b 100644
--- a/builtin/bundle.c
+++ b/builtin/bundle.c
@@ -20,21 +20,15 @@
 	struct bundle_header header;
 	const char *cmd, *bundle_file;
 	int bundle_fd = -1;
-	char buffer[PATH_MAX];
 
 	if (argc < 3)
 		usage(builtin_bundle_usage);
 
 	cmd = argv[1];
-	bundle_file = argv[2];
+	bundle_file = prefix_filename(prefix, argv[2]);
 	argc -= 2;
 	argv += 2;
 
-	if (prefix && bundle_file[0] != '/') {
-		snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
-		bundle_file = buffer;
-	}
-
 	memset(&header, 0, sizeof(header));
 	if (strcmp(cmd, "create") && (bundle_fd =
 				read_bundle_header(bundle_file, &header)) < 0)
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 30383e9..8b85cb8 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -409,20 +409,20 @@
 	return 0;
 }
 
-static int batch_loose_object(const unsigned char *sha1,
+static int batch_loose_object(const struct object_id *oid,
 			      const char *path,
 			      void *data)
 {
-	sha1_array_append(data, sha1);
+	sha1_array_append(data, oid->hash);
 	return 0;
 }
 
-static int batch_packed_object(const unsigned char *sha1,
+static int batch_packed_object(const struct object_id *oid,
 			       struct packed_git *pack,
 			       uint32_t pos,
 			       void *data)
 {
-	sha1_array_append(data, sha1);
+	sha1_array_append(data, oid->hash);
 	return 0;
 }
 
diff --git a/builtin/check-attr.c b/builtin/check-attr.c
index 53a5a18..4d01ca0 100644
--- a/builtin/check-attr.c
+++ b/builtin/check-attr.c
@@ -24,12 +24,13 @@
 	OPT_END()
 };
 
-static void output_attr(int cnt, struct git_attr_check *check,
-	const char *file)
+static void output_attr(struct attr_check *check, const char *file)
 {
 	int j;
+	int cnt = check->nr;
+
 	for (j = 0; j < cnt; j++) {
-		const char *value = check[j].value;
+		const char *value = check->items[j].value;
 
 		if (ATTR_TRUE(value))
 			value = "set";
@@ -42,35 +43,38 @@
 			printf("%s%c" /* path */
 			       "%s%c" /* attrname */
 			       "%s%c" /* attrvalue */,
-			       file, 0, git_attr_name(check[j].attr), 0, value, 0);
+			       file, 0,
+			       git_attr_name(check->items[j].attr), 0, value, 0);
 		} else {
 			quote_c_style(file, NULL, stdout, 0);
-			printf(": %s: %s\n", git_attr_name(check[j].attr), value);
+			printf(": %s: %s\n",
+			       git_attr_name(check->items[j].attr), value);
 		}
-
 	}
 }
 
-static void check_attr(const char *prefix, int cnt,
-	struct git_attr_check *check, const char *file)
+static void check_attr(const char *prefix,
+		       struct attr_check *check,
+		       int collect_all,
+		       const char *file)
 {
 	char *full_path =
 		prefix_path(prefix, prefix ? strlen(prefix) : 0, file);
-	if (check != NULL) {
-		if (git_check_attr(full_path, cnt, check))
-			die("git_check_attr died");
-		output_attr(cnt, check, file);
+
+	if (collect_all) {
+		git_all_attrs(full_path, check);
 	} else {
-		if (git_all_attrs(full_path, &cnt, &check))
-			die("git_all_attrs died");
-		output_attr(cnt, check, file);
-		free(check);
+		if (git_check_attr(full_path, check))
+			die("git_check_attr died");
 	}
+	output_attr(check, file);
+
 	free(full_path);
 }
 
-static void check_attr_stdin_paths(const char *prefix, int cnt,
-	struct git_attr_check *check)
+static void check_attr_stdin_paths(const char *prefix,
+				   struct attr_check *check,
+				   int collect_all)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf unquoted = STRBUF_INIT;
@@ -84,7 +88,7 @@
 				die("line is badly quoted");
 			strbuf_swap(&buf, &unquoted);
 		}
-		check_attr(prefix, cnt, check, buf.buf);
+		check_attr(prefix, check, collect_all, buf.buf);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
 	strbuf_release(&buf);
@@ -99,7 +103,7 @@
 
 int cmd_check_attr(int argc, const char **argv, const char *prefix)
 {
-	struct git_attr_check *check;
+	struct attr_check *check;
 	int cnt, i, doubledash, filei;
 
 	if (!is_bare_repository())
@@ -159,28 +163,26 @@
 			error_with_usage("No file specified");
 	}
 
-	if (all_attrs) {
-		check = NULL;
-	} else {
-		check = xcalloc(cnt, sizeof(*check));
+	check = attr_check_alloc();
+	if (!all_attrs) {
 		for (i = 0; i < cnt; i++) {
-			const char *name;
-			struct git_attr *a;
-			name = argv[i];
-			a = git_attr(name);
+			const struct git_attr *a = git_attr(argv[i]);
+
 			if (!a)
 				return error("%s: not a valid attribute name",
-					name);
-			check[i].attr = a;
+					     argv[i]);
+			attr_check_append(check, a);
 		}
 	}
 
 	if (stdin_paths)
-		check_attr_stdin_paths(prefix, cnt, check);
+		check_attr_stdin_paths(prefix, check, all_attrs);
 	else {
 		for (i = filei; i < argc; i++)
-			check_attr(prefix, cnt, check, argv[i]);
+			check_attr(prefix, check, all_attrs, argv[i]);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
+
+	attr_check_free(check);
 	return 0;
 }
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 81f07c3..3ecc47b 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -21,12 +21,31 @@
 #include "submodule-config.h"
 #include "submodule.h"
 
+static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
+
 static const char * const checkout_usage[] = {
 	N_("git checkout [<options>] <branch>"),
 	N_("git checkout [<options>] [<branch>] -- <file>..."),
 	NULL,
 };
 
+static int option_parse_recurse_submodules(const struct option *opt,
+					   const char *arg, int unset)
+{
+	if (unset) {
+		recurse_submodules = RECURSE_SUBMODULES_OFF;
+		return 0;
+	}
+	if (arg)
+		recurse_submodules =
+			parse_update_recurse_submodules_arg(opt->long_name,
+							    arg);
+	else
+		recurse_submodules = RECURSE_SUBMODULES_ON;
+
+	return 0;
+}
+
 struct checkout_opts {
 	int patch_mode;
 	int quiet;
@@ -1163,6 +1182,9 @@
 				N_("second guess 'git checkout <no-such-branch>'")),
 		OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
 			 N_("do not check if another worktree is holding the given ref")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
 		OPT_END(),
 	};
@@ -1193,6 +1215,12 @@
 		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
 	}
 
+	if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
+		git_config(submodule_config, NULL);
+		if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
+			set_config_update_recurse_submodules(recurse_submodules);
+	}
+
 	if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
 		die(_("-b, -B and --orphan are mutually exclusive"));
 
diff --git a/builtin/clean.c b/builtin/clean.c
index d6bc3aa..d861f83 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -174,8 +174,10 @@
 		/* an empty dir could be removed even if it is unreadble */
 		res = dry_run ? 0 : rmdir(path->buf);
 		if (res) {
+			int saved_errno = errno;
 			quote_path_relative(path->buf, prefix, &quoted);
-			warning(_(msg_warn_remove_failed), quoted.buf);
+			errno = saved_errno;
+			warning_errno(_(msg_warn_remove_failed), quoted.buf);
 			*dir_gone = 0;
 		}
 		return res;
@@ -208,8 +210,10 @@
 				quote_path_relative(path->buf, prefix, &quoted);
 				string_list_append(&dels, quoted.buf);
 			} else {
+				int saved_errno = errno;
 				quote_path_relative(path->buf, prefix, &quoted);
-				warning(_(msg_warn_remove_failed), quoted.buf);
+				errno = saved_errno;
+				warning_errno(_(msg_warn_remove_failed), quoted.buf);
 				*dir_gone = 0;
 				ret = 1;
 			}
@@ -230,8 +234,10 @@
 		if (!res)
 			*dir_gone = 1;
 		else {
+			int saved_errno = errno;
 			quote_path_relative(path->buf, prefix, &quoted);
-			warning(_(msg_warn_remove_failed), quoted.buf);
+			errno = saved_errno;
+			warning_errno(_(msg_warn_remove_failed), quoted.buf);
 			*dir_gone = 0;
 			ret = 1;
 		}
@@ -981,8 +987,10 @@
 		} else {
 			res = dry_run ? 0 : unlink(abs_path.buf);
 			if (res) {
+				int saved_errno = errno;
 				qname = quote_path_relative(item->string, NULL, &buf);
-				warning(_(msg_warn_remove_failed), qname);
+				errno = saved_errno;
+				warning_errno(_(msg_warn_remove_failed), qname);
 				errors++;
 			} else if (!quiet) {
 				qname = quote_path_relative(item->string, NULL, &buf);
diff --git a/builtin/clone.c b/builtin/clone.c
index 3f63edb..b4c929b 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -681,7 +681,7 @@
 
 static int checkout(int submodule_progress)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *head;
 	struct lock_file *lock_file;
 	struct unpack_trees_options opts;
@@ -692,7 +692,7 @@
 	if (option_no_checkout)
 		return 0;
 
-	head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
+	head = resolve_refdup("HEAD", RESOLVE_REF_READING, oid.hash, NULL);
 	if (!head) {
 		warning(_("remote HEAD refers to nonexistent ref, "
 			  "unable to checkout.\n"));
@@ -700,7 +700,7 @@
 	}
 	if (!strcmp(head, "HEAD")) {
 		if (advice_detached_head)
-			detach_advice(sha1_to_hex(sha1));
+			detach_advice(oid_to_hex(&oid));
 	} else {
 		if (!starts_with(head, "refs/heads/"))
 			die(_("HEAD not found below refs/heads!"));
@@ -721,7 +721,7 @@
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
 
-	tree = parse_tree_indirect(sha1);
+	tree = parse_tree_indirect(oid.hash);
 	parse_tree(tree);
 	init_tree_desc(&t, tree->buffer, tree->size);
 	if (unpack_trees(1, &t, &opts) < 0)
@@ -731,7 +731,7 @@
 		die(_("unable to write new index file"));
 
 	err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
-			   sha1_to_hex(sha1), "1", NULL);
+			   oid_to_hex(&oid), "1", NULL);
 
 	if (!err && option_recursive) {
 		struct argv_array args = ARGV_ARRAY_INIT;
diff --git a/builtin/commit.c b/builtin/commit.c
index 2de5f6c..4e288bc 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -496,7 +496,7 @@
 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
 		      struct wt_status *s)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	if (s->relative_paths)
 		s->prefix = prefix;
@@ -509,9 +509,9 @@
 	s->index_file = index_file;
 	s->fp = fp;
 	s->nowarn = nowarn;
-	s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
+	s->is_initial = get_sha1(s->reference, oid.hash) ? 1 : 0;
 	if (!s->is_initial)
-		hashcpy(s->sha1_commit, sha1);
+		hashcpy(s->sha1_commit, oid.hash);
 	s->status_format = status_format;
 	s->ignore_submodule_arg = ignore_submodule_arg;
 
@@ -885,7 +885,7 @@
 		commitable = run_status(s->fp, index_file, prefix, 1, s);
 		s->use_color = saved_color_setting;
 	} else {
-		unsigned char sha1[20];
+		struct object_id oid;
 		const char *parent = "HEAD";
 
 		if (!active_nr && read_cache() < 0)
@@ -894,7 +894,7 @@
 		if (amend)
 			parent = "HEAD^1";
 
-		if (get_sha1(parent, sha1)) {
+		if (get_sha1(parent, oid.hash)) {
 			int i, ita_nr = 0;
 
 			for (i = 0; i < active_nr; i++)
@@ -1332,7 +1332,7 @@
 {
 	static struct wt_status s;
 	int fd;
-	unsigned char sha1[20];
+	struct object_id oid;
 	static struct option builtin_status_options[] = {
 		OPT__VERBOSE(&verbose, N_("be verbose")),
 		OPT_SET_INT('s', "short", &status_format,
@@ -1382,9 +1382,9 @@
 
 	fd = hold_locked_index(&index_lock, 0);
 
-	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
+	s.is_initial = get_sha1(s.reference, oid.hash) ? 1 : 0;
 	if (!s.is_initial)
-		hashcpy(s.sha1_commit, sha1);
+		hashcpy(s.sha1_commit, oid.hash);
 
 	s.ignore_submodule_arg = ignore_submodule_arg;
 	s.status_format = status_format;
@@ -1418,19 +1418,19 @@
 
 }
 
-static void print_summary(const char *prefix, const unsigned char *sha1,
+static void print_summary(const char *prefix, const struct object_id *oid,
 			  int initial_commit)
 {
 	struct rev_info rev;
 	struct commit *commit;
 	struct strbuf format = STRBUF_INIT;
-	unsigned char junk_sha1[20];
+	struct object_id junk_oid;
 	const char *head;
 	struct pretty_print_context pctx = {0};
 	struct strbuf author_ident = STRBUF_INIT;
 	struct strbuf committer_ident = STRBUF_INIT;
 
-	commit = lookup_commit(sha1);
+	commit = lookup_commit(oid->hash);
 	if (!commit)
 		die(_("couldn't look up newly created commit"));
 	if (parse_commit(commit))
@@ -1477,7 +1477,7 @@
 	rev.diffopt.break_opt = 0;
 	diff_setup_done(&rev.diffopt);
 
-	head = resolve_ref_unsafe("HEAD", 0, junk_sha1, NULL);
+	head = resolve_ref_unsafe("HEAD", 0, junk_oid.hash, NULL);
 	if (!strcmp(head, "HEAD"))
 		head = _("detached HEAD");
 	else
@@ -1522,8 +1522,8 @@
 	return git_status_config(k, v, s);
 }
 
-static int run_rewrite_hook(const unsigned char *oldsha1,
-			    const unsigned char *newsha1)
+static int run_rewrite_hook(const struct object_id *oldoid,
+			    const struct object_id *newoid)
 {
 	struct child_process proc = CHILD_PROCESS_INIT;
 	const char *argv[3];
@@ -1544,7 +1544,7 @@
 	code = start_command(&proc);
 	if (code)
 		return code;
-	strbuf_addf(&sb, "%s %s\n", sha1_to_hex(oldsha1), sha1_to_hex(newsha1));
+	strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
 	sigchain_push(SIGPIPE, SIG_IGN);
 	write_in_full(proc.in, sb.buf, sb.len);
 	close(proc.in);
@@ -1636,7 +1636,7 @@
 	struct strbuf author_ident = STRBUF_INIT;
 	const char *index_file, *reflog_msg;
 	char *nl;
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct commit_list *parents = NULL;
 	struct stat statbuf;
 	struct commit *current_head = NULL;
@@ -1651,10 +1651,10 @@
 	status_format = STATUS_FORMAT_NONE; /* Ignore status.short */
 	s.colopts = 0;
 
-	if (get_sha1("HEAD", sha1))
+	if (get_sha1("HEAD", oid.hash))
 		current_head = NULL;
 	else {
-		current_head = lookup_commit_or_die(sha1, "HEAD");
+		current_head = lookup_commit_or_die(oid.hash, "HEAD");
 		if (parse_commit(current_head))
 			die(_("could not parse HEAD commit"));
 	}
@@ -1759,7 +1759,7 @@
 	}
 
 	if (commit_tree_extended(sb.buf, sb.len, active_cache_tree->sha1,
-			 parents, sha1, author_ident.buf, sign_commit, extra)) {
+			 parents, oid.hash, author_ident.buf, sign_commit, extra)) {
 		rollback_index_files();
 		die(_("failed to write commit object"));
 	}
@@ -1776,7 +1776,7 @@
 
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
-	    ref_transaction_update(transaction, "HEAD", sha1,
+	    ref_transaction_update(transaction, "HEAD", oid.hash,
 				   current_head
 				   ? current_head->object.oid.hash : null_sha1,
 				   0, sb.buf, &err) ||
@@ -1805,13 +1805,13 @@
 		cfg = init_copy_notes_for_rewrite("amend");
 		if (cfg) {
 			/* we are amending, so current_head is not NULL */
-			copy_note_for_rewrite(cfg, current_head->object.oid.hash, sha1);
+			copy_note_for_rewrite(cfg, current_head->object.oid.hash, oid.hash);
 			finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
 		}
-		run_rewrite_hook(current_head->object.oid.hash, sha1);
+		run_rewrite_hook(&current_head->object.oid, &oid);
 	}
 	if (!quiet)
-		print_summary(prefix, sha1, !current_head);
+		print_summary(prefix, &oid, !current_head);
 
 	strbuf_release(&err);
 	return 0;
diff --git a/builtin/config.c b/builtin/config.c
index 05843a0..4f49a0e 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -527,9 +527,7 @@
 	else if (given_config_source.file) {
 		if (!is_absolute_path(given_config_source.file) && prefix)
 			given_config_source.file =
-				xstrdup(prefix_filename(prefix,
-							strlen(prefix),
-							given_config_source.file));
+				prefix_filename(prefix, given_config_source.file);
 	}
 
 	if (respect_includes == -1)
diff --git a/builtin/count-objects.c b/builtin/count-objects.c
index a04b4f2..acb0594 100644
--- a/builtin/count-objects.c
+++ b/builtin/count-objects.c
@@ -53,7 +53,7 @@
 		report_garbage(PACKDIR_FILE_GARBAGE, path);
 }
 
-static int count_loose(const unsigned char *sha1, const char *path, void *data)
+static int count_loose(const struct object_id *oid, const char *path, void *data)
 {
 	struct stat st;
 
@@ -62,7 +62,7 @@
 	else {
 		loose_size += on_disk_bytes(st);
 		loose++;
-		if (verbose && has_sha1_pack(sha1))
+		if (verbose && has_sha1_pack(oid->hash))
 			packed_loose++;
 	}
 	return 0;
diff --git a/builtin/describe.c b/builtin/describe.c
index 01490a1..45adbf6 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -9,6 +9,7 @@
 #include "diff.h"
 #include "hashmap.h"
 #include "argv-array.h"
+#include "run-command.h"
 
 #define SEEN		(1u << 0)
 #define MAX_TAGS	(FLAG_BITS - 1)
@@ -28,9 +29,10 @@
 static int max_candidates = 10;
 static struct hashmap names;
 static int have_util;
-static const char *pattern;
+static struct string_list patterns = STRING_LIST_INIT_NODUP;
+static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
 static int always;
-static const char *dirty;
+static const char *suffix, *dirty, *broken;
 
 /* diff-index command arguments to check if working tree is dirty. */
 static const char *diff_index_args[] = {
@@ -39,11 +41,11 @@
 
 struct commit_name {
 	struct hashmap_entry entry;
-	unsigned char peeled[20];
+	struct object_id peeled;
 	struct tag *tag;
 	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
 	unsigned name_checked:1;
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *path;
 };
 
@@ -54,17 +56,17 @@
 static int commit_name_cmp(const struct commit_name *cn1,
 		const struct commit_name *cn2, const void *peeled)
 {
-	return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
+	return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
 }
 
-static inline struct commit_name *find_commit_name(const unsigned char *peeled)
+static inline struct commit_name *find_commit_name(const struct object_id *peeled)
 {
-	return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
+	return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
 }
 
 static int replace_name(struct commit_name *e,
 			       int prio,
-			       const unsigned char *sha1,
+			       const struct object_id *oid,
 			       struct tag **tag)
 {
 	if (!e || e->prio < prio)
@@ -77,13 +79,13 @@
 		struct tag *t;
 
 		if (!e->tag) {
-			t = lookup_tag(e->sha1);
+			t = lookup_tag(e->oid.hash);
 			if (!t || parse_tag(t))
 				return 1;
 			e->tag = t;
 		}
 
-		t = lookup_tag(sha1);
+		t = lookup_tag(oid->hash);
 		if (!t || parse_tag(t))
 			return 0;
 		*tag = t;
@@ -96,24 +98,24 @@
 }
 
 static void add_to_known_names(const char *path,
-			       const unsigned char *peeled,
+			       const struct object_id *peeled,
 			       int prio,
-			       const unsigned char *sha1)
+			       const struct object_id *oid)
 {
 	struct commit_name *e = find_commit_name(peeled);
 	struct tag *tag = NULL;
-	if (replace_name(e, prio, sha1, &tag)) {
+	if (replace_name(e, prio, oid, &tag)) {
 		if (!e) {
 			e = xmalloc(sizeof(struct commit_name));
-			hashcpy(e->peeled, peeled);
-			hashmap_entry_init(e, sha1hash(peeled));
+			oidcpy(&e->peeled, peeled);
+			hashmap_entry_init(e, sha1hash(peeled->hash));
 			hashmap_add(&names, e);
 			e->path = NULL;
 		}
 		e->tag = tag;
 		e->prio = prio;
 		e->name_checked = 0;
-		hashcpy(e->sha1, sha1);
+		oidcpy(&e->oid, oid);
 		free(e->path);
 		e->path = xstrdup(path);
 	}
@@ -129,9 +131,40 @@
 	if (!all && !is_tag)
 		return 0;
 
-	/* Accept only tags that match the pattern, if given */
-	if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
-		return 0;
+	/*
+	 * If we're given exclude patterns, first exclude any tag which match
+	 * any of the exclude pattern.
+	 */
+	if (exclude_patterns.nr) {
+		struct string_list_item *item;
+
+		if (!is_tag)
+			return 0;
+
+		for_each_string_list_item(item, &exclude_patterns) {
+			if (!wildmatch(item->string, path + 10, 0, NULL))
+				return 0;
+		}
+	}
+
+	/*
+	 * If we're given patterns, accept only tags which match at least one
+	 * pattern.
+	 */
+	if (patterns.nr) {
+		struct string_list_item *item;
+
+		if (!is_tag)
+			return 0;
+
+		for_each_string_list_item(item, &patterns) {
+			if (!wildmatch(item->string, path + 10, 0, NULL))
+				break;
+
+			/* If we get here, no pattern matched. */
+			return 0;
+		}
+	}
 
 	/* Is it annotated? */
 	if (!peel_ref(path, peeled.hash)) {
@@ -154,7 +187,7 @@
 	else
 		prio = 0;
 
-	add_to_known_names(all ? path + 5 : path + 10, peeled.hash, prio, oid->hash);
+	add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 	return 0;
 }
 
@@ -212,7 +245,7 @@
 static void display_name(struct commit_name *n)
 {
 	if (n->prio == 2 && !n->tag) {
-		n->tag = lookup_tag(n->sha1);
+		n->tag = lookup_tag(n->oid.hash);
 		if (!n->tag || parse_tag(n->tag))
 			die(_("annotated tag %s not available"), n->path);
 	}
@@ -230,14 +263,14 @@
 		printf("%s", n->path);
 }
 
-static void show_suffix(int depth, const unsigned char *sha1)
+static void show_suffix(int depth, const struct object_id *oid)
 {
-	printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
+	printf("-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
 }
 
 static void describe(const char *arg, int last_one)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct commit *cmit, *gave_up_on = NULL;
 	struct commit_list *list;
 	struct commit_name *n;
@@ -246,22 +279,22 @@
 	unsigned long seen_commits = 0;
 	unsigned int unannotated_cnt = 0;
 
-	if (get_sha1(arg, sha1))
+	if (get_oid(arg, &oid))
 		die(_("Not a valid object name %s"), arg);
-	cmit = lookup_commit_reference(sha1);
+	cmit = lookup_commit_reference(oid.hash);
 	if (!cmit)
 		die(_("%s is not a valid '%s' object"), arg, commit_type);
 
-	n = find_commit_name(cmit->object.oid.hash);
+	n = find_commit_name(&cmit->object.oid);
 	if (n && (tags || all || n->prio == 2)) {
 		/*
 		 * Exact match to an existing ref.
 		 */
 		display_name(n);
 		if (longformat)
-			show_suffix(0, n->tag ? n->tag->tagged->oid.hash : sha1);
-		if (dirty)
-			printf("%s", dirty);
+			show_suffix(0, n->tag ? &n->tag->tagged->oid : &oid);
+		if (suffix)
+			printf("%s", suffix);
 		printf("\n");
 		return;
 	}
@@ -276,7 +309,7 @@
 		struct commit *c;
 		struct commit_name *n = hashmap_iter_first(&names, &iter);
 		for (; n; n = hashmap_iter_next(&iter)) {
-			c = lookup_commit_reference_gently(n->peeled, 1);
+			c = lookup_commit_reference_gently(n->peeled.hash, 1);
 			if (c)
 				c->util = n;
 		}
@@ -337,8 +370,8 @@
 		struct object_id *oid = &cmit->object.oid;
 		if (always) {
 			printf("%s", find_unique_abbrev(oid->hash, abbrev));
-			if (dirty)
-				printf("%s", dirty);
+			if (suffix)
+				printf("%s", suffix);
 			printf("\n");
 			return;
 		}
@@ -380,9 +413,9 @@
 
 	display_name(all_matches[0].name);
 	if (abbrev)
-		show_suffix(all_matches[0].depth, cmit->object.oid.hash);
-	if (dirty)
-		printf("%s", dirty);
+		show_suffix(all_matches[0].depth, &cmit->object.oid);
+	if (suffix)
+		printf("%s", suffix);
 	printf("\n");
 
 	if (!last_one)
@@ -404,13 +437,18 @@
 			    N_("only output exact matches"), 0),
 		OPT_INTEGER(0, "candidates", &max_candidates,
 			    N_("consider <n> most recent tags (default: 10)")),
-		OPT_STRING(0, "match",       &pattern, N_("pattern"),
+		OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 			   N_("only consider tags matching <pattern>")),
+		OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
+			   N_("do not consider tags matching <pattern>")),
 		OPT_BOOL(0, "always",        &always,
 			N_("show abbreviated commit object as fallback")),
 		{OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 			N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 			PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
+		{OPTION_STRING, 0, "broken",  &broken, N_("mark"),
+			N_("append <mark> on broken working tree (default: \"-broken\")"),
+			PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 		OPT_END(),
 	};
 
@@ -430,6 +468,7 @@
 		die(_("--long is incompatible with --abbrev=0"));
 
 	if (contains) {
+		struct string_list_item *item;
 		struct argv_array args;
 
 		argv_array_init(&args);
@@ -440,8 +479,10 @@
 			argv_array_push(&args, "--always");
 		if (!all) {
 			argv_array_push(&args, "--tags");
-			if (pattern)
-				argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
+			for_each_string_list_item(item, &patterns)
+				argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
+			for_each_string_list_item(item, &exclude_patterns)
+				argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 		}
 		if (argc)
 			argv_array_pushv(&args, argv);
@@ -456,7 +497,28 @@
 		die(_("No names found, cannot describe anything."));
 
 	if (argc == 0) {
-		if (dirty) {
+		if (broken) {
+			struct child_process cp = CHILD_PROCESS_INIT;
+			argv_array_pushv(&cp.args, diff_index_args);
+			cp.git_cmd = 1;
+			cp.no_stdin = 1;
+			cp.no_stdout = 1;
+
+			if (!dirty)
+				dirty = "-dirty";
+
+			switch (run_command(&cp)) {
+			case 0:
+				suffix = NULL;
+				break;
+			case 1:
+				suffix = dirty;
+				break;
+			default:
+				/* diff-index aborted abnormally */
+				suffix = broken;
+			}
+		} else if (dirty) {
 			static struct lock_file index_lock;
 			int fd;
 
@@ -469,11 +531,15 @@
 
 			if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 					    diff_index_args, prefix))
-				dirty = NULL;
+				suffix = NULL;
+			else
+				suffix = dirty;
 		}
 		describe("HEAD", 1);
 	} else if (dirty) {
 		die(_("--dirty is incompatible with commit-ishes"));
+	} else if (broken) {
+		die(_("--broken is incompatible with commit-ishes"));
 	} else {
 		while (argc-- > 0)
 			describe(*argv++, argc == 0);
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 8ce0048..326f88b 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -7,46 +7,44 @@
 
 static struct rev_info log_tree_opt;
 
-static int diff_tree_commit_sha1(const unsigned char *sha1)
+static int diff_tree_commit_sha1(const struct object_id *oid)
 {
-	struct commit *commit = lookup_commit_reference(sha1);
+	struct commit *commit = lookup_commit_reference(oid->hash);
 	if (!commit)
 		return -1;
 	return log_tree_commit(&log_tree_opt, commit);
 }
 
 /* Diff one or more commits. */
-static int stdin_diff_commit(struct commit *commit, char *line, int len)
+static int stdin_diff_commit(struct commit *commit, const char *p)
 {
-	unsigned char sha1[20];
-	if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
-		/* Graft the fake parents locally to the commit */
-		int pos = 41;
-		struct commit_list **pptr;
+	struct object_id oid;
+	struct commit_list **pptr = NULL;
 
-		/* Free the real parent list */
-		free_commit_list(commit->parents);
-		commit->parents = NULL;
-		pptr = &(commit->parents);
-		while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
-			struct commit *parent = lookup_commit(sha1);
-			if (parent) {
-				pptr = &commit_list_insert(parent, pptr)->next;
-			}
-			pos += 41;
+	/* Graft the fake parents locally to the commit */
+	while (isspace(*p++) && !parse_oid_hex(p, &oid, &p)) {
+		struct commit *parent = lookup_commit(oid.hash);
+		if (!pptr) {
+			/* Free the real parent list */
+			free_commit_list(commit->parents);
+			commit->parents = NULL;
+			pptr = &(commit->parents);
+		}
+		if (parent) {
+			pptr = &commit_list_insert(parent, pptr)->next;
 		}
 	}
 	return log_tree_commit(&log_tree_opt, commit);
 }
 
 /* Diff two trees. */
-static int stdin_diff_trees(struct tree *tree1, char *line, int len)
+static int stdin_diff_trees(struct tree *tree1, const char *p)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct tree *tree2;
-	if (len != 82 || !isspace(line[40]) || get_sha1_hex(line + 41, sha1))
+	if (!isspace(*p++) || parse_oid_hex(p, &oid, &p) || *p)
 		return error("Need exactly two trees, separated by a space");
-	tree2 = lookup_tree(sha1);
+	tree2 = lookup_tree(oid.hash);
 	if (!tree2 || parse_tree(tree2))
 		return -1;
 	printf("%s %s\n", oid_to_hex(&tree1->object.oid),
@@ -60,23 +58,24 @@
 static int diff_tree_stdin(char *line)
 {
 	int len = strlen(line);
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct object *obj;
+	const char *p;
 
 	if (!len || line[len-1] != '\n')
 		return -1;
 	line[len-1] = 0;
-	if (get_sha1_hex(line, sha1))
+	if (parse_oid_hex(line, &oid, &p))
 		return -1;
-	obj = parse_object(sha1);
+	obj = parse_object(oid.hash);
 	if (!obj)
 		return -1;
 	if (obj->type == OBJ_COMMIT)
-		return stdin_diff_commit((struct commit *)obj, line, len);
+		return stdin_diff_commit((struct commit *)obj, p);
 	if (obj->type == OBJ_TREE)
-		return stdin_diff_trees((struct tree *)obj, line, len);
+		return stdin_diff_trees((struct tree *)obj, p);
 	error("Object %s is a %s, not a commit or tree",
-	      sha1_to_hex(sha1), typename(obj->type));
+	      oid_to_hex(&oid), typename(obj->type));
 	return -1;
 }
 
@@ -141,7 +140,7 @@
 		break;
 	case 1:
 		tree1 = opt->pending.objects[0].item;
-		diff_tree_commit_sha1(tree1->oid.hash);
+		diff_tree_commit_sha1(&tree1->oid);
 		break;
 	case 2:
 		tree1 = opt->pending.objects[0].item;
@@ -164,9 +163,9 @@
 			opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
 					       DIFF_SETUP_USE_CACHE);
 		while (fgets(line, sizeof(line), stdin)) {
-			unsigned char sha1[20];
+			struct object_id oid;
 
-			if (get_sha1_hex(line, sha1)) {
+			if (get_oid_hex(line, &oid)) {
 				fputs(line, stdout);
 				fflush(stdout);
 			}
diff --git a/builtin/difftool.c b/builtin/difftool.c
index d13350c..25e54ad 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -254,6 +254,49 @@
 	}
 }
 
+/*
+ * Unconditional writing of a plain regular file is what
+ * "git difftool --dir-diff" wants to do for symlinks.  We are preparing two
+ * temporary directories to be fed to a Git-unaware tool that knows how to
+ * show a diff of two directories (e.g. "diff -r A B").
+ *
+ * Because the tool is Git-unaware, if a symbolic link appears in either of
+ * these temporary directories, it will try to dereference and show the
+ * difference of the target of the symbolic link, which is not what we want,
+ * as the goal of the dir-diff mode is to produce an output that is logically
+ * equivalent to what "git diff" produces.
+ *
+ * Most importantly, we want to get textual comparison of the result of the
+ * readlink(2).  get_symlink() provides that---it returns the contents of
+ * the symlink that gets written to a regular file to force the external tool
+ * to compare the readlink(2) result as text, even on a filesystem that is
+ * capable of doing a symbolic link.
+ */
+static char *get_symlink(const struct object_id *oid, const char *path)
+{
+	char *data;
+	if (is_null_oid(oid)) {
+		/* The symlink is unknown to Git so read from the filesystem */
+		struct strbuf link = STRBUF_INIT;
+		if (has_symlinks) {
+			if (strbuf_readlink(&link, path, strlen(path)))
+				die(_("could not read symlink %s"), path);
+		} else if (strbuf_read_file(&link, path, 128))
+			die(_("could not read symlink file %s"), path);
+
+		data = strbuf_detach(&link, NULL);
+	} else {
+		enum object_type type;
+		unsigned long size;
+		data = read_sha1_file(oid->hash, &type, &size);
+		if (!data)
+			die(_("could not read object %s for symlink %s"),
+				oid_to_hex(oid), path);
+	}
+
+	return data;
+}
+
 static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 			int argc, const char **argv)
 {
@@ -270,8 +313,6 @@
 	struct hashmap working_tree_dups, submodules, symlinks2;
 	struct hashmap_iter iter;
 	struct pair_entry *entry;
-	enum object_type type;
-	unsigned long size;
 	struct index_state wtindex;
 	struct checkout lstate, rstate;
 	int rc, flags = RUN_GIT_CMD, err = 0;
@@ -377,13 +418,13 @@
 		}
 
 		if (S_ISLNK(lmode)) {
-			char *content = read_sha1_file(loid.hash, &type, &size);
+			char *content = get_symlink(&loid, src_path);
 			add_left_or_right(&symlinks2, src_path, content, 0);
 			free(content);
 		}
 
 		if (S_ISLNK(rmode)) {
-			char *content = read_sha1_file(roid.hash, &type, &size);
+			char *content = get_symlink(&roid, dst_path);
 			add_left_or_right(&symlinks2, dst_path, content, 1);
 			free(content);
 		}
@@ -397,7 +438,7 @@
 				return error("could not write '%s'", src_path);
 		}
 
-		if (rmode) {
+		if (rmode && !S_ISLNK(rmode)) {
 			struct working_tree_entry *entry;
 
 			/* Avoid duplicate working_tree entries */
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 1e815b5..e022063 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -212,7 +212,7 @@
 	return strbuf_detach(&out, NULL);
 }
 
-static void export_blob(const unsigned char *sha1)
+static void export_blob(const struct object_id *oid)
 {
 	unsigned long size;
 	enum object_type type;
@@ -223,34 +223,34 @@
 	if (no_data)
 		return;
 
-	if (is_null_sha1(sha1))
+	if (is_null_oid(oid))
 		return;
 
-	object = lookup_object(sha1);
+	object = lookup_object(oid->hash);
 	if (object && object->flags & SHOWN)
 		return;
 
 	if (anonymize) {
 		buf = anonymize_blob(&size);
-		object = (struct object *)lookup_blob(sha1);
+		object = (struct object *)lookup_blob(oid->hash);
 		eaten = 0;
 	} else {
-		buf = read_sha1_file(sha1, &type, &size);
+		buf = read_sha1_file(oid->hash, &type, &size);
 		if (!buf)
-			die ("Could not read blob %s", sha1_to_hex(sha1));
-		if (check_sha1_signature(sha1, buf, size, typename(type)) < 0)
-			die("sha1 mismatch in blob %s", sha1_to_hex(sha1));
-		object = parse_object_buffer(sha1, type, size, buf, &eaten);
+			die ("Could not read blob %s", oid_to_hex(oid));
+		if (check_sha1_signature(oid->hash, buf, size, typename(type)) < 0)
+			die("sha1 mismatch in blob %s", oid_to_hex(oid));
+		object = parse_object_buffer(oid->hash, type, size, buf, &eaten);
 	}
 
 	if (!object)
-		die("Could not read blob %s", sha1_to_hex(sha1));
+		die("Could not read blob %s", oid_to_hex(oid));
 
 	mark_next_object(object);
 
 	printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 	if (size && fwrite(buf, size, 1, stdout) != 1)
-		die_errno ("Could not write blob '%s'", sha1_to_hex(sha1));
+		die_errno ("Could not write blob '%s'", oid_to_hex(oid));
 	printf("\n");
 
 	show_progress();
@@ -323,19 +323,19 @@
 	}
 }
 
-static void *generate_fake_sha1(const void *old, size_t *len)
+static void *generate_fake_oid(const void *old, size_t *len)
 {
 	static uint32_t counter = 1; /* avoid null sha1 */
-	unsigned char *out = xcalloc(20, 1);
-	put_be32(out + 16, counter++);
+	unsigned char *out = xcalloc(GIT_SHA1_RAWSZ, 1);
+	put_be32(out + GIT_SHA1_RAWSZ - 4, counter++);
 	return out;
 }
 
-static const unsigned char *anonymize_sha1(const unsigned char *sha1)
+static const unsigned char *anonymize_sha1(const struct object_id *oid)
 {
 	static struct hashmap sha1s;
-	size_t len = 20;
-	return anonymize_mem(&sha1s, generate_fake_sha1, sha1, &len);
+	size_t len = GIT_SHA1_RAWSZ;
+	return anonymize_mem(&sha1s, generate_fake_oid, oid, &len);
 }
 
 static void show_filemodify(struct diff_queue_struct *q,
@@ -383,7 +383,7 @@
 			if (no_data || S_ISGITLINK(spec->mode))
 				printf("M %06o %s ", spec->mode,
 				       sha1_to_hex(anonymize ?
-						   anonymize_sha1(spec->oid.hash) :
+						   anonymize_sha1(&spec->oid) :
 						   spec->oid.hash));
 			else {
 				struct object *object = lookup_object(spec->oid.hash);
@@ -572,7 +572,7 @@
 	/* Export the referenced blobs, and remember the marks. */
 	for (i = 0; i < diff_queued_diff.nr; i++)
 		if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
-			export_blob(diff_queued_diff.queue[i]->two->oid.hash);
+			export_blob(&diff_queued_diff.queue[i]->two->oid);
 
 	refname = commit->util;
 	if (anonymize) {
@@ -797,14 +797,14 @@
 
 	for (i = 0; i < info->nr; i++) {
 		struct rev_cmdline_entry *e = info->rev + i;
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct commit *commit;
 		char *full_name;
 
 		if (e->flags & UNINTERESTING)
 			continue;
 
-		if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
+		if (dwim_ref(e->name, strlen(e->name), oid.hash, &full_name) != 1)
 			continue;
 
 		if (refspecs) {
@@ -828,7 +828,7 @@
 		case OBJ_COMMIT:
 			break;
 		case OBJ_BLOB:
-			export_blob(commit->object.oid.hash);
+			export_blob(&commit->object.oid);
 			continue;
 		default: /* OBJ_TAG (nested tags) is already handled */
 			warning("Tag points to object of unexpected type %s, skipping.",
@@ -912,7 +912,7 @@
 	while (fgets(line, sizeof(line), f)) {
 		uint32_t mark;
 		char *line_end, *mark_end;
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct object *object;
 		struct commit *commit;
 		enum object_type type;
@@ -924,28 +924,28 @@
 
 		mark = strtoumax(line + 1, &mark_end, 10);
 		if (!mark || mark_end == line + 1
-			|| *mark_end != ' ' || get_sha1_hex(mark_end + 1, sha1))
+			|| *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 			die("corrupt mark line: %s", line);
 
 		if (last_idnum < mark)
 			last_idnum = mark;
 
-		type = sha1_object_info(sha1, NULL);
+		type = sha1_object_info(oid.hash, NULL);
 		if (type < 0)
-			die("object not found: %s", sha1_to_hex(sha1));
+			die("object not found: %s", oid_to_hex(&oid));
 
 		if (type != OBJ_COMMIT)
 			/* only commits */
 			continue;
 
-		commit = lookup_commit(sha1);
+		commit = lookup_commit(oid.hash);
 		if (!commit)
-			die("not a commit? can't happen: %s", sha1_to_hex(sha1));
+			die("not a commit? can't happen: %s", oid_to_hex(&oid));
 
 		object = &commit->object;
 
 		if (object->flags & SHOWN)
-			error("Object %s already has a mark", sha1_to_hex(sha1));
+			error("Object %s already has a mark", oid_to_hex(&oid));
 
 		mark_object(object, mark);
 
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index efab62f..6faa3c0 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -41,7 +41,7 @@
 };
 
 struct origin_data {
-	unsigned char sha1[20];
+	struct object_id oid;
 	unsigned is_local_branch:1;
 };
 
@@ -59,8 +59,8 @@
 struct merge_parents {
 	int alloc, nr;
 	struct merge_parent {
-		unsigned char given[20];
-		unsigned char commit[20];
+		struct object_id given;
+		struct object_id commit;
 		unsigned char used;
 	} *item;
 };
@@ -70,14 +70,14 @@
  * hundreds of heads at a time anyway.
  */
 static struct merge_parent *find_merge_parent(struct merge_parents *table,
-					      unsigned char *given,
-					      unsigned char *commit)
+					      struct object_id *given,
+					      struct object_id *commit)
 {
 	int i;
 	for (i = 0; i < table->nr; i++) {
-		if (given && hashcmp(table->item[i].given, given))
+		if (given && oidcmp(&table->item[i].given, given))
 			continue;
-		if (commit && hashcmp(table->item[i].commit, commit))
+		if (commit && oidcmp(&table->item[i].commit, commit))
 			continue;
 		return &table->item[i];
 	}
@@ -85,14 +85,14 @@
 }
 
 static void add_merge_parent(struct merge_parents *table,
-			     unsigned char *given,
-			     unsigned char *commit)
+			     struct object_id *given,
+			     struct object_id *commit)
 {
 	if (table->nr && find_merge_parent(table, given, commit))
 		return;
 	ALLOC_GROW(table->item, table->nr + 1, table->alloc);
-	hashcpy(table->item[table->nr].given, given);
-	hashcpy(table->item[table->nr].commit, commit);
+	oidcpy(&table->item[table->nr].given, given);
+	oidcpy(&table->item[table->nr].commit, commit);
 	table->item[table->nr].used = 0;
 	table->nr++;
 }
@@ -106,30 +106,30 @@
 	struct src_data *src_data;
 	struct string_list_item *item;
 	int pulling_head = 0;
-	unsigned char sha1[20];
+	struct object_id oid;
 
-	if (len < 43 || line[40] != '\t')
+	if (len < GIT_SHA1_HEXSZ + 3 || line[GIT_SHA1_HEXSZ] != '\t')
 		return 1;
 
-	if (starts_with(line + 41, "not-for-merge"))
+	if (starts_with(line + GIT_SHA1_HEXSZ + 1, "not-for-merge"))
 		return 0;
 
-	if (line[41] != '\t')
+	if (line[GIT_SHA1_HEXSZ + 1] != '\t')
 		return 2;
 
-	i = get_sha1_hex(line, sha1);
+	i = get_oid_hex(line, &oid);
 	if (i)
 		return 3;
 
-	if (!find_merge_parent(merge_parents, sha1, NULL))
+	if (!find_merge_parent(merge_parents, &oid, NULL))
 		return 0; /* subsumed by other parents */
 
 	origin_data = xcalloc(1, sizeof(struct origin_data));
-	hashcpy(origin_data->sha1, sha1);
+	oidcpy(&origin_data->oid, &oid);
 
 	if (line[len - 1] == '\n')
 		line[len - 1] = 0;
-	line += 42;
+	line += GIT_SHA1_HEXSZ + 2;
 
 	/*
 	 * At this point, line points at the beginning of comment e.g.
@@ -338,10 +338,10 @@
 	struct string_list committers = STRING_LIST_INIT_DUP;
 	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 	struct strbuf sb = STRBUF_INIT;
-	const unsigned char *sha1 = origin_data->sha1;
+	const struct object_id *oid = &origin_data->oid;
 	int limit = opts->shortlog_len;
 
-	branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
+	branch = deref_tag(parse_object(oid->hash), oid_to_hex(oid), GIT_SHA1_HEXSZ);
 	if (!branch || branch->type != OBJ_COMMIT)
 		return;
 
@@ -531,7 +531,7 @@
 }
 
 static void find_merge_parents(struct merge_parents *result,
-			       struct strbuf *in, unsigned char *head)
+			       struct strbuf *in, struct object_id *head)
 {
 	struct commit_list *parents;
 	struct commit *head_commit;
@@ -542,31 +542,31 @@
 		int len;
 		char *p = in->buf + pos;
 		char *newline = strchr(p, '\n');
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct commit *parent;
 		struct object *obj;
 
 		len = newline ? newline - p : strlen(p);
 		pos += len + !!newline;
 
-		if (len < 43 ||
-		    get_sha1_hex(p, sha1) ||
-		    p[40] != '\t' ||
-		    p[41] != '\t')
+		if (len < GIT_SHA1_HEXSZ + 3 ||
+		    get_oid_hex(p, &oid) ||
+		    p[GIT_SHA1_HEXSZ] != '\t' ||
+		    p[GIT_SHA1_HEXSZ + 1] != '\t')
 			continue; /* skip not-for-merge */
 		/*
 		 * Do not use get_merge_parent() here; we do not have
 		 * "name" here and we do not want to contaminate its
 		 * util field yet.
 		 */
-		obj = parse_object(sha1);
+		obj = parse_object(oid.hash);
 		parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 		if (!parent)
 			continue;
 		commit_list_insert(parent, &parents);
-		add_merge_parent(result, obj->oid.hash, parent->object.oid.hash);
+		add_merge_parent(result, &obj->oid, &parent->object.oid);
 	}
-	head_commit = lookup_commit(head);
+	head_commit = lookup_commit(head->hash);
 	if (head_commit)
 		commit_list_insert(head_commit, &parents);
 	parents = reduce_heads(parents);
@@ -574,7 +574,7 @@
 	while (parents) {
 		struct commit *cmit = pop_commit(&parents);
 		for (i = 0; i < result->nr; i++)
-			if (!hashcmp(result->item[i].commit, cmit->object.oid.hash))
+			if (!oidcmp(&result->item[i].commit, &cmit->object.oid))
 				result->item[i].used = 1;
 	}
 
@@ -592,7 +592,7 @@
 		  struct fmt_merge_msg_opts *opts)
 {
 	int i = 0, pos = 0;
-	unsigned char head_sha1[20];
+	struct object_id head_oid;
 	const char *current_branch;
 	void *current_branch_to_free;
 	struct merge_parents merge_parents;
@@ -601,13 +601,13 @@
 
 	/* get current branch */
 	current_branch = current_branch_to_free =
-		resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
+		resolve_refdup("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL);
 	if (!current_branch)
 		die("No current branch");
 	if (starts_with(current_branch, "refs/heads/"))
 		current_branch += 11;
 
-	find_merge_parents(&merge_parents, in, head_sha1);
+	find_merge_parents(&merge_parents, in, &head_oid);
 
 	/* get a line */
 	while (pos < in->len) {
@@ -633,7 +633,7 @@
 		struct commit *head;
 		struct rev_info rev;
 
-		head = lookup_commit_or_die(head_sha1, "HEAD");
+		head = lookup_commit_or_die(head_oid.hash, "HEAD");
 		init_revisions(&rev, NULL);
 		rev.commit_format = CMIT_FMT_ONELINE;
 		rev.ignore_merges = 1;
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 1a5cacc..f76e416 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -396,13 +396,13 @@
 
 static int default_refs;
 
-static void fsck_handle_reflog_sha1(const char *refname, unsigned char *sha1,
+static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
 	unsigned long timestamp)
 {
 	struct object *obj;
 
-	if (!is_null_sha1(sha1)) {
-		obj = lookup_object(sha1);
+	if (!is_null_oid(oid)) {
+		obj = lookup_object(oid->hash);
 		if (obj && (obj->flags & HAS_OBJ)) {
 			if (timestamp && name_objects)
 				add_decoration(fsck_walk_options.object_names,
@@ -411,13 +411,13 @@
 			obj->used = 1;
 			mark_object_reachable(obj);
 		} else {
-			error("%s: invalid reflog entry %s", refname, sha1_to_hex(sha1));
+			error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
 			errors_found |= ERROR_REACHABLE;
 		}
 	}
 }
 
-static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
@@ -425,10 +425,10 @@
 
 	if (verbose)
 		fprintf(stderr, "Checking reflog %s->%s\n",
-			sha1_to_hex(osha1), sha1_to_hex(nsha1));
+			oid_to_hex(ooid), oid_to_hex(noid));
 
-	fsck_handle_reflog_sha1(refname, osha1, 0);
-	fsck_handle_reflog_sha1(refname, nsha1, timestamp);
+	fsck_handle_reflog_oid(refname, ooid, 0);
+	fsck_handle_reflog_oid(refname, noid, timestamp);
 	return 0;
 }
 
@@ -491,7 +491,7 @@
 	}
 }
 
-static struct object *parse_loose_object(const unsigned char *sha1,
+static struct object *parse_loose_object(const struct object_id *oid,
 					 const char *path)
 {
 	struct object *obj;
@@ -500,27 +500,27 @@
 	unsigned long size;
 	int eaten;
 
-	if (read_loose_object(path, sha1, &type, &size, &contents) < 0)
+	if (read_loose_object(path, oid->hash, &type, &size, &contents) < 0)
 		return NULL;
 
 	if (!contents && type != OBJ_BLOB)
 		die("BUG: read_loose_object streamed a non-blob");
 
-	obj = parse_object_buffer(sha1, type, size, contents, &eaten);
+	obj = parse_object_buffer(oid->hash, type, size, contents, &eaten);
 
 	if (!eaten)
 		free(contents);
 	return obj;
 }
 
-static int fsck_loose(const unsigned char *sha1, const char *path, void *data)
+static int fsck_loose(const struct object_id *oid, const char *path, void *data)
 {
-	struct object *obj = parse_loose_object(sha1, path);
+	struct object *obj = parse_loose_object(oid, path);
 
 	if (!obj) {
 		errors_found |= ERROR_OBJECT;
 		error("%s: object corrupt or missing: %s",
-		      sha1_to_hex(sha1), path);
+		      oid_to_hex(oid), path);
 		return 0; /* keep checking other objects */
 	}
 
@@ -619,26 +619,26 @@
 	return err;
 }
 
-static void mark_object_for_connectivity(const unsigned char *sha1)
+static void mark_object_for_connectivity(const struct object_id *oid)
 {
-	struct object *obj = lookup_unknown_object(sha1);
+	struct object *obj = lookup_unknown_object(oid->hash);
 	obj->flags |= HAS_OBJ;
 }
 
-static int mark_loose_for_connectivity(const unsigned char *sha1,
+static int mark_loose_for_connectivity(const struct object_id *oid,
 				       const char *path,
 				       void *data)
 {
-	mark_object_for_connectivity(sha1);
+	mark_object_for_connectivity(oid);
 	return 0;
 }
 
-static int mark_packed_for_connectivity(const unsigned char *sha1,
+static int mark_packed_for_connectivity(const struct object_id *oid,
 					struct packed_git *pack,
 					uint32_t pos,
 					void *data)
 {
-	mark_object_for_connectivity(sha1);
+	mark_object_for_connectivity(oid);
 	return 0;
 }
 
diff --git a/builtin/gc.c b/builtin/gc.c
index a2b9e89..c2c61a5 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -64,17 +64,6 @@
 		string_list_append(&pack_garbage, path);
 }
 
-static void git_config_date_string(const char *key, const char **output)
-{
-	if (git_config_get_string_const(key, output))
-		return;
-	if (strcmp(*output, "now")) {
-		unsigned long now = approxidate("now");
-		if (approxidate(*output) >= now)
-			git_die_config(key, _("Invalid %s: '%s'"), key, *output);
-	}
-}
-
 static void process_log_file(void)
 {
 	struct stat st;
@@ -131,9 +120,9 @@
 	git_config_get_int("gc.auto", &gc_auto_threshold);
 	git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
 	git_config_get_bool("gc.autodetach", &detach_auto);
-	git_config_date_string("gc.pruneexpire", &prune_expire);
-	git_config_date_string("gc.worktreepruneexpire", &prune_worktrees_expire);
-	git_config_date_string("gc.logexpiry", &gc_log_expire);
+	git_config_get_expiry("gc.pruneexpire", &prune_expire);
+	git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
+	git_config_get_expiry("gc.logexpiry", &gc_log_expire);
 
 	git_config(git_default_config, NULL);
 }
diff --git a/builtin/grep.c b/builtin/grep.c
index 9304c33..3f3efa9 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -294,17 +294,17 @@
 	return st;
 }
 
-static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
+static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
 {
 	void *data;
 
 	grep_read_lock();
-	data = read_sha1_file(sha1, type, size);
+	data = read_sha1_file(oid->hash, type, size);
 	grep_read_unlock();
 	return data;
 }
 
-static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
+static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 		     const char *filename, int tree_name_len,
 		     const char *path)
 {
@@ -323,7 +323,7 @@
 
 #ifndef NO_PTHREADS
 	if (num_threads) {
-		add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
+		add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
 		strbuf_release(&pathbuf);
 		return 0;
 	} else
@@ -332,7 +332,7 @@
 		struct grep_source gs;
 		int hit;
 
-		grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
+		grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
 		strbuf_release(&pathbuf);
 		hit = grep_source(opt, &gs);
 
@@ -538,7 +538,7 @@
 	int status, i;
 	const char *end_of_base;
 	const char *name;
-	struct work_item *w = opt->output_priv;
+	struct strbuf child_output = STRBUF_INIT;
 
 	end_of_base = strchr(gs->name, ':');
 	if (gs->identifier && end_of_base)
@@ -593,14 +593,16 @@
 	 * child process.  A '0' indicates a hit, a '1' indicates no hit and
 	 * anything else is an error.
 	 */
-	status = capture_command(&cp, &w->out, 0);
+	status = capture_command(&cp, &child_output, 0);
 	if (status && (status != 1)) {
 		/* flush the buffer */
-		write_or_die(1, w->out.buf, w->out.len);
+		write_or_die(1, child_output.buf, child_output.len);
 		die("process for submodule '%s' failed with exit code: %d",
 		    gs->name, status);
 	}
 
+	opt->output(opt, child_output.buf, child_output.len);
+	strbuf_release(&child_output);
 	/* invert the return code to make a hit equal to 1 */
 	return !status;
 }
@@ -616,7 +618,7 @@
 {
 	if (!is_submodule_initialized(path))
 		return 0;
-	if (!is_submodule_populated(path)) {
+	if (!is_submodule_populated_gently(path, NULL)) {
 		/*
 		 * If searching history, check for the presense of the
 		 * submodule's gitdir before skipping the submodule.
@@ -641,19 +643,14 @@
 	} else
 #endif
 	{
-		struct work_item w;
+		struct grep_source gs;
 		int hit;
 
-		grep_source_init(&w.source, GREP_SOURCE_SUBMODULE,
+		grep_source_init(&gs, GREP_SOURCE_SUBMODULE,
 				 filename, path, sha1);
-		strbuf_init(&w.out, 0);
-		opt->output_priv = &w;
-		hit = grep_submodule_launch(opt, &w.source);
+		hit = grep_submodule_launch(opt, &gs);
 
-		write_or_die(1, w.out.buf, w.out.len);
-
-		grep_source_clear(&w.source);
-		strbuf_release(&w.out);
+		grep_source_clear(&gs);
 		return hit;
 	}
 }
@@ -690,7 +687,7 @@
 			    ce_skip_worktree(ce)) {
 				if (ce_stage(ce) || ce_intent_to_add(ce))
 					continue;
-				hit |= grep_sha1(opt, ce->oid.hash, ce->name,
+				hit |= grep_oid(opt, &ce->oid, ce->name,
 						 0, ce->name);
 			} else {
 				hit |= grep_file(opt, ce->name);
@@ -750,7 +747,7 @@
 		strbuf_add(base, entry.path, te_len);
 
 		if (S_ISREG(entry.mode)) {
-			hit |= grep_sha1(opt, entry.oid->hash, 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;
@@ -758,7 +755,7 @@
 			void *data;
 			unsigned long size;
 
-			data = lock_and_read_sha1_file(entry.oid->hash, &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));
@@ -787,7 +784,7 @@
 		       struct object *obj, const char *name, const char *path)
 {
 	if (obj->type == OBJ_BLOB)
-		return grep_sha1(opt, obj->oid.hash, name, 0, path);
+		return grep_oid(opt, &obj->oid, name, 0, path);
 	if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 		struct tree_desc tree;
 		void *data;
@@ -1169,7 +1166,7 @@
 	allow_revs = use_index && !untracked;
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct object_context oc;
 		struct object *object;
 
@@ -1184,13 +1181,13 @@
 			break;
 		}
 
-		if (get_sha1_with_context(arg, 0, sha1, &oc)) {
+		if (get_sha1_with_context(arg, 0, oid.hash, &oc)) {
 			if (seen_dashdash)
 				die(_("unable to resolve revision: %s"), arg);
 			break;
 		}
 
-		object = parse_object_or_die(sha1, arg);
+		object = parse_object_or_die(oid.hash, arg);
 		if (!seen_dashdash)
 			verify_non_filename(prefix, arg);
 		add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index 9028e1f..bbeaf20 100644
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c
@@ -102,7 +102,6 @@
 		OPT_END()
 	};
 	int i;
-	int prefix_length = -1;
 	const char *errstr = NULL;
 
 	argc = parse_options(argc, argv, NULL, hash_object_options,
@@ -113,9 +112,8 @@
 	else
 		prefix = setup_git_directory_gently(&nongit);
 
-	prefix_length = prefix ? strlen(prefix) : 0;
 	if (vpath && prefix)
-		vpath = prefix_filename(prefix, prefix_length, vpath);
+		vpath = xstrdup(prefix_filename(prefix, vpath));
 
 	git_config(git_default_config, NULL);
 
@@ -144,11 +142,13 @@
 
 	for (i = 0 ; i < argc; i++) {
 		const char *arg = argv[i];
+		char *to_free = NULL;
 
-		if (0 <= prefix_length)
-			arg = prefix_filename(prefix, prefix_length, arg);
+		if (prefix)
+			arg = to_free = prefix_filename(prefix, arg);
 		hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 			    flags, literally);
+		free(to_free);
 	}
 
 	if (stdin_paths)
diff --git a/builtin/log.c b/builtin/log.c
index 55d20cc..670229c 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -989,8 +989,7 @@
 	    open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
 		return;
 
-	log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
-				&need_8bit_cte);
+	log_write_email_headers(rev, head, &pp.after_subject, &need_8bit_cte);
 
 	for (i = 0; !need_8bit_cte && i < nr; i++) {
 		const char *buf = get_commit_buffer(list[i], NULL);
@@ -1005,6 +1004,8 @@
 	msg = body;
 	pp.fmt = CMIT_FMT_EMAIL;
 	pp.date_mode.type = DATE_RFC2822;
+	pp.rev = rev;
+	pp.print_email_subject = 1;
 	pp_user_info(&pp, NULL, &sb, committer, encoding);
 	pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 	pp_remainder(&pp, &msg, &sb, 0);
@@ -1083,8 +1084,7 @@
 	if (!output_directory)
 		return prefix;
 
-	return xstrdup(prefix_filename(prefix, outdir_offset,
-				       output_directory));
+	return prefix_filename(prefix, output_directory);
 }
 
 static const char * const builtin_format_patch_usage[] = {
diff --git a/builtin/mailinfo.c b/builtin/mailinfo.c
index e3b62f2..cfb667a 100644
--- a/builtin/mailinfo.c
+++ b/builtin/mailinfo.c
@@ -11,13 +11,6 @@
 static const char mailinfo_usage[] =
 	"git mailinfo [-k | -b] [-m | --message-id] [-u | --encoding=<encoding> | -n] [--scissors | --no-scissors] <msg> <patch> < mail >info";
 
-static char *prefix_copy(const char *prefix, const char *filename)
-{
-	if (!prefix || is_absolute_path(filename))
-		return xstrdup(filename);
-	return xstrdup(prefix_filename(prefix, strlen(prefix), filename));
-}
-
 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 {
 	const char *def_charset;
@@ -60,8 +53,8 @@
 	mi.input = stdin;
 	mi.output = stdout;
 
-	msgfile = prefix_copy(prefix, argv[1]);
-	patchfile = prefix_copy(prefix, argv[2]);
+	msgfile = prefix_filename(prefix, argv[1]);
+	patchfile = prefix_filename(prefix, argv[2]);
 
 	status = !!mailinfo(&mi, msgfile, patchfile);
 	clear_mailinfo(&mi);
diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index b572a37..cfe2a79 100644
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -36,12 +36,12 @@
 
 static struct commit *get_commit_reference(const char *arg)
 {
-	unsigned char revkey[20];
+	struct object_id revkey;
 	struct commit *r;
 
-	if (get_sha1(arg, revkey))
+	if (get_oid(arg, &revkey))
 		die("Not a valid object name %s", arg);
-	r = lookup_commit_reference(revkey);
+	r = lookup_commit_reference(revkey.hash);
 	if (!r)
 		die("Not a valid commit name %s", arg);
 
@@ -113,14 +113,14 @@
 	unsigned int initial : 1;
 };
 
-static void add_one_commit(unsigned char *sha1, struct rev_collect *revs)
+static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
 {
 	struct commit *commit;
 
-	if (is_null_sha1(sha1))
+	if (is_null_oid(oid))
 		return;
 
-	commit = lookup_commit(sha1);
+	commit = lookup_commit(oid->hash);
 	if (!commit ||
 	    (commit->object.flags & TMP_MARK) ||
 	    parse_commit(commit))
@@ -131,7 +131,7 @@
 	commit->object.flags |= TMP_MARK;
 }
 
-static int collect_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 				  const char *ident, unsigned long timestamp,
 				  int tz, const char *message, void *cbdata)
 {
@@ -139,15 +139,15 @@
 
 	if (revs->initial) {
 		revs->initial = 0;
-		add_one_commit(osha1, revs);
+		add_one_commit(ooid, revs);
 	}
-	add_one_commit(nsha1, revs);
+	add_one_commit(noid, revs);
 	return 0;
 }
 
 static int handle_fork_point(int argc, const char **argv)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *refname;
 	const char *commitname;
 	struct rev_collect revs;
@@ -155,7 +155,7 @@
 	struct commit_list *bases;
 	int i, ret = 0;
 
-	switch (dwim_ref(argv[0], strlen(argv[0]), sha1, &refname)) {
+	switch (dwim_ref(argv[0], strlen(argv[0]), oid.hash, &refname)) {
 	case 0:
 		die("No such ref: '%s'", argv[0]);
 	case 1:
@@ -165,16 +165,16 @@
 	}
 
 	commitname = (argc == 2) ? argv[1] : "HEAD";
-	if (get_sha1(commitname, sha1))
+	if (get_oid(commitname, &oid))
 		die("Not a valid object name: '%s'", commitname);
 
-	derived = lookup_commit_reference(sha1);
+	derived = lookup_commit_reference(oid.hash);
 	memset(&revs, 0, sizeof(revs));
 	revs.initial = 1;
 	for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
 
-	if (!revs.nr && !get_sha1(refname, sha1))
-		add_one_commit(sha1, &revs);
+	if (!revs.nr && !get_oid(refname, &oid))
+		add_one_commit(&oid, &revs);
 
 	for (i = 0; i < revs.nr; i++)
 		revs.commit[i]->object.flags &= ~TMP_MARK;
diff --git a/builtin/merge-file.c b/builtin/merge-file.c
index 13e22a2..47dde7c 100644
--- a/builtin/merge-file.c
+++ b/builtin/merge-file.c
@@ -28,7 +28,6 @@
 	xmparam_t xmp = {{0}};
 	int ret = 0, i = 0, to_stdout = 0;
 	int quiet = 0;
-	int prefixlen = 0;
 	struct option options[] = {
 		OPT_BOOL('p', "stdout", &to_stdout, N_("send results to standard output")),
 		OPT_SET_INT(0, "diff3", &xmp.style, N_("use a diff3 based merge"), XDL_MERGE_DIFF3),
@@ -65,15 +64,19 @@
 			return error_errno("failed to redirect stderr to /dev/null");
 	}
 
-	if (prefix)
-		prefixlen = strlen(prefix);
-
 	for (i = 0; i < 3; i++) {
-		const char *fname = prefix_filename(prefix, prefixlen, argv[i]);
+		char *fname;
+		int ret;
+
 		if (!names[i])
 			names[i] = argv[i];
-		if (read_mmfile(mmfs + i, fname))
+
+		fname = prefix_filename(prefix, argv[i]);
+		ret = read_mmfile(mmfs + i, fname);
+		free(fname);
+		if (ret)
 			return -1;
+
 		if (mmfs[i].size > MAX_XDIFF_SIZE ||
 		    buffer_is_binary(mmfs[i].ptr, mmfs[i].size))
 			return error("Cannot merge binary files: %s",
@@ -90,7 +93,7 @@
 
 	if (ret >= 0) {
 		const char *filename = argv[0];
-		const char *fpath = prefix_filename(prefix, prefixlen, argv[0]);
+		char *fpath = prefix_filename(prefix, argv[0]);
 		FILE *f = to_stdout ? stdout : fopen(fpath, "wb");
 
 		if (!f)
@@ -102,6 +105,7 @@
 		else if (fclose(f))
 			ret = error_errno("Could not close %s", filename);
 		free(result.ptr);
+		free(fpath);
 	}
 
 	if (ret > 127)
diff --git a/builtin/merge.c b/builtin/merge.c
index 848a298..7554b8d 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -244,7 +244,7 @@
 	unlink(git_path_merge_mode());
 }
 
-static int save_state(unsigned char *stash)
+static int save_state(struct object_id *stash)
 {
 	int len;
 	struct child_process cp = CHILD_PROCESS_INIT;
@@ -265,7 +265,7 @@
 	else if (!len)		/* no changes */
 		return -1;
 	strbuf_setlen(&buffer, buffer.len-1);
-	if (get_sha1(buffer.buf, stash))
+	if (get_oid(buffer.buf, stash))
 		die(_("not a valid object: %s"), buffer.buf);
 	return 0;
 }
@@ -305,18 +305,18 @@
 		die(_("read-tree failed"));
 }
 
-static void restore_state(const unsigned char *head,
-			  const unsigned char *stash)
+static void restore_state(const struct object_id *head,
+			  const struct object_id *stash)
 {
 	struct strbuf sb = STRBUF_INIT;
 	const char *args[] = { "stash", "apply", NULL, NULL };
 
-	if (is_null_sha1(stash))
+	if (is_null_oid(stash))
 		return;
 
-	reset_hard(head, 1);
+	reset_hard(head->hash, 1);
 
-	args[2] = sha1_to_hex(stash);
+	args[2] = oid_to_hex(stash);
 
 	/*
 	 * It is OK to ignore error here, for example when there was
@@ -376,10 +376,10 @@
 
 static void finish(struct commit *head_commit,
 		   struct commit_list *remoteheads,
-		   const unsigned char *new_head, const char *msg)
+		   const struct object_id *new_head, const char *msg)
 {
 	struct strbuf reflog_message = STRBUF_INIT;
-	const unsigned char *head = head_commit->object.oid.hash;
+	const struct object_id *head = &head_commit->object.oid;
 
 	if (!msg)
 		strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
@@ -397,7 +397,7 @@
 		else {
 			const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 			update_ref(reflog_message.buf, "HEAD",
-				new_head, head, 0,
+				new_head->hash, head->hash, 0,
 				UPDATE_REFS_DIE_ON_ERR);
 			/*
 			 * We ignore errors in 'gc --auto', since the
@@ -416,7 +416,7 @@
 			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 		opts.detect_rename = DIFF_DETECT_RENAME;
 		diff_setup_done(&opts);
-		diff_tree_sha1(head, new_head, "", &opts);
+		diff_tree_sha1(head->hash, new_head->hash, "", &opts);
 		diffcore_std(&opts);
 		diff_flush(&opts);
 	}
@@ -431,7 +431,7 @@
 static void merge_name(const char *remote, struct strbuf *msg)
 {
 	struct commit *remote_head;
-	unsigned char branch_head[20];
+	struct object_id branch_head;
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf bname = STRBUF_INIT;
 	const char *ptr;
@@ -441,25 +441,25 @@
 	strbuf_branchname(&bname, remote, 0);
 	remote = bname.buf;
 
-	memset(branch_head, 0, sizeof(branch_head));
+	oidclr(&branch_head);
 	remote_head = get_merge_parent(remote);
 	if (!remote_head)
 		die(_("'%s' does not point to a commit"), remote);
 
-	if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
+	if (dwim_ref(remote, strlen(remote), branch_head.hash, &found_ref) > 0) {
 		if (starts_with(found_ref, "refs/heads/")) {
 			strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
-				    sha1_to_hex(branch_head), remote);
+				    oid_to_hex(&branch_head), remote);
 			goto cleanup;
 		}
 		if (starts_with(found_ref, "refs/tags/")) {
 			strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
-				    sha1_to_hex(branch_head), remote);
+				    oid_to_hex(&branch_head), remote);
 			goto cleanup;
 		}
 		if (starts_with(found_ref, "refs/remotes/")) {
 			strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
-				    sha1_to_hex(branch_head), remote);
+				    oid_to_hex(&branch_head), remote);
 			goto cleanup;
 		}
 	}
@@ -590,8 +590,8 @@
 	return git_diff_ui_config(k, v, cb);
 }
 
-static int read_tree_trivial(unsigned char *common, unsigned char *head,
-			     unsigned char *one)
+static int read_tree_trivial(struct object_id *common, struct object_id *head,
+			     struct object_id *one)
 {
 	int i, nr_trees = 0;
 	struct tree *trees[MAX_UNPACK_TREES];
@@ -606,13 +606,13 @@
 	opts.verbose_update = 1;
 	opts.trivial_merges_only = 1;
 	opts.merge = 1;
-	trees[nr_trees] = parse_tree_indirect(common);
+	trees[nr_trees] = parse_tree_indirect(common->hash);
 	if (!trees[nr_trees++])
 		return -1;
-	trees[nr_trees] = parse_tree_indirect(head);
+	trees[nr_trees] = parse_tree_indirect(head->hash);
 	if (!trees[nr_trees++])
 		return -1;
-	trees[nr_trees] = parse_tree_indirect(one);
+	trees[nr_trees] = parse_tree_indirect(one->hash);
 	if (!trees[nr_trees++])
 		return -1;
 	opts.fn = threeway_merge;
@@ -626,9 +626,9 @@
 	return 0;
 }
 
-static void write_tree_trivial(unsigned char *sha1)
+static void write_tree_trivial(struct object_id *oid)
 {
-	if (write_cache_as_tree(sha1, 0, NULL))
+	if (write_cache_as_tree(oid->hash, 0, NULL))
 		die(_("git write-tree failed to write a tree"));
 }
 
@@ -781,7 +781,7 @@
 
 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 {
-	unsigned char result_tree[20], result_commit[20];
+	struct object_id result_tree, result_commit;
 	struct commit_list *parents, **pptr = &parents;
 	static struct lock_file lock;
 
@@ -792,15 +792,15 @@
 		return error(_("Unable to write index."));
 	rollback_lock_file(&lock);
 
-	write_tree_trivial(result_tree);
+	write_tree_trivial(&result_tree);
 	printf(_("Wonderful.\n"));
 	pptr = commit_list_append(head, pptr);
 	pptr = commit_list_append(remoteheads->item, pptr);
 	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
-			result_commit, NULL, sign_commit))
+	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
+			result_commit.hash, NULL, sign_commit))
 		die(_("failed to write commit object"));
-	finish(head, remoteheads, result_commit, "In-index merge");
+	finish(head, remoteheads, &result_commit, "In-index merge");
 	drop_save();
 	return 0;
 }
@@ -809,12 +809,12 @@
 			    int head_subsumed,
 			    struct commit_list *common,
 			    struct commit_list *remoteheads,
-			    unsigned char *result_tree,
+			    struct object_id *result_tree,
 			    const char *wt_strategy)
 {
 	struct commit_list *parents = NULL;
 	struct strbuf buf = STRBUF_INIT;
-	unsigned char result_commit[20];
+	struct object_id result_commit;
 
 	free_commit_list(common);
 	parents = remoteheads;
@@ -822,11 +822,11 @@
 		commit_list_insert(head, &parents);
 	strbuf_addch(&merge_msg, '\n');
 	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
-			result_commit, NULL, sign_commit))
+	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
+			result_commit.hash, NULL, sign_commit))
 		die(_("failed to write commit object"));
 	strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
-	finish(head, remoteheads, result_commit, buf.buf);
+	finish(head, remoteheads, &result_commit, buf.buf);
 	strbuf_release(&buf);
 	drop_save();
 	return 0;
@@ -854,18 +854,18 @@
 }
 
 static struct commit *is_old_style_invocation(int argc, const char **argv,
-					      const unsigned char *head)
+					      const struct object_id *head)
 {
 	struct commit *second_token = NULL;
 	if (argc > 2) {
-		unsigned char second_sha1[20];
+		struct object_id second_oid;
 
-		if (get_sha1(argv[1], second_sha1))
+		if (get_oid(argv[1], &second_oid))
 			return NULL;
-		second_token = lookup_commit_reference_gently(second_sha1, 0);
+		second_token = lookup_commit_reference_gently(second_oid.hash, 0);
 		if (!second_token)
 			die(_("'%s' is not a commit"), argv[1]);
-		if (hashcmp(second_token->object.oid.hash, head))
+		if (oidcmp(&second_token->object.oid, head))
 			return NULL;
 	}
 	return second_token;
@@ -1038,7 +1038,7 @@
 		die_errno(_("could not close '%s'"), filename);
 
 	for (pos = 0; pos < merge_names->len; pos = npos) {
-		unsigned char sha1[20];
+		struct object_id oid;
 		char *ptr;
 		struct commit *commit;
 
@@ -1048,16 +1048,16 @@
 		else
 			npos = merge_names->len;
 
-		if (npos - pos < 40 + 2 ||
-		    get_sha1_hex(merge_names->buf + pos, sha1))
+		if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
+		    get_oid_hex(merge_names->buf + pos, &oid))
 			commit = NULL; /* bad */
-		else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
+		else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
 			continue; /* not-for-merge */
 		else {
-			char saved = merge_names->buf[pos + 40];
-			merge_names->buf[pos + 40] = '\0';
+			char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
+			merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
 			commit = get_merge_parent(merge_names->buf + pos);
-			merge_names->buf[pos + 40] = saved;
+			merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
 		}
 		if (!commit) {
 			if (ptr)
@@ -1117,9 +1117,7 @@
 
 int cmd_merge(int argc, const char **argv, const char *prefix)
 {
-	unsigned char result_tree[20];
-	unsigned char stash[20];
-	unsigned char head_sha1[20];
+	struct object_id result_tree, stash, head_oid;
 	struct commit *head_commit;
 	struct strbuf buf = STRBUF_INIT;
 	const char *head_arg;
@@ -1138,13 +1136,13 @@
 	 * Check if we are _not_ on a detached HEAD, i.e. if there is a
 	 * current branch.
 	 */
-	branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, NULL);
+	branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
 	if (branch && starts_with(branch, "refs/heads/"))
 		branch += 11;
-	if (!branch || is_null_sha1(head_sha1))
+	if (!branch || is_null_oid(&head_oid))
 		head_commit = NULL;
 	else
-		head_commit = lookup_commit_or_die(head_sha1, "HEAD");
+		head_commit = lookup_commit_or_die(head_oid.hash, "HEAD");
 
 	init_diff_ui_defaults();
 	git_config(git_merge_config, NULL);
@@ -1242,7 +1240,7 @@
 		 * to forbid "git merge" into a branch yet to be born.
 		 * We do the same for "git pull".
 		 */
-		unsigned char *remote_head_sha1;
+		struct object_id *remote_head_oid;
 		if (squash)
 			die(_("Squash commit into empty head not supported yet"));
 		if (fast_forward == FF_NO)
@@ -1254,9 +1252,9 @@
 			die(_("%s - not something we can merge"), argv[0]);
 		if (remoteheads->next)
 			die(_("Can merge only exactly one commit into empty head"));
-		remote_head_sha1 = remoteheads->item->object.oid.hash;
-		read_empty(remote_head_sha1, 0);
-		update_ref("initial pull", "HEAD", remote_head_sha1,
+		remote_head_oid = &remoteheads->item->object.oid;
+		read_empty(remote_head_oid->hash, 0);
+		update_ref("initial pull", "HEAD", remote_head_oid->hash,
 			   NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 		goto done;
 	}
@@ -1270,7 +1268,7 @@
 	 * additional safety measure to check for it.
 	 */
 	if (!have_message &&
-	    is_old_style_invocation(argc, argv, head_commit->object.oid.hash)) {
+	    is_old_style_invocation(argc, argv, &head_commit->object.oid)) {
 		warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
 		strbuf_addstr(&merge_msg, argv[0]);
 		head_arg = argv[1];
@@ -1422,7 +1420,7 @@
 			goto done;
 		}
 
-		finish(head_commit, remoteheads, commit->object.oid.hash, msg.buf);
+		finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
 		drop_save();
 		goto done;
 	} else if (!remoteheads->next && common->next)
@@ -1441,9 +1439,9 @@
 			/* See if it is really trivial. */
 			git_committer_info(IDENT_STRICT);
 			printf(_("Trying really trivial in-index merge...\n"));
-			if (!read_tree_trivial(common->item->object.oid.hash,
-					       head_commit->object.oid.hash,
-					       remoteheads->item->object.oid.hash)) {
+			if (!read_tree_trivial(&common->item->object.oid,
+					       &head_commit->object.oid,
+					       &remoteheads->item->object.oid)) {
 				ret = merge_trivial(head_commit, remoteheads);
 				goto done;
 			}
@@ -1495,14 +1493,14 @@
 	    /*
 	     * Stash away the local changes so that we can try more than one.
 	     */
-	    save_state(stash))
-		hashclr(stash);
+	    save_state(&stash))
+		oidclr(&stash);
 
 	for (i = 0; i < use_strategies_nr; i++) {
 		int ret;
 		if (i) {
 			printf(_("Rewinding the tree to pristine...\n"));
-			restore_state(head_commit->object.oid.hash, stash);
+			restore_state(&head_commit->object.oid, &stash);
 		}
 		if (use_strategies_nr != 1)
 			printf(_("Trying merge strategy %s...\n"),
@@ -1547,7 +1545,7 @@
 		}
 
 		/* Automerge succeeded. */
-		write_tree_trivial(result_tree);
+		write_tree_trivial(&result_tree);
 		automerge_was_ok = 1;
 		break;
 	}
@@ -1559,7 +1557,7 @@
 	if (automerge_was_ok) {
 		ret = finish_automerge(head_commit, head_subsumed,
 				       common, remoteheads,
-				       result_tree, wt_strategy);
+				       &result_tree, wt_strategy);
 		goto done;
 	}
 
@@ -1568,7 +1566,7 @@
 	 * it up.
 	 */
 	if (!best_strategy) {
-		restore_state(head_commit->object.oid.hash, stash);
+		restore_state(&head_commit->object.oid, &stash);
 		if (use_strategies_nr > 1)
 			fprintf(stderr,
 				_("No merge strategy handled the merge.\n"));
@@ -1581,7 +1579,7 @@
 		; /* We already have its result in the working tree. */
 	else {
 		printf(_("Rewinding the tree to pristine...\n"));
-		restore_state(head_commit->object.oid.hash, stash);
+		restore_state(&head_commit->object.oid, &stash);
 		printf(_("Using the %s to prepare resolving by hand.\n"),
 			best_strategy);
 		try_merge_strategy(best_strategy, common, remoteheads,
diff --git a/builtin/name-rev.c b/builtin/name-rev.c
index cd89d48..8bdc3ea 100644
--- a/builtin/name-rev.c
+++ b/builtin/name-rev.c
@@ -108,7 +108,8 @@
 struct name_ref_data {
 	int tags_only;
 	int name_only;
-	const char *ref_filter;
+	struct string_list ref_filters;
+	struct string_list exclude_filters;
 };
 
 static struct tip_table {
@@ -150,18 +151,49 @@
 	if (data->tags_only && !starts_with(path, "refs/tags/"))
 		return 0;
 
-	if (data->ref_filter) {
-		switch (subpath_matches(path, data->ref_filter)) {
-		case -1: /* did not match */
-			return 0;
-		case 0:  /* matched fully */
-			break;
-		default: /* matched subpath */
-			can_abbreviate_output = 1;
-			break;
+	if (data->exclude_filters.nr) {
+		struct string_list_item *item;
+
+		for_each_string_list_item(item, &data->exclude_filters) {
+			if (subpath_matches(path, item->string) >= 0)
+				return 0;
 		}
 	}
 
+	if (data->ref_filters.nr) {
+		struct string_list_item *item;
+		int matched = 0;
+
+		/* See if any of the patterns match. */
+		for_each_string_list_item(item, &data->ref_filters) {
+			/*
+			 * Check all patterns even after finding a match, so
+			 * that we can see if a match with a subpath exists.
+			 * When a user asked for 'refs/tags/v*' and 'v1.*',
+			 * both of which match, the user is showing her
+			 * willingness to accept a shortened output by having
+			 * the 'v1.*' in the acceptable refnames, so we
+			 * shouldn't stop when seeing 'refs/tags/v1.4' matches
+			 * 'refs/tags/v*'.  We should show it as 'v1.4'.
+			 */
+			switch (subpath_matches(path, item->string)) {
+			case -1: /* did not match */
+				break;
+			case 0: /* matched fully */
+				matched = 1;
+				break;
+			default: /* matched subpath */
+				matched = 1;
+				can_abbreviate_output = 1;
+				break;
+			}
+		}
+
+		/* If none of the patterns matched, stop now */
+		if (!matched)
+			return 0;
+	}
+
 	add_to_tip_table(oid->hash, path, can_abbreviate_output);
 
 	while (o && o->type == OBJ_TAG) {
@@ -306,12 +338,14 @@
 {
 	struct object_array revs = OBJECT_ARRAY_INIT;
 	int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
-	struct name_ref_data data = { 0, 0, NULL };
+	struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 	struct option opts[] = {
 		OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 		OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
-		OPT_STRING(0, "refs", &data.ref_filter, N_("pattern"),
+		OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 				   N_("only use refs matching <pattern>")),
+		OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
+				   N_("ignore refs matching <pattern>")),
 		OPT_GROUP(""),
 		OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 		OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
diff --git a/builtin/notes.c b/builtin/notes.c
index 5248a9b..0513f74 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -681,9 +681,9 @@
 	 * notes_merge_abort() to remove .git/NOTES_MERGE_WORKTREE.
 	 */
 
-	if (delete_ref("NOTES_MERGE_PARTIAL", NULL, 0))
+	if (delete_ref(NULL, "NOTES_MERGE_PARTIAL", NULL, 0))
 		ret += error(_("failed to delete ref NOTES_MERGE_PARTIAL"));
-	if (delete_ref("NOTES_MERGE_REF", NULL, REF_NODEREF))
+	if (delete_ref(NULL, "NOTES_MERGE_REF", NULL, REF_NODEREF))
 		ret += error(_("failed to delete ref NOTES_MERGE_REF"));
 	if (notes_merge_abort(o))
 		ret += error(_("failed to remove 'git notes merge' worktree"));
@@ -693,7 +693,7 @@
 static int merge_commit(struct notes_merge_options *o)
 {
 	struct strbuf msg = STRBUF_INIT;
-	unsigned char sha1[20], parent_sha1[20];
+	struct object_id oid, parent_oid;
 	struct notes_tree *t;
 	struct commit *partial;
 	struct pretty_print_context pretty_ctx;
@@ -705,27 +705,27 @@
 	 * and target notes ref from .git/NOTES_MERGE_REF.
 	 */
 
-	if (get_sha1("NOTES_MERGE_PARTIAL", sha1))
+	if (get_oid("NOTES_MERGE_PARTIAL", &oid))
 		die(_("failed to read ref NOTES_MERGE_PARTIAL"));
-	else if (!(partial = lookup_commit_reference(sha1)))
+	else if (!(partial = lookup_commit_reference(oid.hash)))
 		die(_("could not find commit from NOTES_MERGE_PARTIAL."));
 	else if (parse_commit(partial))
 		die(_("could not parse commit from NOTES_MERGE_PARTIAL."));
 
 	if (partial->parents)
-		hashcpy(parent_sha1, partial->parents->item->object.oid.hash);
+		oidcpy(&parent_oid, &partial->parents->item->object.oid);
 	else
-		hashclr(parent_sha1);
+		oidclr(&parent_oid);
 
 	t = xcalloc(1, sizeof(struct notes_tree));
 	init_notes(t, "NOTES_MERGE_PARTIAL", combine_notes_overwrite, 0);
 
 	o->local_ref = local_ref_to_free =
-		resolve_refdup("NOTES_MERGE_REF", 0, sha1, NULL);
+		resolve_refdup("NOTES_MERGE_REF", 0, oid.hash, NULL);
 	if (!o->local_ref)
 		die(_("failed to resolve NOTES_MERGE_REF"));
 
-	if (notes_merge_commit(o, t, partial, sha1))
+	if (notes_merge_commit(o, t, partial, oid.hash))
 		die(_("failed to finalize notes merge"));
 
 	/* Reuse existing commit message in reflog message */
@@ -733,8 +733,8 @@
 	format_commit_message(partial, "%s", &msg, &pretty_ctx);
 	strbuf_trim(&msg);
 	strbuf_insert(&msg, 0, "notes: ", 7);
-	update_ref(msg.buf, o->local_ref, sha1,
-		   is_null_sha1(parent_sha1) ? NULL : parent_sha1,
+	update_ref(msg.buf, o->local_ref, oid.hash,
+		   is_null_oid(&parent_oid) ? NULL : parent_oid.hash,
 		   0, UPDATE_REFS_DIE_ON_ERR);
 
 	free_notes(t);
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c7af475..84af7c2 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -239,7 +239,8 @@
 					   unsigned long limit, int usable_delta)
 {
 	unsigned long size, datalen;
-	unsigned char header[10], dheader[10];
+	unsigned char header[MAX_PACK_OBJECT_HEADER],
+		      dheader[MAX_PACK_OBJECT_HEADER];
 	unsigned hdrlen;
 	enum object_type type;
 	void *buf;
@@ -286,7 +287,8 @@
 	 * The object header is a byte of 'type' followed by zero or
 	 * more bytes of length.
 	 */
-	hdrlen = encode_in_pack_object_header(type, size, header);
+	hdrlen = encode_in_pack_object_header(header, sizeof(header),
+					      type, size);
 
 	if (type == OBJ_OFS_DELTA) {
 		/*
@@ -352,13 +354,15 @@
 	off_t offset;
 	enum object_type type = entry->type;
 	off_t datalen;
-	unsigned char header[10], dheader[10];
+	unsigned char header[MAX_PACK_OBJECT_HEADER],
+		      dheader[MAX_PACK_OBJECT_HEADER];
 	unsigned hdrlen;
 
 	if (entry->delta)
 		type = (allow_ofs_delta && entry->delta->idx.offset) ?
 			OBJ_OFS_DELTA : OBJ_REF_DELTA;
-	hdrlen = encode_in_pack_object_header(type, entry->size, header);
+	hdrlen = encode_in_pack_object_header(header, sizeof(header),
+					      type, entry->size);
 
 	offset = entry->in_pack_offset;
 	revidx = find_pack_revindex(p, offset);
@@ -894,24 +898,15 @@
 			written, nr_result);
 }
 
-static void setup_delta_attr_check(struct git_attr_check *check)
-{
-	static struct git_attr *attr_delta;
-
-	if (!attr_delta)
-		attr_delta = git_attr("delta");
-
-	check[0].attr = attr_delta;
-}
-
 static int no_try_delta(const char *path)
 {
-	struct git_attr_check check[1];
+	static struct attr_check *check;
 
-	setup_delta_attr_check(check);
-	if (git_check_attr(path, ARRAY_SIZE(check), check))
+	if (!check)
+		check = attr_check_initl("delta", NULL);
+	if (git_check_attr(path, check))
 		return 0;
-	if (ATTR_FALSE(check->value))
+	if (ATTR_FALSE(check->items[0].value))
 		return 1;
 	return 0;
 }
@@ -2621,17 +2616,17 @@
 	free(in_pack.array);
 }
 
-static int add_loose_object(const unsigned char *sha1, const char *path,
+static int add_loose_object(const struct object_id *oid, const char *path,
 			    void *data)
 {
-	enum object_type type = sha1_object_info(sha1, NULL);
+	enum object_type type = sha1_object_info(oid->hash, NULL);
 
 	if (type < 0) {
 		warning("loose object at %s could not be examined", path);
 		return 0;
 	}
 
-	add_object_entry(sha1, type, "", 0);
+	add_object_entry(oid->hash, type, "", 0);
 	return 0;
 }
 
diff --git a/builtin/prune-packed.c b/builtin/prune-packed.c
index 7cf900e..c026299 100644
--- a/builtin/prune-packed.c
+++ b/builtin/prune-packed.c
@@ -19,12 +19,12 @@
 	return 0;
 }
 
-static int prune_object(const unsigned char *sha1, const char *path,
+static int prune_object(const struct object_id *oid, const char *path,
 			 void *data)
 {
 	int *opts = data;
 
-	if (!has_sha1_pack(sha1))
+	if (!has_sha1_pack(oid->hash))
 		return 0;
 
 	if (*opts & PRUNE_PACKED_DRY_RUN)
diff --git a/builtin/prune.c b/builtin/prune.c
index 8f4f052..42633e0 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -30,7 +30,7 @@
 	return 0;
 }
 
-static int prune_object(const unsigned char *sha1, const char *fullpath,
+static int prune_object(const struct object_id *oid, const char *fullpath,
 			void *data)
 {
 	struct stat st;
@@ -39,7 +39,7 @@
 	 * Do we know about this object?
 	 * It must have been reachable
 	 */
-	if (lookup_object(sha1))
+	if (lookup_object(oid->hash))
 		return 0;
 
 	if (lstat(fullpath, &st)) {
@@ -50,8 +50,8 @@
 	if (st.st_mtime > expire)
 		return 0;
 	if (show_only || verbose) {
-		enum object_type type = sha1_object_info(sha1, NULL);
-		printf("%s %s\n", sha1_to_hex(sha1),
+		enum object_type type = sha1_object_info(oid->hash, NULL);
+		printf("%s %s\n", oid_to_hex(oid),
 		       (type > 0) ? typename(type) : "unknown");
 	}
 	if (!show_only)
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 8ba64bc..23e212e 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -15,10 +15,13 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "resolve-undo.h"
+#include "submodule.h"
+#include "submodule-config.h"
 
 static int nr_trees;
 static int read_empty;
 static struct tree *trees[MAX_UNPACK_TREES];
+static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
 
 static int list_tree(unsigned char *sha1)
 {
@@ -96,6 +99,23 @@
 	return 0;
 }
 
+static int option_parse_recurse_submodules(const struct option *opt,
+					   const char *arg, int unset)
+{
+	if (unset) {
+		recurse_submodules = RECURSE_SUBMODULES_OFF;
+		return 0;
+	}
+	if (arg)
+		recurse_submodules =
+			parse_update_recurse_submodules_arg(opt->long_name,
+							    arg);
+	else
+		recurse_submodules = RECURSE_SUBMODULES_ON;
+
+	return 0;
+}
+
 static struct lock_file lock_file;
 
 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
@@ -137,6 +157,9 @@
 			 N_("skip applying sparse checkout filter")),
 		OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 			 N_("debug unpack-trees")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_END()
 	};
 
@@ -152,6 +175,12 @@
 
 	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
+	if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
+		gitmodules_config();
+		git_config(submodule_config, NULL);
+		set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
+	}
+
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c
new file mode 100644
index 0000000..ca1ebb2
--- /dev/null
+++ b/builtin/rebase--helper.c
@@ -0,0 +1,40 @@
+#include "builtin.h"
+#include "cache.h"
+#include "parse-options.h"
+#include "sequencer.h"
+
+static const char * const builtin_rebase_helper_usage[] = {
+	N_("git rebase--helper [<options>]"),
+	NULL
+};
+
+int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
+{
+	struct replay_opts opts = REPLAY_OPTS_INIT;
+	enum {
+		CONTINUE = 1, ABORT
+	} command = 0;
+	struct option options[] = {
+		OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
+		OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
+				CONTINUE),
+		OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
+				ABORT),
+		OPT_END()
+	};
+
+	git_config(git_default_config, NULL);
+
+	opts.action = REPLAY_INTERACTIVE_REBASE;
+	opts.allow_ff = 1;
+	opts.allow_empty = 1;
+
+	argc = parse_options(argc, argv, NULL, options,
+			builtin_rebase_helper_usage, PARSE_OPT_KEEP_ARGV0);
+
+	if (command == CONTINUE && argc == 1)
+		return !!sequencer_continue(&opts);
+	if (command == ABORT && argc == 1)
+		return !!sequencer_remove_state(&opts);
+	usage_with_options(builtin_rebase_helper_usage, options);
+}
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index b618d52..fb2a090 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -21,6 +21,7 @@
 #include "sigchain.h"
 #include "fsck.h"
 #include "tmp-objdir.h"
+#include "oidset.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),
@@ -250,8 +251,9 @@
 }
 
 static int show_ref_cb(const char *path_full, const struct object_id *oid,
-		       int flag, void *unused)
+		       int flag, void *data)
 {
+	struct oidset *seen = data;
 	const char *path = strip_namespace(path_full);
 
 	if (ref_is_hidden(path, path_full))
@@ -260,37 +262,38 @@
 	/*
 	 * Advertise refs outside our current namespace as ".have"
 	 * refs, so that the client can use them to minimize data
-	 * transfer but will otherwise ignore them. This happens to
-	 * cover ".have" that are thrown in by add_one_alternate_ref()
-	 * to mark histories that are complete in our alternates as
-	 * well.
+	 * transfer but will otherwise ignore them.
 	 */
-	if (!path)
+	if (!path) {
+		if (oidset_insert(seen, oid))
+			return 0;
 		path = ".have";
+	} else {
+		oidset_insert(seen, oid);
+	}
 	show_ref(path, oid->hash);
 	return 0;
 }
 
-static int show_one_alternate_sha1(const unsigned char sha1[20], void *unused)
+static void show_one_alternate_ref(const char *refname,
+				   const struct object_id *oid,
+				   void *data)
 {
-	show_ref(".have", sha1);
-	return 0;
-}
+	struct oidset *seen = data;
 
-static void collect_one_alternate_ref(const struct ref *ref, void *data)
-{
-	struct sha1_array *sa = data;
-	sha1_array_append(sa, ref->old_oid.hash);
+	if (oidset_insert(seen, oid))
+		return;
+
+	show_ref(".have", oid->hash);
 }
 
 static void write_head_info(void)
 {
-	struct sha1_array sa = SHA1_ARRAY_INIT;
+	static struct oidset seen = OIDSET_INIT;
 
-	for_each_alternate_ref(collect_one_alternate_ref, &sa);
-	sha1_array_for_each_unique(&sa, show_one_alternate_sha1, NULL);
-	sha1_array_clear(&sa);
-	for_each_ref(show_ref_cb, NULL);
+	for_each_ref(show_ref_cb, &seen);
+	for_each_alternate_ref(show_one_alternate_ref, &seen);
+	oidset_clear(&seen);
 	if (!sent_capabilities)
 		show_ref("capabilities^{}", null_sha1);
 
@@ -1411,7 +1414,7 @@
 {
 	struct check_connected_options opt = CHECK_CONNECTED_INIT;
 	struct command *cmd;
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct iterate_data data;
 	struct async muxer;
 	int err_fd = 0;
@@ -1468,7 +1471,7 @@
 	check_aliased_updates(commands);
 
 	free(head_name_to_free);
-	head_name = head_name_to_free = resolve_refdup("HEAD", 0, sha1, NULL);
+	head_name = head_name_to_free = resolve_refdup("HEAD", 0, oid.hash, NULL);
 
 	if (use_atomic)
 		execute_commands_atomic(commands, si);
diff --git a/builtin/reflog.c b/builtin/reflog.c
index 7a7136e..7472775 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -615,7 +615,7 @@
 	return status;
 }
 
-static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
diff --git a/builtin/remote.c b/builtin/remote.c
index 7682206..addf97a 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -691,7 +691,7 @@
 		read_ref_full(item->string, RESOLVE_REF_READING, oid.hash, &flag);
 		if (!(flag & REF_ISSYMREF))
 			continue;
-		if (delete_ref(item->string, NULL, REF_NODEREF))
+		if (delete_ref(NULL, item->string, NULL, REF_NODEREF))
 			die(_("deleting '%s' failed"), item->string);
 	}
 	for (i = 0; i < remote_branches.nr; i++) {
@@ -1250,7 +1250,7 @@
 			head_name = xstrdup(states.heads.items[0].string);
 		free_remote_ref_states(&states);
 	} else if (opt_d && !opt_a && argc == 1) {
-		if (delete_ref(buf.buf, NULL, REF_NODEREF))
+		if (delete_ref(NULL, buf.buf, NULL, REF_NODEREF))
 			result |= error(_("Could not delete %s"), buf.buf);
 	} else
 		usage_with_options(builtin_remote_sethead_usage, options);
diff --git a/builtin/replace.c b/builtin/replace.c
index b58c714..f83e7b8 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -88,78 +88,78 @@
 }
 
 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
-				    const unsigned char *sha1);
+				    const struct object_id *oid);
 
 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
 {
 	const char **p, *full_hex;
 	char ref[PATH_MAX];
 	int had_error = 0;
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	for (p = argv; *p; p++) {
-		if (get_sha1(*p, sha1)) {
+		if (get_oid(*p, &oid)) {
 			error("Failed to resolve '%s' as a valid ref.", *p);
 			had_error = 1;
 			continue;
 		}
-		full_hex = sha1_to_hex(sha1);
+		full_hex = oid_to_hex(&oid);
 		snprintf(ref, sizeof(ref), "%s%s", git_replace_ref_base, full_hex);
 		/* read_ref() may reuse the buffer */
 		full_hex = ref + strlen(git_replace_ref_base);
-		if (read_ref(ref, sha1)) {
+		if (read_ref(ref, oid.hash)) {
 			error("replace ref '%s' not found.", full_hex);
 			had_error = 1;
 			continue;
 		}
-		if (fn(full_hex, ref, sha1))
+		if (fn(full_hex, ref, &oid))
 			had_error = 1;
 	}
 	return had_error;
 }
 
 static int delete_replace_ref(const char *name, const char *ref,
-			      const unsigned char *sha1)
+			      const struct object_id *oid)
 {
-	if (delete_ref(ref, sha1, 0))
+	if (delete_ref(NULL, ref, oid->hash, 0))
 		return 1;
 	printf("Deleted replace ref '%s'\n", name);
 	return 0;
 }
 
-static void check_ref_valid(unsigned char object[20],
-			    unsigned char prev[20],
+static void check_ref_valid(struct object_id *object,
+			    struct object_id *prev,
 			    char *ref,
 			    int ref_size,
 			    int force)
 {
 	if (snprintf(ref, ref_size,
 		     "%s%s", git_replace_ref_base,
-		     sha1_to_hex(object)) > ref_size - 1)
+		     oid_to_hex(object)) > ref_size - 1)
 		die("replace ref name too long: %.*s...", 50, ref);
 	if (check_refname_format(ref, 0))
 		die("'%s' is not a valid ref name.", ref);
 
-	if (read_ref(ref, prev))
-		hashclr(prev);
+	if (read_ref(ref, prev->hash))
+		oidclr(prev);
 	else if (!force)
 		die("replace ref '%s' already exists", ref);
 }
 
-static int replace_object_sha1(const char *object_ref,
-			       unsigned char object[20],
+static int replace_object_oid(const char *object_ref,
+			       struct object_id *object,
 			       const char *replace_ref,
-			       unsigned char repl[20],
+			       struct object_id *repl,
 			       int force)
 {
-	unsigned char prev[20];
+	struct object_id prev;
 	enum object_type obj_type, repl_type;
 	char ref[PATH_MAX];
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
 
-	obj_type = sha1_object_info(object, NULL);
-	repl_type = sha1_object_info(repl, NULL);
+	obj_type = sha1_object_info(object->hash, NULL);
+	repl_type = sha1_object_info(repl->hash, NULL);
 	if (!force && obj_type != repl_type)
 		die("Objects must be of the same type.\n"
 		    "'%s' points to a replaced object of type '%s'\n"
@@ -167,11 +167,11 @@
 		    object_ref, typename(obj_type),
 		    replace_ref, typename(repl_type));
 
-	check_ref_valid(object, prev, ref, sizeof(ref), force);
+	check_ref_valid(object, &prev, ref, sizeof(ref), force);
 
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
-	    ref_transaction_update(transaction, ref, repl, prev,
+	    ref_transaction_update(transaction, ref, repl->hash, prev.hash,
 				   0, NULL, &err) ||
 	    ref_transaction_commit(transaction, &err))
 		die("%s", err.buf);
@@ -182,14 +182,14 @@
 
 static int replace_object(const char *object_ref, const char *replace_ref, int force)
 {
-	unsigned char object[20], repl[20];
+	struct object_id object, repl;
 
-	if (get_sha1(object_ref, object))
+	if (get_oid(object_ref, &object))
 		die("Failed to resolve '%s' as a valid ref.", object_ref);
-	if (get_sha1(replace_ref, repl))
+	if (get_oid(replace_ref, &repl))
 		die("Failed to resolve '%s' as a valid ref.", replace_ref);
 
-	return replace_object_sha1(object_ref, object, replace_ref, repl, force);
+	return replace_object_oid(object_ref, &object, replace_ref, &repl, force);
 }
 
 /*
@@ -197,7 +197,7 @@
  * If "raw" is true, then the object's raw contents are printed according to
  * "type". Otherwise, we pretty-print the contents for human editing.
  */
-static void export_object(const unsigned char *sha1, enum object_type type,
+static void export_object(const struct object_id *oid, enum object_type type,
 			  int raw, const char *filename)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
@@ -213,7 +213,7 @@
 		argv_array_push(&cmd.args, typename(type));
 	else
 		argv_array_push(&cmd.args, "-p");
-	argv_array_push(&cmd.args, sha1_to_hex(sha1));
+	argv_array_push(&cmd.args, oid_to_hex(oid));
 	cmd.git_cmd = 1;
 	cmd.out = fd;
 
@@ -226,7 +226,7 @@
  * interpreting it as "type", and writing the result to the object database.
  * The sha1 of the written object is returned via sha1.
  */
-static void import_object(unsigned char *sha1, enum object_type type,
+static void import_object(struct object_id *oid, enum object_type type,
 			  int raw, const char *filename)
 {
 	int fd;
@@ -254,7 +254,7 @@
 
 		if (finish_command(&cmd))
 			die("mktree reported failure");
-		if (get_sha1_hex(result.buf, sha1) < 0)
+		if (get_oid_hex(result.buf, oid) < 0)
 			die("mktree did not return an object name");
 
 		strbuf_release(&result);
@@ -264,7 +264,7 @@
 
 		if (fstat(fd, &st) < 0)
 			die_errno("unable to fstat %s", filename);
-		if (index_fd(sha1, fd, &st, type, NULL, flags) < 0)
+		if (index_fd(oid->hash, fd, &st, type, NULL, flags) < 0)
 			die("unable to write object to database");
 		/* index_fd close()s fd for us */
 	}
@@ -279,29 +279,29 @@
 {
 	char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
 	enum object_type type;
-	unsigned char old[20], new[20], prev[20];
+	struct object_id old, new, prev;
 	char ref[PATH_MAX];
 
-	if (get_sha1(object_ref, old) < 0)
+	if (get_oid(object_ref, &old) < 0)
 		die("Not a valid object name: '%s'", object_ref);
 
-	type = sha1_object_info(old, NULL);
+	type = sha1_object_info(old.hash, NULL);
 	if (type < 0)
-		die("unable to get object type for %s", sha1_to_hex(old));
+		die("unable to get object type for %s", oid_to_hex(&old));
 
-	check_ref_valid(old, prev, ref, sizeof(ref), force);
+	check_ref_valid(&old, &prev, ref, sizeof(ref), force);
 
-	export_object(old, type, raw, tmpfile);
+	export_object(&old, type, raw, tmpfile);
 	if (launch_editor(tmpfile, NULL, NULL) < 0)
 		die("editing object file failed");
-	import_object(new, type, raw, tmpfile);
+	import_object(&new, type, raw, tmpfile);
 
 	free(tmpfile);
 
-	if (!hashcmp(old, new))
-		return error("new object is the same as the old one: '%s'", sha1_to_hex(old));
+	if (!oidcmp(&old, &new))
+		return error("new object is the same as the old one: '%s'", oid_to_hex(&old));
 
-	return replace_object_sha1(object_ref, old, "replacement", new, force);
+	return replace_object_oid(object_ref, &old, "replacement", &new, force);
 }
 
 static void replace_parents(struct strbuf *buf, int argc, const char **argv)
@@ -312,7 +312,7 @@
 
 	/* find existing parents */
 	parent_start = buf->buf;
-	parent_start += 46; /* "tree " + "hex sha1" + "\n" */
+	parent_start += GIT_SHA1_HEXSZ + 6; /* "tree " + "hex sha1" + "\n" */
 	parent_end = parent_start;
 
 	while (starts_with(parent_end, "parent "))
@@ -320,11 +320,11 @@
 
 	/* prepare new parents */
 	for (i = 0; i < argc; i++) {
-		unsigned char sha1[20];
-		if (get_sha1(argv[i], sha1) < 0)
+		struct object_id oid;
+		if (get_oid(argv[i], &oid) < 0)
 			die(_("Not a valid object name: '%s'"), argv[i]);
-		lookup_commit_or_die(sha1, argv[i]);
-		strbuf_addf(&new_parents, "parent %s\n", sha1_to_hex(sha1));
+		lookup_commit_or_die(oid.hash, argv[i]);
+		strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&oid));
 	}
 
 	/* replace existing parents with new ones */
@@ -345,12 +345,12 @@
 {
 	struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
 	const char *ref = mergetag_data->argv[0];
-	unsigned char tag_sha1[20];
+	struct object_id tag_oid;
 	struct tag *tag;
 	int i;
 
-	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_sha1);
-	tag = lookup_tag(tag_sha1);
+	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_oid.hash);
+	tag = lookup_tag(tag_oid.hash);
 	if (!tag)
 		die(_("bad mergetag in commit '%s'"), ref);
 	if (parse_tag_buffer(tag, extra->value, extra->len))
@@ -366,7 +366,7 @@
 	}
 
 	die(_("original commit '%s' contains mergetag '%s' that is discarded; "
-	      "use --edit instead of --graft"), ref, sha1_to_hex(tag_sha1));
+	      "use --edit instead of --graft"), ref, oid_to_hex(&tag_oid));
 }
 
 static void check_mergetags(struct commit *commit, int argc, const char **argv)
@@ -380,16 +380,16 @@
 
 static int create_graft(int argc, const char **argv, int force)
 {
-	unsigned char old[20], new[20];
+	struct object_id old, new;
 	const char *old_ref = argv[0];
 	struct commit *commit;
 	struct strbuf buf = STRBUF_INIT;
 	const char *buffer;
 	unsigned long size;
 
-	if (get_sha1(old_ref, old) < 0)
+	if (get_oid(old_ref, &old) < 0)
 		die(_("Not a valid object name: '%s'"), old_ref);
-	commit = lookup_commit_or_die(old, old_ref);
+	commit = lookup_commit_or_die(old.hash, old_ref);
 
 	buffer = get_commit_buffer(commit, &size);
 	strbuf_add(&buf, buffer, size);
@@ -404,15 +404,15 @@
 
 	check_mergetags(commit, argc, argv);
 
-	if (write_sha1_file(buf.buf, buf.len, commit_type, new))
+	if (write_sha1_file(buf.buf, buf.len, commit_type, new.hash))
 		die(_("could not write replacement commit for: '%s'"), old_ref);
 
 	strbuf_release(&buf);
 
-	if (!hashcmp(old, new))
-		return error("new commit is the same as the old one: '%s'", sha1_to_hex(old));
+	if (!oidcmp(&old, &new))
+		return error("new commit is the same as the old one: '%s'", oid_to_hex(&old));
 
-	return replace_object_sha1(old_ref, old, "replacement", new, force);
+	return replace_object_oid(old_ref, &old, "replacement", &new, force);
 }
 
 int cmd_replace(int argc, const char **argv, const char *prefix)
diff --git a/builtin/reset.c b/builtin/reset.c
index 8ab915b..fc3b906 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -256,7 +256,7 @@
 		update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 			   UPDATE_REFS_MSG_ON_ERR);
 	} else if (old_orig)
-		delete_ref("ORIG_HEAD", old_orig->hash, 0);
+		delete_ref(NULL, "ORIG_HEAD", old_orig->hash, 0);
 	set_reflog_message(&msg, "updating HEAD", rev);
 	update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
 				       UPDATE_REFS_MSG_ON_ERR);
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index ed8819b..9e53a1a 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -12,6 +12,7 @@
 #include "diff.h"
 #include "revision.h"
 #include "split-index.h"
+#include "submodule.h"
 
 #define DO_REVS		1
 #define DO_NOREV	2
@@ -227,9 +228,9 @@
 	if ((filter & (DO_NONFLAGS|DO_NOREV)) == (DO_NONFLAGS|DO_NOREV)) {
 		if (output_prefix) {
 			const char *prefix = startup_info->prefix;
-			show(prefix_filename(prefix,
-					     prefix ? strlen(prefix) : 0,
-					     arg));
+			char *fname = prefix_filename(prefix, arg);
+			show(fname);
+			free(fname);
 		} else
 			show(arg);
 		return 1;
@@ -573,6 +574,7 @@
 	unsigned int flags = 0;
 	const char *name = NULL;
 	struct object_context unused;
+	struct strbuf buf = STRBUF_INIT;
 
 	if (argc > 1 && !strcmp("--parseopt", argv[1]))
 		return cmd_parseopt(argc - 1, argv + 1, prefix);
@@ -627,7 +629,9 @@
 		if (!strcmp(arg, "--git-path")) {
 			if (!argv[i + 1])
 				die("--git-path requires an argument");
-			puts(git_path("%s", argv[i + 1]));
+			strbuf_reset(&buf);
+			puts(relative_path(git_path("%s", argv[i + 1]),
+					   prefix, &buf));
 			i++;
 			continue;
 		}
@@ -781,6 +785,12 @@
 					puts(work_tree);
 				continue;
 			}
+			if (!strcmp(arg, "--show-superproject-working-tree")) {
+				const char *superproject = get_superproject_working_tree();
+				if (superproject)
+					puts(superproject);
+				continue;
+			}
 			if (!strcmp(arg, "--show-prefix")) {
 				if (prefix)
 					puts(prefix);
@@ -807,17 +817,27 @@
 				putchar('\n');
 				continue;
 			}
-			if (!strcmp(arg, "--git-dir")) {
+			if (!strcmp(arg, "--git-dir") ||
+			    !strcmp(arg, "--absolute-git-dir")) {
 				const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
 				char *cwd;
 				int len;
-				if (gitdir) {
-					puts(gitdir);
-					continue;
-				}
-				if (!prefix) {
-					puts(".git");
-					continue;
+				if (arg[2] == 'g') {	/* --git-dir */
+					if (gitdir) {
+						puts(gitdir);
+						continue;
+					}
+					if (!prefix) {
+						puts(".git");
+						continue;
+					}
+				} else {		/* --absolute-git-dir */
+					if (!gitdir && !prefix)
+						gitdir = ".git";
+					if (gitdir) {
+						puts(real_path(gitdir));
+						continue;
+					}
 				}
 				cwd = xgetcwd();
 				len = strlen(cwd);
@@ -826,8 +846,9 @@
 				continue;
 			}
 			if (!strcmp(arg, "--git-common-dir")) {
-				const char *pfx = prefix ? prefix : "";
-				puts(prefix_filename(pfx, strlen(pfx), get_git_common_dir()));
+				strbuf_reset(&buf);
+				puts(relative_path(get_git_common_dir(),
+						   prefix, &buf));
 				continue;
 			}
 			if (!strcmp(arg, "--is-inside-git-dir")) {
@@ -850,7 +871,9 @@
 					die(_("Could not read the index"));
 				if (the_index.split_index) {
 					const unsigned char *sha1 = the_index.split_index->base_sha1;
-					puts(git_path("sharedindex.%s", sha1_to_hex(sha1)));
+					const char *path = git_path("sharedindex.%s", sha1_to_hex(sha1));
+					strbuf_reset(&buf);
+					puts(relative_path(path, prefix, &buf));
 				}
 				continue;
 			}
@@ -902,6 +925,7 @@
 			continue;
 		verify_filename(prefix, arg, 1);
 	}
+	strbuf_release(&buf);
 	if (verify) {
 		if (revs_count == 1) {
 			show_rev(type, sha1, name);
diff --git a/builtin/revert.c b/builtin/revert.c
index 4ca5b51..345d958 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -54,6 +54,24 @@
 	return 0;
 }
 
+static int option_parse_m(const struct option *opt,
+			  const char *arg, int unset)
+{
+	struct replay_opts *replay = opt->value;
+	char *end;
+
+	if (unset) {
+		replay->mainline = 0;
+		return 0;
+	}
+
+	replay->mainline = strtol(arg, &end, 10);
+	if (*end || replay->mainline <= 0)
+		return opterror(opt, "expects a number greater than zero", 0);
+
+	return 0;
+}
+
 LAST_ARG_MUST_BE_NULL
 static void verify_opt_compatible(const char *me, const char *base_opt, ...)
 {
@@ -84,7 +102,8 @@
 		OPT_BOOL('e', "edit", &opts->edit, N_("edit the commit message")),
 		OPT_NOOP_NOARG('r', NULL),
 		OPT_BOOL('s', "signoff", &opts->signoff, N_("add Signed-off-by:")),
-		OPT_INTEGER('m', "mainline", &opts->mainline, N_("parent number")),
+		OPT_CALLBACK('m', "mainline", opts, N_("parent-number"),
+			     N_("select mainline parent"), option_parse_m),
 		OPT_RERERE_AUTOUPDATE(&opts->allow_rerere_auto),
 		OPT_STRING(0, "strategy", &opts->strategy, N_("strategy"), N_("merge strategy")),
 		OPT_CALLBACK('X', "strategy-option", &opts, N_("option"),
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 1ff5a67..832fd7e 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -144,6 +144,7 @@
 	unsigned force_update = 0;
 	unsigned quiet = 0;
 	int push_cert = 0;
+	struct string_list push_options = STRING_LIST_INIT_NODUP;
 	unsigned use_thin_pack = 0;
 	unsigned atomic = 0;
 	unsigned stateless_rpc = 0;
@@ -165,6 +166,9 @@
 		{ OPTION_CALLBACK,
 		  0, "signed", &push_cert, "yes|no|if-asked", N_("GPG sign the push"),
 		  PARSE_OPT_OPTARG, option_parse_push_signed },
+		OPT_STRING_LIST(0, "push-option", &push_options,
+				N_("server-specific"),
+				N_("option to transmit")),
 		OPT_BOOL(0, "progress", &progress, N_("force progress reporting")),
 		OPT_BOOL(0, "thin", &use_thin_pack, N_("use thin pack")),
 		OPT_BOOL(0, "atomic", &atomic, N_("request atomic transaction on remote side")),
@@ -199,6 +203,7 @@
 	args.use_thin_pack = use_thin_pack;
 	args.atomic = atomic;
 	args.stateless_rpc = stateless_rpc;
+	args.push_options = push_options.nr ? &push_options : NULL;
 
 	if (from_stdin) {
 		struct argv_array all_refspecs = ARGV_ARRAY_INIT;
diff --git a/builtin/shortlog.c b/builtin/shortlog.c
index 677f372..7cff183 100644
--- a/builtin/shortlog.c
+++ b/builtin/shortlog.c
@@ -148,7 +148,7 @@
 
 	ctx.fmt = CMIT_FMT_USERFORMAT;
 	ctx.abbrev = log->abbrev;
-	ctx.subject = "";
+	ctx.print_email_subject = 1;
 	ctx.date_mode.type = DATE_NORMAL;
 	ctx.output_encoding = get_log_output_encoding();
 
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 899dc33..be316bb 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -356,12 +356,10 @@
 			strbuf_addf(&remotesb, "remote.%s.url", remote);
 			free(remote);
 
-			if (git_config_get_string(remotesb.buf, &remoteurl))
-				/*
-				 * The repository is its own
-				 * authoritative upstream
-				 */
+			if (git_config_get_string(remotesb.buf, &remoteurl)) {
+				warning(_("could not lookup configuration '%s'. Assuming this repository is its own authoritative upstream."), remotesb.buf);
 				remoteurl = xgetcwd();
+			}
 			relurl = relative_url(remoteurl, url, NULL);
 			strbuf_release(&remotesb);
 			free(remoteurl);
@@ -579,9 +577,7 @@
 	const char *name = NULL, *url = NULL, *depth = NULL;
 	int quiet = 0;
 	int progress = 0;
-	FILE *submodule_dot_git;
 	char *p, *path = NULL, *sm_gitdir;
-	struct strbuf rel_path = STRBUF_INIT;
 	struct strbuf sb = STRBUF_INIT;
 	struct string_list reference = STRING_LIST_INIT_NODUP;
 	char *sm_alternate = NULL, *error_strategy = NULL;
@@ -653,27 +649,12 @@
 		strbuf_reset(&sb);
 	}
 
-	/* Write a .git file in the submodule to redirect to the superproject. */
-	strbuf_addf(&sb, "%s/.git", path);
-	if (safe_create_leading_directories_const(sb.buf) < 0)
-		die(_("could not create leading directories of '%s'"), sb.buf);
-	submodule_dot_git = fopen(sb.buf, "w");
-	if (!submodule_dot_git)
-		die_errno(_("cannot open file '%s'"), sb.buf);
+	/* Connect module worktree and git dir */
+	connect_work_tree_and_git_dir(path, sm_gitdir);
 
-	fprintf_or_die(submodule_dot_git, "gitdir: %s\n",
-		       relative_path(sm_gitdir, path, &rel_path));
-	if (fclose(submodule_dot_git))
-		die(_("could not close file %s"), sb.buf);
-	strbuf_reset(&sb);
-	strbuf_reset(&rel_path);
-
-	/* Redirect the worktree of the submodule in the superproject's config */
 	p = git_pathdup_submodule(path, "config");
 	if (!p)
 		die(_("could not get submodule directory for '%s'"), path);
-	git_config_set_in_file(p, "core.worktree",
-			       relative_path(path, sm_gitdir, &rel_path));
 
 	/* setup alternateLocation and alternateErrorStrategy in the cloned submodule if needed */
 	git_config_get_string("submodule.alternateLocation", &sm_alternate);
@@ -689,7 +670,6 @@
 	free(error_strategy);
 
 	strbuf_release(&sb);
-	strbuf_release(&rel_path);
 	free(sm_gitdir);
 	free(path);
 	free(p);
diff --git a/builtin/symbolic-ref.c b/builtin/symbolic-ref.c
index 96eed94..70addef 100644
--- a/builtin/symbolic-ref.c
+++ b/builtin/symbolic-ref.c
@@ -58,7 +58,7 @@
 			die("Cannot delete %s, not a symbolic ref", argv[0]);
 		if (!strcmp(argv[0], "HEAD"))
 			die("deleting '%s' is not allowed", argv[0]);
-		return delete_ref(argv[0], NULL, REF_NODEREF);
+		return delete_ref(NULL, argv[0], NULL, REF_NODEREF);
 	}
 
 	switch (argc) {
diff --git a/builtin/tag.c b/builtin/tag.c
index e40c4a9..ad29be6 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -45,11 +45,11 @@
 	if (!format) {
 		if (filter->lines) {
 			to_free = xstrfmt("%s %%(contents:lines=%d)",
-					  "%(align:15)%(refname:strip=2)%(end)",
+					  "%(align:15)%(refname:lstrip=2)%(end)",
 					  filter->lines);
 			format = to_free;
 		} else
-			format = "%(refname:strip=2)";
+			format = "%(refname:lstrip=2)";
 	}
 
 	verify_ref_format(format);
@@ -97,7 +97,7 @@
 static int delete_tag(const char *name, const char *ref,
 		      const unsigned char *sha1, const void *cb_data)
 {
-	if (delete_ref(ref, sha1, 0))
+	if (delete_ref(NULL, ref, sha1, 0))
 		return 1;
 	printf(_("Deleted tag '%s' (was %s)\n"), name, find_unique_abbrev(sha1, DEFAULT_ABBREV));
 	return 0;
@@ -302,6 +302,54 @@
 	}
 }
 
+static void create_reflog_msg(const unsigned char *sha1, struct strbuf *sb)
+{
+	enum object_type type;
+	struct commit *c;
+	char *buf;
+	unsigned long size;
+	int subject_len = 0;
+	const char *subject_start;
+
+	char *rla = getenv("GIT_REFLOG_ACTION");
+	if (rla) {
+		strbuf_addstr(sb, rla);
+	} else {
+		strbuf_addstr(sb, _("tag: tagging "));
+		strbuf_add_unique_abbrev(sb, sha1, DEFAULT_ABBREV);
+	}
+
+	strbuf_addstr(sb, " (");
+	type = sha1_object_info(sha1, NULL);
+	switch (type) {
+	default:
+		strbuf_addstr(sb, _("object of unknown type"));
+		break;
+	case OBJ_COMMIT:
+		if ((buf = read_sha1_file(sha1, &type, &size)) != NULL) {
+			subject_len = find_commit_subject(buf, &subject_start);
+			strbuf_insert(sb, sb->len, subject_start, subject_len);
+		} else {
+			strbuf_addstr(sb, _("commit object"));
+		}
+		free(buf);
+
+		if ((c = lookup_commit_reference(sha1)) != NULL)
+			strbuf_addf(sb, ", %s", show_date(c->date, 0, DATE_MODE(SHORT)));
+		break;
+	case OBJ_TREE:
+		strbuf_addstr(sb, _("tree object"));
+		break;
+	case OBJ_BLOB:
+		strbuf_addstr(sb, _("blob object"));
+		break;
+	case OBJ_TAG:
+		strbuf_addstr(sb, _("other tag object"));
+		break;
+	}
+	strbuf_addch(sb, ')');
+}
+
 struct msg_arg {
 	int given;
 	struct strbuf buf;
@@ -335,6 +383,7 @@
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf ref = STRBUF_INIT;
+	struct strbuf reflog_msg = STRBUF_INIT;
 	unsigned char object[20], prev[20];
 	const char *object_ref, *tag;
 	struct create_tag_options opt;
@@ -389,6 +438,8 @@
 		OPT_END()
 	};
 
+	setup_ref_filter_porcelain_msg();
+
 	git_config(git_tag_config, sorting_tail);
 
 	memset(&opt, 0, sizeof(opt));
@@ -494,6 +545,8 @@
 	else
 		die(_("Invalid cleanup mode %s"), cleanup_arg);
 
+	create_reflog_msg(object, &reflog_msg);
+
 	if (create_tag_object) {
 		if (force_sign_annotate && !annotate)
 			opt.sign = 1;
@@ -504,7 +557,7 @@
 	if (!transaction ||
 	    ref_transaction_update(transaction, ref.buf, object, prev,
 				   create_reflog ? REF_FORCE_CREATE_REFLOG : 0,
-				   NULL, &err) ||
+				   reflog_msg.buf, &err) ||
 	    ref_transaction_commit(transaction, &err))
 		die("%s", err.buf);
 	ref_transaction_free(transaction);
@@ -514,5 +567,6 @@
 	strbuf_release(&err);
 	strbuf_release(&buf);
 	strbuf_release(&ref);
+	strbuf_release(&reflog_msg);
 	return 0;
 }
diff --git a/builtin/update-index.c b/builtin/update-index.c
index d530e89..d74d72c 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -1099,17 +1099,20 @@
 	}
 
 	if (split_index > 0) {
-		init_split_index(&the_index);
-		the_index.cache_changed |= SPLIT_INDEX_ORDERED;
-	} else if (!split_index && the_index.split_index) {
-		/*
-		 * can't discard_split_index(&the_index); because that
-		 * will destroy split_index->base->cache[], which may
-		 * be shared with the_index.cache[]. So yeah we're
-		 * leaking a bit here.
-		 */
-		the_index.split_index = NULL;
-		the_index.cache_changed |= SOMETHING_CHANGED;
+		if (git_config_get_split_index() == 0)
+			warning(_("core.splitIndex is set to false; "
+				  "remove or change it, if you really want to "
+				  "enable split index"));
+		if (the_index.split_index)
+			the_index.cache_changed |= SPLIT_INDEX_ORDERED;
+		else
+			add_split_index(&the_index);
+	} else if (!split_index) {
+		if (git_config_get_split_index() == 1)
+			warning(_("core.splitIndex is set to true; "
+				  "remove or change it, if you really want to "
+				  "disable split index"));
+		remove_split_index(&the_index);
 	}
 
 	switch (untracked_cache) {
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 7f30d3a..0b2ecf4 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -433,7 +433,7 @@
 		 * For purposes of backwards compatibility, we treat
 		 * NULL_SHA1 as "don't care" here:
 		 */
-		return delete_ref(refname,
+		return delete_ref(msg, refname,
 				  (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL,
 				  flags);
 	else
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 831fe05..9993ded 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -318,7 +318,8 @@
 {
 	struct add_opts opts;
 	const char *new_branch_force = NULL;
-	const char *path, *branch;
+	char *path;
+	const char *branch;
 	struct option options[] = {
 		OPT__FORCE(&opts.force, N_("checkout <branch> even if already checked out in other worktree")),
 		OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
@@ -338,7 +339,7 @@
 	if (ac < 1 || ac > 2)
 		usage_with_options(worktree_usage, options);
 
-	path = prefix_filename(prefix, strlen(prefix), av[0]);
+	path = prefix_filename(prefix, av[0]);
 	branch = ac < 2 ? "HEAD" : av[1];
 
 	if (!strcmp(branch, "-"))
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 991b4a1..ddb6070 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -105,7 +105,7 @@
 
 	git_deflate_init(&s, pack_compression_level);
 
-	hdrlen = encode_in_pack_object_header(type, size, obuf);
+	hdrlen = encode_in_pack_object_header(obuf, sizeof(obuf), type, size);
 	s.next_out = obuf + hdrlen;
 	s.avail_out = sizeof(obuf) - hdrlen;
 
diff --git a/cache.h b/cache.h
index 900796c..fbdf7a8 100644
--- a/cache.h
+++ b/cache.h
@@ -10,8 +10,8 @@
 #include "trace.h"
 #include "string-list.h"
 #include "pack-revindex.h"
+#include "hash.h"
 
-#include SHA1_HEADER
 #ifndef platform_SHA_CTX
 /*
  * platform's underlying implementation of SHA-1; could be OpenSSL,
@@ -343,6 +343,7 @@
 extern struct index_state the_index;
 
 /* Name hashing */
+extern int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
 extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
 extern void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
 extern void free_name_hash(struct index_state *istate);
@@ -518,11 +519,30 @@
 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 
 extern void setup_work_tree(void);
+/*
+ * Find GIT_DIR of the repository that contains the current working directory,
+ * without changing the working directory or other global state. The result is
+ * appended to gitdir. The return value is either NULL if no repository was
+ * found, or pointing to the path inside gitdir's buffer.
+ */
+extern const char *discover_git_directory(struct strbuf *gitdir);
 extern const char *setup_git_directory_gently(int *);
 extern const char *setup_git_directory(void);
 extern char *prefix_path(const char *prefix, int len, const char *path);
 extern char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
-extern const char *prefix_filename(const char *prefix, int len, const char *path);
+
+/*
+ * Concatenate "prefix" (if len is non-zero) and "path", with no
+ * connecting characters (so "prefix" should end with a "/").
+ * Unlike prefix_path, this should be used if the named file does
+ * not have to interact with index entry; i.e. name of a random file
+ * on the filesystem.
+ *
+ * The return value is always a newly allocated string (even if the
+ * prefix was empty).
+ */
+extern char *prefix_filename(const char *prefix, const char *path);
+
 extern int check_filename(const char *prefix, const char *name);
 extern void verify_filename(const char *prefix,
 			    const char *name,
@@ -1069,8 +1089,9 @@
 
 /*
  * Create the directory containing the named path, using care to be
- * somewhat safe against races.  Return one of the scld_error values
- * to indicate success/failure.
+ * somewhat safe against races. Return one of the scld_error values to
+ * indicate success/failure. On error, set errno to describe the
+ * problem.
  *
  * SCLD_VANISHED indicates that one of the ancestor directories of the
  * path existed at one point during the function call and then
@@ -1094,6 +1115,49 @@
 enum scld_error safe_create_leading_directories(char *path);
 enum scld_error safe_create_leading_directories_const(const char *path);
 
+/*
+ * Callback function for raceproof_create_file(). This function is
+ * expected to do something that makes dirname(path) permanent despite
+ * the fact that other processes might be cleaning up empty
+ * directories at the same time. Usually it will create a file named
+ * path, but alternatively it could create another file in that
+ * directory, or even chdir() into that directory. The function should
+ * return 0 if the action was completed successfully. On error, it
+ * should return a nonzero result and set errno.
+ * raceproof_create_file() treats two errno values specially:
+ *
+ * - ENOENT -- dirname(path) does not exist. In this case,
+ *             raceproof_create_file() tries creating dirname(path)
+ *             (and any parent directories, if necessary) and calls
+ *             the function again.
+ *
+ * - EISDIR -- the file already exists and is a directory. In this
+ *             case, raceproof_create_file() removes the directory if
+ *             it is empty (and recursively any empty directories that
+ *             it contains) and calls the function again.
+ *
+ * Any other errno causes raceproof_create_file() to fail with the
+ * callback's return value and errno.
+ *
+ * Obviously, this function should be OK with being called again if it
+ * fails with ENOENT or EISDIR. In other scenarios it will not be
+ * called again.
+ */
+typedef int create_file_fn(const char *path, void *cb);
+
+/*
+ * Create a file in dirname(path) by calling fn, creating leading
+ * directories if necessary. Retry a few times in case we are racing
+ * with another process that is trying to clean up the directory that
+ * contains path. See the documentation for create_file_fn for more
+ * details.
+ *
+ * Return the value and set the errno that resulted from the most
+ * recent call of fn. fn is always called at least once, and will be
+ * called more than once if it returns ENOENT or EISDIR.
+ */
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
+
 int mkdir_in_gitdir(const char *path);
 extern char *expand_user_path(const char *path);
 const char *enter_repo(const char *path, int strict);
@@ -1125,6 +1189,13 @@
  */
 extern char *xdg_config_home(const char *filename);
 
+/**
+ * Return a newly allocated string with the evaluation of
+ * "$XDG_CACHE_HOME/git/$filename" if $XDG_CACHE_HOME is non-empty, otherwise
+ * "$HOME/.cache/git/$filename". Return NULL upon error.
+ */
+extern char *xdg_cache_home(const char *filename);
+
 /* object replacement */
 #define LOOKUP_REPLACE_OBJECT 1
 #define LOOKUP_UNKNOWN_OBJECT 2
@@ -1226,6 +1297,9 @@
 
 extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);
 
+/* Helper to check and "touch" a file */
+extern int check_and_freshen_file(const char *fn, int freshen);
+
 extern const signed char hexval_table[256];
 static inline unsigned int hexval(unsigned char c)
 {
@@ -1317,6 +1391,15 @@
 extern char *oid_to_hex(const struct object_id *oid);	/* same static buffer as sha1_to_hex */
 
 /*
+ * Parse a 40-character hexadecimal object ID starting from hex, updating the
+ * pointer specified by end when parsing stops.  The resulting object ID is
+ * stored in oid.  Returns 0 on success.  Parsing will stop on the first NUL or
+ * other invalid character.  end is only updated on success; otherwise, it is
+ * unmodified.
+ */
+extern int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
+
+/*
  * This reads short-hand syntax that not only evaluates to a commit
  * object name, but also can act as if the end user spelled the name
  * of the branch from the command line.
@@ -1647,6 +1730,12 @@
  * error.
  */
 extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
+/*
+ * Like nth_packed_object_sha1, but write the data into the object specified by
+ * the the first argument.  Returns the first argument on success, and NULL on
+ * error.
+ */
+extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
 
 /*
  * Return the offset of the nth object within the specified packfile.
@@ -1688,7 +1777,7 @@
  * scratch buffer, but restored to its original contents before
  * the function returns.
  */
-typedef int each_loose_object_fn(const unsigned char *sha1,
+typedef int each_loose_object_fn(const struct object_id *oid,
 				 const char *path,
 				 void *data);
 typedef int each_loose_cruft_fn(const char *basename,
@@ -1714,7 +1803,7 @@
  * LOCAL_ONLY flag is set).
  */
 #define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
-typedef int each_packed_object_fn(const unsigned char *sha1,
+typedef int each_packed_object_fn(const struct object_id *oid,
 				  struct packed_git *pack,
 				  uint32_t pos,
 				  void *data);
@@ -1801,6 +1890,7 @@
 				     const unsigned char *sha1, void *data);
 extern void git_config_push_parameter(const char *text);
 extern int git_config_from_parameters(config_fn_t fn, void *data);
+extern void read_early_config(config_fn_t cb, void *data);
 extern void git_config(config_fn_t fn, void *);
 extern int git_config_with_options(config_fn_t fn, void *,
 				   struct git_config_source *config_source,
@@ -1933,6 +2023,11 @@
 extern int git_config_get_maybe_bool(const char *key, int *dest);
 extern int git_config_get_pathname(const char *key, const char **dest);
 extern int git_config_get_untracked_cache(void);
+extern int git_config_get_split_index(void);
+extern int git_config_get_max_percent_split_change(void);
+
+/* This dies if the configured or default date is in the future */
+extern int git_config_get_expiry(const char *key, const char **output);
 
 /*
  * This is a hack for test programs like test-dump-untracked-cache to
diff --git a/commit.c b/commit.c
index fab8269..73c78c2 100644
--- a/commit.c
+++ b/commit.c
@@ -415,8 +415,7 @@
 		p++;
 	if (*p) {
 		p = skip_blank_lines(p + 2);
-		for (eol = p; *eol && *eol != '\n'; eol++)
-			; /* do nothing */
+		eol = strchrnul(p, '\n');
 	} else
 		eol = p;
 
diff --git a/commit.h b/commit.h
index 9c12abb..528272a 100644
--- a/commit.h
+++ b/commit.h
@@ -142,21 +142,24 @@
 	return (fmt == CMIT_FMT_EMAIL || fmt == CMIT_FMT_MBOXRD);
 }
 
+struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
+
 struct pretty_print_context {
 	/*
 	 * Callers should tweak these to change the behavior of pp_* functions.
 	 */
 	enum cmit_fmt fmt;
 	int abbrev;
-	const char *subject;
 	const char *after_subject;
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
+	int print_email_subject;
 	int expand_tabs_in_log;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
+	struct rev_info *rev;
 	const char *output_encoding;
 	struct string_list *mailmap;
 	int color;
@@ -175,7 +178,6 @@
 };
 
 extern int has_non_ascii(const char *text);
-struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
 extern const char *logmsg_reencode(const struct commit *commit,
 				   char **commit_encoding,
 				   const char *output_encoding);
diff --git a/common-main.c b/common-main.c
index c654f95..6a68900 100644
--- a/common-main.c
+++ b/common-main.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "exec_cmd.h"
+#include "attr.h"
 
 /*
  * Many parts of Git have subprograms communicate via pipe, expect the
@@ -33,6 +34,8 @@
 
 	git_setup_gettext();
 
+	attr_start();
+
 	git_extract_argv0_path(argv[0]);
 
 	restore_sigpipe_to_default();
diff --git a/config.c b/config.c
index 0e9e1eb..1a4d855 100644
--- a/config.c
+++ b/config.c
@@ -13,6 +13,7 @@
 #include "hashmap.h"
 #include "string-list.h"
 #include "utf8.h"
+#include "dir.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -170,9 +171,94 @@
 	return ret;
 }
 
+static int prepare_include_condition_pattern(struct strbuf *pat)
+{
+	struct strbuf path = STRBUF_INIT;
+	char *expanded;
+	int prefix = 0;
+
+	expanded = expand_user_path(pat->buf);
+	if (expanded) {
+		strbuf_reset(pat);
+		strbuf_addstr(pat, expanded);
+		free(expanded);
+	}
+
+	if (pat->buf[0] == '.' && is_dir_sep(pat->buf[1])) {
+		const char *slash;
+
+		if (!cf || !cf->path)
+			return error(_("relative config include "
+				       "conditionals must come from files"));
+
+		strbuf_add_absolute_path(&path, cf->path);
+		slash = find_last_dir_sep(path.buf);
+		if (!slash)
+			die("BUG: how is this possible?");
+		strbuf_splice(pat, 0, 1, path.buf, slash - path.buf);
+		prefix = slash - path.buf + 1 /* slash */;
+	} else if (!is_absolute_path(pat->buf))
+		strbuf_insert(pat, 0, "**/", 3);
+
+	if (pat->len && is_dir_sep(pat->buf[pat->len - 1]))
+		strbuf_addstr(pat, "**");
+
+	strbuf_release(&path);
+	return prefix;
+}
+
+static int include_by_gitdir(const char *cond, size_t cond_len, int icase)
+{
+	struct strbuf text = STRBUF_INIT;
+	struct strbuf pattern = STRBUF_INIT;
+	int ret = 0, prefix;
+
+	strbuf_add_absolute_path(&text, get_git_dir());
+	strbuf_add(&pattern, cond, cond_len);
+	prefix = prepare_include_condition_pattern(&pattern);
+
+	if (prefix < 0)
+		goto done;
+
+	if (prefix > 0) {
+		/*
+		 * perform literal matching on the prefix part so that
+		 * any wildcard character in it can't create side effects.
+		 */
+		if (text.len < prefix)
+			goto done;
+		if (!icase && strncmp(pattern.buf, text.buf, prefix))
+			goto done;
+		if (icase && strncasecmp(pattern.buf, text.buf, prefix))
+			goto done;
+	}
+
+	ret = !wildmatch(pattern.buf + prefix, text.buf + prefix,
+			 icase ? WM_CASEFOLD : 0, NULL);
+
+done:
+	strbuf_release(&pattern);
+	strbuf_release(&text);
+	return ret;
+}
+
+static int include_condition_is_true(const char *cond, size_t cond_len)
+{
+
+	if (skip_prefix_mem(cond, cond_len, "gitdir:", &cond, &cond_len))
+		return include_by_gitdir(cond, cond_len, 0);
+	else if (skip_prefix_mem(cond, cond_len, "gitdir/i:", &cond, &cond_len))
+		return include_by_gitdir(cond, cond_len, 1);
+
+	/* unknown conditionals are always false */
+	return 0;
+}
+
 int git_config_include(const char *var, const char *value, void *data)
 {
 	struct config_include_data *inc = data;
+	const char *cond, *key;
+	int cond_len;
 	int ret;
 
 	/*
@@ -185,6 +271,12 @@
 
 	if (!strcmp(var, "include.path"))
 		ret = handle_path_include(value, inc);
+
+	if (!parse_config_key(var, "includeif", &cond, &cond_len, &key) &&
+	    (cond && include_condition_is_true(cond, cond_len)) &&
+	    !strcmp(key, "path"))
+		ret = handle_path_include(value, inc);
+
 	return ret;
 }
 
@@ -1503,6 +1595,31 @@
 	}
 }
 
+void read_early_config(config_fn_t cb, void *data)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	git_config_with_options(cb, data, NULL, 1);
+
+	/*
+	 * When setup_git_directory() was not yet asked to discover the
+	 * GIT_DIR, we ask discover_git_directory() to figure out whether there
+	 * is any repository config we should use (but unlike
+	 * setup_git_directory_gently(), no global state is changed, most
+	 * notably, the current working directory is still the same after the
+	 * call).
+	 */
+	if (!have_git_dir() && discover_git_directory(&buf)) {
+		struct git_config_source repo_config;
+
+		memset(&repo_config, 0, sizeof(repo_config));
+		strbuf_addstr(&buf, "/config");
+		repo_config.file = buf.buf;
+		git_config_with_options(cb, data, &repo_config, 1);
+	}
+	strbuf_release(&buf);
+}
+
 static void git_config_check_init(void);
 
 void git_config(config_fn_t fn, void *data)
@@ -1803,6 +1920,19 @@
 	return ret;
 }
 
+int git_config_get_expiry(const char *key, const char **output)
+{
+	int ret = git_config_get_string_const(key, output);
+	if (ret)
+		return ret;
+	if (strcmp(*output, "now")) {
+		unsigned long now = approxidate("now");
+		if (approxidate(*output) >= now)
+			git_die_config(key, _("Invalid %s: '%s'"), key, *output);
+	}
+	return ret;
+}
+
 int git_config_get_untracked_cache(void)
 {
 	int val = -1;
@@ -1819,14 +1949,39 @@
 		if (!strcasecmp(v, "keep"))
 			return -1;
 
-		error("unknown core.untrackedCache value '%s'; "
-		      "using 'keep' default value", v);
+		error(_("unknown core.untrackedCache value '%s'; "
+			"using 'keep' default value"), v);
 		return -1;
 	}
 
 	return -1; /* default value */
 }
 
+int git_config_get_split_index(void)
+{
+	int val;
+
+	if (!git_config_get_maybe_bool("core.splitindex", &val))
+		return val;
+
+	return -1; /* default value */
+}
+
+int git_config_get_max_percent_split_change(void)
+{
+	int val = -1;
+
+	if (!git_config_get_int("splitindex.maxpercentchange", &val)) {
+		if (0 <= val && val <= 100)
+			return val;
+
+		return error(_("splitIndex.maxPercentChange value '%d' "
+			       "should be between 0 and 100"), val);
+	}
+
+	return -1; /* default value */
+}
+
 NORETURN
 void git_die_config_linenr(const char *key, const char *filename, int linenr)
 {
diff --git a/connect.c b/connect.c
index 8cb93b0..7d65c1c 100644
--- a/connect.c
+++ b/connect.c
@@ -691,6 +691,68 @@
 	return NULL;
 }
 
+static int override_ssh_variant(int *port_option, int *needs_batch)
+{
+	char *variant;
+
+	variant = xstrdup_or_null(getenv("GIT_SSH_VARIANT"));
+	if (!variant &&
+	    git_config_get_string("ssh.variant", &variant))
+		return 0;
+
+	if (!strcmp(variant, "plink") || !strcmp(variant, "putty")) {
+		*port_option = 'P';
+		*needs_batch = 0;
+	} else if (!strcmp(variant, "tortoiseplink")) {
+		*port_option = 'P';
+		*needs_batch = 1;
+	} else {
+		*port_option = 'p';
+		*needs_batch = 0;
+	}
+	free(variant);
+	return 1;
+}
+
+static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
+			       int *port_option, int *needs_batch)
+{
+	const char *variant;
+	char *p = NULL;
+
+	if (override_ssh_variant(port_option, needs_batch))
+		return;
+
+	if (!is_cmdline) {
+		p = xstrdup(ssh_command);
+		variant = basename(p);
+	} else {
+		const char **ssh_argv;
+
+		p = xstrdup(ssh_command);
+		if (split_cmdline(p, &ssh_argv)) {
+			variant = basename((char *)ssh_argv[0]);
+			/*
+			 * At this point, variant points into the buffer
+			 * referenced by p, hence we do not need ssh_argv
+			 * any longer.
+			 */
+			free(ssh_argv);
+		} else
+			return;
+	}
+
+	if (!strcasecmp(variant, "plink") ||
+	    !strcasecmp(variant, "plink.exe"))
+		*port_option = 'P';
+	else if (!strcasecmp(variant, "tortoiseplink") ||
+		 !strcasecmp(variant, "tortoiseplink.exe")) {
+		*port_option = 'P';
+		*needs_batch = 1;
+	}
+	free(p);
+}
+
 /*
  * This returns a dummy child_process if the transport protocol does not
  * need fork(2), or a struct child_process object if it does.  Once done,
@@ -769,7 +831,8 @@
 		conn->in = conn->out = -1;
 		if (protocol == PROTO_SSH) {
 			const char *ssh;
-			int putty = 0, tortoiseplink = 0;
+			int needs_batch = 0;
+			int port_option = 'p';
 			char *ssh_host = hostandport;
 			const char *port = NULL;
 			transport_check_allowed("ssh");
@@ -792,10 +855,10 @@
 			}
 
 			ssh = get_ssh_command();
-			if (!ssh) {
-				const char *base;
-				char *ssh_dup;
-
+			if (ssh)
+				handle_ssh_variant(ssh, 1, &port_option,
+						   &needs_batch);
+			else {
 				/*
 				 * GIT_SSH is the no-shell version of
 				 * GIT_SSH_COMMAND (and must remain so for
@@ -806,17 +869,10 @@
 				ssh = getenv("GIT_SSH");
 				if (!ssh)
 					ssh = "ssh";
-
-				ssh_dup = xstrdup(ssh);
-				base = basename(ssh_dup);
-
-				tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
-					!strcasecmp(base, "tortoiseplink.exe");
-				putty = tortoiseplink ||
-					!strcasecmp(base, "plink") ||
-					!strcasecmp(base, "plink.exe");
-
-				free(ssh_dup);
+				else
+					handle_ssh_variant(ssh, 0,
+							   &port_option,
+							   &needs_batch);
 			}
 
 			argv_array_push(&conn->args, ssh);
@@ -824,11 +880,11 @@
 				argv_array_push(&conn->args, "-4");
 			else if (flags & CONNECT_IPV6)
 				argv_array_push(&conn->args, "-6");
-			if (tortoiseplink)
+			if (needs_batch)
 				argv_array_push(&conn->args, "-batch");
 			if (port) {
-				/* P is for PuTTY, p is for OpenSSH */
-				argv_array_push(&conn->args, putty ? "-P" : "-p");
+				argv_array_pushf(&conn->args,
+						 "-%c", port_option);
 				argv_array_push(&conn->args, port);
 			}
 			argv_array_push(&conn->args, ssh_host);
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 41ee529..fc32286 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -34,21 +34,41 @@
 *)   COMP_WORDBREAKS="$COMP_WORDBREAKS:"
 esac
 
+# Discovers the path to the git repository taking any '--git-dir=<path>' and
+# '-C <path>' options into account and stores it in the $__git_repo_path
+# variable.
+__git_find_repo_path ()
+{
+	if [ -n "$__git_repo_path" ]; then
+		# we already know where it is
+		return
+	fi
+
+	if [ -n "${__git_C_args-}" ]; then
+		__git_repo_path="$(git "${__git_C_args[@]}" \
+			${__git_dir:+--git-dir="$__git_dir"} \
+			rev-parse --absolute-git-dir 2>/dev/null)"
+	elif [ -n "${__git_dir-}" ]; then
+		test -d "$__git_dir" &&
+		__git_repo_path="$__git_dir"
+	elif [ -n "${GIT_DIR-}" ]; then
+		test -d "${GIT_DIR-}" &&
+		__git_repo_path="$GIT_DIR"
+	elif [ -d .git ]; then
+		__git_repo_path=.git
+	else
+		__git_repo_path="$(git rev-parse --git-dir 2>/dev/null)"
+	fi
+}
+
+# Deprecated: use __git_find_repo_path() and $__git_repo_path instead
 # __gitdir accepts 0 or 1 arguments (i.e., location)
 # returns location of .git repo
 __gitdir ()
 {
 	if [ -z "${1-}" ]; then
-		if [ -n "${__git_dir-}" ]; then
-			echo "$__git_dir"
-		elif [ -n "${GIT_DIR-}" ]; then
-			test -d "${GIT_DIR-}" || return 1
-			echo "$GIT_DIR"
-		elif [ -d .git ]; then
-			echo .git
-		else
-			git rev-parse --git-dir 2>/dev/null
-		fi
+		__git_find_repo_path || return 1
+		echo "$__git_repo_path"
 	elif [ -d "$1/.git" ]; then
 		echo "$1/.git"
 	else
@@ -56,6 +76,14 @@
 	fi
 }
 
+# Runs git with all the options given as argument, respecting any
+# '--git-dir=<path>' and '-C <path>' options present on the command line
+__git ()
+{
+	git ${__git_C_args:+"${__git_C_args[@]}"} \
+		${__git_dir:+--git-dir="$__git_dir"} "$@" 2>/dev/null
+}
+
 # The following function is based on code from:
 #
 #   bash_completion - programmable completion functions for bash 3.2+
@@ -283,11 +311,11 @@
 __git_ls_files_helper ()
 {
 	if [ "$2" == "--committable" ]; then
-		git -C "$1" diff-index --name-only --relative HEAD
+		__git -C "$1" diff-index --name-only --relative HEAD
 	else
 		# NOTE: $2 is not quoted in order to support multiple options
-		git -C "$1" ls-files --exclude-standard $2
-	fi 2>/dev/null
+		__git -C "$1" ls-files --exclude-standard $2
+	fi
 }
 
 
@@ -299,47 +327,61 @@
 #    slash.
 __git_index_files ()
 {
-	local dir="$(__gitdir)" root="${2-.}" file
+	local root="${2-.}" file
 
-	if [ -d "$dir" ]; then
-		__git_ls_files_helper "$root" "$1" |
-		while read -r file; do
-			case "$file" in
-			?*/*) echo "${file%%/*}" ;;
-			*) echo "$file" ;;
-			esac
-		done | sort | uniq
-	fi
+	__git_ls_files_helper "$root" "$1" |
+	while read -r file; do
+		case "$file" in
+		?*/*) echo "${file%%/*}" ;;
+		*) echo "$file" ;;
+		esac
+	done | sort | uniq
 }
 
 __git_heads ()
 {
-	local dir="$(__gitdir)"
-	if [ -d "$dir" ]; then
-		git --git-dir="$dir" for-each-ref --format='%(refname:short)' \
-			refs/heads
-		return
-	fi
+	__git for-each-ref --format='%(refname:short)' refs/heads
 }
 
 __git_tags ()
 {
-	local dir="$(__gitdir)"
-	if [ -d "$dir" ]; then
-		git --git-dir="$dir" for-each-ref --format='%(refname:short)' \
-			refs/tags
-		return
-	fi
+	__git for-each-ref --format='%(refname:short)' refs/tags
 }
 
-# __git_refs accepts 0, 1 (to pass to __gitdir), or 2 arguments
-# presence of 2nd argument means use the guess heuristic employed
-# by checkout for tracking branches
+# Lists refs from the local (by default) or from a remote repository.
+# It accepts 0, 1 or 2 arguments:
+# 1: The remote to list refs from (optional; ignored, if set but empty).
+#    Can be the name of a configured remote, a path, or a URL.
+# 2: In addition to local refs, list unique branches from refs/remotes/ for
+#    'git checkout's tracking DWIMery (optional; ignored, if set but empty).
 __git_refs ()
 {
-	local i hash dir="$(__gitdir "${1-}")" track="${2-}"
+	local i hash dir track="${2-}"
+	local list_refs_from=path remote="${1-}"
 	local format refs pfx
-	if [ -d "$dir" ]; then
+
+	__git_find_repo_path
+	dir="$__git_repo_path"
+
+	if [ -z "$remote" ]; then
+		if [ -z "$dir" ]; then
+			return
+		fi
+	else
+		if __git_is_configured_remote "$remote"; then
+			# configured remote takes precedence over a
+			# local directory with the same name
+			list_refs_from=remote
+		elif [ -d "$remote/.git" ]; then
+			dir="$remote/.git"
+		elif [ -d "$remote" ]; then
+			dir="$remote"
+		else
+			list_refs_from=url
+		fi
+	fi
+
+	if [ "$list_refs_from" = path ]; then
 		case "$cur" in
 		refs|refs/*)
 			format="refname"
@@ -355,14 +397,14 @@
 			refs="refs/tags refs/heads refs/remotes"
 			;;
 		esac
-		git --git-dir="$dir" for-each-ref --format="$pfx%($format)" \
+		__git_dir="$dir" __git for-each-ref --format="$pfx%($format)" \
 			$refs
 		if [ -n "$track" ]; then
 			# employ the heuristic used by git checkout
 			# Try to find a remote branch that matches the completion word
 			# but only output if the branch name is unique
 			local ref entry
-			git --git-dir="$dir" for-each-ref --shell --format="ref=%(refname:short)" \
+			__git for-each-ref --shell --format="ref=%(refname:short)" \
 				"refs/remotes/" | \
 			while read -r entry; do
 				eval "$entry"
@@ -376,7 +418,7 @@
 	fi
 	case "$cur" in
 	refs|refs/*)
-		git ls-remote "$dir" "$cur*" 2>/dev/null | \
+		__git ls-remote "$remote" "$cur*" | \
 		while read -r hash i; do
 			case "$i" in
 			*^{}) ;;
@@ -385,9 +427,21 @@
 		done
 		;;
 	*)
-		echo "HEAD"
-		git for-each-ref --format="%(refname:short)" -- \
-			"refs/remotes/$dir/" 2>/dev/null | sed -e "s#^$dir/##"
+		if [ "$list_refs_from" = remote ]; then
+			echo "HEAD"
+			__git for-each-ref --format="%(refname:short)" \
+				"refs/remotes/$remote/" | sed -e "s#^$remote/##"
+		else
+			__git ls-remote "$remote" HEAD \
+				"refs/tags/*" "refs/heads/*" "refs/remotes/*" |
+			while read -r hash i; do
+				case "$i" in
+				*^{})	;;
+				refs/*)	echo "${i#refs/*/}" ;;
+				*)	echo "$i" ;;  # symbolic refs
+				esac
+			done
+		fi
 		;;
 	esac
 }
@@ -405,7 +459,7 @@
 __git_refs_remotes ()
 {
 	local i hash
-	git ls-remote "$1" 'refs/heads/*' 2>/dev/null | \
+	__git ls-remote "$1" 'refs/heads/*' | \
 	while read -r hash i; do
 		echo "$i:refs/remotes/$1/${i#refs/heads/}"
 	done
@@ -413,9 +467,21 @@
 
 __git_remotes ()
 {
-	local d="$(__gitdir)"
-	test -d "$d/remotes" && ls -1 "$d/remotes"
-	git --git-dir="$d" remote
+	__git_find_repo_path
+	test -d "$__git_repo_path/remotes" && ls -1 "$__git_repo_path/remotes"
+	__git remote
+}
+
+# Returns true if $1 matches the name of a configured remote, false otherwise.
+__git_is_configured_remote ()
+{
+	local remote
+	for remote in $(__git_remotes); do
+		if [ "$remote" = "$1" ]; then
+			return 0
+		fi
+	done
+	return 1
 }
 
 __git_list_merge_strategies ()
@@ -469,7 +535,7 @@
 		*)   pfx="$ref:$pfx" ;;
 		esac
 
-		__gitcomp_nl "$(git --git-dir="$(__gitdir)" ls-tree "$ls" 2>/dev/null \
+		__gitcomp_nl "$(__git ls-tree "$ls" \
 				| sed '/^100... blob /{
 				           s,^.*	,,
 				           s,$, ,
@@ -747,7 +813,7 @@
 __git_get_config_variables ()
 {
 	local section="$1" i IFS=$'\n'
-	for i in $(git --git-dir="$(__gitdir)" config --name-only --get-regexp "^$section\..*" 2>/dev/null); do
+	for i in $(__git config --name-only --get-regexp "^$section\..*"); do
 		echo "${i#$section.}"
 	done
 }
@@ -765,8 +831,7 @@
 # __git_aliased_command requires 1 argument
 __git_aliased_command ()
 {
-	local word cmdline=$(git --git-dir="$(__gitdir)" \
-		config --get "alias.$1")
+	local word cmdline=$(__git config --get "alias.$1")
 	for word in $cmdline; do
 		case "$word" in
 		\!gitk|gitk)
@@ -842,7 +907,7 @@
 	done
 
 	if [ -n "$config_key" ] && [ -z "$result" ]; then
-		result="$(git --git-dir="$(__gitdir)" config "$config_key")"
+		result="$(__git config "$config_key")"
 	fi
 
 	echo "$result"
@@ -901,8 +966,8 @@
 
 _git_am ()
 {
-	local dir="$(__gitdir)"
-	if [ -d "$dir"/rebase-apply ]; then
+	__git_find_repo_path
+	if [ -d "$__git_repo_path"/rebase-apply ]; then
 		__gitcomp "--skip --continue --resolved --abort"
 		return
 	fi
@@ -990,7 +1055,8 @@
 	local subcommands="start bad good skip reset visualize replay log run"
 	local subcommand="$(__git_find_on_cmdline "$subcommands")"
 	if [ -z "$subcommand" ]; then
-		if [ -f "$(__gitdir)"/BISECT_START ]; then
+		__git_find_repo_path
+		if [ -f "$__git_repo_path"/BISECT_START ]; then
 			__gitcomp "$subcommands"
 		else
 			__gitcomp "replay start"
@@ -1096,8 +1162,8 @@
 
 _git_cherry_pick ()
 {
-	local dir="$(__gitdir)"
-	if [ -f "$dir"/CHERRY_PICK_HEAD ]; then
+	__git_find_repo_path
+	if [ -f "$__git_repo_path"/CHERRY_PICK_HEAD ]; then
 		__gitcomp "--continue --quit --abort"
 		return
 	fi
@@ -1192,7 +1258,7 @@
 		return
 	esac
 
-	if git rev-parse --verify --quiet HEAD >/dev/null; then
+	if __git rev-parse --verify --quiet HEAD >/dev/null; then
 		__git_complete_index_file "--committable"
 	else
 		# This is the first commit
@@ -1207,6 +1273,7 @@
 		__gitcomp "
 			--all --tags --contains --abbrev= --candidates=
 			--exact-match --debug --long --match --always --first-parent
+			--exclude
 			"
 		return
 	esac
@@ -1500,10 +1567,10 @@
 _git_log ()
 {
 	__git_has_doubledash && return
+	__git_find_repo_path
 
-	local g="$(git rev-parse --git-dir 2>/dev/null)"
 	local merge=""
-	if [ -f "$g/MERGE_HEAD" ]; then
+	if [ -f "$__git_repo_path/MERGE_HEAD" ]; then
 		merge="--merge"
 	fi
 	case "$cur" in
@@ -1750,11 +1817,12 @@
 
 _git_rebase ()
 {
-	local dir="$(__gitdir)"
-	if [ -f "$dir"/rebase-merge/interactive ]; then
+	__git_find_repo_path
+	if [ -f "$__git_repo_path"/rebase-merge/interactive ]; then
 		__gitcomp "--continue --skip --abort --quit --edit-todo"
 		return
-	elif [ -d "$dir"/rebase-apply ] || [ -d "$dir"/rebase-merge ]; then
+	elif [ -d "$__git_repo_path"/rebase-apply ] || \
+	     [ -d "$__git_repo_path"/rebase-merge ]; then
 		__gitcomp "--continue --skip --abort --quit"
 		return
 	fi
@@ -1802,9 +1870,7 @@
 {
 	case "$prev" in
 	--to|--cc|--bcc|--from)
-		__gitcomp "
-		$(git --git-dir="$(__gitdir)" send-email --dump-aliases 2>/dev/null)
-		"
+		__gitcomp "$(__git send-email --dump-aliases)"
 		return
 		;;
 	esac
@@ -1834,9 +1900,7 @@
 		return
 		;;
 	--to=*|--cc=*|--bcc=*|--from=*)
-		__gitcomp "
-		$(git --git-dir="$(__gitdir)" send-email --dump-aliases 2>/dev/null)
-		" "" "${cur#--*=}"
+		__gitcomp "$(__git send-email --dump-aliases)" "" "${cur#--*=}"
 		return
 		;;
 	--*)
@@ -1930,7 +1994,7 @@
 		c=$((--c))
 	done
 
-	git --git-dir="$(__gitdir)" config $config_file --name-only --list 2>/dev/null
+	__git config $config_file --name-only --list
 }
 
 _git_config ()
@@ -1965,9 +2029,8 @@
 	remote.*.push)
 		local remote="${prev#remote.}"
 		remote="${remote%.push}"
-		__gitcomp_nl "$(git --git-dir="$(__gitdir)" \
-			for-each-ref --format='%(refname):%(refname)' \
-			refs/heads)"
+		__gitcomp_nl "$(__git for-each-ref \
+			--format='%(refname):%(refname)' refs/heads)"
 		return
 		;;
 	pull.twohead|pull.octopus)
@@ -2482,8 +2545,8 @@
 
 _git_revert ()
 {
-	local dir="$(__gitdir)"
-	if [ -f "$dir"/REVERT_HEAD ]; then
+	__git_find_repo_path
+	if [ -f "$__git_repo_path"/REVERT_HEAD ]; then
 		__gitcomp "--continue --quit --abort"
 		return
 	fi
@@ -2606,12 +2669,12 @@
 			if [ $cword -eq 3 ]; then
 				__gitcomp_nl "$(__git_refs)";
 			else
-				__gitcomp_nl "$(git --git-dir="$(__gitdir)" stash list \
+				__gitcomp_nl "$(__git stash list \
 						| sed -n -e 's/:.*//p')"
 			fi
 			;;
 		show,*|apply,*|drop,*|pop,*)
-			__gitcomp_nl "$(git --git-dir="$(__gitdir)" stash list \
+			__gitcomp_nl "$(__git stash list \
 					| sed -n -e 's/:.*//p')"
 			;;
 		*)
@@ -2838,7 +2901,8 @@
 
 __git_main ()
 {
-	local i c=1 command __git_dir
+	local i c=1 command __git_dir __git_repo_path
+	local __git_C_args C_args_count=0
 
 	while [ $c -lt $cword ]; do
 		i="${words[c]}"
@@ -2848,6 +2912,10 @@
 		--bare)      __git_dir="." ;;
 		--help) command="help"; break ;;
 		-c|--work-tree|--namespace) ((c++)) ;;
+		-C)	__git_C_args[C_args_count++]=-C
+			((c++))
+			__git_C_args[C_args_count++]="${words[c]}"
+			;;
 		-*) ;;
 		*) command="$i"; break ;;
 		esac
@@ -2855,6 +2923,17 @@
 	done
 
 	if [ -z "$command" ]; then
+		case "$prev" in
+		--git-dir|-C|--work-tree)
+			# these need a path argument, let's fall back to
+			# Bash filename completion
+			return
+			;;
+		-c|--namespace)
+			# we don't support completing these options' arguments
+			return
+			;;
+		esac
 		case "$cur" in
 		--*)   __gitcomp "
 			--paginate
@@ -2880,13 +2959,13 @@
 	fi
 
 	local completion_func="_git_${command//-/_}"
-	declare -f $completion_func >/dev/null && $completion_func && return
+	declare -f $completion_func >/dev/null 2>/dev/null && $completion_func && return
 
 	local expansion=$(__git_aliased_command "$command")
 	if [ -n "$expansion" ]; then
 		words[1]=$expansion
 		completion_func="_git_${expansion//-/_}"
-		declare -f $completion_func >/dev/null && $completion_func
+		declare -f $completion_func >/dev/null 2>/dev/null && $completion_func
 	fi
 }
 
@@ -2894,9 +2973,11 @@
 {
 	__git_has_doubledash && return
 
-	local g="$(__gitdir)"
+	local __git_repo_path
+	__git_find_repo_path
+
 	local merge=""
-	if [ -f "$g/MERGE_HEAD" ]; then
+	if [ -f "$__git_repo_path/MERGE_HEAD" ]; then
 		merge="--merge"
 	fi
 	case "$cur" in
diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index 97eacd7..c6cbef3 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -82,6 +82,7 @@
 #     contains      relative to newer annotated tag (v1.6.3.2~35)
 #     branch        relative to newer tag or branch (master~4)
 #     describe      relative to older annotated tag (v1.6.3.1-13-gdd42c2f)
+#     tag           relative to any older tag (v1.6.3.1-13-gdd42c2f)
 #     default       exactly matching tag
 #
 # If you would like a colored hint about the current dirty state, set
@@ -443,6 +444,8 @@
 					git describe --contains HEAD ;;
 				(branch)
 					git describe --contains --all HEAD ;;
+				(tag)
+					git describe --tags HEAD ;;
 				(describe)
 					git describe HEAD ;;
 				(* | default)
diff --git a/convert.c b/convert.c
index 4e17e45..8d652bf 100644
--- a/convert.c
+++ b/convert.c
@@ -1028,7 +1028,7 @@
 	return 1;
 }
 
-static enum crlf_action git_path_check_crlf(struct git_attr_check *check)
+static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
 {
 	const char *value = check->value;
 
@@ -1045,7 +1045,7 @@
 	return CRLF_UNDEFINED;
 }
 
-static enum eol git_path_check_eol(struct git_attr_check *check)
+static enum eol git_path_check_eol(struct attr_check_item *check)
 {
 	const char *value = check->value;
 
@@ -1058,7 +1058,7 @@
 	return EOL_UNSET;
 }
 
-static struct convert_driver *git_path_check_convert(struct git_attr_check *check)
+static struct convert_driver *git_path_check_convert(struct attr_check_item *check)
 {
 	const char *value = check->value;
 	struct convert_driver *drv;
@@ -1071,7 +1071,7 @@
 	return NULL;
 }
 
-static int git_path_check_ident(struct git_attr_check *check)
+static int git_path_check_ident(struct attr_check_item *check)
 {
 	const char *value = check->value;
 
@@ -1085,24 +1085,19 @@
 	int ident;
 };
 
-static const char *conv_attr_name[] = {
-	"crlf", "ident", "filter", "eol", "text",
-};
-#define NUM_CONV_ATTRS ARRAY_SIZE(conv_attr_name)
-
 static void convert_attrs(struct conv_attrs *ca, const char *path)
 {
-	int i;
-	static struct git_attr_check ccheck[NUM_CONV_ATTRS];
+	static struct attr_check *check;
 
-	if (!ccheck[0].attr) {
-		for (i = 0; i < NUM_CONV_ATTRS; i++)
-			ccheck[i].attr = git_attr(conv_attr_name[i]);
+	if (!check) {
+		check = attr_check_initl("crlf", "ident", "filter",
+					 "eol", "text", NULL);
 		user_convert_tail = &user_convert;
 		git_config(read_convert_config, NULL);
 	}
 
-	if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
+	if (!git_check_attr(path, check)) {
+		struct attr_check_item *ccheck = check->items;
 		ca->crlf_action = git_path_check_crlf(ccheck + 4);
 		if (ca->crlf_action == CRLF_UNDEFINED)
 			ca->crlf_action = git_path_check_crlf(ccheck + 0);
diff --git a/credential-cache.c b/credential-cache.c
index cc8a6ee..3cbd420 100644
--- a/credential-cache.c
+++ b/credential-cache.c
@@ -83,6 +83,19 @@
 	strbuf_release(&buf);
 }
 
+static char *get_socket_path(void)
+{
+	struct stat sb;
+	char *old_dir, *socket;
+	old_dir = expand_user_path("~/.git-credential-cache");
+	if (old_dir && !stat(old_dir, &sb) && S_ISDIR(sb.st_mode))
+		socket = xstrfmt("%s/socket", old_dir);
+	else
+		socket = xdg_cache_home("credential/socket");
+	free(old_dir);
+	return socket;
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	char *socket_path = NULL;
@@ -106,7 +119,7 @@
 	op = argv[0];
 
 	if (!socket_path)
-		socket_path = expand_user_path("~/.git-credential-cache/socket");
+		socket_path = get_socket_path();
 	if (!socket_path)
 		die("unable to find a suitable socket path; use --socket");
 
diff --git a/diff-no-index.c b/diff-no-index.c
index df762fd..7922938 100644
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -236,7 +236,7 @@
 void diff_no_index(struct rev_info *revs,
 		   int argc, const char **argv)
 {
-	int i, prefixlen;
+	int i;
 	const char *paths[2];
 	struct strbuf replacement = STRBUF_INIT;
 	const char *prefix = revs->prefix;
@@ -257,7 +257,6 @@
 		}
 	}
 
-	prefixlen = prefix ? strlen(prefix) : 0;
 	for (i = 0; i < 2; i++) {
 		const char *p = argv[argc - 2 + i];
 		if (!strcmp(p, "-"))
@@ -266,8 +265,8 @@
 			 * path that is "-", spell it as "./-".
 			 */
 			p = file_from_standard_input;
-		else if (prefixlen)
-			p = xstrdup(prefix_filename(prefix, prefixlen, p));
+		else if (prefix)
+			p = prefix_filename(prefix, p);
 		paths[i] = p;
 	}
 
diff --git a/diff.c b/diff.c
index a628ac3..58cb72d 100644
--- a/diff.c
+++ b/diff.c
@@ -4023,8 +4023,7 @@
 	else if (!strcmp(arg, "--pickaxe-regex"))
 		options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 	else if ((argcount = short_opt('O', av, &optarg))) {
-		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
-		options->orderfile = xstrdup(path);
+		options->orderfile = prefix_filename(prefix, optarg);
 		return argcount;
 	}
 	else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -4071,13 +4070,14 @@
 	else if (!strcmp(arg, "--no-function-context"))
 		DIFF_OPT_CLR(options, FUNCCONTEXT);
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
-		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		char *path = prefix_filename(prefix, optarg);
 		options->file = fopen(path, "w");
 		if (!options->file)
 			die_errno("Could not open '%s'", path);
 		options->close_file = 1;
 		if (options->use_color != GIT_COLOR_ALWAYS)
 			options->use_color = GIT_COLOR_NEVER;
+		free(path);
 		return argcount;
 	} else
 		return 0;
diff --git a/dir.c b/dir.c
index aeeb5ce..f451bfa 100644
--- a/dir.c
+++ b/dir.c
@@ -9,6 +9,7 @@
  */
 #include "cache.h"
 #include "dir.h"
+#include "attr.h"
 #include "refs.h"
 #include "wildmatch.h"
 #include "pathspec.h"
@@ -134,7 +135,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	for (n = 0; n < pathspec->nr; n++) {
 		size_t i = 0, len = 0, item_len;
@@ -209,6 +211,36 @@
 #define DO_MATCH_DIRECTORY (1<<1)
 #define DO_MATCH_SUBMODULE (1<<2)
 
+static int match_attrs(const char *name, int namelen,
+		       const struct pathspec_item *item)
+{
+	int i;
+
+	git_check_attr(name, item->attr_check);
+	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
@@ -261,6 +293,9 @@
 	    strncmp(item->match, name - prefix, item->prefix))
 		return 0;
 
+	if (item->attr_match_nr && !match_attrs(name, namelen, item))
+		return 0;
+
 	/* If the match was just the prefix, we matched */
 	if (!*match)
 		return MATCHED_RECURSIVELY;
@@ -339,7 +374,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	if (!ps->nr) {
 		if (!ps->recursive ||
@@ -1361,7 +1397,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	for (i = 0; i < pathspec->nr; i++) {
 		const struct pathspec_item *item = &pathspec->items[i];
@@ -2728,23 +2765,33 @@
 /* Update gitfile and core.worktree setting to connect work tree and git dir */
 void connect_work_tree_and_git_dir(const char *work_tree_, const char *git_dir_)
 {
-	struct strbuf file_name = STRBUF_INIT;
+	struct strbuf gitfile_sb = STRBUF_INIT;
+	struct strbuf cfg_sb = STRBUF_INIT;
 	struct strbuf rel_path = STRBUF_INIT;
-	char *git_dir = real_pathdup(git_dir_, 1);
-	char *work_tree = real_pathdup(work_tree_, 1);
+	char *git_dir, *work_tree;
 
-	/* Update gitfile */
-	strbuf_addf(&file_name, "%s/.git", work_tree);
-	write_file(file_name.buf, "gitdir: %s",
+	/* Prepare .git file */
+	strbuf_addf(&gitfile_sb, "%s/.git", work_tree_);
+	if (safe_create_leading_directories_const(gitfile_sb.buf))
+		die(_("could not create directories for %s"), gitfile_sb.buf);
+
+	/* Prepare config file */
+	strbuf_addf(&cfg_sb, "%s/config", git_dir_);
+	if (safe_create_leading_directories_const(cfg_sb.buf))
+		die(_("could not create directories for %s"), cfg_sb.buf);
+
+	git_dir = real_pathdup(git_dir_, 1);
+	work_tree = real_pathdup(work_tree_, 1);
+
+	/* Write .git file */
+	write_file(gitfile_sb.buf, "gitdir: %s",
 		   relative_path(git_dir, work_tree, &rel_path));
-
 	/* Update core.worktree setting */
-	strbuf_reset(&file_name);
-	strbuf_addf(&file_name, "%s/config", git_dir);
-	git_config_set_in_file(file_name.buf, "core.worktree",
+	git_config_set_in_file(cfg_sb.buf, "core.worktree",
 			       relative_path(work_tree, git_dir, &rel_path));
 
-	strbuf_release(&file_name);
+	strbuf_release(&gitfile_sb);
+	strbuf_release(&cfg_sb);
 	strbuf_release(&rel_path);
 	free(work_tree);
 	free(git_dir);
diff --git a/entry.c b/entry.c
index c6eea24..d2b512d 100644
--- a/entry.c
+++ b/entry.c
@@ -2,6 +2,7 @@
 #include "blob.h"
 #include "dir.h"
 #include "streaming.h"
+#include "submodule.h"
 
 static void create_directories(const char *path, int path_len,
 			       const struct checkout *state)
@@ -146,6 +147,7 @@
 	unsigned long size;
 	size_t wrote, newsize = 0;
 	struct stat st;
+	const struct submodule *sub;
 
 	if (ce_mode_s_ifmt == S_IFREG) {
 		struct stream_filter *filter = get_stream_filter(ce->name,
@@ -203,6 +205,10 @@
 			return error("cannot create temporary submodule %s", path);
 		if (mkdir(path, 0777) < 0)
 			return error("cannot create submodule directory %s", path);
+		sub = submodule_from_ce(ce);
+		if (sub)
+			return submodule_move_head(ce->name,
+				NULL, oid_to_hex(&ce->oid), SUBMODULE_MOVE_HEAD_FORCE);
 		break;
 	default:
 		return error("unknown file mode for %s in index", path);
@@ -259,7 +265,31 @@
 	strbuf_add(&path, ce->name, ce_namelen(ce));
 
 	if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
+		const struct submodule *sub;
 		unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
+		/*
+		 * Needs to be checked before !changed returns early,
+		 * as the possibly empty directory was not changed
+		 */
+		sub = submodule_from_ce(ce);
+		if (sub) {
+			int err;
+			if (!is_submodule_populated_gently(ce->name, &err)) {
+				struct stat sb;
+				if (lstat(ce->name, &sb))
+					die(_("could not stat file '%s'"), ce->name);
+				if (!(st.st_mode & S_IFDIR))
+					unlink_or_warn(ce->name);
+
+				return submodule_move_head(ce->name,
+					NULL, oid_to_hex(&ce->oid),
+					SUBMODULE_MOVE_HEAD_FORCE);
+			} else
+				return submodule_move_head(ce->name,
+					"HEAD", oid_to_hex(&ce->oid),
+					SUBMODULE_MOVE_HEAD_FORCE);
+		}
+
 		if (!changed)
 			return 0;
 		if (!state->force) {
diff --git a/fast-import.c b/fast-import.c
index 4d5a7f5..f6f416f 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1173,7 +1173,8 @@
 		delta_count_by_type[type]++;
 		e->depth = last->depth + 1;
 
-		hdrlen = encode_in_pack_object_header(OBJ_OFS_DELTA, deltalen, hdr);
+		hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
+						      OBJ_OFS_DELTA, deltalen);
 		sha1write(pack_file, hdr, hdrlen);
 		pack_size += hdrlen;
 
@@ -1184,7 +1185,8 @@
 		pack_size += sizeof(hdr) - pos;
 	} else {
 		e->depth = 0;
-		hdrlen = encode_in_pack_object_header(type, dat->len, hdr);
+		hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
+						      type, dat->len);
 		sha1write(pack_file, hdr, hdrlen);
 		pack_size += hdrlen;
 	}
@@ -1237,9 +1239,7 @@
 	sha1file_checkpoint(pack_file, &checkpoint);
 	offset = checkpoint.offset;
 
-	hdrlen = snprintf((char *)out_buf, out_sz, "blob %" PRIuMAX, len) + 1;
-	if (out_sz <= hdrlen)
-		die("impossibly large object header");
+	hdrlen = xsnprintf((char *)out_buf, out_sz, "blob %" PRIuMAX, len) + 1;
 
 	git_SHA1_Init(&c);
 	git_SHA1_Update(&c, out_buf, hdrlen);
@@ -1248,9 +1248,7 @@
 
 	git_deflate_init(&s, pack_compression_level);
 
-	hdrlen = encode_in_pack_object_header(OBJ_BLOB, len, out_buf);
-	if (out_sz <= hdrlen)
-		die("impossibly large object header");
+	hdrlen = encode_in_pack_object_header(out_buf, out_sz, OBJ_BLOB, len);
 
 	s.next_out = out_buf + hdrlen;
 	s.avail_out = out_sz - hdrlen;
@@ -1752,7 +1750,7 @@
 
 	if (is_null_sha1(b->sha1)) {
 		if (b->delete)
-			delete_ref(b->name, NULL, 0);
+			delete_ref(NULL, b->name, NULL, 0);
 		return 0;
 	}
 	if (read_ref(b->name, old_sha1))
@@ -3003,7 +3001,7 @@
 	if (!oe)
 		die("Unknown mark: %s", command_buf.buf);
 
-	snprintf(output, sizeof(output), "%s\n", sha1_to_hex(oe->idx.sha1));
+	xsnprintf(output, sizeof(output), "%s\n", sha1_to_hex(oe->idx.sha1));
 	cat_blob_write(output, 41);
 }
 
diff --git a/fetch-pack.c b/fetch-pack.c
index f12bfcd..d07d85c 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -35,6 +35,7 @@
 #define COMMON_REF	(1U << 2)
 #define SEEN		(1U << 3)
 #define POPPED		(1U << 4)
+#define ALTERNATE	(1U << 5)
 
 static int marked;
 
@@ -67,6 +68,41 @@
 	fputc('\n', stderr);
 }
 
+struct alternate_object_cache {
+	struct object **items;
+	size_t nr, alloc;
+};
+
+static void cache_one_alternate(const char *refname,
+				const struct object_id *oid,
+				void *vcache)
+{
+	struct alternate_object_cache *cache = vcache;
+	struct object *obj = parse_object(oid->hash);
+
+	if (!obj || (obj->flags & ALTERNATE))
+		return;
+
+	obj->flags |= ALTERNATE;
+	ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
+	cache->items[cache->nr++] = obj;
+}
+
+static void for_each_cached_alternate(void (*cb)(struct object *))
+{
+	static int initialized;
+	static struct alternate_object_cache cache;
+	size_t i;
+
+	if (!initialized) {
+		for_each_alternate_ref(cache_one_alternate, &cache);
+		initialized = 1;
+	}
+
+	for (i = 0; i < cache.nr; i++)
+		cb(cache.items[i]);
+}
+
 static void rev_list_push(struct commit *commit, int mark)
 {
 	if (!(commit->object.flags & mark)) {
@@ -253,9 +289,9 @@
 		write_or_die(fd, buf->buf, buf->len);
 }
 
-static void insert_one_alternate_ref(const struct ref *ref, void *unused)
+static void insert_one_alternate_object(struct object *obj)
 {
-	rev_list_insert_ref(NULL, ref->old_oid.hash);
+	rev_list_insert_ref(NULL, obj->oid.hash);
 }
 
 #define INITIAL_FLUSH 16
@@ -298,7 +334,7 @@
 	marked = 1;
 
 	for_each_ref(rev_list_insert_ref_oid, NULL);
-	for_each_alternate_ref(insert_one_alternate_ref, NULL);
+	for_each_cached_alternate(insert_one_alternate_object);
 
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
@@ -621,9 +657,9 @@
 	*refs = newlist;
 }
 
-static void mark_alternate_complete(const struct ref *ref, void *unused)
+static void mark_alternate_complete(struct object *obj)
 {
-	mark_complete(ref->old_oid.hash);
+	mark_complete(obj->oid.hash);
 }
 
 static int everything_local(struct fetch_pack_args *args,
@@ -659,7 +695,7 @@
 
 	if (!args->deepen) {
 		for_each_ref(mark_complete_oid, NULL);
-		for_each_alternate_ref(mark_alternate_complete, NULL);
+		for_each_cached_alternate(mark_alternate_complete);
 		commit_list_sort_by_date(&complete);
 		if (cutoff)
 			mark_recent_complete_commits(args, cutoff);
diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index f5c816e..77b4ed5 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -275,20 +275,11 @@
 	my ($only) = @_;
 	my (%data, @return);
 	my ($add, $del, $adddel, $file);
-	my @tracked = ();
-
-	if (@ARGV) {
-		@tracked = map {
-			chomp $_;
-			unquote_path($_);
-		} run_cmd_pipe(qw(git ls-files --), @ARGV);
-		return if (!@tracked);
-	}
 
 	my $reference = get_diff_reference($patch_mode_revision);
 	for (run_cmd_pipe(qw(git diff-index --cached
 			     --numstat --summary), $reference,
-			     '--', @tracked)) {
+			     '--', @ARGV)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			my ($change, $bin);
@@ -313,7 +304,7 @@
 		}
 	}
 
-	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @tracked)) {
+	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @ARGV)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			$file = unquote_path($file);
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 4734094..2c9c016 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -1069,6 +1069,10 @@
 
 case "$action" in
 continue)
+	if test ! -d "$rewritten"
+	then
+		exec git rebase--helper ${force_rebase:+--no-ff} --continue
+	fi
 	# do we have anything to commit?
 	if git diff-index --cached --quiet HEAD --
 	then
@@ -1128,6 +1132,10 @@
 skip)
 	git rerere clear
 
+	if test ! -d "$rewritten"
+	then
+		exec git rebase--helper ${force_rebase:+--no-ff} --continue
+	fi
 	do_rest
 	return 0
 	;;
@@ -1314,6 +1322,11 @@
 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
 
 checkout_onto
+if test -z "$rebase_root" && test ! -d "$rewritten"
+then
+	require_clean_work_tree "rebase"
+	exec git rebase--helper ${force_rebase:+--no-ff} --continue
+fi
 do_rest
 
 }
diff --git a/git-stash.sh b/git-stash.sh
index 10c284d..2fb651b 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -7,8 +7,11 @@
    or: $dashless drop [-q|--quiet] [<stash>]
    or: $dashless ( pop | apply ) [--index] [-q|--quiet] [<stash>]
    or: $dashless branch <branchname> [<stash>]
-   or: $dashless [save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
-		       [-u|--include-untracked] [-a|--all] [<message>]]
+   or: $dashless save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
+		      [-u|--include-untracked] [-a|--all] [<message>]
+   or: $dashless [push [--patch] [-k|--[no-]keep-index] [-q|--quiet]
+		       [-u|--include-untracked] [-a|--all] [-m <message>]
+		       [-- <pathspec>...]]
    or: $dashless clear"
 
 SUBDIRECTORY_OK=Yes
@@ -33,15 +36,15 @@
 fi
 
 no_changes () {
-	git diff-index --quiet --cached HEAD --ignore-submodules -- &&
-	git diff-files --quiet --ignore-submodules &&
+	git diff-index --quiet --cached HEAD --ignore-submodules -- "$@" &&
+	git diff-files --quiet --ignore-submodules -- "$@" &&
 	(test -z "$untracked" || test -z "$(untracked_files)")
 }
 
 untracked_files () {
 	excl_opt=--exclude-standard
 	test "$untracked" = "all" && excl_opt=
-	git ls-files -o -z $excl_opt
+	git ls-files -o -z $excl_opt -- "$@"
 }
 
 clear_stash () {
@@ -56,11 +59,29 @@
 }
 
 create_stash () {
-	stash_msg="$1"
-	untracked="$2"
+	stash_msg=
+	untracked=
+	while test $# != 0
+	do
+		case "$1" in
+		-m|--message)
+			shift
+			stash_msg=${1?"BUG: create_stash () -m requires an argument"}
+			;;
+		-u|--include-untracked)
+			shift
+			untracked=${1?"BUG: create_stash () -u requires an argument"}
+			;;
+		--)
+			shift
+			break
+			;;
+		esac
+		shift
+	done
 
 	git update-index -q --refresh
-	if no_changes
+	if no_changes "$@"
 	then
 		exit 0
 	fi
@@ -92,7 +113,7 @@
 		# Untracked files are stored by themselves in a parentless commit, for
 		# ease of unpacking later.
 		u_commit=$(
-			untracked_files | (
+			untracked_files "$@" | (
 				GIT_INDEX_FILE="$TMPindex" &&
 				export GIT_INDEX_FILE &&
 				rm -f "$TMPindex" &&
@@ -115,7 +136,7 @@
 			git read-tree --index-output="$TMPindex" -m $i_tree &&
 			GIT_INDEX_FILE="$TMPindex" &&
 			export GIT_INDEX_FILE &&
-			git diff-index --name-only -z HEAD -- >"$TMP-stagenames" &&
+			git diff-index --name-only -z HEAD -- "$@" >"$TMP-stagenames" &&
 			git update-index -z --add --remove --stdin <"$TMP-stagenames" &&
 			git write-tree &&
 			rm -f "$TMPindex"
@@ -129,7 +150,7 @@
 
 		# find out what the user wants
 		GIT_INDEX_FILE="$TMP-index" \
-			git add--interactive --patch=stash -- &&
+			git add--interactive --patch=stash -- "$@" &&
 
 		# state of the working tree
 		w_tree=$(GIT_INDEX_FILE="$TMP-index" git write-tree) ||
@@ -189,10 +210,11 @@
 	return $ret
 }
 
-save_stash () {
+push_stash () {
 	keep_index=
 	patch_mode=
 	untracked=
+	stash_msg=
 	while test $# != 0
 	do
 		case "$1" in
@@ -216,6 +238,11 @@
 		-a|--all)
 			untracked=all
 			;;
+		-m|--message)
+			shift
+			test -z ${1+x} && usage
+			stash_msg=$1
+			;;
 		--help)
 			show_help
 			;;
@@ -251,34 +278,45 @@
 		die "$(gettext "Can't use --patch and --include-untracked or --all at the same time")"
 	fi
 
-	stash_msg="$*"
+	test -n "$untracked" || git ls-files --error-unmatch -- "$@" >/dev/null || exit 1
 
 	git update-index -q --refresh
-	if no_changes
+	if no_changes "$@"
 	then
 		say "$(gettext "No local changes to save")"
 		exit 0
 	fi
+
 	git reflog exists $ref_stash ||
 		clear_stash || die "$(gettext "Cannot initialize stash")"
 
-	create_stash "$stash_msg" $untracked
+	create_stash -m "$stash_msg" -u "$untracked" -- "$@"
 	store_stash -m "$stash_msg" -q $w_commit ||
 	die "$(gettext "Cannot save the current status")"
 	say "$(eval_gettext "Saved working directory and index state \$stash_msg")"
 
 	if test -z "$patch_mode"
 	then
-		git reset --hard ${GIT_QUIET:+-q}
+		if test $# != 0
+		then
+			git reset -q -- "$@"
+			git ls-files -z --modified -- "$@" |
+			git checkout-index -z --force --stdin
+			git clean --force -q -d -- "$@"
+		else
+			git reset --hard -q
+		fi
 		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
 		if test -n "$untracked"
 		then
-			git clean --force --quiet -d $CLEAN_X_OPTION
+			git clean --force --quiet -d $CLEAN_X_OPTION -- "$@"
 		fi
 
 		if test "$keep_index" = "t" && test -n "$i_tree"
 		then
-			git read-tree --reset -u $i_tree
+			git read-tree --reset $i_tree
+			git ls-files -z --modified -- "$@" |
+			git checkout-index -z --force --stdin
 		fi
 	else
 		git apply -R < "$TMP-patch" ||
@@ -286,11 +324,41 @@
 
 		if test "$keep_index" != "t"
 		then
-			git reset
+			git reset -q -- "$@"
 		fi
 	fi
 }
 
+save_stash () {
+	push_options=
+	while test $# != 0
+	do
+		case "$1" in
+		--)
+			shift
+			break
+			;;
+		-*)
+			# pass all options through to push_stash
+			push_options="$push_options $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	stash_msg="$*"
+
+	if test -z "$stash_msg"
+	then
+		push_stash $push_options
+	else
+		push_stash $push_options -m "$stash_msg"
+	fi
+}
+
 have_stash () {
 	git rev-parse --verify --quiet $ref_stash >/dev/null
 }
@@ -590,18 +658,21 @@
 	}
 }
 
+test "$1" = "-p" && set "push" "$@"
+
 PARSE_CACHE='--not-parsed'
-# The default command is "save" if nothing but options are given
+# The default command is "push" if nothing but options are given
 seen_non_option=
 for opt
 do
 	case "$opt" in
+	--) break ;;
 	-*) ;;
 	*) seen_non_option=t; break ;;
 	esac
 done
 
-test -n "$seen_non_option" || set "save" "$@"
+test -n "$seen_non_option" || set "push" "$@"
 
 # Main command set
 case "$1" in
@@ -617,6 +688,10 @@
 	shift
 	save_stash "$@"
 	;;
+push)
+	shift
+	push_stash "$@"
+	;;
 apply)
 	shift
 	apply_stash "$@"
@@ -627,7 +702,7 @@
 	;;
 create)
 	shift
-	create_stash "$*" && echo "$w_commit"
+	create_stash -m "$*" && echo "$w_commit"
 	;;
 store)
 	shift
@@ -648,7 +723,7 @@
 *)
 	case $# in
 	0)
-		save_stash &&
+		push_stash &&
 		say "$(gettext "(To restore them type \"git stash apply\")")"
 		;;
 	*)
diff --git a/git-svn.perl b/git-svn.perl
index fa42364..d240418 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -1175,10 +1175,10 @@
 	::_req_svn();
 	require SVN::Client;
 
+	my ($config, $baton, undef) = Git::SVN::Ra::prepare_config_once();
 	my $ctx = SVN::Client->new(
-		config => SVN::Core::config_get_config(
-			$Git::SVN::Ra::config_dir
-		),
+		auth => $baton,
+		config => $config,
 		log_msg => sub {
 			${ $_[0] } = defined $_message
 				? $_message
diff --git a/git.c b/git.c
index c887272..33f52ac 100644
--- a/git.c
+++ b/git.c
@@ -473,6 +473,7 @@
 	{ "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 	{ "push", cmd_push, RUN_SETUP },
 	{ "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
+	{ "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 	{ "receive-pack", cmd_receive_pack },
 	{ "reflog", cmd_reflog, RUN_SETUP },
 	{ "remote", cmd_remote, RUN_SETUP },
diff --git a/grep.c b/grep.c
index 0dbdc1d..56ef0ec 100644
--- a/grep.c
+++ b/grep.c
@@ -12,6 +12,11 @@
 
 static struct grep_opt grep_defaults;
 
+static void std_output(struct grep_opt *opt, const void *buf, size_t size)
+{
+	fwrite(buf, size, 1, stdout);
+}
+
 /*
  * Initialize the grep_defaults template with hardcoded defaults.
  * We could let the compiler do this, but without C99 initializers
@@ -42,6 +47,7 @@
 	color_set(opt->color_selected, "");
 	color_set(opt->color_sep, GIT_COLOR_CYAN);
 	opt->color = -1;
+	opt->output = std_output;
 }
 
 static int parse_pattern_type_arg(const char *opt, const char *arg)
@@ -152,6 +158,7 @@
 	opt->pathname = def->pathname;
 	opt->regflags = def->regflags;
 	opt->relative = def->relative;
+	opt->output = def->output;
 
 	color_set(opt->color_context, def->color_context);
 	color_set(opt->color_filename, def->color_filename);
@@ -1379,11 +1386,6 @@
 	return 0;
 }
 
-static void std_output(struct grep_opt *opt, const void *buf, size_t size)
-{
-	fwrite(buf, size, 1, stdout);
-}
-
 static int fill_textconv_grep(struct userdiff_driver *driver,
 			      struct grep_source *gs)
 {
diff --git a/hash.h b/hash.h
new file mode 100644
index 0000000..a11fc92
--- /dev/null
+++ b/hash.h
@@ -0,0 +1,16 @@
+#ifndef HASH_H
+#define HASH_H
+
+#if defined(SHA1_PPC)
+#include "ppc/sha1.h"
+#elif defined(SHA1_APPLE)
+#include <CommonCrypto/CommonDigest.h>
+#elif defined(SHA1_OPENSSL)
+#include <openssl/sha.h>
+#elif defined(SHA1_DC)
+#include "sha1dc/sha1.h"
+#else /* SHA1_BLK */
+#include "block-sha1/sha1.h"
+#endif
+
+#endif
diff --git a/hashmap.c b/hashmap.c
index b10b642..7d1044e 100644
--- a/hashmap.c
+++ b/hashmap.c
@@ -50,6 +50,23 @@
 	return hash;
 }
 
+/*
+ * Incoporate another chunk of data into a memihash
+ * computation.
+ */
+unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len)
+{
+	unsigned int hash = hash_seed;
+	unsigned char *ucbuf = (unsigned char *) buf;
+	while (len--) {
+		unsigned int c = *ucbuf++;
+		if (c >= 'a' && c <= 'z')
+			c -= 'a' - 'A';
+		hash = (hash * FNV32_PRIME) ^ c;
+	}
+	return hash;
+}
+
 #define HASHMAP_INITIAL_SIZE 64
 /* grow / shrink by 2^2 */
 #define HASHMAP_RESIZE_BITS 2
@@ -87,11 +104,19 @@
 	return key->hash & (map->tablesize - 1);
 }
 
+int hashmap_bucket(const struct hashmap *map, unsigned int hash)
+{
+	return hash & (map->tablesize - 1);
+}
+
 static void rehash(struct hashmap *map, unsigned int newsize)
 {
 	unsigned int i, oldsize = map->tablesize;
 	struct hashmap_entry **oldtable = map->table;
 
+	if (map->disallow_rehash)
+		return;
+
 	alloc_table(map, newsize);
 	for (i = 0; i < oldsize; i++) {
 		struct hashmap_entry *e = oldtable[i];
@@ -124,7 +149,9 @@
 		size_t initial_size)
 {
 	unsigned int size = HASHMAP_INITIAL_SIZE;
-	map->size = 0;
+
+	memset(map, 0, sizeof(*map));
+
 	map->cmpfn = equals_function ? equals_function : always_equal;
 
 	/* calculate initial table size and allocate the table */
diff --git a/hashmap.h b/hashmap.h
index ab7958a..de6022a 100644
--- a/hashmap.h
+++ b/hashmap.h
@@ -12,6 +12,7 @@
 extern unsigned int strihash(const char *buf);
 extern unsigned int memhash(const void *buf, size_t len);
 extern unsigned int memihash(const void *buf, size_t len);
+extern unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len);
 
 static inline unsigned int sha1hash(const unsigned char *sha1)
 {
@@ -38,6 +39,7 @@
 	struct hashmap_entry **table;
 	hashmap_cmp_fn cmpfn;
 	unsigned int size, tablesize, grow_at, shrink_at;
+	unsigned disallow_rehash : 1;
 };
 
 struct hashmap_iter {
@@ -76,6 +78,29 @@
 	return hashmap_get(map, &key, keydata);
 }
 
+int hashmap_bucket(const struct hashmap *map, unsigned int hash);
+
+/*
+ * Disallow/allow rehashing of the hashmap.
+ * This is useful if the caller knows that the hashmap
+ * needs multi-threaded access.  The caller is still
+ * required to guard/lock searches and inserts in a
+ * manner appropriate to their usage.  This simply
+ * prevents the table from being unexpectedly re-mapped.
+ *
+ * If is up to the caller to ensure that the hashmap is
+ * initialized to a reasonable size to prevent poor
+ * performance.
+ *
+ * When value=1, prevent future rehashes on adds and deleted.
+ * When value=0, allow future rehahses.  This DOES NOT force
+ * a rehash now.
+ */
+static inline void hashmap_disallow_rehash(struct hashmap *map, unsigned value)
+{
+	map->disallow_rehash = value;
+}
+
 /* hashmap_iter functions */
 
 extern void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
diff --git a/hex.c b/hex.c
index 845b01a..eab7b62 100644
--- a/hex.c
+++ b/hex.c
@@ -53,6 +53,14 @@
 	return get_sha1_hex(hex, oid->hash);
 }
 
+int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
+{
+	int ret = get_oid_hex(hex, oid);
+	if (!ret)
+		*end = hex + GIT_SHA1_HEXSZ;
+	return ret;
+}
+
 char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
 {
 	static const char hex[] = "0123456789abcdef";
diff --git a/ll-merge.c b/ll-merge.c
index ad8be42..ac0d4a5 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -336,15 +336,6 @@
 	return &ll_merge_drv[LL_TEXT_MERGE];
 }
 
-static int git_path_check_merge(const char *path, struct git_attr_check check[2])
-{
-	if (!check[0].attr) {
-		check[0].attr = git_attr("merge");
-		check[1].attr = git_attr("conflict-marker-size");
-	}
-	return git_check_attr(path, 2, check);
-}
-
 static void normalize_file(mmfile_t *mm, const char *path)
 {
 	struct strbuf strbuf = STRBUF_INIT;
@@ -362,7 +353,7 @@
 	     mmfile_t *theirs, const char *their_label,
 	     const struct ll_merge_options *opts)
 {
-	static struct git_attr_check check[2];
+	static struct attr_check *check;
 	static const struct ll_merge_options default_opts;
 	const char *ll_driver_name = NULL;
 	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
@@ -376,10 +367,14 @@
 		normalize_file(ours, path);
 		normalize_file(theirs, path);
 	}
-	if (!git_path_check_merge(path, check)) {
-		ll_driver_name = check[0].value;
-		if (check[1].value) {
-			marker_size = atoi(check[1].value);
+
+	if (!check)
+		check = attr_check_initl("merge", "conflict-marker-size", NULL);
+
+	if (!git_check_attr(path, check)) {
+		ll_driver_name = check->items[0].value;
+		if (check->items[1].value) {
+			marker_size = atoi(check->items[1].value);
 			if (marker_size <= 0)
 				marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 		}
@@ -398,13 +393,13 @@
 
 int ll_merge_marker_size(const char *path)
 {
-	static struct git_attr_check check;
+	static struct attr_check *check;
 	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 
-	if (!check.attr)
-		check.attr = git_attr("conflict-marker-size");
-	if (!git_check_attr(path, 1, &check) && check.value) {
-		marker_size = atoi(check.value);
+	if (!check)
+		check = attr_check_initl("conflict-marker-size", NULL);
+	if (!git_check_attr(path, check) && check->items[0].value) {
+		marker_size = atoi(check->items[0].value);
 		if (marker_size <= 0)
 			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 	}
diff --git a/log-tree.c b/log-tree.c
index 8c24157..4618dd0 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -332,35 +332,31 @@
 	strbuf_release(&subject);
 }
 
+void fmt_output_email_subject(struct strbuf *sb, struct rev_info *opt)
+{
+	if (opt->total > 0) {
+		strbuf_addf(sb, "Subject: [%s%s%0*d/%d] ",
+			    opt->subject_prefix,
+			    *opt->subject_prefix ? " " : "",
+			    digits_in_number(opt->total),
+			    opt->nr, opt->total);
+	} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
+		strbuf_addf(sb, "Subject: [%s] ",
+			    opt->subject_prefix);
+	} else {
+		strbuf_addstr(sb, "Subject: ");
+	}
+}
+
 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
-			     const char **subject_p,
 			     const char **extra_headers_p,
 			     int *need_8bit_cte_p)
 {
-	const char *subject = NULL;
 	const char *extra_headers = opt->extra_headers;
 	const char *name = oid_to_hex(opt->zero_commit ?
 				      &null_oid : &commit->object.oid);
 
 	*need_8bit_cte_p = 0; /* unknown */
-	if (opt->total > 0) {
-		static char buffer[64];
-		snprintf(buffer, sizeof(buffer),
-			 "Subject: [%s%s%0*d/%d] ",
-			 opt->subject_prefix,
-			 *opt->subject_prefix ? " " : "",
-			 digits_in_number(opt->total),
-			 opt->nr, opt->total);
-		subject = buffer;
-	} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
-		static char buffer[256];
-		snprintf(buffer, sizeof(buffer),
-			 "Subject: [%s] ",
-			 opt->subject_prefix);
-		subject = buffer;
-	} else {
-		subject = "Subject: ";
-	}
 
 	fprintf(opt->diffopt.file, "From %s Mon Sep 17 00:00:00 2001\n", name);
 	graph_show_oneline(opt->graph);
@@ -417,7 +413,6 @@
 		opt->diffopt.stat_sep = buffer;
 		strbuf_release(&filename);
 	}
-	*subject_p = subject;
 	*extra_headers_p = extra_headers;
 }
 
@@ -602,8 +597,10 @@
 	 */
 
 	if (cmit_fmt_is_mail(opt->commit_format)) {
-		log_write_email_headers(opt, commit, &ctx.subject, &extra_headers,
+		log_write_email_headers(opt, commit, &extra_headers,
 					&ctx.need_8bit_cte);
+		ctx.rev = opt;
+		ctx.print_email_subject = 1;
 	} else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
 		fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), opt->diffopt.file);
 		if (opt->commit_format != CMIT_FMT_ONELINE)
diff --git a/log-tree.h b/log-tree.h
index c8116e6..48f11fb 100644
--- a/log-tree.h
+++ b/log-tree.h
@@ -22,7 +22,6 @@
 			     format_decorations_extended((strbuf), (commit), (color), " (", ", ", ")")
 void show_decorations(struct rev_info *opt, struct commit *commit);
 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
-			     const char **subject_p,
 			     const char **extra_headers_p,
 			     int *need_8bit_cte_p);
 void load_ref_decorations(int flags);
@@ -30,5 +29,6 @@
 #define FORMAT_PATCH_NAME_MAX 64
 void fmt_output_commit(struct strbuf *, struct commit *, struct rev_info *);
 void fmt_output_subject(struct strbuf *, const char *subject, struct rev_info *);
+void fmt_output_email_subject(struct strbuf *, struct rev_info *);
 
 #endif
diff --git a/merge-recursive.c b/merge-recursive.c
index b7ff1ad..62decd5 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1061,16 +1061,20 @@
 }
 
 static int handle_change_delete(struct merge_options *o,
-				 const char *path,
+				 const char *path, const char *old_path,
 				 const struct object_id *o_oid, int o_mode,
-				 const struct object_id *a_oid, int a_mode,
-				 const struct object_id *b_oid, int b_mode,
+				 const struct object_id *changed_oid,
+				 int changed_mode,
+				 const char *change_branch,
+				 const char *delete_branch,
 				 const char *change, const char *change_past)
 {
-	char *renamed = NULL;
+	char *alt_path = NULL;
+	const char *update_path = path;
 	int ret = 0;
+
 	if (dir_in_way(path, !o->call_depth, 0)) {
-		renamed = unique_path(o, path, a_oid ? o->branch1 : o->branch2);
+		update_path = alt_path = unique_path(o, path, change_branch);
 	}
 
 	if (o->call_depth) {
@@ -1081,43 +1085,43 @@
 		 */
 		ret = remove_file_from_cache(path);
 		if (!ret)
-			ret = update_file(o, 0, o_oid, o_mode,
-					  renamed ? renamed : path);
-	} else if (!a_oid) {
-		if (!renamed) {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree."),
-			       change, path, o->branch1, change_past,
-			       o->branch2, o->branch2, path);
-			ret = update_file(o, 0, b_oid, b_mode, path);
-		} else {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree at %s."),
-			       change, path, o->branch1, change_past,
-			       o->branch2, o->branch2, path, renamed);
-			ret = update_file(o, 0, b_oid, b_mode, renamed);
-		}
+			ret = update_file(o, 0, o_oid, o_mode, update_path);
 	} else {
-		if (!renamed) {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree."),
-			       change, path, o->branch2, change_past,
-			       o->branch1, o->branch1, path);
+		if (!alt_path) {
+			if (!old_path) {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s in %s. Version %s of %s left in tree."),
+				       change, path, delete_branch, change_past,
+				       change_branch, change_branch, path);
+			} else {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s to %s in %s. Version %s of %s left in tree."),
+				       change, old_path, delete_branch, change_past, path,
+				       change_branch, change_branch, path);
+			}
 		} else {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree at %s."),
-			       change, path, o->branch2, change_past,
-			       o->branch1, o->branch1, path, renamed);
-			ret = update_file(o, 0, a_oid, a_mode, renamed);
+			if (!old_path) {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s in %s. Version %s of %s left in tree at %s."),
+				       change, path, delete_branch, change_past,
+				       change_branch, change_branch, path, alt_path);
+			} else {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s to %s in %s. Version %s of %s left in tree at %s."),
+				       change, old_path, delete_branch, change_past, path,
+				       change_branch, change_branch, path, alt_path);
+			}
 		}
 		/*
-		 * No need to call update_file() on path when !renamed, since
-		 * that would needlessly touch path.  We could call
-		 * update_file_flags() with update_cache=0 and update_wd=0,
-		 * but that's a no-op.
+		 * No need to call update_file() on path when change_branch ==
+		 * o->branch1 && !alt_path, since that would needlessly touch
+		 * path.  We could call update_file_flags() with update_cache=0
+		 * and update_wd=0, but that's a no-op.
 		 */
+		if (change_branch != o->branch1 || alt_path)
+			ret = update_file(o, 0, changed_oid, changed_mode, update_path);
 	}
-	free(renamed);
+	free(alt_path);
 
 	return ret;
 }
@@ -1125,28 +1129,17 @@
 static int conflict_rename_delete(struct merge_options *o,
 				   struct diff_filepair *pair,
 				   const char *rename_branch,
-				   const char *other_branch)
+				   const char *delete_branch)
 {
 	const struct diff_filespec *orig = pair->one;
 	const struct diff_filespec *dest = pair->two;
-	const struct object_id *a_oid = NULL;
-	const struct object_id *b_oid = NULL;
-	int a_mode = 0;
-	int b_mode = 0;
-
-	if (rename_branch == o->branch1) {
-		a_oid = &dest->oid;
-		a_mode = dest->mode;
-	} else {
-		b_oid = &dest->oid;
-		b_mode = dest->mode;
-	}
 
 	if (handle_change_delete(o,
 				 o->call_depth ? orig->path : dest->path,
+				 o->call_depth ? NULL : orig->path,
 				 &orig->oid, orig->mode,
-				 a_oid, a_mode,
-				 b_oid, b_mode,
+				 &dest->oid, dest->mode,
+				 rename_branch, delete_branch,
 				 _("rename"), _("renamed")))
 		return -1;
 
@@ -1662,11 +1655,27 @@
 				 struct object_id *a_oid, int a_mode,
 				 struct object_id *b_oid, int b_mode)
 {
+	const char *modify_branch, *delete_branch;
+	struct object_id *changed_oid;
+	int changed_mode;
+
+	if (a_oid) {
+		modify_branch = o->branch1;
+		delete_branch = o->branch2;
+		changed_oid = a_oid;
+		changed_mode = a_mode;
+	} else {
+		modify_branch = o->branch2;
+		delete_branch = o->branch1;
+		changed_oid = b_oid;
+		changed_mode = b_mode;
+	}
+
 	return handle_change_delete(o,
-				    path,
+				    path, NULL,
 				    o_oid, o_mode,
-				    a_oid, a_mode,
-				    b_oid, b_mode,
+				    changed_oid, changed_mode,
+				    modify_branch, delete_branch,
 				    _("modify"), _("modified"));
 }
 
diff --git a/name-hash.c b/name-hash.c
index 6d9f23e..cac313c 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -23,13 +23,19 @@
 			name ? name : e2->name, e1->namelen);
 }
 
+static struct dir_entry *find_dir_entry__hash(struct index_state *istate,
+		const char *name, unsigned int namelen, unsigned int hash)
+{
+	struct dir_entry key;
+	hashmap_entry_init(&key, hash);
+	key.namelen = namelen;
+	return hashmap_get(&istate->dir_hash, &key, name);
+}
+
 static struct dir_entry *find_dir_entry(struct index_state *istate,
 		const char *name, unsigned int namelen)
 {
-	struct dir_entry key;
-	hashmap_entry_init(&key, memihash(name, namelen));
-	key.namelen = namelen;
-	return hashmap_get(&istate->dir_hash, &key, name);
+	return find_dir_entry__hash(istate, name, namelen, memihash(name, namelen));
 }
 
 static struct dir_entry *hash_dir_entry(struct index_state *istate,
@@ -112,20 +118,493 @@
 	return remove ? !(ce1 == ce2) : 0;
 }
 
+static int lazy_try_threaded = 1;
+static int lazy_nr_dir_threads;
+
+#ifdef NO_PTHREADS
+
+static inline int lookup_lazy_params(struct index_state *istate)
+{
+	return 0;
+}
+
+static inline void threaded_lazy_init_name_hash(
+	struct index_state *istate)
+{
+}
+
+#else
+
+#include "thread-utils.h"
+
+/*
+ * Set a minimum number of cache_entries that we will handle per
+ * thread and use that to decide how many threads to run (upto
+ * the number on the system).
+ *
+ * For guidance setting the lower per-thread bound, see:
+ *     t/helper/test-lazy-init-name-hash --analyze
+ */
+#define LAZY_THREAD_COST (2000)
+
+/*
+ * We use n mutexes to guard n partitions of the "istate->dir_hash"
+ * hashtable.  Since "find" and "insert" operations will hash to a
+ * particular bucket and modify/search a single chain, we can say
+ * that "all chains mod n" are guarded by the same mutex -- rather
+ * than having a single mutex to guard the entire table.  (This does
+ * require that we disable "rehashing" on the hashtable.)
+ *
+ * So, a larger value here decreases the probability of a collision
+ * and the time that each thread must wait for the mutex.
+ */
+#define LAZY_MAX_MUTEX   (32)
+
+static pthread_mutex_t *lazy_dir_mutex_array;
+
+/*
+ * An array of lazy_entry items is used by the n threads in
+ * the directory parse (first) phase to (lock-free) store the
+ * intermediate results.  These values are then referenced by
+ * the 2 threads in the second phase.
+ */
+struct lazy_entry {
+	struct dir_entry *dir;
+	unsigned int hash_dir;
+	unsigned int hash_name;
+};
+
+/*
+ * Decide if we want to use threads (if available) to load
+ * the hash tables.  We set "lazy_nr_dir_threads" to zero when
+ * it is not worth it.
+ */
+static int lookup_lazy_params(struct index_state *istate)
+{
+	int nr_cpus;
+
+	lazy_nr_dir_threads = 0;
+
+	if (!lazy_try_threaded)
+		return 0;
+
+	/*
+	 * If we are respecting case, just use the original
+	 * code to build the "istate->name_hash".  We don't
+	 * need the complexity here.
+	 */
+	if (!ignore_case)
+		return 0;
+
+	nr_cpus = online_cpus();
+	if (nr_cpus < 2)
+		return 0;
+
+	if (istate->cache_nr < 2 * LAZY_THREAD_COST)
+		return 0;
+
+	if (istate->cache_nr < nr_cpus * LAZY_THREAD_COST)
+		nr_cpus = istate->cache_nr / LAZY_THREAD_COST;
+	lazy_nr_dir_threads = nr_cpus;
+	return lazy_nr_dir_threads;
+}
+
+/*
+ * Initialize n mutexes for use when searching and inserting
+ * into "istate->dir_hash".  All "dir" threads are trying
+ * to insert partial pathnames into the hash as they iterate
+ * over their portions of the index, so lock contention is
+ * high.
+ *
+ * However, the hashmap is going to put items into bucket
+ * chains based on their hash values.  Use that to create n
+ * mutexes and lock on mutex[bucket(hash) % n].  This will
+ * decrease the collision rate by (hopefully) by a factor of n.
+ */
+static void init_dir_mutex(void)
+{
+	int j;
+
+	lazy_dir_mutex_array = xcalloc(LAZY_MAX_MUTEX, sizeof(pthread_mutex_t));
+
+	for (j = 0; j < LAZY_MAX_MUTEX; j++)
+		init_recursive_mutex(&lazy_dir_mutex_array[j]);
+}
+
+static void cleanup_dir_mutex(void)
+{
+	int j;
+
+	for (j = 0; j < LAZY_MAX_MUTEX; j++)
+		pthread_mutex_destroy(&lazy_dir_mutex_array[j]);
+
+	free(lazy_dir_mutex_array);
+}
+
+static void lock_dir_mutex(int j)
+{
+	pthread_mutex_lock(&lazy_dir_mutex_array[j]);
+}
+
+static void unlock_dir_mutex(int j)
+{
+	pthread_mutex_unlock(&lazy_dir_mutex_array[j]);
+}
+
+static inline int compute_dir_lock_nr(
+	const struct hashmap *map,
+	unsigned int hash)
+{
+	return hashmap_bucket(map, hash) % LAZY_MAX_MUTEX;
+}
+
+static struct dir_entry *hash_dir_entry_with_parent_and_prefix(
+	struct index_state *istate,
+	struct dir_entry *parent,
+	struct strbuf *prefix)
+{
+	struct dir_entry *dir;
+	unsigned int hash;
+	int lock_nr;
+
+	/*
+	 * Either we have a parent directory and path with slash(es)
+	 * or the directory is an immediate child of the root directory.
+	 */
+	assert((parent != NULL) ^ (strchr(prefix->buf, '/') == NULL));
+
+	if (parent)
+		hash = memihash_cont(parent->ent.hash,
+			prefix->buf + parent->namelen,
+			prefix->len - parent->namelen);
+	else
+		hash = memihash(prefix->buf, prefix->len);
+
+	lock_nr = compute_dir_lock_nr(&istate->dir_hash, hash);
+	lock_dir_mutex(lock_nr);
+
+	dir = find_dir_entry__hash(istate, prefix->buf, prefix->len, hash);
+	if (!dir) {
+		FLEX_ALLOC_MEM(dir, name, prefix->buf, prefix->len);
+		hashmap_entry_init(dir, hash);
+		dir->namelen = prefix->len;
+		dir->parent = parent;
+		hashmap_add(&istate->dir_hash, dir);
+
+		if (parent) {
+			unlock_dir_mutex(lock_nr);
+
+			/* All I really need here is an InterlockedIncrement(&(parent->nr)) */
+			lock_nr = compute_dir_lock_nr(&istate->dir_hash, parent->ent.hash);
+			lock_dir_mutex(lock_nr);
+			parent->nr++;
+		}
+	}
+
+	unlock_dir_mutex(lock_nr);
+
+	return dir;
+}
+
+/*
+ * handle_range_1() and handle_range_dir() are derived from
+ * clear_ce_flags_1() and clear_ce_flags_dir() in unpack-trees.c
+ * and handle the iteration over the entire array of index entries.
+ * They use recursion for adjacent entries in the same parent
+ * directory.
+ */
+static int handle_range_1(
+	struct index_state *istate,
+	int k_start,
+	int k_end,
+	struct dir_entry *parent,
+	struct strbuf *prefix,
+	struct lazy_entry *lazy_entries);
+
+static int handle_range_dir(
+	struct index_state *istate,
+	int k_start,
+	int k_end,
+	struct dir_entry *parent,
+	struct strbuf *prefix,
+	struct lazy_entry *lazy_entries,
+	struct dir_entry **dir_new_out)
+{
+	int rc, k;
+	int input_prefix_len = prefix->len;
+	struct dir_entry *dir_new;
+
+	dir_new = hash_dir_entry_with_parent_and_prefix(istate, parent, prefix);
+
+	strbuf_addch(prefix, '/');
+
+	/*
+	 * Scan forward in the index array for index entries having the same
+	 * path prefix (that are also in this directory).
+	 */
+	if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0)
+		k = k_start + 1;
+	else if (strncmp(istate->cache[k_end - 1]->name, prefix->buf, prefix->len) == 0)
+		k = k_end;
+	else {
+		int begin = k_start;
+		int end = k_end;
+		while (begin < end) {
+			int mid = (begin + end) >> 1;
+			int cmp = strncmp(istate->cache[mid]->name, prefix->buf, prefix->len);
+			if (cmp == 0) /* mid has same prefix; look in second part */
+				begin = mid + 1;
+			else if (cmp > 0) /* mid is past group; look in first part */
+				end = mid;
+			else
+				die("cache entry out of order");
+		}
+		k = begin;
+	}
+
+	/*
+	 * Recurse and process what we can of this subset [k_start, k).
+	 */
+	rc = handle_range_1(istate, k_start, k, dir_new, prefix, lazy_entries);
+
+	strbuf_setlen(prefix, input_prefix_len);
+
+	*dir_new_out = dir_new;
+	return rc;
+}
+
+static int handle_range_1(
+	struct index_state *istate,
+	int k_start,
+	int k_end,
+	struct dir_entry *parent,
+	struct strbuf *prefix,
+	struct lazy_entry *lazy_entries)
+{
+	int input_prefix_len = prefix->len;
+	int k = k_start;
+
+	while (k < k_end) {
+		struct cache_entry *ce_k = istate->cache[k];
+		const char *name, *slash;
+
+		if (prefix->len && strncmp(ce_k->name, prefix->buf, prefix->len))
+			break;
+
+		name = ce_k->name + prefix->len;
+		slash = strchr(name, '/');
+
+		if (slash) {
+			int len = slash - name;
+			int processed;
+			struct dir_entry *dir_new;
+
+			strbuf_add(prefix, name, len);
+			processed = handle_range_dir(istate, k, k_end, parent, prefix, lazy_entries, &dir_new);
+			if (processed) {
+				k += processed;
+				strbuf_setlen(prefix, input_prefix_len);
+				continue;
+			}
+
+			strbuf_addch(prefix, '/');
+			processed = handle_range_1(istate, k, k_end, dir_new, prefix, lazy_entries);
+			k += processed;
+			strbuf_setlen(prefix, input_prefix_len);
+			continue;
+		}
+
+		/*
+		 * It is too expensive to take a lock to insert "ce_k"
+		 * into "istate->name_hash" and increment the ref-count
+		 * on the "parent" dir.  So we defer actually updating
+		 * permanent data structures until phase 2 (where we
+		 * can change the locking requirements) and simply
+		 * accumulate our current results into the lazy_entries
+		 * data array).
+		 *
+		 * We do not need to lock the lazy_entries array because
+		 * we have exclusive access to the cells in the range
+		 * [k_start,k_end) that this thread was given.
+		 */
+		lazy_entries[k].dir = parent;
+		if (parent) {
+			lazy_entries[k].hash_name = memihash_cont(
+				parent->ent.hash,
+				ce_k->name + parent->namelen,
+				ce_namelen(ce_k) - parent->namelen);
+			lazy_entries[k].hash_dir = parent->ent.hash;
+		} else {
+			lazy_entries[k].hash_name = memihash(ce_k->name, ce_namelen(ce_k));
+		}
+
+		k++;
+	}
+
+	return k - k_start;
+}
+
+struct lazy_dir_thread_data {
+	pthread_t pthread;
+	struct index_state *istate;
+	struct lazy_entry *lazy_entries;
+	int k_start;
+	int k_end;
+};
+
+static void *lazy_dir_thread_proc(void *_data)
+{
+	struct lazy_dir_thread_data *d = _data;
+	struct strbuf prefix = STRBUF_INIT;
+	handle_range_1(d->istate, d->k_start, d->k_end, NULL, &prefix, d->lazy_entries);
+	strbuf_release(&prefix);
+	return NULL;
+}
+
+struct lazy_name_thread_data {
+	pthread_t pthread;
+	struct index_state *istate;
+	struct lazy_entry *lazy_entries;
+};
+
+static void *lazy_name_thread_proc(void *_data)
+{
+	struct lazy_name_thread_data *d = _data;
+	int k;
+
+	for (k = 0; k < d->istate->cache_nr; k++) {
+		struct cache_entry *ce_k = d->istate->cache[k];
+		ce_k->ce_flags |= CE_HASHED;
+		hashmap_entry_init(ce_k, d->lazy_entries[k].hash_name);
+		hashmap_add(&d->istate->name_hash, ce_k);
+	}
+
+	return NULL;
+}
+
+static inline void lazy_update_dir_ref_counts(
+	struct index_state *istate,
+	struct lazy_entry *lazy_entries)
+{
+	int k;
+
+	for (k = 0; k < istate->cache_nr; k++) {
+		if (lazy_entries[k].dir)
+			lazy_entries[k].dir->nr++;
+	}
+}
+
+static void threaded_lazy_init_name_hash(
+	struct index_state *istate)
+{
+	int nr_each;
+	int k_start;
+	int t;
+	struct lazy_entry *lazy_entries;
+	struct lazy_dir_thread_data *td_dir;
+	struct lazy_name_thread_data *td_name;
+
+	k_start = 0;
+	nr_each = DIV_ROUND_UP(istate->cache_nr, lazy_nr_dir_threads);
+
+	lazy_entries = xcalloc(istate->cache_nr, sizeof(struct lazy_entry));
+	td_dir = xcalloc(lazy_nr_dir_threads, sizeof(struct lazy_dir_thread_data));
+	td_name = xcalloc(1, sizeof(struct lazy_name_thread_data));
+
+	init_dir_mutex();
+
+	/*
+	 * Phase 1:
+	 * Build "istate->dir_hash" using n "dir" threads (and a read-only index).
+	 */
+	for (t = 0; t < lazy_nr_dir_threads; t++) {
+		struct lazy_dir_thread_data *td_dir_t = td_dir + t;
+		td_dir_t->istate = istate;
+		td_dir_t->lazy_entries = lazy_entries;
+		td_dir_t->k_start = k_start;
+		k_start += nr_each;
+		if (k_start > istate->cache_nr)
+			k_start = istate->cache_nr;
+		td_dir_t->k_end = k_start;
+		if (pthread_create(&td_dir_t->pthread, NULL, lazy_dir_thread_proc, td_dir_t))
+			die("unable to create lazy_dir_thread");
+	}
+	for (t = 0; t < lazy_nr_dir_threads; t++) {
+		struct lazy_dir_thread_data *td_dir_t = td_dir + t;
+		if (pthread_join(td_dir_t->pthread, NULL))
+			die("unable to join lazy_dir_thread");
+	}
+
+	/*
+	 * Phase 2:
+	 * Iterate over all index entries and add them to the "istate->name_hash"
+	 * using a single "name" background thread.
+	 * (Testing showed it wasn't worth running more than 1 thread for this.)
+	 *
+	 * Meanwhile, finish updating the parent directory ref-counts for each
+	 * index entry using the current thread.  (This step is very fast and
+	 * doesn't need threading.)
+	 */
+	td_name->istate = istate;
+	td_name->lazy_entries = lazy_entries;
+	if (pthread_create(&td_name->pthread, NULL, lazy_name_thread_proc, td_name))
+		die("unable to create lazy_name_thread");
+
+	lazy_update_dir_ref_counts(istate, lazy_entries);
+
+	if (pthread_join(td_name->pthread, NULL))
+		die("unable to join lazy_name_thread");
+
+	cleanup_dir_mutex();
+
+	free(td_name);
+	free(td_dir);
+	free(lazy_entries);
+}
+
+#endif
+
 static void lazy_init_name_hash(struct index_state *istate)
 {
-	int nr;
-
 	if (istate->name_hash_initialized)
 		return;
 	hashmap_init(&istate->name_hash, (hashmap_cmp_fn) cache_entry_cmp,
 			istate->cache_nr);
-	hashmap_init(&istate->dir_hash, (hashmap_cmp_fn) dir_entry_cmp, 0);
-	for (nr = 0; nr < istate->cache_nr; nr++)
-		hash_index_entry(istate, istate->cache[nr]);
+	hashmap_init(&istate->dir_hash, (hashmap_cmp_fn) dir_entry_cmp,
+			istate->cache_nr);
+
+	if (lookup_lazy_params(istate)) {
+		hashmap_disallow_rehash(&istate->dir_hash, 1);
+		threaded_lazy_init_name_hash(istate);
+		hashmap_disallow_rehash(&istate->dir_hash, 0);
+	} else {
+		int nr;
+		for (nr = 0; nr < istate->cache_nr; nr++)
+			hash_index_entry(istate, istate->cache[nr]);
+	}
+
 	istate->name_hash_initialized = 1;
 }
 
+/*
+ * A test routine for t/helper/ sources.
+ *
+ * Returns the number of threads used or 0 when
+ * the non-threaded code path was used.
+ *
+ * Requesting threading WILL NOT override guards
+ * in lookup_lazy_params().
+ */
+int test_lazy_init_name_hash(struct index_state *istate, int try_threaded)
+{
+	lazy_nr_dir_threads = 0;
+	lazy_try_threaded = try_threaded;
+
+	lazy_init_name_hash(istate);
+
+	return lazy_nr_dir_threads;
+}
+
 void add_name_hash(struct index_state *istate, struct cache_entry *ce)
 {
 	if (istate->name_hash_initialized)
diff --git a/object.h b/object.h
index 614a006..f52957d 100644
--- a/object.h
+++ b/object.h
@@ -29,7 +29,7 @@
 /*
  * object flag allocation:
  * revision.h:      0---------10                                26
- * fetch-pack.c:    0---4
+ * fetch-pack.c:    0---5
  * walker.c:        0-2
  * upload-pack.c:       4       11----------------19
  * builtin/blame.c:               12-13
diff --git a/oidset.c b/oidset.c
new file mode 100644
index 0000000..ac169f0
--- /dev/null
+++ b/oidset.c
@@ -0,0 +1,49 @@
+#include "cache.h"
+#include "oidset.h"
+
+struct oidset_entry {
+	struct hashmap_entry hash;
+	struct object_id oid;
+};
+
+static int oidset_hashcmp(const void *va, const void *vb,
+			  const void *vkey)
+{
+	const struct oidset_entry *a = va, *b = vb;
+	const struct object_id *key = vkey;
+	return oidcmp(&a->oid, key ? key : &b->oid);
+}
+
+int oidset_contains(const struct oidset *set, const struct object_id *oid)
+{
+	struct hashmap_entry key;
+
+	if (!set->map.cmpfn)
+		return 0;
+
+	hashmap_entry_init(&key, sha1hash(oid->hash));
+	return !!hashmap_get(&set->map, &key, oid);
+}
+
+int oidset_insert(struct oidset *set, const struct object_id *oid)
+{
+	struct oidset_entry *entry;
+
+	if (!set->map.cmpfn)
+		hashmap_init(&set->map, oidset_hashcmp, 0);
+
+	if (oidset_contains(set, oid))
+		return 1;
+
+	entry = xmalloc(sizeof(*entry));
+	hashmap_entry_init(&entry->hash, sha1hash(oid->hash));
+	oidcpy(&entry->oid, oid);
+
+	hashmap_add(&set->map, entry);
+	return 0;
+}
+
+void oidset_clear(struct oidset *set)
+{
+	hashmap_free(&set->map, 1);
+}
diff --git a/oidset.h b/oidset.h
new file mode 100644
index 0000000..b7eaab5
--- /dev/null
+++ b/oidset.h
@@ -0,0 +1,45 @@
+#ifndef OIDSET_H
+#define OIDSET_H
+
+/**
+ * This API is similar to sha1-array, in that it maintains a set of object ids
+ * in a memory-efficient way. The major differences are:
+ *
+ *   1. It uses a hash, so we can do online duplicate removal, rather than
+ *      sort-and-uniq at the end. This can reduce memory footprint if you have
+ *      a large list of oids with many duplicates.
+ *
+ *   2. The per-unique-oid memory footprint is slightly higher due to hash
+ *      table overhead.
+ */
+
+/**
+ * A single oidset; should be zero-initialized (or use OIDSET_INIT).
+ */
+struct oidset {
+	struct hashmap map;
+};
+
+#define OIDSET_INIT { { NULL } }
+
+/**
+ * Returns true iff `set` contains `oid`.
+ */
+int oidset_contains(const struct oidset *set, const struct object_id *oid);
+
+/**
+ * Insert the oid into the set; a copy is made, so "oid" does not need
+ * to persist after this function is called.
+ *
+ * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
+ * to perform an efficient check-and-add.
+ */
+int oidset_insert(struct oidset *set, const struct object_id *oid);
+
+/**
+ * Remove all entries from the oidset, freeing any resources associated with
+ * it.
+ */
+void oidset_clear(struct oidset *set);
+
+#endif /* OIDSET_H */
diff --git a/pack-write.c b/pack-write.c
index 88bc7f9..c057513 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -304,7 +304,8 @@
  *  - each byte afterwards: low seven bits are size continuation,
  *    with the high bit being "size continues"
  */
-int encode_in_pack_object_header(enum object_type type, uintmax_t size, unsigned char *hdr)
+int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
+				 enum object_type type, uintmax_t size)
 {
 	int n = 1;
 	unsigned char c;
@@ -315,6 +316,8 @@
 	c = (type << 4) | (size & 15);
 	size >>= 4;
 	while (size) {
+		if (n == hdr_len)
+			die("object size is too enormous to format");
 		*hdr++ = c | 0x80;
 		c = size & 0x7f;
 		size >>= 7;
diff --git a/pack.h b/pack.h
index 0e77429..5c21587 100644
--- a/pack.h
+++ b/pack.h
@@ -84,7 +84,14 @@
 extern off_t write_pack_header(struct sha1file *f, uint32_t);
 extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
 extern char *index_pack_lockfile(int fd);
-extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned char *);
+
+/*
+ * The "hdr" output buffer should be at least this big, which will handle sizes
+ * up to 2^67.
+ */
+#define MAX_PACK_OBJECT_HEADER 10
+extern int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
+					enum object_type, uintmax_t);
 
 #define PH_ERROR_EOF		(-1)
 #define PH_ERROR_PACK_SIGNATURE	(-2)
diff --git a/pager.c b/pager.c
index ae79643..c113d89 100644
--- a/pager.c
+++ b/pager.c
@@ -43,37 +43,6 @@
 	return 0;
 }
 
-static void read_early_config(config_fn_t cb, void *data)
-{
-	git_config_with_options(cb, data, NULL, 1);
-
-	/*
-	 * Note that this is a really dirty hack that does the wrong thing in
-	 * many cases. The crux of the problem is that we cannot run
-	 * setup_git_directory() early on in git's setup, so we have no idea if
-	 * we are in a repository or not, and therefore are not sure whether
-	 * and how to read repository-local config.
-	 *
-	 * So if we _aren't_ in a repository (or we are but we would reject its
-	 * core.repositoryformatversion), we'll read whatever is in .git/config
-	 * blindly. Similarly, if we _are_ in a repository, but not at the
-	 * root, we'll fail to find .git/config (because it's really
-	 * ../.git/config, etc). See t7006 for a complete set of failures.
-	 *
-	 * However, we have historically provided this hack because it does
-	 * work some of the time (namely when you are at the top-level of a
-	 * valid repository), and would rarely make things worse (i.e., you do
-	 * not generally have a .git/config file sitting around).
-	 */
-	if (!startup_info->have_repository) {
-		struct git_config_source repo_config;
-
-		memset(&repo_config, 0, sizeof(repo_config));
-		repo_config.file = ".git/config";
-		git_config_with_options(cb, data, &repo_config, 1);
-	}
-}
-
 const char *git_pager(int stdout_is_tty)
 {
 	const char *pager;
@@ -166,9 +135,7 @@
 
 int pager_in_use(void)
 {
-	const char *env;
-	env = getenv("GIT_PAGER_IN_USE");
-	return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
+	return git_env_bool("GIT_PAGER_IN_USE", 0);
 }
 
 /*
diff --git a/parse-options.c b/parse-options.c
index 4fbe924..a23a1e6 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -40,7 +40,7 @@
 	if (!file || !*file || !prefix || is_absolute_path(*file)
 	    || !strcmp("-", *file))
 		return;
-	*file = xstrdup(prefix_filename(prefix, strlen(prefix), *file));
+	*file = prefix_filename(prefix, *file);
 }
 
 static int opt_command_mode_error(const struct option *opt,
diff --git a/path.c b/path.c
index efcedaf..2224843 100644
--- a/path.c
+++ b/path.c
@@ -1272,6 +1272,21 @@
 	return NULL;
 }
 
+char *xdg_cache_home(const char *filename)
+{
+	const char *home, *cache_home;
+
+	assert(filename);
+	cache_home = getenv("XDG_CACHE_HOME");
+	if (cache_home && *cache_home)
+		return mkpathdup("%s/git/%s", cache_home, filename);
+
+	home = getenv("HOME");
+	if (home)
+		return mkpathdup("%s/.cache/git/%s", home, filename);
+	return NULL;
+}
+
 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
diff --git a/pathspec.c b/pathspec.c
index 7ababb3..303efda 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "dir.h"
 #include "pathspec.h"
+#include "attr.h"
 
 /*
  * Finds which of the given pathspecs match items in the index.
@@ -72,6 +73,7 @@
 	{ PATHSPEC_GLOB,    '\0', "glob" },
 	{ PATHSPEC_ICASE,   '\0', "icase" },
 	{ PATHSPEC_EXCLUDE,  '!', "exclude" },
+	{ PATHSPEC_ATTR,    '\0', "attr" },
 };
 
 static void prefix_magic(struct strbuf *sb, int prefixlen, unsigned magic)
@@ -87,6 +89,116 @@
 	strbuf_addf(sb, ",prefix:%d)", prefixlen);
 }
 
+static size_t strcspn_escaped(const char *s, const char *stop)
+{
+	const char *i;
+
+	for (i = s; *i; i++) {
+		/* skip the escaped character */
+		if (i[0] == '\\' && i[1]) {
+			i++;
+			continue;
+		}
+
+		if (strchr(stop, *i))
+			break;
+	}
+	return i - s;
+}
+
+static inline int invalid_value_char(const char ch)
+{
+	if (isalnum(ch) || strchr(",-_", ch))
+		return 0;
+	return -1;
+}
+
+static char *attr_value_unescape(const char *value)
+{
+	const char *src;
+	char *dst, *ret;
+
+	ret = xmallocz(strlen(value));
+	for (src = value, dst = ret; *src; src++, dst++) {
+		if (*src == '\\') {
+			if (!src[1])
+				die(_("Escape character '\\' not allowed as "
+				      "last character in attr value"));
+			src++;
+		}
+		if (invalid_value_char(*src))
+			die("cannot use '%c' for value matching", *src);
+		*dst = *src;
+	}
+	*dst = '\0';
+	return ret;
+}
+
+static void parse_pathspec_attr_match(struct pathspec_item *item, const char *value)
+{
+	struct string_list_item *si;
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	if (item->attr_check || item->attr_match)
+		die(_("Only one 'attr:' specification is allowed."));
+
+	if (!value || !*value)
+		die(_("attr spec must not be empty"));
+
+	string_list_split(&list, value, ' ', -1);
+	string_list_remove_empty_items(&list, 0);
+
+	item->attr_check = attr_check_alloc();
+	item->attr_match = xcalloc(list.nr, sizeof(struct attr_match));
+
+	for_each_string_list_item(si, &list) {
+		size_t attr_len;
+		char *attr_name;
+		const struct git_attr *a;
+
+		int j = item->attr_match_nr++;
+		const char *attr = si->string;
+		struct attr_match *am = &item->attr_match[j];
+
+		switch (*attr) {
+		case '!':
+			am->match_mode = MATCH_UNSPECIFIED;
+			attr++;
+			attr_len = strlen(attr);
+			break;
+		case '-':
+			am->match_mode = MATCH_UNSET;
+			attr++;
+			attr_len = strlen(attr);
+			break;
+		default:
+			attr_len = strcspn(attr, "=");
+			if (attr[attr_len] != '=')
+				am->match_mode = MATCH_SET;
+			else {
+				const char *v = &attr[attr_len + 1];
+				am->match_mode = MATCH_VALUE;
+				am->value = attr_value_unescape(v);
+			}
+			break;
+		}
+
+		attr_name = xmemdupz(attr, attr_len);
+		a = git_attr(attr_name);
+		if (!a)
+			die(_("invalid attribute name %s"), attr_name);
+
+		attr_check_append(item->attr_check, a);
+
+		free(attr_name);
+	}
+
+	if (item->attr_check->nr != item->attr_match_nr)
+		die("BUG: should have same number of entries");
+
+	string_list_clear(&list, 0);
+}
+
 static inline int get_literal_global(void)
 {
 	static int literal = -1;
@@ -164,13 +276,14 @@
  * returns the position in 'elem' after all magic has been parsed
  */
 static const char *parse_long_magic(unsigned *magic, int *prefix_len,
+				    struct pathspec_item *item,
 				    const char *elem)
 {
 	const char *pos;
 	const char *nextat;
 
 	for (pos = elem + 2; *pos && *pos != ')'; pos = nextat) {
-		size_t len = strcspn(pos, ",)");
+		size_t len = strcspn_escaped(pos, ",)");
 		int i;
 
 		if (pos[len] == ',')
@@ -189,6 +302,14 @@
 			continue;
 		}
 
+		if (starts_with(pos, "attr:")) {
+			char *attr_body = xmemdupz(pos + 5, len - 5);
+			parse_pathspec_attr_match(item, attr_body);
+			*magic |= PATHSPEC_ATTR;
+			free(attr_body);
+			continue;
+		}
+
 		for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
 			if (strlen(pathspec_magic[i].name) == len &&
 			    !strncmp(pathspec_magic[i].name, pos, len)) {
@@ -224,6 +345,12 @@
 		char ch = *pos;
 		int i;
 
+		/* Special case alias for '!' */
+		if (ch == '^') {
+			*magic |= PATHSPEC_EXCLUDE;
+			continue;
+		}
+
 		if (!is_pathspec_magic(ch))
 			break;
 
@@ -246,13 +373,14 @@
 }
 
 static const char *parse_element_magic(unsigned *magic, int *prefix_len,
+				       struct pathspec_item *item,
 				       const char *elem)
 {
 	if (elem[0] != ':' || get_literal_global())
 		return elem; /* nothing to do */
 	else if (elem[1] == '(')
 		/* longhand */
-		return parse_long_magic(magic, prefix_len, elem);
+		return parse_long_magic(magic, prefix_len, item, elem);
 	else
 		/* shorthand */
 		return parse_short_magic(magic, elem);
@@ -329,12 +457,17 @@
 	char *match;
 	int pathspec_prefix = -1;
 
+	item->attr_check = NULL;
+	item->attr_match = NULL;
+	item->attr_match_nr = 0;
+
 	/* PATHSPEC_LITERAL_PATH ignores magic */
 	if (flags & PATHSPEC_LITERAL_PATH) {
 		magic = PATHSPEC_LITERAL;
 	} else {
 		copyfrom = parse_element_magic(&element_magic,
 					       &pathspec_prefix,
+					       item,
 					       elt);
 		magic |= element_magic;
 		magic |= get_global_magic(element_magic);
@@ -516,7 +649,7 @@
 	}
 
 	pathspec->nr = n;
-	ALLOC_ARRAY(pathspec->items, n);
+	ALLOC_ARRAY(pathspec->items, n + 1);
 	item = pathspec->items;
 	prefixlen = prefix ? strlen(prefix) : 0;
 
@@ -540,10 +673,15 @@
 		pathspec->magic |= item[i].magic;
 	}
 
-	if (nr_exclude == n)
-		die(_("There is nothing to exclude from by :(exclude) patterns.\n"
-		      "Perhaps you forgot to add either ':/' or '.' ?"));
-
+	/*
+	 * If everything is an exclude pattern, add one positive pattern
+	 * that matches everyting. We allocated an extra one for this.
+	 */
+	if (nr_exclude == n) {
+		int plen = (!(flags & PATHSPEC_PREFER_CWD)) ? 0 : prefixlen;
+		init_pathspec_item(item + n, 0, prefix, plen, "");
+		pathspec->nr++;
+	}
 
 	if (pathspec->magic & PATHSPEC_MAXDEPTH) {
 		if (flags & PATHSPEC_KEEP_ORDER)
@@ -554,26 +692,46 @@
 
 void copy_pathspec(struct pathspec *dst, const struct pathspec *src)
 {
-	int i;
+	int i, j;
 
 	*dst = *src;
 	ALLOC_ARRAY(dst->items, dst->nr);
 	COPY_ARRAY(dst->items, src->items, dst->nr);
 
 	for (i = 0; i < dst->nr; i++) {
-		dst->items[i].match = xstrdup(src->items[i].match);
-		dst->items[i].original = xstrdup(src->items[i].original);
+		struct pathspec_item *d = &dst->items[i];
+		struct pathspec_item *s = &src->items[i];
+
+		d->match = xstrdup(s->match);
+		d->original = xstrdup(s->original);
+
+		ALLOC_ARRAY(d->attr_match, d->attr_match_nr);
+		COPY_ARRAY(d->attr_match, s->attr_match, d->attr_match_nr);
+		for (j = 0; j < d->attr_match_nr; j++) {
+			const char *value = s->attr_match[j].value;
+			d->attr_match[j].value = xstrdup_or_null(value);
+		}
+
+		d->attr_check = attr_check_dup(s->attr_check);
 	}
 }
 
 void clear_pathspec(struct pathspec *pathspec)
 {
-	int i;
+	int i, j;
 
 	for (i = 0; i < pathspec->nr; i++) {
 		free(pathspec->items[i].match);
 		free(pathspec->items[i].original);
+
+		for (j = 0; j < pathspec->items[j].attr_match_nr; j++)
+			free(pathspec->items[i].attr_match[j].value);
+		free(pathspec->items[i].attr_match);
+
+		if (pathspec->items[i].attr_check)
+			attr_check_free(pathspec->items[i].attr_check);
 	}
+
 	free(pathspec->items);
 	pathspec->items = NULL;
 	pathspec->nr = 0;
diff --git a/pathspec.h b/pathspec.h
index 49fd823..55e9769 100644
--- a/pathspec.h
+++ b/pathspec.h
@@ -8,13 +8,15 @@
 #define PATHSPEC_GLOB		(1<<3)
 #define PATHSPEC_ICASE		(1<<4)
 #define PATHSPEC_EXCLUDE	(1<<5)
+#define PATHSPEC_ATTR		(1<<6)
 #define PATHSPEC_ALL_MAGIC	  \
 	(PATHSPEC_FROMTOP	| \
 	 PATHSPEC_MAXDEPTH	| \
 	 PATHSPEC_LITERAL	| \
 	 PATHSPEC_GLOB		| \
 	 PATHSPEC_ICASE		| \
-	 PATHSPEC_EXCLUDE)
+	 PATHSPEC_EXCLUDE	| \
+	 PATHSPEC_ATTR)
 
 #define PATHSPEC_ONESTAR 1	/* the pathspec pattern satisfies GFNM_ONESTAR */
 
@@ -31,6 +33,17 @@
 		int len, prefix;
 		int nowildcard_len;
 		int flags;
+		int attr_match_nr;
+		struct attr_match {
+			char *value;
+			enum attr_match_mode {
+				MATCH_SET,
+				MATCH_UNSET,
+				MATCH_VALUE,
+				MATCH_UNSPECIFIED
+			} match_mode;
+		} *attr_match;
+		struct attr_check *attr_check;
 	} *items;
 };
 
diff --git a/preload-index.c b/preload-index.c
index c1fe3a3..70a4c80 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -53,6 +53,8 @@
 			continue;
 		if (ce_uptodate(ce))
 			continue;
+		if (ce_skip_worktree(ce))
+			continue;
 		if (!ce_path_match(ce, &p->pathspec, NULL))
 			continue;
 		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
diff --git a/pretty.c b/pretty.c
index 5e68383..d0f86f5 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1607,8 +1607,9 @@
 				pp->preserve_subject ? "\n" : " ");
 
 	strbuf_grow(sb, title.len + 1024);
-	if (pp->subject) {
-		strbuf_addstr(sb, pp->subject);
+	if (pp->print_email_subject) {
+		if (pp->rev)
+			fmt_output_email_subject(sb, pp->rev);
 		if (needs_rfc2047_encoding(title.buf, title.len, RFC2047_SUBJECT))
 			add_rfc2047(sb, title.buf, title.len,
 						encoding, RFC2047_SUBJECT);
@@ -1818,7 +1819,7 @@
 	}
 
 	pp_header(pp, encoding, commit, &msg, sb);
-	if (pp->fmt != CMIT_FMT_ONELINE && !pp->subject) {
+	if (pp->fmt != CMIT_FMT_ONELINE && !pp->print_email_subject) {
 		strbuf_addch(sb, '\n');
 	}
 
diff --git a/reachable.c b/reachable.c
index d0199ca..a8a979b 100644
--- a/reachable.c
+++ b/reachable.c
@@ -58,7 +58,7 @@
 	unsigned long timestamp;
 };
 
-static void add_recent_object(const unsigned char *sha1,
+static void add_recent_object(const struct object_id *oid,
 			      unsigned long mtime,
 			      struct recent_data *data)
 {
@@ -75,37 +75,37 @@
 	 * later processing, and the revision machinery expects
 	 * commits and tags to have been parsed.
 	 */
-	type = sha1_object_info(sha1, NULL);
+	type = sha1_object_info(oid->hash, NULL);
 	if (type < 0)
-		die("unable to get object info for %s", sha1_to_hex(sha1));
+		die("unable to get object info for %s", oid_to_hex(oid));
 
 	switch (type) {
 	case OBJ_TAG:
 	case OBJ_COMMIT:
-		obj = parse_object_or_die(sha1, NULL);
+		obj = parse_object_or_die(oid->hash, NULL);
 		break;
 	case OBJ_TREE:
-		obj = (struct object *)lookup_tree(sha1);
+		obj = (struct object *)lookup_tree(oid->hash);
 		break;
 	case OBJ_BLOB:
-		obj = (struct object *)lookup_blob(sha1);
+		obj = (struct object *)lookup_blob(oid->hash);
 		break;
 	default:
 		die("unknown object type for %s: %s",
-		    sha1_to_hex(sha1), typename(type));
+		    oid_to_hex(oid), typename(type));
 	}
 
 	if (!obj)
-		die("unable to lookup %s", sha1_to_hex(sha1));
+		die("unable to lookup %s", oid_to_hex(oid));
 
 	add_pending_object(data->revs, obj, "");
 }
 
-static int add_recent_loose(const unsigned char *sha1,
+static int add_recent_loose(const struct object_id *oid,
 			    const char *path, void *data)
 {
 	struct stat st;
-	struct object *obj = lookup_object(sha1);
+	struct object *obj = lookup_object(oid->hash);
 
 	if (obj && obj->flags & SEEN)
 		return 0;
@@ -119,22 +119,22 @@
 		 */
 		if (errno == ENOENT)
 			return 0;
-		return error_errno("unable to stat %s", sha1_to_hex(sha1));
+		return error_errno("unable to stat %s", oid_to_hex(oid));
 	}
 
-	add_recent_object(sha1, st.st_mtime, data);
+	add_recent_object(oid, st.st_mtime, data);
 	return 0;
 }
 
-static int add_recent_packed(const unsigned char *sha1,
+static int add_recent_packed(const struct object_id *oid,
 			     struct packed_git *p, uint32_t pos,
 			     void *data)
 {
-	struct object *obj = lookup_object(sha1);
+	struct object *obj = lookup_object(oid->hash);
 
 	if (obj && obj->flags & SEEN)
 		return 0;
-	add_recent_object(sha1, p->mtime, data);
+	add_recent_object(oid, p->mtime, data);
 	return 0;
 }
 
diff --git a/read-cache.c b/read-cache.c
index 9054369..e447751 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1558,10 +1558,27 @@
 	}
 }
 
+static void tweak_split_index(struct index_state *istate)
+{
+	switch (git_config_get_split_index()) {
+	case -1: /* unset: do nothing */
+		break;
+	case 0: /* false */
+		remove_split_index(istate);
+		break;
+	case 1: /* true */
+		add_split_index(istate);
+		break;
+	default: /* unknown value: do nothing */
+		break;
+	}
+}
+
 static void post_read_index_from(struct index_state *istate)
 {
 	check_ce_order(istate);
 	tweak_untracked_cache(istate);
+	tweak_split_index(istate);
 }
 
 /* remember to discard_cache() before reading a different cache! */
@@ -1657,10 +1674,25 @@
 	die("index file corrupt");
 }
 
+/*
+ * Signal that the shared index is used by updating its mtime.
+ *
+ * This way, shared index can be removed if they have not been used
+ * for some time.
+ */
+static void freshen_shared_index(char *base_sha1_hex, int warn)
+{
+	const char *shared_index = git_path("sharedindex.%s", base_sha1_hex);
+	if (!check_and_freshen_file(shared_index, 1) && warn)
+		warning("could not freshen shared index '%s'", shared_index);
+}
+
 int read_index_from(struct index_state *istate, const char *path)
 {
 	struct split_index *split_index;
 	int ret;
+	char *base_sha1_hex;
+	const char *base_path;
 
 	/* istate->initialized covers both .git/index and .git/sharedindex.xxx */
 	if (istate->initialized)
@@ -1678,15 +1710,16 @@
 		discard_index(split_index->base);
 	else
 		split_index->base = xcalloc(1, sizeof(*split_index->base));
-	ret = do_read_index(split_index->base,
-			    git_path("sharedindex.%s",
-				     sha1_to_hex(split_index->base_sha1)), 1);
+
+	base_sha1_hex = sha1_to_hex(split_index->base_sha1);
+	base_path = git_path("sharedindex.%s", base_sha1_hex);
+	ret = do_read_index(split_index->base, base_path, 1);
 	if (hashcmp(split_index->base_sha1, split_index->base->sha1))
 		die("broken index, expect %s in %s, got %s",
-		    sha1_to_hex(split_index->base_sha1),
-		    git_path("sharedindex.%s",
-			     sha1_to_hex(split_index->base_sha1)),
+		    base_sha1_hex, base_path,
 		    sha1_to_hex(split_index->base->sha1));
+
+	freshen_shared_index(base_sha1_hex, 0);
 	merge_base_index(istate);
 	post_read_index_from(istate);
 	return ret;
@@ -2169,6 +2202,65 @@
 	return ret;
 }
 
+static const char *shared_index_expire = "2.weeks.ago";
+
+static unsigned long get_shared_index_expire_date(void)
+{
+	static unsigned long shared_index_expire_date;
+	static int shared_index_expire_date_prepared;
+
+	if (!shared_index_expire_date_prepared) {
+		git_config_get_expiry("splitindex.sharedindexexpire",
+				      &shared_index_expire);
+		shared_index_expire_date = approxidate(shared_index_expire);
+		shared_index_expire_date_prepared = 1;
+	}
+
+	return shared_index_expire_date;
+}
+
+static int should_delete_shared_index(const char *shared_index_path)
+{
+	struct stat st;
+	unsigned long expiration;
+
+	/* Check timestamp */
+	expiration = get_shared_index_expire_date();
+	if (!expiration)
+		return 0;
+	if (stat(shared_index_path, &st))
+		return error_errno(_("could not stat '%s"), shared_index_path);
+	if (st.st_mtime > expiration)
+		return 0;
+
+	return 1;
+}
+
+static int clean_shared_index_files(const char *current_hex)
+{
+	struct dirent *de;
+	DIR *dir = opendir(get_git_dir());
+
+	if (!dir)
+		return error_errno(_("unable to open git dir: %s"), get_git_dir());
+
+	while ((de = readdir(dir)) != NULL) {
+		const char *sha1_hex;
+		const char *shared_index_path;
+		if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex))
+			continue;
+		if (!strcmp(sha1_hex, current_hex))
+			continue;
+		shared_index_path = git_path("%s", de->d_name);
+		if (should_delete_shared_index(shared_index_path) > 0 &&
+		    unlink(shared_index_path))
+			warning_errno(_("unable to unlink: %s"), shared_index_path);
+	}
+	closedir(dir);
+
+	return 0;
+}
+
 static struct tempfile temporary_sharedindex;
 
 static int write_shared_index(struct index_state *istate,
@@ -2190,14 +2282,48 @@
 	}
 	ret = rename_tempfile(&temporary_sharedindex,
 			      git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
-	if (!ret)
+	if (!ret) {
 		hashcpy(si->base_sha1, si->base->sha1);
+		clean_shared_index_files(sha1_to_hex(si->base->sha1));
+	}
+
 	return ret;
 }
 
+static const int default_max_percent_split_change = 20;
+
+static int too_many_not_shared_entries(struct index_state *istate)
+{
+	int i, not_shared = 0;
+	int max_split = git_config_get_max_percent_split_change();
+
+	switch (max_split) {
+	case -1:
+		/* not or badly configured: use the default value */
+		max_split = default_max_percent_split_change;
+		break;
+	case 0:
+		return 1; /* 0% means always write a new shared index */
+	case 100:
+		return 0; /* 100% means never write a new shared index */
+	default:
+		break; /* just use the configured value */
+	}
+
+	/* Count not shared entries */
+	for (i = 0; i < istate->cache_nr; i++) {
+		struct cache_entry *ce = istate->cache[i];
+		if (!ce->index)
+			not_shared++;
+	}
+
+	return (int64_t)istate->cache_nr * max_split < (int64_t)not_shared * 100;
+}
+
 int write_locked_index(struct index_state *istate, struct lock_file *lock,
 		       unsigned flags)
 {
+	int new_shared_index, ret;
 	struct split_index *si = istate->split_index;
 
 	if (!si || alternate_index_output ||
@@ -2212,13 +2338,24 @@
 		if ((v & 15) < 6)
 			istate->cache_changed |= SPLIT_INDEX_ORDERED;
 	}
-	if (istate->cache_changed & SPLIT_INDEX_ORDERED) {
-		int ret = write_shared_index(istate, lock, flags);
+	if (too_many_not_shared_entries(istate))
+		istate->cache_changed |= SPLIT_INDEX_ORDERED;
+
+	new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED;
+
+	if (new_shared_index) {
+		ret = write_shared_index(istate, lock, flags);
 		if (ret)
 			return ret;
 	}
 
-	return write_split_index(istate, lock, flags);
+	ret = write_split_index(istate, lock, flags);
+
+	/* Freshen the shared index only if the split-index was written */
+	if (!ret && !new_shared_index)
+		freshen_shared_index(sha1_to_hex(si->base_sha1), 1);
+
+	return ret;
 }
 
 /*
diff --git a/ref-filter.c b/ref-filter.c
index 3820b21..9c82b5b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -14,14 +14,51 @@
 #include "git-compat-util.h"
 #include "version.h"
 #include "trailer.h"
+#include "wt-status.h"
+#include "commit-slab.h"
+
+static struct ref_msg {
+	const char *gone;
+	const char *ahead;
+	const char *behind;
+	const char *ahead_behind;
+} msgs = {
+	 /* Untranslated plumbing messages: */
+	"gone",
+	"ahead %d",
+	"behind %d",
+	"ahead %d, behind %d"
+};
+
+void setup_ref_filter_porcelain_msg(void)
+{
+	msgs.gone = _("gone");
+	msgs.ahead = _("ahead %d");
+	msgs.behind = _("behind %d");
+	msgs.ahead_behind = _("ahead %d, behind %d");
+}
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
+typedef enum { COMPARE_EQUAL, COMPARE_UNEQUAL, COMPARE_NONE } cmp_status;
 
 struct align {
 	align_type position;
 	unsigned int width;
 };
 
+struct if_then_else {
+	cmp_status cmp_status;
+	const char *str;
+	unsigned int then_atom_seen : 1,
+		else_atom_seen : 1,
+		condition_satisfied : 1;
+};
+
+struct refname_atom {
+	enum { R_NORMAL, R_SHORT, R_LSTRIP, R_RSTRIP } option;
+	int lstrip, rstrip;
+};
+
 /*
  * An atom is a valid field atom listed below, possibly prefixed with
  * a "*" to denote deref_tag().
@@ -38,13 +75,24 @@
 	union {
 		char color[COLOR_MAXLEN];
 		struct align align;
-		enum { RR_NORMAL, RR_SHORTEN, RR_TRACK, RR_TRACKSHORT }
-			remote_ref;
+		struct {
+			enum { RR_REF, RR_TRACK, RR_TRACKSHORT } option;
+			struct refname_atom refname;
+			unsigned int nobracket : 1;
+		} remote_ref;
 		struct {
 			enum { C_BARE, C_BODY, C_BODY_DEP, C_LINES, C_SIG, C_SUB, C_TRAILERS } option;
 			unsigned int nlines;
 		} contents;
-		enum { O_FULL, O_SHORT } objectname;
+		struct {
+			cmp_status cmp_status;
+			const char *str;
+		} if_then_else;
+		struct {
+			enum { O_FULL, O_LENGTH, O_SHORT } option;
+			unsigned int length;
+		} objectname;
+		struct refname_atom refname;
 	} u;
 } *used_atom;
 static int used_atom_cnt, need_tagged, need_symref;
@@ -58,18 +106,58 @@
 		die(_("unrecognized color: %%(color:%s)"), color_value);
 }
 
-static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
+static void refname_atom_parser_internal(struct refname_atom *atom,
+					 const char *arg, const char *name)
 {
 	if (!arg)
-		atom->u.remote_ref = RR_NORMAL;
+		atom->option = R_NORMAL;
 	else if (!strcmp(arg, "short"))
-		atom->u.remote_ref = RR_SHORTEN;
-	else if (!strcmp(arg, "track"))
-		atom->u.remote_ref = RR_TRACK;
-	else if (!strcmp(arg, "trackshort"))
-		atom->u.remote_ref = RR_TRACKSHORT;
-	else
-		die(_("unrecognized format: %%(%s)"), atom->name);
+		atom->option = R_SHORT;
+	else if (skip_prefix(arg, "lstrip=", &arg) ||
+		 skip_prefix(arg, "strip=", &arg)) {
+		atom->option = R_LSTRIP;
+		if (strtol_i(arg, 10, &atom->lstrip))
+			die(_("Integer value expected refname:lstrip=%s"), arg);
+	} else if (skip_prefix(arg, "rstrip=", &arg)) {
+		atom->option = R_RSTRIP;
+		if (strtol_i(arg, 10, &atom->rstrip))
+			die(_("Integer value expected refname:rstrip=%s"), arg);
+	} else
+		die(_("unrecognized %%(%s) argument: %s"), name, arg);
+}
+
+static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
+{
+	struct string_list params = STRING_LIST_INIT_DUP;
+	int i;
+
+	if (!arg) {
+		atom->u.remote_ref.option = RR_REF;
+		refname_atom_parser_internal(&atom->u.remote_ref.refname,
+					     arg, atom->name);
+		return;
+	}
+
+	atom->u.remote_ref.nobracket = 0;
+	string_list_split(&params, arg, ',', -1);
+
+	for (i = 0; i < params.nr; i++) {
+		const char *s = params.items[i].string;
+
+		if (!strcmp(s, "track"))
+			atom->u.remote_ref.option = RR_TRACK;
+		else if (!strcmp(s, "trackshort"))
+			atom->u.remote_ref.option = RR_TRACKSHORT;
+		else if (!strcmp(s, "nobracket"))
+			atom->u.remote_ref.nobracket = 1;
+		else {
+			atom->u.remote_ref.option = RR_REF;
+			refname_atom_parser_internal(&atom->u.remote_ref.refname,
+						     arg, atom->name);
+		}
+	}
+
+	string_list_clear(&params, 0);
 }
 
 static void body_atom_parser(struct used_atom *atom, const char *arg)
@@ -116,13 +204,25 @@
 static void objectname_atom_parser(struct used_atom *atom, const char *arg)
 {
 	if (!arg)
-		atom->u.objectname = O_FULL;
+		atom->u.objectname.option = O_FULL;
 	else if (!strcmp(arg, "short"))
-		atom->u.objectname = O_SHORT;
-	else
+		atom->u.objectname.option = O_SHORT;
+	else if (skip_prefix(arg, "short=", &arg)) {
+		atom->u.objectname.option = O_LENGTH;
+		if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
+		    atom->u.objectname.length == 0)
+			die(_("positive value expected objectname:short=%s"), arg);
+		if (atom->u.objectname.length < MINIMUM_ABBREV)
+			atom->u.objectname.length = MINIMUM_ABBREV;
+	} else
 		die(_("unrecognized %%(objectname) argument: %s"), arg);
 }
 
+static void refname_atom_parser(struct used_atom *atom, const char *arg)
+{
+	return refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
+}
+
 static align_type parse_align_position(const char *s)
 {
 	if (!strcmp(s, "right"))
@@ -173,12 +273,27 @@
 	string_list_clear(&params, 0);
 }
 
+static void if_atom_parser(struct used_atom *atom, const char *arg)
+{
+	if (!arg) {
+		atom->u.if_then_else.cmp_status = COMPARE_NONE;
+		return;
+	} else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
+		atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
+	} else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
+		atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
+	} else {
+		die(_("unrecognized %%(if) argument: %s"), arg);
+	}
+}
+
+
 static struct {
 	const char *name;
 	cmp_type cmp_type;
 	void (*parser)(struct used_atom *atom, const char *arg);
 } valid_atom[] = {
-	{ "refname" },
+	{ "refname" , FIELD_STR, refname_atom_parser },
 	{ "objecttype" },
 	{ "objectsize", FIELD_ULONG },
 	{ "objectname", FIELD_STR, objectname_atom_parser },
@@ -208,12 +323,15 @@
 	{ "contents", FIELD_STR, contents_atom_parser },
 	{ "upstream", FIELD_STR, remote_ref_atom_parser },
 	{ "push", FIELD_STR, remote_ref_atom_parser },
-	{ "symref" },
+	{ "symref", FIELD_STR, refname_atom_parser },
 	{ "flag" },
 	{ "HEAD" },
 	{ "color", FIELD_STR, color_atom_parser },
 	{ "align", FIELD_STR, align_atom_parser },
 	{ "end" },
+	{ "if", FIELD_STR, if_atom_parser },
+	{ "then" },
+	{ "else" },
 };
 
 #define REF_FORMATTING_STATE_INIT  { 0, NULL }
@@ -221,7 +339,7 @@
 struct ref_formatting_stack {
 	struct ref_formatting_stack *prev;
 	struct strbuf output;
-	void (*at_end)(struct ref_formatting_stack *stack);
+	void (*at_end)(struct ref_formatting_stack **stack);
 	void *at_end_data;
 };
 
@@ -232,11 +350,9 @@
 
 struct atom_value {
 	const char *s;
-	union {
-		struct align align;
-	} u;
 	void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
 	unsigned long ul; /* used for sorting when not FIELD_STR */
+	struct used_atom *atom;
 };
 
 /*
@@ -293,7 +409,7 @@
 		valid_atom[i].parser(&used_atom[at], arg);
 	if (*atom == '*')
 		need_tagged = 1;
-	if (!strcmp(used_atom[at].name, "symref"))
+	if (!strcmp(valid_atom[i].name, "symref"))
 		need_symref = 1;
 	return at;
 }
@@ -354,13 +470,14 @@
 	*stack = prev;
 }
 
-static void end_align_handler(struct ref_formatting_stack *stack)
+static void end_align_handler(struct ref_formatting_stack **stack)
 {
-	struct align *align = (struct align *)stack->at_end_data;
+	struct ref_formatting_stack *cur = *stack;
+	struct align *align = (struct align *)cur->at_end_data;
 	struct strbuf s = STRBUF_INIT;
 
-	strbuf_utf8_align(&s, align->position, align->width, stack->output.buf);
-	strbuf_swap(&stack->output, &s);
+	strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
+	strbuf_swap(&cur->output, &s);
 	strbuf_release(&s);
 }
 
@@ -371,7 +488,115 @@
 	push_stack_element(&state->stack);
 	new = state->stack;
 	new->at_end = end_align_handler;
-	new->at_end_data = &atomv->u.align;
+	new->at_end_data = &atomv->atom->u.align;
+}
+
+static void if_then_else_handler(struct ref_formatting_stack **stack)
+{
+	struct ref_formatting_stack *cur = *stack;
+	struct ref_formatting_stack *prev = cur->prev;
+	struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
+
+	if (!if_then_else->then_atom_seen)
+		die(_("format: %%(if) atom used without a %%(then) atom"));
+
+	if (if_then_else->else_atom_seen) {
+		/*
+		 * There is an %(else) atom: we need to drop one state from the
+		 * stack, either the %(else) branch if the condition is satisfied, or
+		 * the %(then) branch if it isn't.
+		 */
+		if (if_then_else->condition_satisfied) {
+			strbuf_reset(&cur->output);
+			pop_stack_element(&cur);
+		} else {
+			strbuf_swap(&cur->output, &prev->output);
+			strbuf_reset(&cur->output);
+			pop_stack_element(&cur);
+		}
+	} else if (!if_then_else->condition_satisfied) {
+		/*
+		 * No %(else) atom: just drop the %(then) branch if the
+		 * condition is not satisfied.
+		 */
+		strbuf_reset(&cur->output);
+	}
+
+	*stack = cur;
+	free(if_then_else);
+}
+
+static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+	struct ref_formatting_stack *new;
+	struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
+
+	if_then_else->str = atomv->atom->u.if_then_else.str;
+	if_then_else->cmp_status = atomv->atom->u.if_then_else.cmp_status;
+
+	push_stack_element(&state->stack);
+	new = state->stack;
+	new->at_end = if_then_else_handler;
+	new->at_end_data = if_then_else;
+}
+
+static int is_empty(const char *s)
+{
+	while (*s != '\0') {
+		if (!isspace(*s))
+			return 0;
+		s++;
+	}
+	return 1;
+}
+
+static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+	struct ref_formatting_stack *cur = state->stack;
+	struct if_then_else *if_then_else = NULL;
+
+	if (cur->at_end == if_then_else_handler)
+		if_then_else = (struct if_then_else *)cur->at_end_data;
+	if (!if_then_else)
+		die(_("format: %%(then) atom used without an %%(if) atom"));
+	if (if_then_else->then_atom_seen)
+		die(_("format: %%(then) atom used more than once"));
+	if (if_then_else->else_atom_seen)
+		die(_("format: %%(then) atom used after %%(else)"));
+	if_then_else->then_atom_seen = 1;
+	/*
+	 * If the 'equals' or 'notequals' attribute is used then
+	 * perform the required comparison. If not, only non-empty
+	 * strings satisfy the 'if' condition.
+	 */
+	if (if_then_else->cmp_status == COMPARE_EQUAL) {
+		if (!strcmp(if_then_else->str, cur->output.buf))
+			if_then_else->condition_satisfied = 1;
+	} else if (if_then_else->cmp_status == COMPARE_UNEQUAL) {
+		if (strcmp(if_then_else->str, cur->output.buf))
+			if_then_else->condition_satisfied = 1;
+	} else if (cur->output.len && !is_empty(cur->output.buf))
+		if_then_else->condition_satisfied = 1;
+	strbuf_reset(&cur->output);
+}
+
+static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+	struct ref_formatting_stack *prev = state->stack;
+	struct if_then_else *if_then_else = NULL;
+
+	if (prev->at_end == if_then_else_handler)
+		if_then_else = (struct if_then_else *)prev->at_end_data;
+	if (!if_then_else)
+		die(_("format: %%(else) atom used without an %%(if) atom"));
+	if (!if_then_else->then_atom_seen)
+		die(_("format: %%(else) atom used without a %%(then) atom"));
+	if (if_then_else->else_atom_seen)
+		die(_("format: %%(else) atom used more than once"));
+	if_then_else->else_atom_seen = 1;
+	push_stack_element(&state->stack);
+	state->stack->at_end_data = prev->at_end_data;
+	state->stack->at_end = prev->at_end;
 }
 
 static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
@@ -381,14 +606,17 @@
 
 	if (!current->at_end)
 		die(_("format: %%(end) atom used without corresponding atom"));
-	current->at_end(current);
+	current->at_end(&state->stack);
+
+	/*  Stack may have been popped within at_end(), hence reset the current pointer */
+	current = state->stack;
 
 	/*
 	 * Perform quote formatting when the stack element is that of
 	 * a supporting atom. If nested then perform quote formatting
 	 * only on the topmost supporting atom.
 	 */
-	if (!state->stack->prev->prev) {
+	if (!current->prev->prev) {
 		quote_formatting(&s, current->output.buf, state->quote_style);
 		strbuf_swap(&current->output, &s);
 	}
@@ -465,12 +693,15 @@
 			   struct atom_value *v, struct used_atom *atom)
 {
 	if (starts_with(name, "objectname")) {
-		if (atom->u.objectname == O_SHORT) {
+		if (atom->u.objectname.option == O_SHORT) {
 			v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
 			return 1;
-		} else if (atom->u.objectname == O_FULL) {
+		} else if (atom->u.objectname.option == O_FULL) {
 			v->s = xstrdup(sha1_to_hex(sha1));
 			return 1;
+		} else if (atom->u.objectname.option == O_LENGTH) {
+			v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
+			return 1;
 		} else
 			die("BUG: unknown %%(objectname) option");
 	}
@@ -887,50 +1118,108 @@
 	return dst;
 }
 
-static const char *strip_ref_components(const char *refname, const char *nr_arg)
+static const char *lstrip_ref_components(const char *refname, int len)
 {
-	char *end;
-	long nr = strtol(nr_arg, &end, 10);
-	long remaining = nr;
+	long remaining = len;
 	const char *start = refname;
 
-	if (nr < 1 || *end != '\0')
-		die(_(":strip= requires a positive integer argument"));
+	if (len < 0) {
+		int i;
+		const char *p = refname;
 
-	while (remaining) {
+		/* Find total no of '/' separated path-components */
+		for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
+			;
+		/*
+		 * The number of components we need to strip is now
+		 * the total minus the components to be left (Plus one
+		 * because we count the number of '/', but the number
+		 * of components is one more than the no of '/').
+		 */
+		remaining = i + len + 1;
+	}
+
+	while (remaining > 0) {
 		switch (*start++) {
 		case '\0':
-			die(_("ref '%s' does not have %ld components to :strip"),
-			    refname, nr);
+			return "";
 		case '/':
 			remaining--;
 			break;
 		}
 	}
+
 	return start;
 }
 
+static const char *rstrip_ref_components(const char *refname, int len)
+{
+	long remaining = len;
+	char *start = xstrdup(refname);
+
+	if (len < 0) {
+		int i;
+		const char *p = refname;
+
+		/* Find total no of '/' separated path-components */
+		for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
+			;
+		/*
+		 * The number of components we need to strip is now
+		 * the total minus the components to be left (Plus one
+		 * because we count the number of '/', but the number
+		 * of components is one more than the no of '/').
+		 */
+		remaining = i + len + 1;
+	}
+
+	while (remaining-- > 0) {
+		char *p = strrchr(start, '/');
+		if (p == NULL)
+			return "";
+		else
+			p[0] = '\0';
+	}
+	return start;
+}
+
+static const char *show_ref(struct refname_atom *atom, const char *refname)
+{
+	if (atom->option == R_SHORT)
+		return shorten_unambiguous_ref(refname, warn_ambiguous_refs);
+	else if (atom->option == R_LSTRIP)
+		return lstrip_ref_components(refname, atom->lstrip);
+	else if (atom->option == R_RSTRIP)
+		return rstrip_ref_components(refname, atom->rstrip);
+	else
+		return refname;
+}
+
 static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
 				    struct branch *branch, const char **s)
 {
 	int num_ours, num_theirs;
-	if (atom->u.remote_ref == RR_SHORTEN)
-		*s = shorten_unambiguous_ref(refname, warn_ambiguous_refs);
-	else if (atom->u.remote_ref == RR_TRACK) {
+	if (atom->u.remote_ref.option == RR_REF)
+		*s = show_ref(&atom->u.remote_ref.refname, refname);
+	else if (atom->u.remote_ref.option == RR_TRACK) {
 		if (stat_tracking_info(branch, &num_ours,
-				       &num_theirs, NULL))
-			return;
-
-		if (!num_ours && !num_theirs)
+				       &num_theirs, NULL)) {
+			*s = xstrdup(msgs.gone);
+		} else if (!num_ours && !num_theirs)
 			*s = "";
 		else if (!num_ours)
-			*s = xstrfmt("[behind %d]", num_theirs);
+			*s = xstrfmt(msgs.behind, num_theirs);
 		else if (!num_theirs)
-			*s = xstrfmt("[ahead %d]", num_ours);
+			*s = xstrfmt(msgs.ahead, num_ours);
 		else
-			*s = xstrfmt("[ahead %d, behind %d]",
+			*s = xstrfmt(msgs.ahead_behind,
 				     num_ours, num_theirs);
-	} else if (atom->u.remote_ref == RR_TRACKSHORT) {
+		if (!atom->u.remote_ref.nobracket && *s[0]) {
+			const char *to_free = *s;
+			*s = xstrfmt("[%s]", *s);
+			free((void *)to_free);
+		}
+	} else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
 		if (stat_tracking_info(branch, &num_ours,
 				       &num_theirs, NULL))
 			return;
@@ -943,8 +1232,56 @@
 			*s = ">";
 		else
 			*s = "<>";
-	} else /* RR_NORMAL */
-		*s = refname;
+	} else
+		die("BUG: unhandled RR_* enum");
+}
+
+char *get_head_description(void)
+{
+	struct strbuf desc = STRBUF_INIT;
+	struct wt_status_state state;
+	memset(&state, 0, sizeof(state));
+	wt_status_get_state(&state, 1);
+	if (state.rebase_in_progress ||
+	    state.rebase_interactive_in_progress)
+		strbuf_addf(&desc, _("(no branch, rebasing %s)"),
+			    state.branch);
+	else if (state.bisect_in_progress)
+		strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
+			    state.branch);
+	else if (state.detached_from) {
+		if (state.detached_at)
+			/* TRANSLATORS: make sure this matches
+			   "HEAD detached at " in wt-status.c */
+			strbuf_addf(&desc, _("(HEAD detached at %s)"),
+				state.detached_from);
+		else
+			/* TRANSLATORS: make sure this matches
+			   "HEAD detached from " in wt-status.c */
+			strbuf_addf(&desc, _("(HEAD detached from %s)"),
+				state.detached_from);
+	}
+	else
+		strbuf_addstr(&desc, _("(no branch)"));
+	free(state.branch);
+	free(state.onto);
+	free(state.detached_from);
+	return strbuf_detach(&desc, NULL);
+}
+
+static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
+{
+	if (!ref->symref)
+		return "";
+	else
+		return show_ref(&atom->u.refname, ref->symref);
+}
+
+static const char *get_refname(struct used_atom *atom, struct ref_array_item *ref)
+{
+	if (ref->kind & FILTER_REFS_DETACHED_HEAD)
+		return get_head_description();
+	return show_ref(&atom->u.refname, ref->refname);
 }
 
 /*
@@ -961,9 +1298,9 @@
 	ref->value = xcalloc(used_atom_cnt, sizeof(struct atom_value));
 
 	if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
-		unsigned char unused1[20];
+		struct object_id unused1;
 		ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
-					     unused1, NULL);
+					     unused1.hash, NULL);
 		if (!ref->symref)
 			ref->symref = "";
 	}
@@ -975,10 +1312,10 @@
 		struct atom_value *v = &ref->value[i];
 		int deref = 0;
 		const char *refname;
-		const char *formatp;
 		struct branch *branch = NULL;
 
 		v->handler = append_atom;
+		v->atom = atom;
 
 		if (*name == '*') {
 			deref = 1;
@@ -986,9 +1323,9 @@
 		}
 
 		if (starts_with(name, "refname"))
-			refname = ref->refname;
+			refname = get_refname(atom, ref);
 		else if (starts_with(name, "symref"))
-			refname = ref->symref ? ref->symref : "";
+			refname = get_symref(atom, ref);
 		else if (starts_with(name, "upstream")) {
 			const char *branch_name;
 			/* only local branches may have an upstream */
@@ -1043,30 +1380,27 @@
 				v->s = " ";
 			continue;
 		} else if (starts_with(name, "align")) {
-			v->u.align = atom->u.align;
 			v->handler = align_atom_handler;
 			continue;
 		} else if (!strcmp(name, "end")) {
 			v->handler = end_atom_handler;
 			continue;
+		} else if (starts_with(name, "if")) {
+			const char *s;
+
+			if (skip_prefix(name, "if:", &s))
+				v->s = xstrdup(s);
+			v->handler = if_atom_handler;
+			continue;
+		} else if (!strcmp(name, "then")) {
+			v->handler = then_atom_handler;
+			continue;
+		} else if (!strcmp(name, "else")) {
+			v->handler = else_atom_handler;
+			continue;
 		} else
 			continue;
 
-		formatp = strchr(name, ':');
-		if (formatp) {
-			const char *arg;
-
-			formatp++;
-			if (!strcmp(formatp, "short"))
-				refname = shorten_unambiguous_ref(refname,
-						      warn_ambiguous_refs);
-			else if (skip_prefix(formatp, "strip=", &arg))
-				refname = strip_ref_components(refname, arg);
-			else
-				die(_("unknown %.*s format %s"),
-				    (int)(formatp - name), name, formatp);
-		}
-
 		if (!deref)
 			v->s = refname;
 		else
@@ -1137,10 +1471,22 @@
 	*v = &ref->value[atom];
 }
 
+/*
+ * Unknown has to be "0" here, because that's the default value for
+ * contains_cache slab entries that have not yet been assigned.
+ */
 enum contains_result {
-	CONTAINS_UNKNOWN = -1,
-	CONTAINS_NO = 0,
-	CONTAINS_YES = 1
+	CONTAINS_UNKNOWN = 0,
+	CONTAINS_NO,
+	CONTAINS_YES
+};
+
+define_commit_slab(contains_cache, enum contains_result);
+
+struct ref_filter_cbdata {
+	struct ref_array *array;
+	struct ref_filter *filter;
+	struct contains_cache contains_cache;
 };
 
 /*
@@ -1171,24 +1517,24 @@
  * Do not recurse to find out, though, but return -1 if inconclusive.
  */
 static enum contains_result contains_test(struct commit *candidate,
-			    const struct commit_list *want)
+					  const struct commit_list *want,
+					  struct contains_cache *cache)
 {
-	/* was it previously marked as containing a want commit? */
-	if (candidate->object.flags & TMP_MARK)
-		return 1;
-	/* or marked as not possibly containing a want commit? */
-	if (candidate->object.flags & UNINTERESTING)
-		return 0;
+	enum contains_result *cached = contains_cache_at(cache, candidate);
+
+	/* If we already have the answer cached, return that. */
+	if (*cached)
+		return *cached;
+
 	/* or are we it? */
 	if (in_commit_list(want, candidate)) {
-		candidate->object.flags |= TMP_MARK;
-		return 1;
+		*cached = CONTAINS_YES;
+		return CONTAINS_YES;
 	}
 
-	if (parse_commit(candidate) < 0)
-		return 0;
-
-	return -1;
+	/* Otherwise, we don't know; prepare to recurse */
+	parse_commit_or_die(candidate);
+	return CONTAINS_UNKNOWN;
 }
 
 static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
@@ -1199,10 +1545,11 @@
 }
 
 static enum contains_result contains_tag_algo(struct commit *candidate,
-		const struct commit_list *want)
+					      const struct commit_list *want,
+					      struct contains_cache *cache)
 {
 	struct contains_stack contains_stack = { 0, 0, NULL };
-	int result = contains_test(candidate, want);
+	enum contains_result result = contains_test(candidate, want, cache);
 
 	if (result != CONTAINS_UNKNOWN)
 		return result;
@@ -1214,16 +1561,16 @@
 		struct commit_list *parents = entry->parents;
 
 		if (!parents) {
-			commit->object.flags |= UNINTERESTING;
+			*contains_cache_at(cache, commit) = CONTAINS_NO;
 			contains_stack.nr--;
 		}
 		/*
 		 * If we just popped the stack, parents->item has been marked,
-		 * therefore contains_test will return a meaningful 0 or 1.
+		 * therefore contains_test will return a meaningful yes/no.
 		 */
-		else switch (contains_test(parents->item, want)) {
+		else switch (contains_test(parents->item, want, cache)) {
 		case CONTAINS_YES:
-			commit->object.flags |= TMP_MARK;
+			*contains_cache_at(cache, commit) = CONTAINS_YES;
 			contains_stack.nr--;
 			break;
 		case CONTAINS_NO:
@@ -1235,13 +1582,14 @@
 		}
 	}
 	free(contains_stack.contains_stack);
-	return contains_test(candidate, want);
+	return contains_test(candidate, want, cache);
 }
 
-static int commit_contains(struct ref_filter *filter, struct commit *commit)
+static int commit_contains(struct ref_filter *filter, struct commit *commit,
+			   struct contains_cache *cache)
 {
 	if (filter->with_commit_tag_algo)
-		return contains_tag_algo(commit, filter->with_commit);
+		return contains_tag_algo(commit, filter->with_commit, cache) == CONTAINS_YES;
 	return is_descendant_of(commit, filter->with_commit);
 }
 
@@ -1438,7 +1786,7 @@
 			return 0;
 		/* We perform the filtering for the '--contains' option */
 		if (filter->with_commit &&
-		    !commit_contains(filter, commit))
+		    !commit_contains(filter, commit, &ref_cbdata->contains_cache))
 			return 0;
 	}
 
@@ -1538,6 +1886,8 @@
 		broken = 1;
 	filter->kind = type & FILTER_REFS_KIND_MASK;
 
+	init_contains_cache(&ref_cbdata.contains_cache);
+
 	/*  Simple per-ref filtering */
 	if (!filter->kind)
 		die("filter_refs: invalid type");
@@ -1560,6 +1910,7 @@
 			head_ref(ref_filter_handler, &ref_cbdata);
 	}
 
+	clear_contains_cache(&ref_cbdata.contains_cache);
 
 	/*  Filters that need revision walking */
 	if (filter->merge_commit)
@@ -1635,10 +1986,10 @@
 	}
 }
 
-void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+			   int quote_style, struct strbuf *final_buf)
 {
 	const char *cp, *sp, *ep;
-	struct strbuf *final_buf;
 	struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
 
 	state.quote_style = quote_style;
@@ -1668,9 +2019,17 @@
 	}
 	if (state.stack->prev)
 		die(_("format: %%(end) atom missing"));
-	final_buf = &state.stack->output;
-	fwrite(final_buf->buf, 1, final_buf->len, stdout);
+	strbuf_addbuf(final_buf, &state.stack->output);
 	pop_stack_element(&state.stack);
+}
+
+void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+{
+	struct strbuf final_buf = STRBUF_INIT;
+
+	format_ref_array_item(info, format, quote_style, &final_buf);
+	fwrite(final_buf.buf, 1, final_buf.len, stdout);
+	strbuf_release(&final_buf);
 	putchar('\n');
 }
 
diff --git a/ref-filter.h b/ref-filter.h
index 7b05592..e738c5d 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -71,11 +71,6 @@
 		verbose;
 };
 
-struct ref_filter_cbdata {
-	struct ref_array *array;
-	struct ref_filter *filter;
-};
-
 /*  Macros for checking --merged and --no-merged options */
 #define _OPT_MERGED_NO_MERGED(option, filter, h) \
 	{ OPTION_CALLBACK, 0, option, (filter), N_("commit"), (h), \
@@ -100,6 +95,9 @@
 int verify_ref_format(const char *format);
 /*  Sort the given ref_array as per the ref_sorting provided */
 void ref_array_sort(struct ref_sorting *sort, struct ref_array *array);
+/*  Based on the given format and quote_style, fill the strbuf */
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+			   int quote_style, struct strbuf *final_buf);
 /*  Print the ref using the given format and quote_style */
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style);
 /*  Callback function for parsing the sort option */
@@ -108,6 +106,10 @@
 struct ref_sorting *ref_default_sorting(void);
 /*  Function to parse --merged and --no-merged options */
 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset);
+/*  Get the current HEAD's description */
+char *get_head_description(void);
+/*  Set up translated strings in the output. */
+void setup_ref_filter_porcelain_msg(void);
 
 /*
  * Print a single ref, outside of any ref-filter. Note that the
diff --git a/reflog-walk.c b/reflog-walk.c
index a246af2..99679f5 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -10,7 +10,7 @@
 	char *ref;
 	const char *short_ref;
 	struct reflog_info {
-		unsigned char osha1[20], nsha1[20];
+		struct object_id ooid, noid;
 		char *email;
 		unsigned long timestamp;
 		int tz;
@@ -19,7 +19,7 @@
 	int nr, alloc;
 };
 
-static int read_one_reflog(unsigned char *osha1, unsigned char *nsha1,
+static int read_one_reflog(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
@@ -28,8 +28,8 @@
 
 	ALLOC_GROW(array->items, array->nr + 1, array->alloc);
 	item = array->items + array->nr;
-	hashcpy(item->osha1, osha1);
-	hashcpy(item->nsha1, nsha1);
+	oidcpy(&item->ooid, ooid);
+	oidcpy(&item->noid, noid);
 	item->email = xstrdup(email);
 	item->timestamp = timestamp;
 	item->tz = tz;
@@ -45,11 +45,11 @@
 	reflogs->ref = xstrdup(ref);
 	for_each_reflog_ent(ref, read_one_reflog, reflogs);
 	if (reflogs->nr == 0) {
-		unsigned char sha1[20];
+		struct object_id oid;
 		const char *name;
 		void *name_to_free;
 		name = name_to_free = resolve_refdup(ref, RESOLVE_REF_READING,
-						     sha1, NULL);
+						     oid.hash, NULL);
 		if (name) {
 			for_each_reflog_ent(name, read_one_reflog, reflogs);
 			free(name_to_free);
@@ -172,18 +172,18 @@
 		reflogs = item->util;
 	else {
 		if (*branch == '\0') {
-			unsigned char sha1[20];
+			struct object_id oid;
 			free(branch);
-			branch = resolve_refdup("HEAD", 0, sha1, NULL);
+			branch = resolve_refdup("HEAD", 0, oid.hash, NULL);
 			if (!branch)
 				die ("No current branch");
 
 		}
 		reflogs = read_complete_reflog(branch);
 		if (!reflogs || reflogs->nr == 0) {
-			unsigned char sha1[20];
+			struct object_id oid;
 			char *b;
-			if (dwim_log(branch, strlen(branch), sha1, &b) == 1) {
+			if (dwim_log(branch, strlen(branch), oid.hash, &b) == 1) {
 				if (reflogs) {
 					free(reflogs->ref);
 					free(reflogs);
@@ -238,13 +238,13 @@
 	do {
 		reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
 		commit_reflog->recno--;
-		logobj = parse_object(reflog->osha1);
+		logobj = parse_object(reflog->ooid.hash);
 	} while (commit_reflog->recno && (logobj && logobj->type != OBJ_COMMIT));
 
-	if (!logobj && commit_reflog->recno >= 0 && is_null_sha1(reflog->osha1)) {
+	if (!logobj && commit_reflog->recno >= 0 && is_null_sha1(reflog->ooid.hash)) {
 		/* a root commit, but there are still more entries to show */
 		reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
-		logobj = parse_object(reflog->nsha1);
+		logobj = parse_object(reflog->noid.hash);
 	}
 
 	if (!logobj || logobj->type != OBJ_COMMIT) {
diff --git a/refs.c b/refs.c
index 2d71774..0272e33 100644
--- a/refs.c
+++ b/refs.c
@@ -3,6 +3,7 @@
  */
 
 #include "cache.h"
+#include "hashmap.h"
 #include "lockfile.h"
 #include "refs.h"
 #include "refs/refs-internal.h"
@@ -365,11 +366,11 @@
 
 const char *prettify_refname(const char *name)
 {
-	return name + (
-		starts_with(name, "refs/heads/") ? 11 :
-		starts_with(name, "refs/tags/") ? 10 :
-		starts_with(name, "refs/remotes/") ? 13 :
-		0);
+	if (skip_prefix(name, "refs/heads/", &name) ||
+	    skip_prefix(name, "refs/tags/", &name) ||
+	    skip_prefix(name, "refs/remotes/", &name))
+		; /* nothing */
+	return name;
 }
 
 static const char *ref_rev_parse_rules[] = {
@@ -591,8 +592,8 @@
 	return 0;
 }
 
-int delete_ref(const char *refname, const unsigned char *old_sha1,
-	       unsigned int flags)
+int delete_ref(const char *msg, const char *refname,
+	       const unsigned char *old_sha1, unsigned int flags)
 {
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
@@ -603,7 +604,7 @@
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_delete(transaction, refname, old_sha1,
-				   flags, NULL, &err) ||
+				   flags, msg, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
 		error("%s", err.buf);
 		ref_transaction_free(transaction);
@@ -674,7 +675,7 @@
 	int *cutoff_cnt;
 };
 
-static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
+static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
@@ -698,30 +699,30 @@
 		 * hold the values for the previous record.
 		 */
 		if (!is_null_sha1(cb->osha1)) {
-			hashcpy(cb->sha1, nsha1);
-			if (hashcmp(cb->osha1, nsha1))
+			hashcpy(cb->sha1, noid->hash);
+			if (hashcmp(cb->osha1, noid->hash))
 				warning("Log for ref %s has gap after %s.",
 					cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 		}
 		else if (cb->date == cb->at_time)
-			hashcpy(cb->sha1, nsha1);
-		else if (hashcmp(nsha1, cb->sha1))
+			hashcpy(cb->sha1, noid->hash);
+		else if (hashcmp(noid->hash, cb->sha1))
 			warning("Log for ref %s unexpectedly ended on %s.",
 				cb->refname, show_date(cb->date, cb->tz,
 						       DATE_MODE(RFC2822)));
-		hashcpy(cb->osha1, osha1);
-		hashcpy(cb->nsha1, nsha1);
+		hashcpy(cb->osha1, ooid->hash);
+		hashcpy(cb->nsha1, noid->hash);
 		cb->found_it = 1;
 		return 1;
 	}
-	hashcpy(cb->osha1, osha1);
-	hashcpy(cb->nsha1, nsha1);
+	hashcpy(cb->osha1, ooid->hash);
+	hashcpy(cb->nsha1, noid->hash);
 	if (cb->cnt > 0)
 		cb->cnt--;
 	return 0;
 }
 
-static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
+static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 				  const char *email, unsigned long timestamp,
 				  int tz, const char *message, void *cb_data)
 {
@@ -735,9 +736,9 @@
 		*cb->cutoff_tz = tz;
 	if (cb->cutoff_cnt)
 		*cb->cutoff_cnt = cb->reccnt;
-	hashcpy(cb->sha1, osha1);
+	hashcpy(cb->sha1, ooid->hash);
 	if (is_null_sha1(cb->sha1))
-		hashcpy(cb->sha1, nsha1);
+		hashcpy(cb->sha1, noid->hash);
 	/* We just want the first entry */
 	return 1;
 }
@@ -1234,10 +1235,10 @@
 }
 
 /* This function needs to return a meaningful errno on failure */
-static const char *resolve_ref_recursively(struct ref_store *refs,
-					   const char *refname,
-					   int resolve_flags,
-					   unsigned char *sha1, int *flags)
+const char *resolve_ref_recursively(struct ref_store *refs,
+				    const char *refname,
+				    int resolve_flags,
+				    unsigned char *sha1, int *flags)
 {
 	static struct strbuf sb_refname = STRBUF_INIT;
 	int unused_flags;
@@ -1357,62 +1358,102 @@
 	return 0;
 }
 
+struct submodule_hash_entry
+{
+	struct hashmap_entry ent; /* must be the first member! */
+
+	struct ref_store *refs;
+
+	/* NUL-terminated name of submodule: */
+	char submodule[FLEX_ARRAY];
+};
+
+static int submodule_hash_cmp(const void *entry, const void *entry_or_key,
+			      const void *keydata)
+{
+	const struct submodule_hash_entry *e1 = entry, *e2 = entry_or_key;
+	const char *submodule = keydata ? keydata : e2->submodule;
+
+	return strcmp(e1->submodule, submodule);
+}
+
+static struct submodule_hash_entry *alloc_submodule_hash_entry(
+		const char *submodule, struct ref_store *refs)
+{
+	struct submodule_hash_entry *entry;
+
+	FLEX_ALLOC_STR(entry, submodule, submodule);
+	hashmap_entry_init(entry, strhash(submodule));
+	entry->refs = refs;
+	return entry;
+}
+
 /* A pointer to the ref_store for the main repository: */
 static struct ref_store *main_ref_store;
 
-/* A linked list of ref_stores for submodules: */
-static struct ref_store *submodule_ref_stores;
+/* A hashmap of ref_stores, stored by submodule name: */
+static struct hashmap submodule_ref_stores;
 
-void base_ref_store_init(struct ref_store *refs,
-			 const struct ref_storage_be *be,
-			 const char *submodule)
+/*
+ * Return the ref_store instance for the specified submodule (or the
+ * main repository if submodule is NULL). If that ref_store hasn't
+ * been initialized yet, return NULL.
+ */
+static struct ref_store *lookup_ref_store(const char *submodule)
 {
-	refs->be = be;
+	struct submodule_hash_entry *entry;
+
+	if (!submodule)
+		return main_ref_store;
+
+	if (!submodule_ref_stores.tablesize)
+		/* It's initialized on demand in register_ref_store(). */
+		return NULL;
+
+	entry = hashmap_get_from_hash(&submodule_ref_stores,
+				      strhash(submodule), submodule);
+	return entry ? entry->refs : NULL;
+}
+
+/*
+ * Register the specified ref_store to be the one that should be used
+ * for submodule (or the main repository if submodule is NULL). It is
+ * a fatal error to call this function twice for the same submodule.
+ */
+static void register_ref_store(struct ref_store *refs, const char *submodule)
+{
 	if (!submodule) {
 		if (main_ref_store)
 			die("BUG: main_ref_store initialized twice");
 
-		refs->submodule = "";
-		refs->next = NULL;
 		main_ref_store = refs;
 	} else {
-		if (lookup_ref_store(submodule))
+		if (!submodule_ref_stores.tablesize)
+			hashmap_init(&submodule_ref_stores, submodule_hash_cmp, 0);
+
+		if (hashmap_put(&submodule_ref_stores,
+				alloc_submodule_hash_entry(submodule, refs)))
 			die("BUG: ref_store for submodule '%s' initialized twice",
 			    submodule);
-
-		refs->submodule = xstrdup(submodule);
-		refs->next = submodule_ref_stores;
-		submodule_ref_stores = refs;
 	}
 }
 
-struct ref_store *ref_store_init(const char *submodule)
+/*
+ * Create, record, and return a ref_store instance for the specified
+ * submodule (or the main repository if submodule is NULL).
+ */
+static struct ref_store *ref_store_init(const char *submodule)
 {
 	const char *be_name = "files";
 	struct ref_storage_be *be = find_ref_storage_backend(be_name);
+	struct ref_store *refs;
 
 	if (!be)
 		die("BUG: reference backend %s is unknown", be_name);
 
-	if (!submodule || !*submodule)
-		return be->init(NULL);
-	else
-		return be->init(submodule);
-}
-
-struct ref_store *lookup_ref_store(const char *submodule)
-{
-	struct ref_store *refs;
-
-	if (!submodule || !*submodule)
-		return main_ref_store;
-
-	for (refs = submodule_ref_stores; refs; refs = refs->next) {
-		if (!strcmp(submodule, refs->submodule))
-			return refs;
-	}
-
-	return NULL;
+	refs = be->init(submodule);
+	register_ref_store(refs, submodule);
+	return refs;
 }
 
 struct ref_store *get_ref_store(const char *submodule)
@@ -1440,10 +1481,10 @@
 	return refs;
 }
 
-void assert_main_repository(struct ref_store *refs, const char *caller)
+void base_ref_store_init(struct ref_store *refs,
+			 const struct ref_storage_be *be)
 {
-	if (*refs->submodule)
-		die("BUG: %s called for a submodule", caller);
+	refs->be = be;
 }
 
 /* backend functions */
diff --git a/refs.h b/refs.h
index 9fbff90..3df0d45 100644
--- a/refs.h
+++ b/refs.h
@@ -276,8 +276,8 @@
  * exists, regardless of its old value. It is an error for old_sha1 to
  * be NULL_SHA1. flags is passed through to ref_transaction_delete().
  */
-int delete_ref(const char *refname, const unsigned char *old_sha1,
-	       unsigned int flags);
+int delete_ref(const char *msg, const char *refname,
+	       const unsigned char *old_sha1, unsigned int flags);
 
 /*
  * Delete the specified references. If there are any problems, emit
@@ -292,7 +292,7 @@
 
 /* iterate over reflog entries */
 typedef int each_reflog_ent_fn(
-		unsigned char *old_sha1, unsigned char *new_sha1,
+		struct object_id *old_oid, struct object_id *new_oid,
 		const char *committer, unsigned long timestamp,
 		int tz, const char *msg, void *cb_data);
 
@@ -334,7 +334,8 @@
  * $GIT_DIR points to.
  * Return 0 if successful, non-zero otherwise.
  * */
-int set_worktree_head_symref(const char *gitdir, const char *target);
+int set_worktree_head_symref(const char *gitdir, const char *target,
+			     const char *logmsg);
 
 enum action_on_err {
 	UPDATE_REFS_MSG_ON_ERR,
diff --git a/refs/files-backend.c b/refs/files-backend.c
index c041d4b..50188e9 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -912,6 +912,14 @@
  */
 struct files_ref_store {
 	struct ref_store base;
+
+	/*
+	 * The name of the submodule represented by this object, or
+	 * NULL if it represents the main repository's reference
+	 * store:
+	 */
+	const char *submodule;
+
 	struct ref_entry *loose;
 	struct packed_ref_cache *packed;
 };
@@ -972,12 +980,25 @@
 	struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
 	struct ref_store *ref_store = (struct ref_store *)refs;
 
-	base_ref_store_init(ref_store, &refs_be_files, submodule);
+	base_ref_store_init(ref_store, &refs_be_files);
+
+	refs->submodule = xstrdup_or_null(submodule);
 
 	return ref_store;
 }
 
 /*
+ * Die if refs is for a submodule (i.e., not for the main repository).
+ * caller is used in any necessary error messages.
+ */
+static void files_assert_main_repository(struct files_ref_store *refs,
+					 const char *caller)
+{
+	if (refs->submodule)
+		die("BUG: %s called for a submodule", caller);
+}
+
+/*
  * Downcast ref_store to files_ref_store. Die if ref_store is not a
  * files_ref_store. If submodule_allowed is not true, then also die if
  * files_ref_store is for a submodule (i.e., not for the main
@@ -987,14 +1008,18 @@
 		struct ref_store *ref_store, int submodule_allowed,
 		const char *caller)
 {
+	struct files_ref_store *refs;
+
 	if (ref_store->be != &refs_be_files)
 		die("BUG: ref_store is type \"%s\" not \"files\" in %s",
 		    ref_store->be->name, caller);
 
-	if (!submodule_allowed)
-		assert_main_repository(ref_store, caller);
+	refs = (struct files_ref_store *)ref_store;
 
-	return (struct files_ref_store *)ref_store;
+	if (!submodule_allowed)
+		files_assert_main_repository(refs, caller);
+
+	return refs;
 }
 
 /* The length of a peeled reference line in packed-refs, including EOL: */
@@ -1133,8 +1158,8 @@
 {
 	char *packed_refs_file;
 
-	if (*refs->base.submodule)
-		packed_refs_file = git_pathdup_submodule(refs->base.submodule,
+	if (refs->submodule)
+		packed_refs_file = git_pathdup_submodule(refs->submodule,
 							 "packed-refs");
 	else
 		packed_refs_file = git_pathdup("packed-refs");
@@ -1203,8 +1228,8 @@
 	size_t path_baselen;
 	int err = 0;
 
-	if (*refs->base.submodule)
-		err = strbuf_git_path_submodule(&path, refs->base.submodule, "%s", dirname);
+	if (refs->submodule)
+		err = strbuf_git_path_submodule(&path, refs->submodule, "%s", dirname);
 	else
 		strbuf_git_path(&path, "%s", dirname);
 	path_baselen = path.len;
@@ -1242,20 +1267,10 @@
 					 create_dir_entry(refs, refname.buf,
 							  refname.len, 1));
 		} else {
-			int read_ok;
-
-			if (*refs->base.submodule) {
-				hashclr(sha1);
-				flag = 0;
-				read_ok = !resolve_gitlink_ref(refs->base.submodule,
-							       refname.buf, sha1);
-			} else {
-				read_ok = !read_ref_full(refname.buf,
-							 RESOLVE_REF_READING,
-							 sha1, &flag);
-			}
-
-			if (!read_ok) {
+			if (!resolve_ref_recursively(&refs->base,
+						     refname.buf,
+						     RESOLVE_REF_READING,
+						     sha1, &flag)) {
 				hashclr(sha1);
 				flag |= REF_ISBROKEN;
 			} else if (is_null_sha1(sha1)) {
@@ -1358,8 +1373,8 @@
 	*type = 0;
 	strbuf_reset(&sb_path);
 
-	if (*refs->base.submodule)
-		strbuf_git_path_submodule(&sb_path, refs->base.submodule, "%s", refname);
+	if (refs->submodule)
+		strbuf_git_path_submodule(&sb_path, refs->submodule, "%s", refname);
 	else
 		strbuf_git_path(&sb_path, "%s", refname);
 
@@ -1540,7 +1555,7 @@
 	int ret = TRANSACTION_GENERIC_ERROR;
 
 	assert(err);
-	assert_main_repository(&refs->base, "lock_raw_ref");
+	files_assert_main_repository(refs, "lock_raw_ref");
 
 	*type = 0;
 
@@ -1985,6 +2000,13 @@
 	return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
 }
 
+static int create_reflock(const char *path, void *cb)
+{
+	struct lock_file *lk = cb;
+
+	return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;
+}
+
 /*
  * Locks a ref returning the lock on success and NULL on failure.
  * On failure errno is set to something meaningful.
@@ -2000,13 +2022,11 @@
 	struct strbuf ref_file = STRBUF_INIT;
 	struct ref_lock *lock;
 	int last_errno = 0;
-	int lflags = LOCK_NO_DEREF;
 	int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 	int resolve_flags = RESOLVE_REF_NO_RECURSE;
-	int attempts_remaining = 3;
 	int resolved;
 
-	assert_main_repository(&refs->base, "lock_ref_sha1_basic");
+	files_assert_main_repository(refs, "lock_ref_sha1_basic");
 	assert(err);
 
 	lock = xcalloc(1, sizeof(struct ref_lock));
@@ -2068,35 +2088,12 @@
 
 	lock->ref_name = xstrdup(refname);
 
- retry:
-	switch (safe_create_leading_directories_const(ref_file.buf)) {
-	case SCLD_OK:
-		break; /* success */
-	case SCLD_VANISHED:
-		if (--attempts_remaining > 0)
-			goto retry;
-		/* fall through */
-	default:
+	if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {
 		last_errno = errno;
-		strbuf_addf(err, "unable to create directory for '%s'",
-			    ref_file.buf);
+		unable_to_lock_message(ref_file.buf, errno, err);
 		goto error_return;
 	}
 
-	if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {
-		last_errno = errno;
-		if (errno == ENOENT && --attempts_remaining > 0)
-			/*
-			 * Maybe somebody just deleted one of the
-			 * directories leading to ref_file.  Try
-			 * again:
-			 */
-			goto retry;
-		else {
-			unable_to_lock_message(ref_file.buf, errno, err);
-			goto error_return;
-		}
-	}
 	if (verify_lock(lock, old_sha1, mustexist, err)) {
 		last_errno = errno;
 		goto error_return;
@@ -2152,7 +2149,7 @@
 	static int timeout_value = 1000;
 	struct packed_ref_cache *packed_ref_cache;
 
-	assert_main_repository(&refs->base, "lock_packed_refs");
+	files_assert_main_repository(refs, "lock_packed_refs");
 
 	if (!timeout_configured) {
 		git_config_get_int("core.packedrefstimeout", &timeout_value);
@@ -2190,7 +2187,7 @@
 	int save_errno = 0;
 	FILE *out;
 
-	assert_main_repository(&refs->base, "commit_packed_refs");
+	files_assert_main_repository(refs, "commit_packed_refs");
 
 	if (!packed_ref_cache->lock)
 		die("internal error: packed-refs not locked");
@@ -2223,7 +2220,7 @@
 	struct packed_ref_cache *packed_ref_cache =
 		get_packed_ref_cache(refs);
 
-	assert_main_repository(&refs->base, "rollback_packed_refs");
+	files_assert_main_repository(refs, "rollback_packed_refs");
 
 	if (!packed_ref_cache->lock)
 		die("internal error: packed-refs not locked");
@@ -2298,15 +2295,25 @@
 	return 0;
 }
 
+enum {
+	REMOVE_EMPTY_PARENTS_REF = 0x01,
+	REMOVE_EMPTY_PARENTS_REFLOG = 0x02
+};
+
 /*
- * Remove empty parents, but spare refs/ and immediate subdirs.
- * Note: munges *name.
+ * Remove empty parent directories associated with the specified
+ * reference and/or its reflog, but spare [logs/]refs/ and immediate
+ * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
+ * REMOVE_EMPTY_PARENTS_REFLOG.
  */
-static void try_remove_empty_parents(char *name)
+static void try_remove_empty_parents(const char *refname, unsigned int flags)
 {
+	struct strbuf buf = STRBUF_INIT;
 	char *p, *q;
 	int i;
-	p = name;
+
+	strbuf_addstr(&buf, refname);
+	p = buf.buf;
 	for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
 		while (*p && *p != '/')
 			p++;
@@ -2314,19 +2321,23 @@
 		while (*p == '/')
 			p++;
 	}
-	for (q = p; *q; q++)
-		;
-	while (1) {
+	q = buf.buf + buf.len;
+	while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
 		while (q > p && *q != '/')
 			q--;
 		while (q > p && *(q-1) == '/')
 			q--;
 		if (q == p)
 			break;
-		*q = '\0';
-		if (rmdir(git_path("%s", name)))
-			break;
+		strbuf_setlen(&buf, q - buf.buf);
+		if ((flags & REMOVE_EMPTY_PARENTS_REF) &&
+		    rmdir(git_path("%s", buf.buf)))
+			flags &= ~REMOVE_EMPTY_PARENTS_REF;
+		if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) &&
+		    rmdir(git_path("logs/%s", buf.buf)))
+			flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
 	}
+	strbuf_release(&buf);
 }
 
 /* make sure nobody touched the ref, and unlink */
@@ -2350,7 +2361,6 @@
 	}
 	ref_transaction_free(transaction);
 	strbuf_release(&err);
-	try_remove_empty_parents(r->name);
 }
 
 static void prune_refs(struct ref_to_prune *r)
@@ -2397,7 +2407,7 @@
 	struct string_list_item *refname;
 	int ret, needs_repacking = 0, removed = 0;
 
-	assert_main_repository(&refs->base, "repack_without_refs");
+	files_assert_main_repository(refs, "repack_without_refs");
 	assert(err);
 
 	/* Look for a packed ref */
@@ -2439,24 +2449,6 @@
 	return ret;
 }
 
-static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
-{
-	assert(err);
-
-	if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
-		/*
-		 * loose.  The loose file name is the same as the
-		 * lockfile name, minus ".lock":
-		 */
-		char *loose_filename = get_locked_file_path(lock->lk);
-		int res = unlink_or_msg(loose_filename, err);
-		free(loose_filename);
-		if (res)
-			return 1;
-	}
-	return 0;
-}
-
 static int files_delete_refs(struct ref_store *ref_store,
 			     struct string_list *refnames, unsigned int flags)
 {
@@ -2489,7 +2481,7 @@
 	for (i = 0; i < refnames->nr; i++) {
 		const char *refname = refnames->items[i].string;
 
-		if (delete_ref(refname, NULL, flags))
+		if (delete_ref(NULL, refname, NULL, flags))
 			result |= error(_("could not remove reference %s"), refname);
 	}
 
@@ -2507,55 +2499,43 @@
  */
 #define TMP_RENAMED_LOG  "logs/refs/.tmp-renamed-log"
 
+static int rename_tmp_log_callback(const char *path, void *cb)
+{
+	int *true_errno = cb;
+
+	if (rename(git_path(TMP_RENAMED_LOG), path)) {
+		/*
+		 * rename(a, b) when b is an existing directory ought
+		 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
+		 * Sheesh. Record the true errno for error reporting,
+		 * but report EISDIR to raceproof_create_file() so
+		 * that it knows to retry.
+		 */
+		*true_errno = errno;
+		if (errno == ENOTDIR)
+			errno = EISDIR;
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
 static int rename_tmp_log(const char *newrefname)
 {
-	int attempts_remaining = 4;
-	struct strbuf path = STRBUF_INIT;
-	int ret = -1;
+	char *path = git_pathdup("logs/%s", newrefname);
+	int ret, true_errno;
 
- retry:
-	strbuf_reset(&path);
-	strbuf_git_path(&path, "logs/%s", newrefname);
-	switch (safe_create_leading_directories_const(path.buf)) {
-	case SCLD_OK:
-		break; /* success */
-	case SCLD_VANISHED:
-		if (--attempts_remaining > 0)
-			goto retry;
-		/* fall through */
-	default:
-		error("unable to create directory for %s", newrefname);
-		goto out;
+	ret = raceproof_create_file(path, rename_tmp_log_callback, &true_errno);
+	if (ret) {
+		if (errno == EISDIR)
+			error("directory not empty: %s", path);
+		else
+			error("unable to move logfile %s to %s: %s",
+			      git_path(TMP_RENAMED_LOG), path,
+			      strerror(true_errno));
 	}
 
-	if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {
-		if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
-			/*
-			 * rename(a, b) when b is an existing
-			 * directory ought to result in ISDIR, but
-			 * Solaris 5.8 gives ENOTDIR.  Sheesh.
-			 */
-			if (remove_empty_directories(&path)) {
-				error("Directory not empty: logs/%s", newrefname);
-				goto out;
-			}
-			goto retry;
-		} else if (errno == ENOENT && --attempts_remaining > 0) {
-			/*
-			 * Maybe another process just deleted one of
-			 * the directories in the path to newrefname.
-			 * Try again from the beginning.
-			 */
-			goto retry;
-		} else {
-			error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
-				newrefname, strerror(errno));
-			goto out;
-		}
-	}
-	ret = 0;
-out:
-	strbuf_release(&path);
+	free(path);
 	return ret;
 }
 
@@ -2616,7 +2596,7 @@
 		return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
 			oldrefname, strerror(errno));
 
-	if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
+	if (delete_ref(logmsg, oldrefname, orig_sha1, REF_NODEREF)) {
 		error("unable to delete old %s", oldrefname);
 		goto rollback;
 	}
@@ -2630,8 +2610,8 @@
 	 */
 	if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
 			   sha1, NULL) &&
-	    delete_ref(newrefname, NULL, REF_NODEREF)) {
-		if (errno==EISDIR) {
+	    delete_ref(NULL, newrefname, NULL, REF_NODEREF)) {
+		if (errno == EISDIR) {
 			struct strbuf path = STRBUF_INIT;
 			int result;
 
@@ -2740,66 +2720,89 @@
 	return 0;
 }
 
-/*
- * Create a reflog for a ref.  If force_create = 0, the reflog will
- * only be created for certain refs (those for which
- * should_autocreate_reflog returns non-zero.  Otherwise, create it
- * regardless of the ref name.  Fill in *err and return -1 on failure.
- */
-static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)
+static int open_or_create_logfile(const char *path, void *cb)
 {
-	int logfd, oflags = O_APPEND | O_WRONLY;
+	int *fd = cb;
 
-	strbuf_git_path(logfile, "logs/%s", refname);
-	if (force_create || should_autocreate_reflog(refname)) {
-		if (safe_create_leading_directories(logfile->buf) < 0) {
-			strbuf_addf(err, "unable to create directory for '%s': "
-				    "%s", logfile->buf, strerror(errno));
-			return -1;
-		}
-		oflags |= O_CREAT;
-	}
-
-	logfd = open(logfile->buf, oflags, 0666);
-	if (logfd < 0) {
-		if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
-			return 0;
-
-		if (errno == EISDIR) {
-			if (remove_empty_directories(logfile)) {
-				strbuf_addf(err, "there are still logs under "
-					    "'%s'", logfile->buf);
-				return -1;
-			}
-			logfd = open(logfile->buf, oflags, 0666);
-		}
-
-		if (logfd < 0) {
-			strbuf_addf(err, "unable to append to '%s': %s",
-				    logfile->buf, strerror(errno));
-			return -1;
-		}
-	}
-
-	adjust_shared_perm(logfile->buf);
-	close(logfd);
-	return 0;
+	*fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
+	return (*fd < 0) ? -1 : 0;
 }
 
+/*
+ * Create a reflog for a ref. If force_create = 0, only create the
+ * reflog for certain refs (those for which should_autocreate_reflog
+ * returns non-zero). Otherwise, create it regardless of the reference
+ * name. If the logfile already existed or was created, return 0 and
+ * set *logfd to the file descriptor opened for appending to the file.
+ * If no logfile exists and we decided not to create one, return 0 and
+ * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
+ * return -1.
+ */
+static int log_ref_setup(const char *refname, int force_create,
+			 int *logfd, struct strbuf *err)
+{
+	char *logfile = git_pathdup("logs/%s", refname);
+
+	if (force_create || should_autocreate_reflog(refname)) {
+		if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
+			if (errno == ENOENT)
+				strbuf_addf(err, "unable to create directory for '%s': "
+					    "%s", logfile, strerror(errno));
+			else if (errno == EISDIR)
+				strbuf_addf(err, "there are still logs under '%s'",
+					    logfile);
+			else
+				strbuf_addf(err, "unable to append to '%s': %s",
+					    logfile, strerror(errno));
+
+			goto error;
+		}
+	} else {
+		*logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
+		if (*logfd < 0) {
+			if (errno == ENOENT || errno == EISDIR) {
+				/*
+				 * The logfile doesn't already exist,
+				 * but that is not an error; it only
+				 * means that we won't write log
+				 * entries to it.
+				 */
+				;
+			} else {
+				strbuf_addf(err, "unable to append to '%s': %s",
+					    logfile, strerror(errno));
+				goto error;
+			}
+		}
+	}
+
+	if (*logfd >= 0)
+		adjust_shared_perm(logfile);
+
+	free(logfile);
+	return 0;
+
+error:
+	free(logfile);
+	return -1;
+}
 
 static int files_create_reflog(struct ref_store *ref_store,
 			       const char *refname, int force_create,
 			       struct strbuf *err)
 {
-	int ret;
-	struct strbuf sb = STRBUF_INIT;
+	int fd;
 
 	/* Check validity (but we don't need the result): */
 	files_downcast(ref_store, 0, "create_reflog");
 
-	ret = log_ref_setup(refname, &sb, err, force_create);
-	strbuf_release(&sb);
-	return ret;
+	if (log_ref_setup(refname, force_create, &fd, err))
+		return -1;
+
+	if (fd >= 0)
+		close(fd);
+
+	return 0;
 }
 
 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
@@ -2828,59 +2831,43 @@
 	return 0;
 }
 
-static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,
-			   const unsigned char *new_sha1, const char *msg,
-			   struct strbuf *logfile, int flags,
-			   struct strbuf *err)
+int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
+			const unsigned char *new_sha1, const char *msg,
+			int flags, struct strbuf *err)
 {
-	int logfd, result, oflags = O_APPEND | O_WRONLY;
+	int logfd, result;
 
 	if (log_all_ref_updates == LOG_REFS_UNSET)
 		log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
 
-	result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);
+	result = log_ref_setup(refname, flags & REF_FORCE_CREATE_REFLOG,
+			       &logfd, err);
 
 	if (result)
 		return result;
 
-	logfd = open(logfile->buf, oflags);
 	if (logfd < 0)
 		return 0;
 	result = log_ref_write_fd(logfd, old_sha1, new_sha1,
 				  git_committer_info(0), msg);
 	if (result) {
-		strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
-			    strerror(errno));
+		int save_errno = errno;
+
+		strbuf_addf(err, "unable to append to '%s': %s",
+			    git_path("logs/%s", refname), strerror(save_errno));
 		close(logfd);
 		return -1;
 	}
 	if (close(logfd)) {
-		strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
-			    strerror(errno));
+		int save_errno = errno;
+
+		strbuf_addf(err, "unable to append to '%s': %s",
+			    git_path("logs/%s", refname), strerror(save_errno));
 		return -1;
 	}
 	return 0;
 }
 
-static int log_ref_write(const char *refname, const unsigned char *old_sha1,
-			 const unsigned char *new_sha1, const char *msg,
-			 int flags, struct strbuf *err)
-{
-	return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,
-				   err);
-}
-
-int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
-			const unsigned char *new_sha1, const char *msg,
-			int flags, struct strbuf *err)
-{
-	struct strbuf sb = STRBUF_INIT;
-	int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,
-				  err);
-	strbuf_release(&sb);
-	return ret;
-}
-
 /*
  * Write sha1 into the open lockfile, then close the lockfile. On
  * errors, rollback the lockfile, fill in *err and
@@ -2930,10 +2917,11 @@
 			     const unsigned char *sha1, const char *logmsg,
 			     struct strbuf *err)
 {
-	assert_main_repository(&refs->base, "commit_ref_update");
+	files_assert_main_repository(refs, "commit_ref_update");
 
 	clear_loose_ref_cache(refs);
-	if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {
+	if (files_log_ref_write(lock->ref_name, lock->old_oid.hash, sha1,
+				logmsg, 0, err)) {
 		char *old_msg = strbuf_detach(err, NULL);
 		strbuf_addf(err, "cannot update the ref '%s': %s",
 			    lock->ref_name, old_msg);
@@ -2964,7 +2952,7 @@
 		if (head_ref && (head_flag & REF_ISSYMREF) &&
 		    !strcmp(head_ref, lock->ref_name)) {
 			struct strbuf log_err = STRBUF_INIT;
-			if (log_ref_write("HEAD", lock->old_oid.hash, sha1,
+			if (files_log_ref_write("HEAD", lock->old_oid.hash, sha1,
 					  logmsg, 0, &log_err)) {
 				error("%s", log_err.buf);
 				strbuf_release(&log_err);
@@ -3003,7 +2991,8 @@
 	struct strbuf err = STRBUF_INIT;
 	unsigned char new_sha1[20];
 	if (logmsg && !read_ref(target, new_sha1) &&
-	    log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {
+	    files_log_ref_write(refname, lock->old_oid.hash, new_sha1,
+				logmsg, 0, &err)) {
 		error("%s", err.buf);
 		strbuf_release(&err);
 	}
@@ -3055,7 +3044,7 @@
 	return ret;
 }
 
-int set_worktree_head_symref(const char *gitdir, const char *target)
+int set_worktree_head_symref(const char *gitdir, const char *target, const char *logmsg)
 {
 	static struct lock_file head_lock;
 	struct ref_lock *lock;
@@ -3083,7 +3072,7 @@
 	lock->lk = &head_lock;
 	lock->ref_name = xstrdup(head_rel);
 
-	ret = create_symref_locked(lock, head_rel, target, NULL);
+	ret = create_symref_locked(lock, head_rel, target, logmsg);
 
 	unlock_ref(lock); /* will free lock */
 	strbuf_release(&head_path);
@@ -3113,16 +3102,17 @@
 
 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
 {
-	unsigned char osha1[20], nsha1[20];
+	struct object_id ooid, noid;
 	char *email_end, *message;
 	unsigned long timestamp;
 	int tz;
+	const char *p = sb->buf;
 
 	/* old SP new SP name <email> SP time TAB msg LF */
-	if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
-	    get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
-	    get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
-	    !(email_end = strchr(sb->buf + 82, '>')) ||
+	if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
+	    parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
+	    parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
+	    !(email_end = strchr(p, '>')) ||
 	    email_end[1] != ' ' ||
 	    !(timestamp = strtoul(email_end + 2, &message, 10)) ||
 	    !message || message[0] != ' ' ||
@@ -3136,7 +3126,7 @@
 		message += 6;
 	else
 		message += 7;
-	return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
+	return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
 }
 
 static char *find_beginning_of_line(char *bob, char *scan)
@@ -3560,7 +3550,7 @@
 	int ret;
 	struct ref_lock *lock;
 
-	assert_main_repository(&refs->base, "lock_ref_for_update");
+	files_assert_main_repository(refs, "lock_ref_for_update");
 
 	if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
 		update->flags |= REF_DELETING;
@@ -3778,9 +3768,11 @@
 
 		if (update->flags & REF_NEEDS_COMMIT ||
 		    update->flags & REF_LOG_ONLY) {
-			if (log_ref_write(lock->ref_name, lock->old_oid.hash,
-					  update->new_sha1,
-					  update->msg, update->flags, err)) {
+			if (files_log_ref_write(lock->ref_name,
+						lock->old_oid.hash,
+						update->new_sha1,
+						update->msg, update->flags,
+						err)) {
 				char *old_msg = strbuf_detach(err, NULL);
 
 				strbuf_addf(err, "cannot update the ref '%s': %s",
@@ -3810,9 +3802,14 @@
 
 		if (update->flags & REF_DELETING &&
 		    !(update->flags & REF_LOG_ONLY)) {
-			if (delete_ref_loose(lock, update->type, err)) {
-				ret = TRANSACTION_GENERIC_ERROR;
-				goto cleanup;
+			if (!(update->type & REF_ISPACKED) ||
+			    update->type & REF_ISSYMREF) {
+				/* It is a loose reference. */
+				if (unlink_or_msg(git_path("%s", lock->ref_name), err)) {
+					ret = TRANSACTION_GENERIC_ERROR;
+					goto cleanup;
+				}
+				update->flags |= REF_DELETED_LOOSE;
 			}
 
 			if (!(update->flags & REF_ISPRUNING))
@@ -3825,16 +3822,38 @@
 		ret = TRANSACTION_GENERIC_ERROR;
 		goto cleanup;
 	}
-	for_each_string_list_item(ref_to_delete, &refs_to_delete)
-		unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
+
+	/* Delete the reflogs of any references that were deleted: */
+	for_each_string_list_item(ref_to_delete, &refs_to_delete) {
+		if (!unlink_or_warn(git_path("logs/%s", ref_to_delete->string)))
+			try_remove_empty_parents(ref_to_delete->string,
+						 REMOVE_EMPTY_PARENTS_REFLOG);
+	}
+
 	clear_loose_ref_cache(refs);
 
 cleanup:
 	transaction->state = REF_TRANSACTION_CLOSED;
 
-	for (i = 0; i < transaction->nr; i++)
-		if (transaction->updates[i]->backend_data)
-			unlock_ref(transaction->updates[i]->backend_data);
+	for (i = 0; i < transaction->nr; i++) {
+		struct ref_update *update = transaction->updates[i];
+		struct ref_lock *lock = update->backend_data;
+
+		if (lock)
+			unlock_ref(lock);
+
+		if (update->flags & REF_DELETED_LOOSE) {
+			/*
+			 * The loose reference was deleted. Delete any
+			 * empty parent directories. (Note that this
+			 * can only work because we have already
+			 * removed the lockfile.)
+			 */
+			try_remove_empty_parents(update->refname,
+						 REMOVE_EMPTY_PARENTS_REF);
+		}
+	}
+
 	string_list_clear(&refs_to_delete, 0);
 	free(head_ref);
 	string_list_clear(&affected_refnames, 0);
@@ -3936,10 +3955,10 @@
 	reflog_expiry_should_prune_fn *should_prune_fn;
 	void *policy_cb;
 	FILE *newlog;
-	unsigned char last_kept_sha1[20];
+	struct object_id last_kept_oid;
 };
 
-static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 			     const char *email, unsigned long timestamp, int tz,
 			     const char *message, void *cb_data)
 {
@@ -3947,9 +3966,9 @@
 	struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
 
 	if (cb->flags & EXPIRE_REFLOGS_REWRITE)
-		osha1 = cb->last_kept_sha1;
+		ooid = &cb->last_kept_oid;
 
-	if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
+	if ((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,
 				   message, policy_cb)) {
 		if (!cb->newlog)
 			printf("would prune %s", message);
@@ -3958,9 +3977,9 @@
 	} else {
 		if (cb->newlog) {
 			fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
-				sha1_to_hex(osha1), sha1_to_hex(nsha1),
+				oid_to_hex(ooid), oid_to_hex(noid),
 				email, timestamp, tz, message);
-			hashcpy(cb->last_kept_sha1, nsha1);
+			oidcpy(&cb->last_kept_oid, noid);
 		}
 		if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
 			printf("keep %s", message);
@@ -4047,14 +4066,14 @@
 		 */
 		int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
 			!(type & REF_ISSYMREF) &&
-			!is_null_sha1(cb.last_kept_sha1);
+			!is_null_oid(&cb.last_kept_oid);
 
 		if (close_lock_file(&reflog_lock)) {
 			status |= error("couldn't write %s: %s", log_file,
 					strerror(errno));
 		} else if (update &&
 			   (write_in_full(get_lock_file_fd(lock->lk),
-				sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
+				oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||
 			    write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||
 			    close_ref(lock) < 0)) {
 			status |= error("couldn't write %s",
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 25444cf..fa93c9a 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -56,17 +56,24 @@
 #define REF_UPDATE_VIA_HEAD 0x100
 
 /*
+ * Used as a flag in ref_update::flags when the loose reference has
+ * been deleted.
+ */
+#define REF_DELETED_LOOSE 0x200
+
+/*
  * Return true iff refname is minimally safe. "Safe" here means that
  * deleting a loose reference by this name will not do any damage, for
  * example by causing a file that is not a reference to be deleted.
  * This function does not check that the reference name is legal; for
  * that, use check_refname_format().
  *
- * We consider a refname that starts with "refs/" to be safe as long
- * as any ".." components that it might contain do not escape "refs/".
- * Names that do not start with "refs/" are considered safe iff they
- * consist entirely of upper case characters and '_' (like "HEAD" and
- * "MERGE_HEAD" but not "config" or "FOO/BAR").
+ * A refname that starts with "refs/" is considered safe iff it
+ * doesn't contain any "." or ".." components or consecutive '/'
+ * characters, end with '/', or (on Windows) contain any '\'
+ * characters. Names that do not start with "refs/" are considered
+ * safe iff they consist entirely of upper case characters and '_'
+ * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
  */
 int refname_is_safe(const char *refname);
 
@@ -155,8 +162,9 @@
 
 	/*
 	 * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,
-	 * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY, and
-	 * REF_UPDATE_VIA_HEAD:
+	 * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY,
+	 * REF_UPDATE_VIA_HEAD, REF_NEEDS_COMMIT, and
+	 * REF_DELETED_LOOSE:
 	 */
 	unsigned int flags;
 
@@ -627,47 +635,14 @@
 struct ref_store {
 	/* The backend describing this ref_store's storage scheme: */
 	const struct ref_storage_be *be;
-
-	/*
-	 * The name of the submodule represented by this object, or
-	 * the empty string if it represents the main repository's
-	 * reference store:
-	 */
-	const char *submodule;
-
-	/*
-	 * Submodule reference store instances are stored in a linked
-	 * list using this pointer.
-	 */
-	struct ref_store *next;
 };
 
 /*
- * Fill in the generic part of refs for the specified submodule and
- * add it to our collection of reference stores.
+ * Fill in the generic part of refs and add it to our collection of
+ * reference stores.
  */
 void base_ref_store_init(struct ref_store *refs,
-			 const struct ref_storage_be *be,
-			 const char *submodule);
-
-/*
- * Create, record, and return a ref_store instance for the specified
- * submodule (or the main repository if submodule is NULL).
- *
- * For backwards compatibility, submodule=="" is treated the same as
- * submodule==NULL.
- */
-struct ref_store *ref_store_init(const char *submodule);
-
-/*
- * Return the ref_store instance for the specified submodule (or the
- * main repository if submodule is NULL). If that ref_store hasn't
- * been initialized yet, return NULL.
- *
- * For backwards compatibility, submodule=="" is treated the same as
- * submodule==NULL.
- */
-struct ref_store *lookup_ref_store(const char *submodule);
+			 const struct ref_storage_be *be);
 
 /*
  * Return the ref_store instance for the specified submodule. For the
@@ -681,10 +656,9 @@
  */
 struct ref_store *get_ref_store(const char *submodule);
 
-/*
- * Die if refs is for a submodule (i.e., not for the main repository).
- * caller is used in any necessary error messages.
- */
-void assert_main_repository(struct ref_store *refs, const char *caller);
+const char *resolve_ref_recursively(struct ref_store *refs,
+				    const char *refname,
+				    int resolve_flags,
+				    unsigned char *sha1, int *flags);
 
 #endif /* REFS_REFS_INTERNAL_H */
diff --git a/remote-curl.c b/remote-curl.c
index 34a97e7..e953d06 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -22,6 +22,7 @@
 	unsigned long depth;
 	char *deepen_since;
 	struct string_list deepen_not;
+	struct string_list push_options;
 	unsigned progress : 1,
 		check_self_contained_and_connected : 1,
 		cloning : 1,
@@ -139,6 +140,9 @@
 		else
 			return -1;
 		return 0;
+	} else if (!strcmp(name, "push-option")) {
+		string_list_append(&options.push_options, value);
+		return 0;
 
 #if LIBCURL_VERSION_NUM >= 0x070a08
 	} else if (!strcmp(name, "family")) {
@@ -943,6 +947,9 @@
 		argv_array_push(&args, "--quiet");
 	else if (options.verbosity > 1)
 		argv_array_push(&args, "--verbose");
+	for (i = 0; i < options.push_options.nr; i++)
+		argv_array_pushf(&args, "--push-option=%s",
+				 options.push_options.items[i].string);
 	argv_array_push(&args, options.progress ? "--progress" : "--no-progress");
 	for_each_string_list_item(cas_option, &cas_options)
 		argv_array_push(&args, cas_option->string);
@@ -1028,6 +1035,7 @@
 	options.progress = !!isatty(2);
 	options.thin = 1;
 	string_list_init(&options.deepen_not, 1);
+	string_list_init(&options.push_options, 1);
 
 	remote = remote_get(argv[1]);
 
diff --git a/revision.c b/revision.c
index 771d079..7ff61ff 100644
--- a/revision.c
+++ b/revision.c
@@ -1196,11 +1196,11 @@
 	for_each(submodule, handle_one_ref, &cb);
 }
 
-static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
+static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
 {
 	struct all_refs_cb *cb = cb_data;
-	if (!is_null_sha1(sha1)) {
-		struct object *o = parse_object(sha1);
+	if (!is_null_oid(oid)) {
+		struct object *o = parse_object(oid->hash);
 		if (o) {
 			o->flags |= cb->all_flags;
 			/* ??? CMDLINEFLAGS ??? */
@@ -1214,12 +1214,12 @@
 	}
 }
 
-static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
-	handle_one_reflog_commit(osha1, cb_data);
-	handle_one_reflog_commit(nsha1, cb_data);
+	handle_one_reflog_commit(ooid, cb_data);
+	handle_one_reflog_commit(noid, cb_data);
 	return 0;
 }
 
diff --git a/send-pack.c b/send-pack.c
index d2d2a49..66e652f 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -532,6 +532,14 @@
 		}
 	}
 
+	if (use_push_options) {
+		struct string_list_item *item;
+
+		packet_buf_flush(&req_buf);
+		for_each_string_list_item(item, args->push_options)
+			packet_buf_write(&req_buf, "%s", item->string);
+	}
+
 	if (args->stateless_rpc) {
 		if (!args->dry_run && (cmds_sent || is_repository_shallow())) {
 			packet_buf_flush(&req_buf);
@@ -544,18 +552,6 @@
 	strbuf_release(&req_buf);
 	strbuf_release(&cap_buf);
 
-	if (use_push_options) {
-		struct string_list_item *item;
-		struct strbuf sb = STRBUF_INIT;
-
-		for_each_string_list_item(item, args->push_options)
-			packet_buf_write(&sb, "%s", item->string);
-
-		write_or_die(out, sb.buf, sb.len);
-		packet_flush(out);
-		strbuf_release(&sb);
-	}
-
 	if (use_sideband && cmds_sent) {
 		memset(&demux, 0, sizeof(demux));
 		demux.proc = sideband_demux;
diff --git a/sequencer.c b/sequencer.c
index 1f729b0..d76dc9c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1997,7 +1997,8 @@
 			if (item->command == TODO_EDIT) {
 				struct commit *commit = item->commit;
 				if (!res)
-					warning(_("stopped at %s... %.*s"),
+					fprintf(stderr,
+						_("Stopped at %s...  %.*s\n"),
 						short_commit_name(commit),
 						item->arg_len, item->arg);
 				return error_with_patch(commit,
diff --git a/setup.c b/setup.c
index 8f64fbd..5c7946d 100644
--- a/setup.c
+++ b/setup.c
@@ -135,6 +135,7 @@
 int check_filename(const char *prefix, const char *arg)
 {
 	const char *name;
+	char *to_free = NULL;
 	struct stat st;
 
 	if (starts_with(arg, ":/")) {
@@ -142,13 +143,17 @@
 			return 1;
 		name = arg + 2;
 	} else if (prefix)
-		name = prefix_filename(prefix, strlen(prefix), arg);
+		name = to_free = prefix_filename(prefix, arg);
 	else
 		name = arg;
-	if (!lstat(name, &st))
+	if (!lstat(name, &st)) {
+		free(to_free);
 		return 1; /* file exists */
-	if (errno == ENOENT || errno == ENOTDIR)
+	}
+	if (errno == ENOENT || errno == ENOTDIR) {
+		free(to_free);
 		return 0; /* file does not exist */
+	}
 	die_errno("failed to stat '%s'", arg);
 }
 
@@ -531,6 +536,7 @@
 	ssize_t len;
 
 	if (stat(path, &st)) {
+		/* NEEDSWORK: discern between ENOENT vs other errors */
 		error_code = READ_GITFILE_ERR_STAT_FAILED;
 		goto cleanup_return;
 	}
@@ -721,8 +727,10 @@
 	if (offset == cwd->len)
 		return NULL;
 
-	/* Make "offset" point to past the '/', and add a '/' at the end */
-	offset++;
+	/* Make "offset" point past the '/' (already the case for root dirs) */
+	if (offset != offset_1st_component(cwd->buf))
+		offset++;
+	/* Add a '/' at the end */
 	strbuf_addch(cwd, '/');
 	return cwd->buf + offset;
 }
@@ -816,22 +824,172 @@
 	}
 }
 
+enum discovery_result {
+	GIT_DIR_NONE = 0,
+	GIT_DIR_EXPLICIT,
+	GIT_DIR_DISCOVERED,
+	GIT_DIR_BARE,
+	/* these are errors */
+	GIT_DIR_HIT_CEILING = -1,
+	GIT_DIR_HIT_MOUNT_POINT = -2,
+	GIT_DIR_INVALID_GITFILE = -3
+};
+
 /*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
+ *
+ * Also, we avoid changing any global state (such as the current working
+ * directory) to allow early callers.
+ *
+ * The directory where the search should start needs to be passed in via the
+ * `dir` parameter; upon return, the `dir` buffer will contain the path of
+ * the directory where the search ended, and `gitdir` will contain the path of
+ * the discovered .git/ directory, if any. If `gitdir` is not absolute, it
+ * is relative to `dir` (i.e. *not* necessarily the cwd).
  */
-static const char *setup_git_directory_gently_1(int *nongit_ok)
+static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
+							  struct strbuf *gitdir,
+							  int die_on_error)
 {
 	const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 	struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
-	static struct strbuf cwd = STRBUF_INIT;
-	const char *gitdirenv, *ret;
-	char *gitfile;
-	int offset, offset_parent, ceil_offset = -1;
+	const char *gitdirenv;
+	int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
 	dev_t current_device = 0;
 	int one_filesystem = 1;
 
 	/*
+	 * If GIT_DIR is set explicitly, we're not going
+	 * to do any discovery, but we still do repository
+	 * validation.
+	 */
+	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
+	if (gitdirenv) {
+		strbuf_addstr(gitdir, gitdirenv);
+		return GIT_DIR_EXPLICIT;
+	}
+
+	if (env_ceiling_dirs) {
+		int empty_entry_found = 0;
+
+		string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
+		filter_string_list(&ceiling_dirs, 0,
+				   canonicalize_ceiling_entry, &empty_entry_found);
+		ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
+		string_list_clear(&ceiling_dirs, 0);
+	}
+
+	if (ceil_offset < 0)
+		ceil_offset = min_offset - 2;
+
+	/*
+	 * Test in the following order (relative to the dir):
+	 * - .git (file containing "gitdir: <path>")
+	 * - .git/
+	 * - ./ (bare)
+	 * - ../.git
+	 * - ../.git/
+	 * - ../ (bare)
+	 * - ../../.git/
+	 *   etc.
+	 */
+	one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
+	if (one_filesystem)
+		current_device = get_device_or_die(dir->buf, NULL, 0);
+	for (;;) {
+		int offset = dir->len, error_code = 0;
+
+		if (offset > min_offset)
+			strbuf_addch(dir, '/');
+		strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
+		gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
+						NULL : &error_code);
+		if (!gitdirenv) {
+			if (die_on_error ||
+			    error_code == READ_GITFILE_ERR_NOT_A_FILE) {
+				/* NEEDSWORK: fail if .git is not file nor dir */
+				if (is_git_directory(dir->buf))
+					gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
+			} else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
+				return GIT_DIR_INVALID_GITFILE;
+		}
+		strbuf_setlen(dir, offset);
+		if (gitdirenv) {
+			strbuf_addstr(gitdir, gitdirenv);
+			return GIT_DIR_DISCOVERED;
+		}
+
+		if (is_git_directory(dir->buf)) {
+			strbuf_addstr(gitdir, ".");
+			return GIT_DIR_BARE;
+		}
+
+		if (offset <= min_offset)
+			return GIT_DIR_HIT_CEILING;
+
+		while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
+			; /* continue */
+		if (offset <= ceil_offset)
+			return GIT_DIR_HIT_CEILING;
+
+		strbuf_setlen(dir, offset > min_offset ?  offset : min_offset);
+		if (one_filesystem &&
+		    current_device != get_device_or_die(dir->buf, NULL, offset))
+			return GIT_DIR_HIT_MOUNT_POINT;
+	}
+}
+
+const char *discover_git_directory(struct strbuf *gitdir)
+{
+	struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
+	size_t gitdir_offset = gitdir->len, cwd_len;
+	struct repository_format candidate;
+
+	if (strbuf_getcwd(&dir))
+		return NULL;
+
+	cwd_len = dir.len;
+	if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
+		strbuf_release(&dir);
+		return NULL;
+	}
+
+	/*
+	 * The returned gitdir is relative to dir, and if dir does not reflect
+	 * the current working directory, we simply make the gitdir absolute.
+	 */
+	if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
+		/* Avoid a trailing "/." */
+		if (!strcmp(".", gitdir->buf + gitdir_offset))
+			strbuf_setlen(gitdir, gitdir_offset);
+		else
+			strbuf_addch(&dir, '/');
+		strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
+	}
+
+	strbuf_reset(&dir);
+	strbuf_addf(&dir, "%s/config", gitdir->buf + gitdir_offset);
+	read_repository_format(&candidate, dir.buf);
+	strbuf_release(&dir);
+
+	if (verify_repository_format(&candidate, &err) < 0) {
+		warning("ignoring git dir '%s': %s",
+			gitdir->buf + gitdir_offset, err.buf);
+		strbuf_release(&err);
+		return NULL;
+	}
+
+	return gitdir->buf + gitdir_offset;
+}
+
+const char *setup_git_directory_gently(int *nongit_ok)
+{
+	static struct strbuf cwd = STRBUF_INIT;
+	struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
+	const char *prefix;
+
+	/*
 	 * We may have read an incomplete configuration before
 	 * setting-up the git directory. If so, clear the cache so
 	 * that the next queries to the configuration reload complete
@@ -850,98 +1008,43 @@
 
 	if (strbuf_getcwd(&cwd))
 		die_errno(_("Unable to read current working directory"));
-	offset = cwd.len;
+	strbuf_addbuf(&dir, &cwd);
 
-	/*
-	 * If GIT_DIR is set explicitly, we're not going
-	 * to do any discovery, but we still do repository
-	 * validation.
-	 */
-	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
-	if (gitdirenv)
-		return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
-
-	if (env_ceiling_dirs) {
-		int empty_entry_found = 0;
-
-		string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
-		filter_string_list(&ceiling_dirs, 0,
-				   canonicalize_ceiling_entry, &empty_entry_found);
-		ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
-		string_list_clear(&ceiling_dirs, 0);
+	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, nongit_ok);
+		break;
+	case GIT_DIR_DISCOVERED:
+		if (dir.len < cwd.len && chdir(dir.buf))
+			die(_("Cannot change to '%s'"), dir.buf);
+		prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
+						  nongit_ok);
+		break;
+	case GIT_DIR_BARE:
+		if (dir.len < cwd.len && chdir(dir.buf))
+			die(_("Cannot change to '%s'"), dir.buf);
+		prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
+		break;
+	case GIT_DIR_HIT_CEILING:
+		prefix = setup_nongit(cwd.buf, nongit_ok);
+		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);
+	default:
+		die("BUG: unhandled setup_git_directory_1() result");
 	}
 
-	if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
-		ceil_offset = 1;
-
-	/*
-	 * Test in the following order (relative to the cwd):
-	 * - .git (file containing "gitdir: <path>")
-	 * - .git/
-	 * - ./ (bare)
-	 * - ../.git
-	 * - ../.git/
-	 * - ../ (bare)
-	 * - ../../.git/
-	 *   etc.
-	 */
-	one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
-	if (one_filesystem)
-		current_device = get_device_or_die(".", NULL, 0);
-	for (;;) {
-		gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
-		if (gitfile)
-			gitdirenv = gitfile = xstrdup(gitfile);
-		else {
-			if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
-				gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
-		}
-
-		if (gitdirenv) {
-			ret = setup_discovered_git_dir(gitdirenv,
-						       &cwd, offset,
-						       nongit_ok);
-			free(gitfile);
-			return ret;
-		}
-		free(gitfile);
-
-		if (is_git_directory("."))
-			return setup_bare_git_dir(&cwd, offset, nongit_ok);
-
-		offset_parent = offset;
-		while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
-		if (offset_parent <= ceil_offset)
-			return setup_nongit(cwd.buf, nongit_ok);
-		if (one_filesystem) {
-			dev_t parent_device = get_device_or_die("..", cwd.buf,
-								offset);
-			if (parent_device != current_device) {
-				if (nongit_ok) {
-					if (chdir(cwd.buf))
-						die_errno(_("Cannot come back to cwd"));
-					*nongit_ok = 1;
-					return NULL;
-				}
-				strbuf_setlen(&cwd, offset);
-				die(_("Not a git repository (or any parent up to mount point %s)\n"
-				"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
-				    cwd.buf);
-			}
-		}
-		if (chdir("..")) {
-			strbuf_setlen(&cwd, offset);
-			die_errno(_("Cannot change to '%s/..'"), cwd.buf);
-		}
-		offset = offset_parent;
-	}
-}
-
-const char *setup_git_directory_gently(int *nongit_ok)
-{
-	const char *prefix;
-
-	prefix = setup_git_directory_gently_1(nongit_ok);
 	if (prefix)
 		setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 	else
@@ -950,6 +1053,9 @@
 	startup_info->have_repository = !nongit_ok || !*nongit_ok;
 	startup_info->prefix = prefix;
 
+	strbuf_release(&dir);
+	strbuf_release(&gitdir);
+
 	return prefix;
 }
 
diff --git a/sha1_file.c b/sha1_file.c
index d77b915..7106389 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -129,8 +129,10 @@
 		*slash = '\0';
 		if (!stat(path, &st)) {
 			/* path exists */
-			if (!S_ISDIR(st.st_mode))
+			if (!S_ISDIR(st.st_mode)) {
+				errno = ENOTDIR;
 				ret = SCLD_EXISTS;
+			}
 		} else if (mkdir(path, 0777)) {
 			if (errno == EEXIST &&
 			    !stat(path, &st) && S_ISDIR(st.st_mode))
@@ -158,13 +160,85 @@
 
 enum scld_error safe_create_leading_directories_const(const char *path)
 {
+	int save_errno;
 	/* path points to cache entries, so xstrdup before messing with it */
 	char *buf = xstrdup(path);
 	enum scld_error result = safe_create_leading_directories(buf);
+
+	save_errno = errno;
 	free(buf);
+	errno = save_errno;
 	return result;
 }
 
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
+{
+	/*
+	 * The number of times we will try to remove empty directories
+	 * in the way of path. This is only 1 because if another
+	 * process is racily creating directories that conflict with
+	 * us, we don't want to fight against them.
+	 */
+	int remove_directories_remaining = 1;
+
+	/*
+	 * The number of times that we will try to create the
+	 * directories containing path. We are willing to attempt this
+	 * more than once, because another process could be trying to
+	 * clean up empty directories at the same time as we are
+	 * trying to create them.
+	 */
+	int create_directories_remaining = 3;
+
+	/* A scratch copy of path, filled lazily if we need it: */
+	struct strbuf path_copy = STRBUF_INIT;
+
+	int ret, save_errno;
+
+	/* Sanity check: */
+	assert(*path);
+
+retry_fn:
+	ret = fn(path, cb);
+	save_errno = errno;
+	if (!ret)
+		goto out;
+
+	if (errno == EISDIR && remove_directories_remaining-- > 0) {
+		/*
+		 * A directory is in the way. Maybe it is empty; try
+		 * to remove it:
+		 */
+		if (!path_copy.len)
+			strbuf_addstr(&path_copy, path);
+
+		if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
+			goto retry_fn;
+	} else if (errno == ENOENT && create_directories_remaining-- > 0) {
+		/*
+		 * Maybe the containing directory didn't exist, or
+		 * maybe it was just deleted by a process that is
+		 * racing with us to clean up empty directories. Try
+		 * to create it:
+		 */
+		enum scld_error scld_result;
+
+		if (!path_copy.len)
+			strbuf_addstr(&path_copy, path);
+
+		do {
+			scld_result = safe_create_leading_directories(path_copy.buf);
+			if (scld_result == SCLD_OK)
+				goto retry_fn;
+		} while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
+	}
+
+out:
+	strbuf_release(&path_copy);
+	errno = save_errno;
+	return ret;
+}
+
 static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
 {
 	int i;
@@ -588,7 +662,7 @@
  * either does not exist on disk, or has a stale mtime and may be subject to
  * pruning).
  */
-static int check_and_freshen_file(const char *fn, int freshen)
+int check_and_freshen_file(const char *fn, int freshen)
 {
 	if (access(fn, F_OK))
 		return 0;
@@ -2627,6 +2701,17 @@
 	}
 }
 
+const struct object_id *nth_packed_object_oid(struct object_id *oid,
+					      struct packed_git *p,
+					      uint32_t n)
+{
+	const unsigned char *hash = nth_packed_object_sha1(p, n);
+	if (!hash)
+		return NULL;
+	hashcpy(oid->hash, hash);
+	return oid;
+}
+
 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
 {
 	const unsigned char *ptr = vptr;
@@ -3673,15 +3758,15 @@
 		strbuf_setlen(path, baselen);
 		strbuf_addf(path, "/%s", de->d_name);
 
-		if (strlen(de->d_name) == 38)  {
-			char hex[41];
-			unsigned char sha1[20];
+		if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2)  {
+			char hex[GIT_SHA1_HEXSZ+1];
+			struct object_id oid;
 
 			snprintf(hex, sizeof(hex), "%02x%s",
 				 subdir_nr, de->d_name);
-			if (!get_sha1_hex(hex, sha1)) {
+			if (!get_oid_hex(hex, &oid)) {
 				if (obj_cb) {
-					r = obj_cb(sha1, path->buf, data);
+					r = obj_cb(&oid, path->buf, data);
 					if (r)
 						break;
 				}
@@ -3787,13 +3872,13 @@
 	int r = 0;
 
 	for (i = 0; i < p->num_objects; i++) {
-		const unsigned char *sha1 = nth_packed_object_sha1(p, i);
+		struct object_id oid;
 
-		if (!sha1)
+		if (!nth_packed_object_oid(&oid, p, i))
 			return error("unable to get sha1 of object %u in %s",
 				     i, p->pack_name);
 
-		r = cb(sha1, p, i, data);
+		r = cb(&oid, p, i, data);
 		if (r)
 			break;
 	}
diff --git a/sha1_name.c b/sha1_name.c
index 26ceec1..cda9e49 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1051,7 +1051,7 @@
 	struct strbuf buf;
 };
 
-static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
+static int grab_nth_branch_switch(struct object_id *ooid, struct object_id *noid,
 				  const char *email, unsigned long timestamp, int tz,
 				  const char *message, void *cb_data)
 {
diff --git a/sha1dc/LICENSE.txt b/sha1dc/LICENSE.txt
new file mode 100644
index 0000000..4a3e6a1
--- /dev/null
+++ b/sha1dc/LICENSE.txt
@@ -0,0 +1,30 @@
+MIT License
+
+Copyright (c) 2017:
+    Marc Stevens
+    Cryptology Group
+    Centrum Wiskunde & Informatica
+    P.O. Box 94079, 1090 GB Amsterdam, Netherlands
+    marc@marc-stevens.nl
+
+    Dan Shumow
+    Microsoft Research
+    danshu@microsoft.com
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/sha1dc/sha1.c b/sha1dc/sha1.c
new file mode 100644
index 0000000..35e9dd5
--- /dev/null
+++ b/sha1dc/sha1.c
@@ -0,0 +1,1809 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow (danshu@microsoft.com)
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+#include "cache.h"
+#include "sha1dc/sha1.h"
+#include "sha1dc/ubc_check.h"
+
+
+/*
+   Because Little-Endian architectures are most common,
+   we only set SHA1DC_BIGENDIAN if one of these conditions is met.
+   Note that all MSFT platforms are little endian,
+   so none of these will be defined under the MSC compiler.
+   If you are compiling on a big endian platform and your compiler does not define one of these,
+   you will have to add whatever macros your tool chain defines to indicate Big-Endianness.
+ */
+#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || \
+    (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __BIG_ENDIAN__)) || \
+    defined(__BIG_ENDIAN__) || defined(__ARMEB__) || defined(__THUMBEB__) ||  defined(__AARCH64EB__) || \
+    defined(_MIPSEB) || defined(__MIPSEB) || defined(__MIPSEB__)
+
+#define SHA1DC_BIGENDIAN	1
+#else
+#undef SHA1DC_BIGENDIAN
+#endif /*ENDIANNESS SELECTION*/
+
+#define rotate_right(x,n) (((x)>>(n))|((x)<<(32-(n))))
+#define rotate_left(x,n)  (((x)<<(n))|((x)>>(32-(n))))
+
+#define sha1_bswap32(x) \
+	{x = ((x << 8) & 0xFF00FF00) | ((x >> 8) & 0xFF00FF); x = (x << 16) | (x >> 16);}
+
+#define sha1_mix(W, t)  (rotate_left(W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16], 1))
+
+#if defined(SHA1DC_BIGENDIAN)
+	#define sha1_load(m, t, temp)  { temp = m[t]; }
+#else
+	#define sha1_load(m, t, temp)  { temp = m[t]; sha1_bswap32(temp); }
+#endif /* !defined(SHA1DC_BIGENDIAN) */
+
+#define sha1_store(W, t, x)	*(volatile uint32_t *)&W[t] = x
+
+#define sha1_f1(b,c,d) ((d)^((b)&((c)^(d))))
+#define sha1_f2(b,c,d) ((b)^(c)^(d))
+#define sha1_f3(b,c,d) (((b)&(c))+((d)&((b)^(c))))
+#define sha1_f4(b,c,d) ((b)^(c)^(d))
+
+#define HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999 + m[t]; b = rotate_left(b, 30); }
+#define HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f2(b,c,d) + 0x6ED9EBA1 + m[t]; b = rotate_left(b, 30); }
+#define HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f3(b,c,d) + 0x8F1BBCDC + m[t]; b = rotate_left(b, 30); }
+#define HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, m, t) \
+	{ e += rotate_left(a, 5) + sha1_f4(b,c,d) + 0xCA62C1D6 + m[t]; b = rotate_left(b, 30); }
+
+#define HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999 + m[t]; }
+#define HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f2(b,c,d) + 0x6ED9EBA1 + m[t]; }
+#define HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f3(b,c,d) + 0x8F1BBCDC + m[t]; }
+#define HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, m, t) \
+	{ b = rotate_right(b, 30); e -= rotate_left(a, 5) + sha1_f4(b,c,d) + 0xCA62C1D6 + m[t]; }
+
+#define SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, t, temp) \
+	{sha1_load(m, t, temp); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999; b = rotate_left(b, 30);}
+
+#define SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f1(b,c,d) + 0x5A827999; b = rotate_left(b, 30); }
+
+#define SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f2(b,c,d) + 0x6ED9EBA1; b = rotate_left(b, 30); }
+
+#define SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f3(b,c,d) + 0x8F1BBCDC; b = rotate_left(b, 30); }
+
+#define SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, t, temp) \
+	{temp = sha1_mix(W, t); sha1_store(W, t, temp); e += temp + rotate_left(a, 5) + sha1_f4(b,c,d) + 0xCA62C1D6; b = rotate_left(b, 30); }
+
+
+#define SHA1_STORE_STATE(i) states[i][0] = a; states[i][1] = b; states[i][2] = c; states[i][3] = d; states[i][4] = e;
+
+#ifdef BUILDNOCOLLDETECTSHA1COMPRESSION
+void sha1_compression(uint32_t ihv[5], const uint32_t m[16])
+{
+	uint32_t W[80];
+	uint32_t a,b,c,d,e;
+	unsigned i;
+
+	memcpy(W, m, 16 * 4);
+	for (i = 16; i < 80; ++i)
+		W[i] = sha1_mix(W, i);
+
+	a = ihv[0]; b = ihv[1]; c = ihv[2]; d = ihv[3]; e = ihv[4];
+
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 0);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 1);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 2);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 3);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 4);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 5);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 6);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 7);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 8);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 9);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 10);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 11);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 12);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 13);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 14);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 15);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 16);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 17);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 18);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 19);
+
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 20);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 21);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 22);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 23);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 24);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 25);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 26);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 27);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 28);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 29);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 30);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 31);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 32);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 33);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 34);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 35);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 36);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 37);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 38);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 39);
+
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 40);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 41);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 42);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 43);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 44);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 45);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 46);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 47);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 48);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 49);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 50);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 51);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 52);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 53);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 54);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 55);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 56);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 57);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 58);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 59);
+
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 60);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 61);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 62);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 63);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 64);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 65);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 66);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 67);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 68);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 69);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 70);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 71);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 72);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 73);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 74);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 75);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 76);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 77);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 78);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 79);
+
+	ihv[0] += a; ihv[1] += b; ihv[2] += c; ihv[3] += d; ihv[4] += e;
+}
+#endif /*BUILDNOCOLLDETECTSHA1COMPRESSION*/
+
+
+static void sha1_compression_W(uint32_t ihv[5], const uint32_t W[80])
+{
+	uint32_t a = ihv[0], b = ihv[1], c = ihv[2], d = ihv[3], e = ihv[4];
+
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 0);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 1);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 2);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 3);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 4);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 5);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 6);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 7);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 8);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 9);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 10);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 11);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 12);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 13);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 14);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, W, 15);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, W, 16);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, W, 17);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, W, 18);
+	HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, W, 19);
+
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 20);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 21);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 22);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 23);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 24);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 25);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 26);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 27);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 28);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 29);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 30);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 31);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 32);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 33);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 34);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, W, 35);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, W, 36);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, W, 37);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, W, 38);
+	HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, W, 39);
+
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 40);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 41);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 42);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 43);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 44);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 45);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 46);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 47);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 48);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 49);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 50);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 51);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 52);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 53);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 54);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, W, 55);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, W, 56);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, W, 57);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, W, 58);
+	HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, W, 59);
+
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 60);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 61);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 62);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 63);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 64);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 65);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 66);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 67);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 68);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 69);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 70);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 71);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 72);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 73);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 74);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, W, 75);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, W, 76);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, W, 77);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, W, 78);
+	HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, W, 79);
+
+	ihv[0] += a; ihv[1] += b; ihv[2] += c; ihv[3] += d; ihv[4] += e;
+}
+
+
+
+void sha1_compression_states(uint32_t ihv[5], const uint32_t m[16], uint32_t W[80], uint32_t states[80][5])
+{
+	uint32_t a = ihv[0], b = ihv[1], c = ihv[2], d = ihv[3], e = ihv[4];
+	uint32_t temp;
+
+#ifdef DOSTORESTATE00
+	SHA1_STORE_STATE(0)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 0, temp);
+
+#ifdef DOSTORESTATE01
+	SHA1_STORE_STATE(1)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(e, a, b, c, d, m, W, 1, temp);
+
+#ifdef DOSTORESTATE02
+	SHA1_STORE_STATE(2)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(d, e, a, b, c, m, W, 2, temp);
+
+#ifdef DOSTORESTATE03
+	SHA1_STORE_STATE(3)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(c, d, e, a, b, m, W, 3, temp);
+
+#ifdef DOSTORESTATE04
+	SHA1_STORE_STATE(4)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(b, c, d, e, a, m, W, 4, temp);
+
+#ifdef DOSTORESTATE05
+	SHA1_STORE_STATE(5)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 5, temp);
+
+#ifdef DOSTORESTATE06
+	SHA1_STORE_STATE(6)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(e, a, b, c, d, m, W, 6, temp);
+
+#ifdef DOSTORESTATE07
+	SHA1_STORE_STATE(7)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(d, e, a, b, c, m, W, 7, temp);
+
+#ifdef DOSTORESTATE08
+	SHA1_STORE_STATE(8)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(c, d, e, a, b, m, W, 8, temp);
+
+#ifdef DOSTORESTATE09
+	SHA1_STORE_STATE(9)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(b, c, d, e, a, m, W, 9, temp);
+
+#ifdef DOSTORESTATE10
+	SHA1_STORE_STATE(10)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 10, temp);
+
+#ifdef DOSTORESTATE11
+	SHA1_STORE_STATE(11)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(e, a, b, c, d, m, W, 11, temp);
+
+#ifdef DOSTORESTATE12
+	SHA1_STORE_STATE(12)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(d, e, a, b, c, m, W, 12, temp);
+
+#ifdef DOSTORESTATE13
+	SHA1_STORE_STATE(13)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(c, d, e, a, b, m, W, 13, temp);
+
+#ifdef DOSTORESTATE14
+	SHA1_STORE_STATE(14)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(b, c, d, e, a, m, W, 14, temp);
+
+#ifdef DOSTORESTATE15
+	SHA1_STORE_STATE(15)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_LOAD(a, b, c, d, e, m, W, 15, temp);
+
+#ifdef DOSTORESTATE16
+	SHA1_STORE_STATE(16)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(e, a, b, c, d, W, 16, temp);
+
+#ifdef DOSTORESTATE17
+	SHA1_STORE_STATE(17)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(d, e, a, b, c, W, 17, temp);
+
+#ifdef DOSTORESTATE18
+	SHA1_STORE_STATE(18)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(c, d, e, a, b, W, 18, temp);
+
+#ifdef DOSTORESTATE19
+	SHA1_STORE_STATE(19)
+#endif
+	SHA1COMPRESS_FULL_ROUND1_STEP_EXPAND(b, c, d, e, a, W, 19, temp);
+
+
+
+#ifdef DOSTORESTATE20
+	SHA1_STORE_STATE(20)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 20, temp);
+
+#ifdef DOSTORESTATE21
+	SHA1_STORE_STATE(21)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 21, temp);
+
+#ifdef DOSTORESTATE22
+	SHA1_STORE_STATE(22)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 22, temp);
+
+#ifdef DOSTORESTATE23
+	SHA1_STORE_STATE(23)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 23, temp);
+
+#ifdef DOSTORESTATE24
+	SHA1_STORE_STATE(24)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 24, temp);
+
+#ifdef DOSTORESTATE25
+	SHA1_STORE_STATE(25)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 25, temp);
+
+#ifdef DOSTORESTATE26
+	SHA1_STORE_STATE(26)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 26, temp);
+
+#ifdef DOSTORESTATE27
+	SHA1_STORE_STATE(27)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 27, temp);
+
+#ifdef DOSTORESTATE28
+	SHA1_STORE_STATE(28)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 28, temp);
+
+#ifdef DOSTORESTATE29
+	SHA1_STORE_STATE(29)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 29, temp);
+
+#ifdef DOSTORESTATE30
+	SHA1_STORE_STATE(30)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 30, temp);
+
+#ifdef DOSTORESTATE31
+	SHA1_STORE_STATE(31)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 31, temp);
+
+#ifdef DOSTORESTATE32
+	SHA1_STORE_STATE(32)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 32, temp);
+
+#ifdef DOSTORESTATE33
+	SHA1_STORE_STATE(33)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 33, temp);
+
+#ifdef DOSTORESTATE34
+	SHA1_STORE_STATE(34)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 34, temp);
+
+#ifdef DOSTORESTATE35
+	SHA1_STORE_STATE(35)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(a, b, c, d, e, W, 35, temp);
+
+#ifdef DOSTORESTATE36
+	SHA1_STORE_STATE(36)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(e, a, b, c, d, W, 36, temp);
+
+#ifdef DOSTORESTATE37
+	SHA1_STORE_STATE(37)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(d, e, a, b, c, W, 37, temp);
+
+#ifdef DOSTORESTATE38
+	SHA1_STORE_STATE(38)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(c, d, e, a, b, W, 38, temp);
+
+#ifdef DOSTORESTATE39
+	SHA1_STORE_STATE(39)
+#endif
+	SHA1COMPRESS_FULL_ROUND2_STEP(b, c, d, e, a, W, 39, temp);
+
+
+
+#ifdef DOSTORESTATE40
+	SHA1_STORE_STATE(40)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 40, temp);
+
+#ifdef DOSTORESTATE41
+	SHA1_STORE_STATE(41)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 41, temp);
+
+#ifdef DOSTORESTATE42
+	SHA1_STORE_STATE(42)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 42, temp);
+
+#ifdef DOSTORESTATE43
+	SHA1_STORE_STATE(43)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 43, temp);
+
+#ifdef DOSTORESTATE44
+	SHA1_STORE_STATE(44)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 44, temp);
+
+#ifdef DOSTORESTATE45
+	SHA1_STORE_STATE(45)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 45, temp);
+
+#ifdef DOSTORESTATE46
+	SHA1_STORE_STATE(46)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 46, temp);
+
+#ifdef DOSTORESTATE47
+	SHA1_STORE_STATE(47)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 47, temp);
+
+#ifdef DOSTORESTATE48
+	SHA1_STORE_STATE(48)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 48, temp);
+
+#ifdef DOSTORESTATE49
+	SHA1_STORE_STATE(49)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 49, temp);
+
+#ifdef DOSTORESTATE50
+	SHA1_STORE_STATE(50)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 50, temp);
+
+#ifdef DOSTORESTATE51
+	SHA1_STORE_STATE(51)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 51, temp);
+
+#ifdef DOSTORESTATE52
+	SHA1_STORE_STATE(52)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 52, temp);
+
+#ifdef DOSTORESTATE53
+	SHA1_STORE_STATE(53)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 53, temp);
+
+#ifdef DOSTORESTATE54
+	SHA1_STORE_STATE(54)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 54, temp);
+
+#ifdef DOSTORESTATE55
+	SHA1_STORE_STATE(55)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(a, b, c, d, e, W, 55, temp);
+
+#ifdef DOSTORESTATE56
+	SHA1_STORE_STATE(56)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(e, a, b, c, d, W, 56, temp);
+
+#ifdef DOSTORESTATE57
+	SHA1_STORE_STATE(57)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(d, e, a, b, c, W, 57, temp);
+
+#ifdef DOSTORESTATE58
+	SHA1_STORE_STATE(58)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(c, d, e, a, b, W, 58, temp);
+
+#ifdef DOSTORESTATE59
+	SHA1_STORE_STATE(59)
+#endif
+	SHA1COMPRESS_FULL_ROUND3_STEP(b, c, d, e, a, W, 59, temp);
+
+
+
+
+#ifdef DOSTORESTATE60
+	SHA1_STORE_STATE(60)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 60, temp);
+
+#ifdef DOSTORESTATE61
+	SHA1_STORE_STATE(61)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 61, temp);
+
+#ifdef DOSTORESTATE62
+	SHA1_STORE_STATE(62)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 62, temp);
+
+#ifdef DOSTORESTATE63
+	SHA1_STORE_STATE(63)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 63, temp);
+
+#ifdef DOSTORESTATE64
+	SHA1_STORE_STATE(64)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 64, temp);
+
+#ifdef DOSTORESTATE65
+	SHA1_STORE_STATE(65)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 65, temp);
+
+#ifdef DOSTORESTATE66
+	SHA1_STORE_STATE(66)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 66, temp);
+
+#ifdef DOSTORESTATE67
+	SHA1_STORE_STATE(67)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 67, temp);
+
+#ifdef DOSTORESTATE68
+	SHA1_STORE_STATE(68)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 68, temp);
+
+#ifdef DOSTORESTATE69
+	SHA1_STORE_STATE(69)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 69, temp);
+
+#ifdef DOSTORESTATE70
+	SHA1_STORE_STATE(70)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 70, temp);
+
+#ifdef DOSTORESTATE71
+	SHA1_STORE_STATE(71)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 71, temp);
+
+#ifdef DOSTORESTATE72
+	SHA1_STORE_STATE(72)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 72, temp);
+
+#ifdef DOSTORESTATE73
+	SHA1_STORE_STATE(73)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 73, temp);
+
+#ifdef DOSTORESTATE74
+	SHA1_STORE_STATE(74)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 74, temp);
+
+#ifdef DOSTORESTATE75
+	SHA1_STORE_STATE(75)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(a, b, c, d, e, W, 75, temp);
+
+#ifdef DOSTORESTATE76
+	SHA1_STORE_STATE(76)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(e, a, b, c, d, W, 76, temp);
+
+#ifdef DOSTORESTATE77
+	SHA1_STORE_STATE(77)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(d, e, a, b, c, W, 77, temp);
+
+#ifdef DOSTORESTATE78
+	SHA1_STORE_STATE(78)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(c, d, e, a, b, W, 78, temp);
+
+#ifdef DOSTORESTATE79
+	SHA1_STORE_STATE(79)
+#endif
+	SHA1COMPRESS_FULL_ROUND4_STEP(b, c, d, e, a, W, 79, temp);
+
+
+
+	ihv[0] += a; ihv[1] += b; ihv[2] += c; ihv[3] += d; ihv[4] += e;
+}
+
+
+
+
+#define SHA1_RECOMPRESS(t) \
+static void sha1recompress_fast_ ## t (uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5]) \
+{ \
+	uint32_t a = state[0], b = state[1], c = state[2], d = state[3], e = state[4]; \
+	if (t > 79) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 79); \
+	if (t > 78) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 78); \
+	if (t > 77) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 77); \
+	if (t > 76) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 76); \
+	if (t > 75) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 75); \
+	if (t > 74) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 74); \
+	if (t > 73) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 73); \
+	if (t > 72) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 72); \
+	if (t > 71) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 71); \
+	if (t > 70) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 70); \
+	if (t > 69) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 69); \
+	if (t > 68) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 68); \
+	if (t > 67) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 67); \
+	if (t > 66) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 66); \
+	if (t > 65) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 65); \
+	if (t > 64) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(b, c, d, e, a, me2, 64); \
+	if (t > 63) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(c, d, e, a, b, me2, 63); \
+	if (t > 62) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(d, e, a, b, c, me2, 62); \
+	if (t > 61) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(e, a, b, c, d, me2, 61); \
+	if (t > 60) HASHCLASH_SHA1COMPRESS_ROUND4_STEP_BW(a, b, c, d, e, me2, 60); \
+	if (t > 59) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 59); \
+	if (t > 58) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 58); \
+	if (t > 57) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 57); \
+	if (t > 56) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 56); \
+	if (t > 55) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 55); \
+	if (t > 54) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 54); \
+	if (t > 53) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 53); \
+	if (t > 52) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 52); \
+	if (t > 51) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 51); \
+	if (t > 50) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 50); \
+	if (t > 49) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 49); \
+	if (t > 48) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 48); \
+	if (t > 47) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 47); \
+	if (t > 46) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 46); \
+	if (t > 45) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 45); \
+	if (t > 44) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(b, c, d, e, a, me2, 44); \
+	if (t > 43) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(c, d, e, a, b, me2, 43); \
+	if (t > 42) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(d, e, a, b, c, me2, 42); \
+	if (t > 41) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(e, a, b, c, d, me2, 41); \
+	if (t > 40) HASHCLASH_SHA1COMPRESS_ROUND3_STEP_BW(a, b, c, d, e, me2, 40); \
+	if (t > 39) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 39); \
+	if (t > 38) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 38); \
+	if (t > 37) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 37); \
+	if (t > 36) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 36); \
+	if (t > 35) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 35); \
+	if (t > 34) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 34); \
+	if (t > 33) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 33); \
+	if (t > 32) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 32); \
+	if (t > 31) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 31); \
+	if (t > 30) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 30); \
+	if (t > 29) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 29); \
+	if (t > 28) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 28); \
+	if (t > 27) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 27); \
+	if (t > 26) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 26); \
+	if (t > 25) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 25); \
+	if (t > 24) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(b, c, d, e, a, me2, 24); \
+	if (t > 23) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(c, d, e, a, b, me2, 23); \
+	if (t > 22) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(d, e, a, b, c, me2, 22); \
+	if (t > 21) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(e, a, b, c, d, me2, 21); \
+	if (t > 20) HASHCLASH_SHA1COMPRESS_ROUND2_STEP_BW(a, b, c, d, e, me2, 20); \
+	if (t > 19) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 19); \
+	if (t > 18) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 18); \
+	if (t > 17) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 17); \
+	if (t > 16) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 16); \
+	if (t > 15) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 15); \
+	if (t > 14) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 14); \
+	if (t > 13) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 13); \
+	if (t > 12) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 12); \
+	if (t > 11) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 11); \
+	if (t > 10) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 10); \
+	if (t > 9) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 9); \
+	if (t > 8) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 8); \
+	if (t > 7) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 7); \
+	if (t > 6) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 6); \
+	if (t > 5) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 5); \
+	if (t > 4) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(b, c, d, e, a, me2, 4); \
+	if (t > 3) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(c, d, e, a, b, me2, 3); \
+	if (t > 2) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(d, e, a, b, c, me2, 2); \
+	if (t > 1) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(e, a, b, c, d, me2, 1); \
+	if (t > 0) HASHCLASH_SHA1COMPRESS_ROUND1_STEP_BW(a, b, c, d, e, me2, 0); \
+	ihvin[0] = a; ihvin[1] = b; ihvin[2] = c; ihvin[3] = d; ihvin[4] = e; \
+	a = state[0]; b = state[1]; c = state[2]; d = state[3]; e = state[4]; \
+	if (t <= 0) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 0); \
+	if (t <= 1) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 1); \
+	if (t <= 2) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 2); \
+	if (t <= 3) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 3); \
+	if (t <= 4) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 4); \
+	if (t <= 5) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 5); \
+	if (t <= 6) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 6); \
+	if (t <= 7) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 7); \
+	if (t <= 8) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 8); \
+	if (t <= 9) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 9); \
+	if (t <= 10) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 10); \
+	if (t <= 11) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 11); \
+	if (t <= 12) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 12); \
+	if (t <= 13) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 13); \
+	if (t <= 14) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 14); \
+	if (t <= 15) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(a, b, c, d, e, me2, 15); \
+	if (t <= 16) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(e, a, b, c, d, me2, 16); \
+	if (t <= 17) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(d, e, a, b, c, me2, 17); \
+	if (t <= 18) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(c, d, e, a, b, me2, 18); \
+	if (t <= 19) HASHCLASH_SHA1COMPRESS_ROUND1_STEP(b, c, d, e, a, me2, 19); \
+	if (t <= 20) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 20); \
+	if (t <= 21) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 21); \
+	if (t <= 22) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 22); \
+	if (t <= 23) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 23); \
+	if (t <= 24) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 24); \
+	if (t <= 25) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 25); \
+	if (t <= 26) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 26); \
+	if (t <= 27) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 27); \
+	if (t <= 28) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 28); \
+	if (t <= 29) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 29); \
+	if (t <= 30) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 30); \
+	if (t <= 31) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 31); \
+	if (t <= 32) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 32); \
+	if (t <= 33) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 33); \
+	if (t <= 34) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 34); \
+	if (t <= 35) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(a, b, c, d, e, me2, 35); \
+	if (t <= 36) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(e, a, b, c, d, me2, 36); \
+	if (t <= 37) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(d, e, a, b, c, me2, 37); \
+	if (t <= 38) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(c, d, e, a, b, me2, 38); \
+	if (t <= 39) HASHCLASH_SHA1COMPRESS_ROUND2_STEP(b, c, d, e, a, me2, 39); \
+	if (t <= 40) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 40); \
+	if (t <= 41) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 41); \
+	if (t <= 42) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 42); \
+	if (t <= 43) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 43); \
+	if (t <= 44) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 44); \
+	if (t <= 45) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 45); \
+	if (t <= 46) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 46); \
+	if (t <= 47) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 47); \
+	if (t <= 48) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 48); \
+	if (t <= 49) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 49); \
+	if (t <= 50) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 50); \
+	if (t <= 51) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 51); \
+	if (t <= 52) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 52); \
+	if (t <= 53) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 53); \
+	if (t <= 54) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 54); \
+	if (t <= 55) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(a, b, c, d, e, me2, 55); \
+	if (t <= 56) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(e, a, b, c, d, me2, 56); \
+	if (t <= 57) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(d, e, a, b, c, me2, 57); \
+	if (t <= 58) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(c, d, e, a, b, me2, 58); \
+	if (t <= 59) HASHCLASH_SHA1COMPRESS_ROUND3_STEP(b, c, d, e, a, me2, 59); \
+	if (t <= 60) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 60); \
+	if (t <= 61) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 61); \
+	if (t <= 62) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 62); \
+	if (t <= 63) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 63); \
+	if (t <= 64) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 64); \
+	if (t <= 65) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 65); \
+	if (t <= 66) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 66); \
+	if (t <= 67) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 67); \
+	if (t <= 68) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 68); \
+	if (t <= 69) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 69); \
+	if (t <= 70) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 70); \
+	if (t <= 71) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 71); \
+	if (t <= 72) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 72); \
+	if (t <= 73) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 73); \
+	if (t <= 74) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 74); \
+	if (t <= 75) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(a, b, c, d, e, me2, 75); \
+	if (t <= 76) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(e, a, b, c, d, me2, 76); \
+	if (t <= 77) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(d, e, a, b, c, me2, 77); \
+	if (t <= 78) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(c, d, e, a, b, me2, 78); \
+	if (t <= 79) HASHCLASH_SHA1COMPRESS_ROUND4_STEP(b, c, d, e, a, me2, 79); \
+	ihvout[0] = ihvin[0] + a; ihvout[1] = ihvin[1] + b; ihvout[2] = ihvin[2] + c; ihvout[3] = ihvin[3] + d; ihvout[4] = ihvin[4] + e; \
+}
+
+#ifdef DOSTORESTATE0
+SHA1_RECOMPRESS(0)
+#endif
+
+#ifdef DOSTORESTATE1
+SHA1_RECOMPRESS(1)
+#endif
+
+#ifdef DOSTORESTATE2
+SHA1_RECOMPRESS(2)
+#endif
+
+#ifdef DOSTORESTATE3
+SHA1_RECOMPRESS(3)
+#endif
+
+#ifdef DOSTORESTATE4
+SHA1_RECOMPRESS(4)
+#endif
+
+#ifdef DOSTORESTATE5
+SHA1_RECOMPRESS(5)
+#endif
+
+#ifdef DOSTORESTATE6
+SHA1_RECOMPRESS(6)
+#endif
+
+#ifdef DOSTORESTATE7
+SHA1_RECOMPRESS(7)
+#endif
+
+#ifdef DOSTORESTATE8
+SHA1_RECOMPRESS(8)
+#endif
+
+#ifdef DOSTORESTATE9
+SHA1_RECOMPRESS(9)
+#endif
+
+#ifdef DOSTORESTATE10
+SHA1_RECOMPRESS(10)
+#endif
+
+#ifdef DOSTORESTATE11
+SHA1_RECOMPRESS(11)
+#endif
+
+#ifdef DOSTORESTATE12
+SHA1_RECOMPRESS(12)
+#endif
+
+#ifdef DOSTORESTATE13
+SHA1_RECOMPRESS(13)
+#endif
+
+#ifdef DOSTORESTATE14
+SHA1_RECOMPRESS(14)
+#endif
+
+#ifdef DOSTORESTATE15
+SHA1_RECOMPRESS(15)
+#endif
+
+#ifdef DOSTORESTATE16
+SHA1_RECOMPRESS(16)
+#endif
+
+#ifdef DOSTORESTATE17
+SHA1_RECOMPRESS(17)
+#endif
+
+#ifdef DOSTORESTATE18
+SHA1_RECOMPRESS(18)
+#endif
+
+#ifdef DOSTORESTATE19
+SHA1_RECOMPRESS(19)
+#endif
+
+#ifdef DOSTORESTATE20
+SHA1_RECOMPRESS(20)
+#endif
+
+#ifdef DOSTORESTATE21
+SHA1_RECOMPRESS(21)
+#endif
+
+#ifdef DOSTORESTATE22
+SHA1_RECOMPRESS(22)
+#endif
+
+#ifdef DOSTORESTATE23
+SHA1_RECOMPRESS(23)
+#endif
+
+#ifdef DOSTORESTATE24
+SHA1_RECOMPRESS(24)
+#endif
+
+#ifdef DOSTORESTATE25
+SHA1_RECOMPRESS(25)
+#endif
+
+#ifdef DOSTORESTATE26
+SHA1_RECOMPRESS(26)
+#endif
+
+#ifdef DOSTORESTATE27
+SHA1_RECOMPRESS(27)
+#endif
+
+#ifdef DOSTORESTATE28
+SHA1_RECOMPRESS(28)
+#endif
+
+#ifdef DOSTORESTATE29
+SHA1_RECOMPRESS(29)
+#endif
+
+#ifdef DOSTORESTATE30
+SHA1_RECOMPRESS(30)
+#endif
+
+#ifdef DOSTORESTATE31
+SHA1_RECOMPRESS(31)
+#endif
+
+#ifdef DOSTORESTATE32
+SHA1_RECOMPRESS(32)
+#endif
+
+#ifdef DOSTORESTATE33
+SHA1_RECOMPRESS(33)
+#endif
+
+#ifdef DOSTORESTATE34
+SHA1_RECOMPRESS(34)
+#endif
+
+#ifdef DOSTORESTATE35
+SHA1_RECOMPRESS(35)
+#endif
+
+#ifdef DOSTORESTATE36
+SHA1_RECOMPRESS(36)
+#endif
+
+#ifdef DOSTORESTATE37
+SHA1_RECOMPRESS(37)
+#endif
+
+#ifdef DOSTORESTATE38
+SHA1_RECOMPRESS(38)
+#endif
+
+#ifdef DOSTORESTATE39
+SHA1_RECOMPRESS(39)
+#endif
+
+#ifdef DOSTORESTATE40
+SHA1_RECOMPRESS(40)
+#endif
+
+#ifdef DOSTORESTATE41
+SHA1_RECOMPRESS(41)
+#endif
+
+#ifdef DOSTORESTATE42
+SHA1_RECOMPRESS(42)
+#endif
+
+#ifdef DOSTORESTATE43
+SHA1_RECOMPRESS(43)
+#endif
+
+#ifdef DOSTORESTATE44
+SHA1_RECOMPRESS(44)
+#endif
+
+#ifdef DOSTORESTATE45
+SHA1_RECOMPRESS(45)
+#endif
+
+#ifdef DOSTORESTATE46
+SHA1_RECOMPRESS(46)
+#endif
+
+#ifdef DOSTORESTATE47
+SHA1_RECOMPRESS(47)
+#endif
+
+#ifdef DOSTORESTATE48
+SHA1_RECOMPRESS(48)
+#endif
+
+#ifdef DOSTORESTATE49
+SHA1_RECOMPRESS(49)
+#endif
+
+#ifdef DOSTORESTATE50
+SHA1_RECOMPRESS(50)
+#endif
+
+#ifdef DOSTORESTATE51
+SHA1_RECOMPRESS(51)
+#endif
+
+#ifdef DOSTORESTATE52
+SHA1_RECOMPRESS(52)
+#endif
+
+#ifdef DOSTORESTATE53
+SHA1_RECOMPRESS(53)
+#endif
+
+#ifdef DOSTORESTATE54
+SHA1_RECOMPRESS(54)
+#endif
+
+#ifdef DOSTORESTATE55
+SHA1_RECOMPRESS(55)
+#endif
+
+#ifdef DOSTORESTATE56
+SHA1_RECOMPRESS(56)
+#endif
+
+#ifdef DOSTORESTATE57
+SHA1_RECOMPRESS(57)
+#endif
+
+#ifdef DOSTORESTATE58
+SHA1_RECOMPRESS(58)
+#endif
+
+#ifdef DOSTORESTATE59
+SHA1_RECOMPRESS(59)
+#endif
+
+#ifdef DOSTORESTATE60
+SHA1_RECOMPRESS(60)
+#endif
+
+#ifdef DOSTORESTATE61
+SHA1_RECOMPRESS(61)
+#endif
+
+#ifdef DOSTORESTATE62
+SHA1_RECOMPRESS(62)
+#endif
+
+#ifdef DOSTORESTATE63
+SHA1_RECOMPRESS(63)
+#endif
+
+#ifdef DOSTORESTATE64
+SHA1_RECOMPRESS(64)
+#endif
+
+#ifdef DOSTORESTATE65
+SHA1_RECOMPRESS(65)
+#endif
+
+#ifdef DOSTORESTATE66
+SHA1_RECOMPRESS(66)
+#endif
+
+#ifdef DOSTORESTATE67
+SHA1_RECOMPRESS(67)
+#endif
+
+#ifdef DOSTORESTATE68
+SHA1_RECOMPRESS(68)
+#endif
+
+#ifdef DOSTORESTATE69
+SHA1_RECOMPRESS(69)
+#endif
+
+#ifdef DOSTORESTATE70
+SHA1_RECOMPRESS(70)
+#endif
+
+#ifdef DOSTORESTATE71
+SHA1_RECOMPRESS(71)
+#endif
+
+#ifdef DOSTORESTATE72
+SHA1_RECOMPRESS(72)
+#endif
+
+#ifdef DOSTORESTATE73
+SHA1_RECOMPRESS(73)
+#endif
+
+#ifdef DOSTORESTATE74
+SHA1_RECOMPRESS(74)
+#endif
+
+#ifdef DOSTORESTATE75
+SHA1_RECOMPRESS(75)
+#endif
+
+#ifdef DOSTORESTATE76
+SHA1_RECOMPRESS(76)
+#endif
+
+#ifdef DOSTORESTATE77
+SHA1_RECOMPRESS(77)
+#endif
+
+#ifdef DOSTORESTATE78
+SHA1_RECOMPRESS(78)
+#endif
+
+#ifdef DOSTORESTATE79
+SHA1_RECOMPRESS(79)
+#endif
+
+static void sha1_recompression_step(uint32_t step, uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5])
+{
+	switch (step)
+	{
+#ifdef DOSTORESTATE0
+	case 0:
+		sha1recompress_fast_0(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE1
+	case 1:
+		sha1recompress_fast_1(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE2
+	case 2:
+		sha1recompress_fast_2(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE3
+	case 3:
+		sha1recompress_fast_3(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE4
+	case 4:
+		sha1recompress_fast_4(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE5
+	case 5:
+		sha1recompress_fast_5(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE6
+	case 6:
+		sha1recompress_fast_6(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE7
+	case 7:
+		sha1recompress_fast_7(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE8
+	case 8:
+		sha1recompress_fast_8(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE9
+	case 9:
+		sha1recompress_fast_9(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE10
+	case 10:
+		sha1recompress_fast_10(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE11
+	case 11:
+		sha1recompress_fast_11(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE12
+	case 12:
+		sha1recompress_fast_12(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE13
+	case 13:
+		sha1recompress_fast_13(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE14
+	case 14:
+		sha1recompress_fast_14(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE15
+	case 15:
+		sha1recompress_fast_15(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE16
+	case 16:
+		sha1recompress_fast_16(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE17
+	case 17:
+		sha1recompress_fast_17(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE18
+	case 18:
+		sha1recompress_fast_18(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE19
+	case 19:
+		sha1recompress_fast_19(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE20
+	case 20:
+		sha1recompress_fast_20(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE21
+	case 21:
+		sha1recompress_fast_21(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE22
+	case 22:
+		sha1recompress_fast_22(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE23
+	case 23:
+		sha1recompress_fast_23(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE24
+	case 24:
+		sha1recompress_fast_24(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE25
+	case 25:
+		sha1recompress_fast_25(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE26
+	case 26:
+		sha1recompress_fast_26(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE27
+	case 27:
+		sha1recompress_fast_27(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE28
+	case 28:
+		sha1recompress_fast_28(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE29
+	case 29:
+		sha1recompress_fast_29(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE30
+	case 30:
+		sha1recompress_fast_30(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE31
+	case 31:
+		sha1recompress_fast_31(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE32
+	case 32:
+		sha1recompress_fast_32(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE33
+	case 33:
+		sha1recompress_fast_33(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE34
+	case 34:
+		sha1recompress_fast_34(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE35
+	case 35:
+		sha1recompress_fast_35(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE36
+	case 36:
+		sha1recompress_fast_36(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE37
+	case 37:
+		sha1recompress_fast_37(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE38
+	case 38:
+		sha1recompress_fast_38(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE39
+	case 39:
+		sha1recompress_fast_39(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE40
+	case 40:
+		sha1recompress_fast_40(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE41
+	case 41:
+		sha1recompress_fast_41(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE42
+	case 42:
+		sha1recompress_fast_42(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE43
+	case 43:
+		sha1recompress_fast_43(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE44
+	case 44:
+		sha1recompress_fast_44(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE45
+	case 45:
+		sha1recompress_fast_45(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE46
+	case 46:
+		sha1recompress_fast_46(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE47
+	case 47:
+		sha1recompress_fast_47(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE48
+	case 48:
+		sha1recompress_fast_48(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE49
+	case 49:
+		sha1recompress_fast_49(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE50
+	case 50:
+		sha1recompress_fast_50(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE51
+	case 51:
+		sha1recompress_fast_51(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE52
+	case 52:
+		sha1recompress_fast_52(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE53
+	case 53:
+		sha1recompress_fast_53(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE54
+	case 54:
+		sha1recompress_fast_54(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE55
+	case 55:
+		sha1recompress_fast_55(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE56
+	case 56:
+		sha1recompress_fast_56(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE57
+	case 57:
+		sha1recompress_fast_57(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE58
+	case 58:
+		sha1recompress_fast_58(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE59
+	case 59:
+		sha1recompress_fast_59(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE60
+	case 60:
+		sha1recompress_fast_60(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE61
+	case 61:
+		sha1recompress_fast_61(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE62
+	case 62:
+		sha1recompress_fast_62(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE63
+	case 63:
+		sha1recompress_fast_63(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE64
+	case 64:
+		sha1recompress_fast_64(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE65
+	case 65:
+		sha1recompress_fast_65(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE66
+	case 66:
+		sha1recompress_fast_66(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE67
+	case 67:
+		sha1recompress_fast_67(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE68
+	case 68:
+		sha1recompress_fast_68(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE69
+	case 69:
+		sha1recompress_fast_69(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE70
+	case 70:
+		sha1recompress_fast_70(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE71
+	case 71:
+		sha1recompress_fast_71(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE72
+	case 72:
+		sha1recompress_fast_72(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE73
+	case 73:
+		sha1recompress_fast_73(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE74
+	case 74:
+		sha1recompress_fast_74(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE75
+	case 75:
+		sha1recompress_fast_75(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE76
+	case 76:
+		sha1recompress_fast_76(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE77
+	case 77:
+		sha1recompress_fast_77(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE78
+	case 78:
+		sha1recompress_fast_78(ihvin, ihvout, me2, state);
+		break;
+#endif
+#ifdef DOSTORESTATE79
+	case 79:
+		sha1recompress_fast_79(ihvin, ihvout, me2, state);
+		break;
+#endif
+	default:
+		abort();
+	}
+
+}
+
+
+
+static void sha1_process(SHA1_CTX* ctx, const uint32_t block[16])
+{
+	unsigned i, j;
+	uint32_t ubc_dv_mask[DVMASKSIZE] = { 0xFFFFFFFF };
+	uint32_t ihvtmp[5];
+
+	ctx->ihv1[0] = ctx->ihv[0];
+	ctx->ihv1[1] = ctx->ihv[1];
+	ctx->ihv1[2] = ctx->ihv[2];
+	ctx->ihv1[3] = ctx->ihv[3];
+	ctx->ihv1[4] = ctx->ihv[4];
+
+	sha1_compression_states(ctx->ihv, block, ctx->m1, ctx->states);
+
+	if (ctx->detect_coll)
+	{
+		if (ctx->ubc_check)
+		{
+			ubc_check(ctx->m1, ubc_dv_mask);
+		}
+
+		if (ubc_dv_mask[0] != 0)
+		{
+			for (i = 0; sha1_dvs[i].dvType != 0; ++i)
+			{
+				if (ubc_dv_mask[0] & ((uint32_t)(1) << sha1_dvs[i].maskb))
+				{
+					for (j = 0; j < 80; ++j)
+						ctx->m2[j] = ctx->m1[j] ^ sha1_dvs[i].dm[j];
+
+					sha1_recompression_step(sha1_dvs[i].testt, ctx->ihv2, ihvtmp, ctx->m2, ctx->states[sha1_dvs[i].testt]);
+
+					/* to verify SHA-1 collision detection code with collisions for reduced-step SHA-1 */
+					if ((0 == ((ihvtmp[0] ^ ctx->ihv[0]) | (ihvtmp[1] ^ ctx->ihv[1]) | (ihvtmp[2] ^ ctx->ihv[2]) | (ihvtmp[3] ^ ctx->ihv[3]) | (ihvtmp[4] ^ ctx->ihv[4])))
+						|| (ctx->reduced_round_coll && 0==((ctx->ihv1[0] ^ ctx->ihv2[0]) | (ctx->ihv1[1] ^ ctx->ihv2[1]) | (ctx->ihv1[2] ^ ctx->ihv2[2]) | (ctx->ihv1[3] ^ ctx->ihv2[3]) | (ctx->ihv1[4] ^ ctx->ihv2[4]))))
+					{
+						ctx->found_collision = 1;
+
+						if (ctx->safe_hash)
+						{
+							sha1_compression_W(ctx->ihv, ctx->m1);
+							sha1_compression_W(ctx->ihv, ctx->m1);
+						}
+
+						break;
+					}
+				}
+			}
+		}
+	}
+}
+
+void SHA1DCInit(SHA1_CTX* ctx)
+{
+	ctx->total = 0;
+	ctx->ihv[0] = 0x67452301;
+	ctx->ihv[1] = 0xEFCDAB89;
+	ctx->ihv[2] = 0x98BADCFE;
+	ctx->ihv[3] = 0x10325476;
+	ctx->ihv[4] = 0xC3D2E1F0;
+	ctx->found_collision = 0;
+	ctx->safe_hash = 0;
+	ctx->ubc_check = 1;
+	ctx->detect_coll = 1;
+	ctx->reduced_round_coll = 0;
+	ctx->callback = NULL;
+}
+
+void SHA1DCSetSafeHash(SHA1_CTX* ctx, int safehash)
+{
+	if (safehash)
+		ctx->safe_hash = 1;
+	else
+		ctx->safe_hash = 0;
+}
+
+
+void SHA1DCSetUseUBC(SHA1_CTX* ctx, int ubc_check)
+{
+	if (ubc_check)
+		ctx->ubc_check = 1;
+	else
+		ctx->ubc_check = 0;
+}
+
+void SHA1DCSetUseDetectColl(SHA1_CTX* ctx, int detect_coll)
+{
+	if (detect_coll)
+		ctx->detect_coll = 1;
+	else
+		ctx->detect_coll = 0;
+}
+
+void SHA1DCSetDetectReducedRoundCollision(SHA1_CTX* ctx, int reduced_round_coll)
+{
+	if (reduced_round_coll)
+		ctx->reduced_round_coll = 1;
+	else
+		ctx->reduced_round_coll = 0;
+}
+
+void SHA1DCSetCallback(SHA1_CTX* ctx, collision_block_callback callback)
+{
+	ctx->callback = callback;
+}
+
+void SHA1DCUpdate(SHA1_CTX* ctx, const char* buf, size_t len)
+{
+	unsigned left, fill;
+	if (len == 0)
+		return;
+
+	left = ctx->total & 63;
+	fill = 64 - left;
+
+	if (left && len >= fill)
+	{
+		ctx->total += fill;
+		memcpy(ctx->buffer + left, buf, fill);
+		sha1_process(ctx, (uint32_t*)(ctx->buffer));
+		buf += fill;
+		len -= fill;
+		left = 0;
+	}
+	while (len >= 64)
+	{
+		ctx->total += 64;
+		sha1_process(ctx, (uint32_t*)(buf));
+		buf += 64;
+		len -= 64;
+	}
+	if (len > 0)
+	{
+		ctx->total += len;
+		memcpy(ctx->buffer + left, buf, len);
+	}
+}
+
+static const unsigned char sha1_padding[64] =
+{
+	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+int SHA1DCFinal(unsigned char output[20], SHA1_CTX *ctx)
+{
+	uint32_t last = ctx->total & 63;
+	uint32_t padn = (last < 56) ? (56 - last) : (120 - last);
+	uint64_t total;
+	SHA1DCUpdate(ctx, (const char*)(sha1_padding), padn);
+
+	total = ctx->total - padn;
+	total <<= 3;
+	ctx->buffer[56] = (unsigned char)(total >> 56);
+	ctx->buffer[57] = (unsigned char)(total >> 48);
+	ctx->buffer[58] = (unsigned char)(total >> 40);
+	ctx->buffer[59] = (unsigned char)(total >> 32);
+	ctx->buffer[60] = (unsigned char)(total >> 24);
+	ctx->buffer[61] = (unsigned char)(total >> 16);
+	ctx->buffer[62] = (unsigned char)(total >> 8);
+	ctx->buffer[63] = (unsigned char)(total);
+	sha1_process(ctx, (uint32_t*)(ctx->buffer));
+	output[0] = (unsigned char)(ctx->ihv[0] >> 24);
+	output[1] = (unsigned char)(ctx->ihv[0] >> 16);
+	output[2] = (unsigned char)(ctx->ihv[0] >> 8);
+	output[3] = (unsigned char)(ctx->ihv[0]);
+	output[4] = (unsigned char)(ctx->ihv[1] >> 24);
+	output[5] = (unsigned char)(ctx->ihv[1] >> 16);
+	output[6] = (unsigned char)(ctx->ihv[1] >> 8);
+	output[7] = (unsigned char)(ctx->ihv[1]);
+	output[8] = (unsigned char)(ctx->ihv[2] >> 24);
+	output[9] = (unsigned char)(ctx->ihv[2] >> 16);
+	output[10] = (unsigned char)(ctx->ihv[2] >> 8);
+	output[11] = (unsigned char)(ctx->ihv[2]);
+	output[12] = (unsigned char)(ctx->ihv[3] >> 24);
+	output[13] = (unsigned char)(ctx->ihv[3] >> 16);
+	output[14] = (unsigned char)(ctx->ihv[3] >> 8);
+	output[15] = (unsigned char)(ctx->ihv[3]);
+	output[16] = (unsigned char)(ctx->ihv[4] >> 24);
+	output[17] = (unsigned char)(ctx->ihv[4] >> 16);
+	output[18] = (unsigned char)(ctx->ihv[4] >> 8);
+	output[19] = (unsigned char)(ctx->ihv[4]);
+	return ctx->found_collision;
+}
+
+void git_SHA1DCFinal(unsigned char hash[20], SHA1_CTX *ctx)
+{
+	if (!SHA1DCFinal(hash, ctx))
+		return;
+	die("SHA-1 appears to be part of a collision attack: %s",
+	    sha1_to_hex(hash));
+}
+
+void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *vdata, unsigned long len)
+{
+	const char *data = vdata;
+	/* We expect an unsigned long, but sha1dc only takes an int */
+	while (len > INT_MAX) {
+		SHA1DCUpdate(ctx, data, INT_MAX);
+		data += INT_MAX;
+		len -= INT_MAX;
+	}
+	SHA1DCUpdate(ctx, data, len);
+}
diff --git a/sha1dc/sha1.h b/sha1dc/sha1.h
new file mode 100644
index 0000000..bd8bd92
--- /dev/null
+++ b/sha1dc/sha1.h
@@ -0,0 +1,122 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com>
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+#ifndef SHA1DC_SHA1_H
+#define SHA1DC_SHA1_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+/* uses SHA-1 message expansion to expand the first 16 words of W[] to 80 words */
+/* void sha1_message_expansion(uint32_t W[80]); */
+
+/* sha-1 compression function; first version takes a message block pre-parsed as 16 32-bit integers, second version takes an already expanded message) */
+/* void sha1_compression(uint32_t ihv[5], const uint32_t m[16]);
+void sha1_compression_W(uint32_t ihv[5], const uint32_t W[80]); */
+
+/* same as sha1_compression_W, but additionally store intermediate states */
+/* only stores states ii (the state between step ii-1 and step ii) when DOSTORESTATEii is defined in ubc_check.h */
+void sha1_compression_states(uint32_t[5], const uint32_t[16], uint32_t[80], uint32_t[80][5]);
+
+/*
+// function type for sha1_recompression_step_T (uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5])
+// where 0 <= T < 80
+//       me2 is an expanded message (the expansion of an original message block XOR'ed with a disturbance vector's message block difference)
+//       state is the internal state (a,b,c,d,e) before step T of the SHA-1 compression function while processing the original message block
+// the function will return:
+//       ihvin: the reconstructed input chaining value
+//       ihvout: the reconstructed output chaining value
+*/
+typedef void(*sha1_recompression_type)(uint32_t*, uint32_t*, const uint32_t*, const uint32_t*);
+
+/* table of sha1_recompression_step_0, ... , sha1_recompression_step_79 */
+/* extern sha1_recompression_type sha1_recompression_step[80];*/
+
+/* a callback function type that can be set to be called when a collision block has been found: */
+/* void collision_block_callback(uint64_t byteoffset, const uint32_t ihvin1[5], const uint32_t ihvin2[5], const uint32_t m1[80], const uint32_t m2[80]) */
+typedef void(*collision_block_callback)(uint64_t, const uint32_t*, const uint32_t*, const uint32_t*, const uint32_t*);
+
+/* the SHA-1 context */
+typedef struct {
+	uint64_t total;
+	uint32_t ihv[5];
+	unsigned char buffer[64];
+	int found_collision;
+	int safe_hash;
+	int detect_coll;
+	int ubc_check;
+	int reduced_round_coll;
+	collision_block_callback callback;
+
+	uint32_t ihv1[5];
+	uint32_t ihv2[5];
+	uint32_t m1[80];
+	uint32_t m2[80];
+	uint32_t states[80][5];
+} SHA1_CTX;
+
+/* initialize SHA-1 context */
+void SHA1DCInit(SHA1_CTX*);
+
+/*
+// function to enable safe SHA-1 hashing:
+// collision attacks are thwarted by hashing a detected near-collision block 3 times
+// think of it as extending SHA-1 from 80-steps to 240-steps for such blocks:
+//   the best collision attacks against SHA-1 have complexity about 2^60,
+//   thus for 240-steps an immediate lower-bound for the best cryptanalytic attacks would 2^180
+//   an attacker would be better off using a generic birthday search of complexity 2^80
+//
+// enabling safe SHA-1 hashing will result in the correct SHA-1 hash for messages where no collision attack was detected
+// but it will result in a different SHA-1 hash for messages where a collision attack was detected
+// this will automatically invalidate SHA-1 based digital signature forgeries
+// enabled by default
+*/
+void SHA1DCSetSafeHash(SHA1_CTX*, int);
+
+/* function to disable or enable the use of Unavoidable Bitconditions (provides a significant speed up) */
+/* enabled by default */
+void SHA1DCSetUseUBC(SHA1_CTX*, int);
+
+/* function to disable or enable the use of Collision Detection */
+/* enabled by default */
+void SHA1DCSetUseDetectColl(SHA1_CTX*, int);
+
+/* function to disable or enable the detection of reduced-round SHA-1 collisions */
+/* disabled by default */
+void SHA1DCSetDetectReducedRoundCollision(SHA1_CTX*, int);
+
+/* function to set a callback function, pass NULL to disable */
+/* by default no callback set */
+void SHA1DCSetCallback(SHA1_CTX*, collision_block_callback);
+
+/* update SHA-1 context with buffer contents */
+void SHA1DCUpdate(SHA1_CTX*, const char*, size_t);
+
+/* obtain SHA-1 hash from SHA-1 context */
+/* returns: 0 = no collision detected, otherwise = collision found => warn user for active attack */
+int  SHA1DCFinal(unsigned char[20], SHA1_CTX*);
+
+/*
+ * Same as SHA1DCFinal, but convert collision attack case into a verbose die().
+ */
+void git_SHA1DCFinal(unsigned char [20], SHA1_CTX *);
+
+/*
+ * Same as SHA1DCUpdate, but adjust types to match git's usual interface.
+ */
+void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *data, unsigned long len);
+
+#define platform_SHA_CTX SHA1_CTX
+#define platform_SHA1_Init SHA1DCInit
+#define platform_SHA1_Update git_SHA1DCUpdate
+#define platform_SHA1_Final git_SHA1DCFinal
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* SHA1DC_SHA1_H */
diff --git a/sha1dc/ubc_check.c b/sha1dc/ubc_check.c
new file mode 100644
index 0000000..089dd47
--- /dev/null
+++ b/sha1dc/ubc_check.c
@@ -0,0 +1,363 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com>
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+/*
+// this file was generated by the 'parse_bitrel' program in the tools section
+// using the data files from directory 'tools/data/3565'
+//
+// sha1_dvs contains a list of SHA-1 Disturbance Vectors (DV) to check
+// dvType, dvK and dvB define the DV: I(K,B) or II(K,B) (see the paper)
+// dm[80] is the expanded message block XOR-difference defined by the DV
+// testt is the step to do the recompression from for collision detection
+// maski and maskb define the bit to check for each DV in the dvmask returned by ubc_check
+//
+// ubc_check takes as input an expanded message block and verifies the unavoidable bitconditions for all listed DVs
+// it returns a dvmask where each bit belonging to a DV is set if all unavoidable bitconditions for that DV have been met
+// thus one needs to do the recompression check for each DV that has its bit set
+//
+// ubc_check is programmatically generated and the unavoidable bitconditions have been hardcoded
+// a directly verifiable version named ubc_check_verify can be found in ubc_check_verify.c
+// ubc_check has been verified against ubc_check_verify using the 'ubc_check_test' program in the tools section
+*/
+
+#include "git-compat-util.h"
+#include "sha1dc/ubc_check.h"
+
+static const uint32_t DV_I_43_0_bit 	= (uint32_t)(1) << 0;
+static const uint32_t DV_I_44_0_bit 	= (uint32_t)(1) << 1;
+static const uint32_t DV_I_45_0_bit 	= (uint32_t)(1) << 2;
+static const uint32_t DV_I_46_0_bit 	= (uint32_t)(1) << 3;
+static const uint32_t DV_I_46_2_bit 	= (uint32_t)(1) << 4;
+static const uint32_t DV_I_47_0_bit 	= (uint32_t)(1) << 5;
+static const uint32_t DV_I_47_2_bit 	= (uint32_t)(1) << 6;
+static const uint32_t DV_I_48_0_bit 	= (uint32_t)(1) << 7;
+static const uint32_t DV_I_48_2_bit 	= (uint32_t)(1) << 8;
+static const uint32_t DV_I_49_0_bit 	= (uint32_t)(1) << 9;
+static const uint32_t DV_I_49_2_bit 	= (uint32_t)(1) << 10;
+static const uint32_t DV_I_50_0_bit 	= (uint32_t)(1) << 11;
+static const uint32_t DV_I_50_2_bit 	= (uint32_t)(1) << 12;
+static const uint32_t DV_I_51_0_bit 	= (uint32_t)(1) << 13;
+static const uint32_t DV_I_51_2_bit 	= (uint32_t)(1) << 14;
+static const uint32_t DV_I_52_0_bit 	= (uint32_t)(1) << 15;
+static const uint32_t DV_II_45_0_bit 	= (uint32_t)(1) << 16;
+static const uint32_t DV_II_46_0_bit 	= (uint32_t)(1) << 17;
+static const uint32_t DV_II_46_2_bit 	= (uint32_t)(1) << 18;
+static const uint32_t DV_II_47_0_bit 	= (uint32_t)(1) << 19;
+static const uint32_t DV_II_48_0_bit 	= (uint32_t)(1) << 20;
+static const uint32_t DV_II_49_0_bit 	= (uint32_t)(1) << 21;
+static const uint32_t DV_II_49_2_bit 	= (uint32_t)(1) << 22;
+static const uint32_t DV_II_50_0_bit 	= (uint32_t)(1) << 23;
+static const uint32_t DV_II_50_2_bit 	= (uint32_t)(1) << 24;
+static const uint32_t DV_II_51_0_bit 	= (uint32_t)(1) << 25;
+static const uint32_t DV_II_51_2_bit 	= (uint32_t)(1) << 26;
+static const uint32_t DV_II_52_0_bit 	= (uint32_t)(1) << 27;
+static const uint32_t DV_II_53_0_bit 	= (uint32_t)(1) << 28;
+static const uint32_t DV_II_54_0_bit 	= (uint32_t)(1) << 29;
+static const uint32_t DV_II_55_0_bit 	= (uint32_t)(1) << 30;
+static const uint32_t DV_II_56_0_bit 	= (uint32_t)(1) << 31;
+
+dv_info_t sha1_dvs[] =
+{
+  {1,43,0,58,0,0, { 0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c,0x00000803,0x80000161,0x80000599 } }
+, {1,44,0,58,0,1, { 0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c,0x00000803,0x80000161 } }
+, {1,45,0,58,0,2, { 0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c,0x00000803 } }
+, {1,46,0,58,0,3, { 0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6,0x8000004c } }
+, {1,46,2,58,0,4, { 0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590,0x00001020,0x0000039a,0x00000132 } }
+, {1,47,0,58,0,5, { 0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408,0x800000e6 } }
+, {1,47,2,58,0,6, { 0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590,0x00001020,0x0000039a } }
+, {1,48,0,58,0,7, { 0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164,0x00000408 } }
+, {1,48,2,58,0,8, { 0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590,0x00001020 } }
+, {1,49,0,58,0,9, { 0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018,0x00000164 } }
+, {1,49,2,58,0,10, { 0x60000000,0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060,0x00000590 } }
+, {1,50,0,65,0,11, { 0x0800000c,0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202,0x00000018 } }
+, {1,50,2,65,0,12, { 0x20000030,0x60000000,0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a,0x00000060 } }
+, {1,51,0,65,0,13, { 0xe8000000,0x0800000c,0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012,0x80000202 } }
+, {1,51,2,65,0,14, { 0xa0000003,0x20000030,0x60000000,0xe000002a,0x20000043,0xb0000040,0xd0000053,0xd0000022,0x20000000,0x60000032,0x60000043,0x20000040,0xe0000042,0x60000002,0x80000001,0x00000020,0x00000003,0x40000052,0x40000040,0xe0000052,0xa0000000,0x80000040,0x20000001,0x20000060,0x80000001,0x40000042,0xc0000043,0x40000022,0x00000003,0x40000042,0xc0000043,0xc0000022,0x00000001,0x40000002,0xc0000043,0x40000062,0x80000001,0x40000042,0x40000042,0x40000002,0x00000002,0x00000040,0x80000002,0x80000000,0x80000002,0x80000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000000,0x00000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000101,0x00000009,0x00000012,0x00000202,0x0000001a,0x00000124,0x0000040c,0x00000026,0x0000004a,0x0000080a } }
+, {1,52,0,65,0,15, { 0x04000010,0xe8000000,0x0800000c,0x18000000,0xb800000a,0xc8000010,0x2c000010,0xf4000014,0xb4000008,0x08000000,0x9800000c,0xd8000010,0x08000010,0xb8000010,0x98000000,0x60000000,0x00000008,0xc0000000,0x90000014,0x10000010,0xb8000014,0x28000000,0x20000010,0x48000000,0x08000018,0x60000000,0x90000010,0xf0000010,0x90000008,0xc0000000,0x90000010,0xf0000010,0xb0000008,0x40000000,0x90000000,0xf0000010,0x90000018,0x60000000,0x90000010,0x90000010,0x90000000,0x80000000,0x00000010,0xa0000000,0x20000000,0xa0000000,0x20000010,0x00000000,0x20000010,0x20000000,0x00000010,0x20000000,0x00000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000040,0x40000002,0x80000004,0x80000080,0x80000006,0x00000049,0x00000103,0x80000009,0x80000012 } }
+, {2,45,0,58,0,16, { 0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a,0x000002e4,0x80000054,0x00000967 } }
+, {2,46,0,58,0,17, { 0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a,0x000002e4,0x80000054 } }
+, {2,46,2,58,0,18, { 0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e,0x0000046c,0x000005b6,0x0000106a,0x00000b90,0x00000152 } }
+, {2,47,0,58,0,19, { 0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a,0x000002e4 } }
+, {2,48,0,58,0,20, { 0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d,0x8000041a } }
+, {2,49,0,58,0,21, { 0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b,0x8000016d } }
+, {2,49,2,58,0,22, { 0xf0000010,0xf000006a,0x80000040,0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e,0x0000046c,0x000005b6 } }
+, {2,50,0,65,0,23, { 0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b,0x0000011b } }
+, {2,50,2,65,0,24, { 0xd0000072,0xf0000010,0xf000006a,0x80000040,0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e,0x0000046c } }
+, {2,51,0,65,0,25, { 0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014,0x8000024b } }
+, {2,51,2,65,0,26, { 0x00000043,0xd0000072,0xf0000010,0xf000006a,0x80000040,0x90000070,0xb0000053,0x30000008,0x00000043,0xd0000072,0xb0000010,0xf0000062,0xc0000042,0x00000030,0xe0000042,0x20000060,0xe0000041,0x20000050,0xc0000041,0xe0000072,0xa0000003,0xc0000012,0x60000041,0xc0000032,0x20000001,0xc0000002,0xe0000042,0x60000042,0x80000002,0x00000000,0x00000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000000,0x00000040,0x80000001,0x00000060,0x80000003,0x40000002,0xc0000040,0xc0000002,0x80000000,0x80000000,0x80000002,0x00000040,0x00000002,0x80000000,0x80000000,0x80000000,0x00000002,0x00000040,0x00000000,0x80000040,0x80000002,0x00000000,0x80000000,0x80000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000004,0x00000080,0x00000004,0x00000009,0x00000105,0x00000089,0x00000016,0x0000020b,0x0000011b,0x0000012d,0x0000041e,0x00000224,0x00000050,0x0000092e } }
+, {2,52,0,65,0,27, { 0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089,0x00000014 } }
+, {2,53,0,65,0,28, { 0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107,0x00000089 } }
+, {2,54,0,65,0,29, { 0x0400001c,0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b,0x80000107 } }
+, {2,55,0,65,0,30, { 0x00000010,0x0400001c,0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046,0x4000004b } }
+, {2,56,0,65,0,31, { 0x2600001a,0x00000010,0x0400001c,0xcc000014,0x0c000002,0xc0000010,0xb400001c,0x3c000004,0xbc00001a,0x20000010,0x2400001c,0xec000014,0x0c000002,0xc0000010,0xb400001c,0x2c000004,0xbc000018,0xb0000010,0x0000000c,0xb8000010,0x08000018,0x78000010,0x08000014,0x70000010,0xb800001c,0xe8000000,0xb0000004,0x58000010,0xb000000c,0x48000000,0xb0000000,0xb8000010,0x98000010,0xa0000000,0x00000000,0x00000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0x20000000,0x00000010,0x60000000,0x00000018,0xe0000000,0x90000000,0x30000010,0xb0000000,0x20000000,0x20000000,0xa0000000,0x00000010,0x80000000,0x20000000,0x20000000,0x20000000,0x80000000,0x00000010,0x00000000,0x20000010,0xa0000000,0x00000000,0x20000000,0x20000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000001,0x00000020,0x00000001,0x40000002,0x40000041,0x40000022,0x80000005,0xc0000082,0xc0000046 } }
+, {0,0,0,0,0,0, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}
+};
+void ubc_check(const uint32_t W[80], uint32_t dvmask[1])
+{
+	uint32_t mask = ~((uint32_t)(0));
+	mask &= (((((W[44]^W[45])>>29)&1)-1) | ~(DV_I_48_0_bit|DV_I_51_0_bit|DV_I_52_0_bit|DV_II_45_0_bit|DV_II_46_0_bit|DV_II_50_0_bit|DV_II_51_0_bit));
+	mask &= (((((W[49]^W[50])>>29)&1)-1) | ~(DV_I_46_0_bit|DV_II_45_0_bit|DV_II_50_0_bit|DV_II_51_0_bit|DV_II_55_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[48]^W[49])>>29)&1)-1) | ~(DV_I_45_0_bit|DV_I_52_0_bit|DV_II_49_0_bit|DV_II_50_0_bit|DV_II_54_0_bit|DV_II_55_0_bit));
+	mask &= ((((W[47]^(W[50]>>25))&(1<<4))-(1<<4)) | ~(DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_51_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[47]^W[48])>>29)&1)-1) | ~(DV_I_44_0_bit|DV_I_51_0_bit|DV_II_48_0_bit|DV_II_49_0_bit|DV_II_53_0_bit|DV_II_54_0_bit));
+	mask &= (((((W[46]>>4)^(W[49]>>29))&1)-1) | ~(DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit|DV_II_50_0_bit|DV_II_55_0_bit));
+	mask &= (((((W[46]^W[47])>>29)&1)-1) | ~(DV_I_43_0_bit|DV_I_50_0_bit|DV_II_47_0_bit|DV_II_48_0_bit|DV_II_52_0_bit|DV_II_53_0_bit));
+	mask &= (((((W[45]>>4)^(W[48]>>29))&1)-1) | ~(DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit|DV_II_49_0_bit|DV_II_54_0_bit));
+	mask &= (((((W[45]^W[46])>>29)&1)-1) | ~(DV_I_49_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_47_0_bit|DV_II_51_0_bit|DV_II_52_0_bit));
+	mask &= (((((W[44]>>4)^(W[47]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit|DV_II_48_0_bit|DV_II_53_0_bit));
+	mask &= (((((W[43]>>4)^(W[46]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit|DV_II_47_0_bit|DV_II_52_0_bit));
+	mask &= (((((W[43]^W[44])>>29)&1)-1) | ~(DV_I_47_0_bit|DV_I_50_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_49_0_bit|DV_II_50_0_bit));
+	mask &= (((((W[42]>>4)^(W[45]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_51_0_bit));
+	mask &= (((((W[41]>>4)^(W[44]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_50_0_bit));
+	mask &= (((((W[40]^W[41])>>29)&1)-1) | ~(DV_I_44_0_bit|DV_I_47_0_bit|DV_I_48_0_bit|DV_II_46_0_bit|DV_II_47_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[54]^W[55])>>29)&1)-1) | ~(DV_I_51_0_bit|DV_II_47_0_bit|DV_II_50_0_bit|DV_II_55_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[53]^W[54])>>29)&1)-1) | ~(DV_I_50_0_bit|DV_II_46_0_bit|DV_II_49_0_bit|DV_II_54_0_bit|DV_II_55_0_bit));
+	mask &= (((((W[52]^W[53])>>29)&1)-1) | ~(DV_I_49_0_bit|DV_II_45_0_bit|DV_II_48_0_bit|DV_II_53_0_bit|DV_II_54_0_bit));
+	mask &= ((((W[50]^(W[53]>>25))&(1<<4))-(1<<4)) | ~(DV_I_50_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_48_0_bit|DV_II_54_0_bit));
+	mask &= (((((W[50]^W[51])>>29)&1)-1) | ~(DV_I_47_0_bit|DV_II_46_0_bit|DV_II_51_0_bit|DV_II_52_0_bit|DV_II_56_0_bit));
+	mask &= ((((W[49]^(W[52]>>25))&(1<<4))-(1<<4)) | ~(DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit|DV_II_47_0_bit|DV_II_53_0_bit));
+	mask &= ((((W[48]^(W[51]>>25))&(1<<4))-(1<<4)) | ~(DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit|DV_II_46_0_bit|DV_II_52_0_bit));
+	mask &= (((((W[42]^W[43])>>29)&1)-1) | ~(DV_I_46_0_bit|DV_I_49_0_bit|DV_I_50_0_bit|DV_II_48_0_bit|DV_II_49_0_bit));
+	mask &= (((((W[41]^W[42])>>29)&1)-1) | ~(DV_I_45_0_bit|DV_I_48_0_bit|DV_I_49_0_bit|DV_II_47_0_bit|DV_II_48_0_bit));
+	mask &= (((((W[40]>>4)^(W[43]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_50_0_bit|DV_II_49_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[39]>>4)^(W[42]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_49_0_bit|DV_II_48_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_44_0_bit|DV_I_48_0_bit|DV_II_47_0_bit|DV_II_54_0_bit|DV_II_56_0_bit))
+		mask &= (((((W[38]>>4)^(W[41]>>29))&1)-1) | ~(DV_I_44_0_bit|DV_I_48_0_bit|DV_II_47_0_bit|DV_II_54_0_bit|DV_II_56_0_bit));
+	mask &= (((((W[37]>>4)^(W[40]>>29))&1)-1) | ~(DV_I_43_0_bit|DV_I_47_0_bit|DV_II_46_0_bit|DV_II_53_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_48_0_bit|DV_II_51_0_bit|DV_II_56_0_bit))
+		mask &= (((((W[55]^W[56])>>29)&1)-1) | ~(DV_I_52_0_bit|DV_II_48_0_bit|DV_II_51_0_bit|DV_II_56_0_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_48_0_bit|DV_II_50_0_bit|DV_II_56_0_bit))
+		mask &= ((((W[52]^(W[55]>>25))&(1<<4))-(1<<4)) | ~(DV_I_52_0_bit|DV_II_48_0_bit|DV_II_50_0_bit|DV_II_56_0_bit));
+	if (mask & (DV_I_51_0_bit|DV_II_47_0_bit|DV_II_49_0_bit|DV_II_55_0_bit))
+		mask &= ((((W[51]^(W[54]>>25))&(1<<4))-(1<<4)) | ~(DV_I_51_0_bit|DV_II_47_0_bit|DV_II_49_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_48_0_bit|DV_II_47_0_bit|DV_II_52_0_bit|DV_II_53_0_bit))
+		mask &= (((((W[51]^W[52])>>29)&1)-1) | ~(DV_I_48_0_bit|DV_II_47_0_bit|DV_II_52_0_bit|DV_II_53_0_bit));
+	if (mask & (DV_I_46_0_bit|DV_I_49_0_bit|DV_II_45_0_bit|DV_II_48_0_bit))
+		mask &= (((((W[36]>>4)^(W[40]>>29))&1)-1) | ~(DV_I_46_0_bit|DV_I_49_0_bit|DV_II_45_0_bit|DV_II_48_0_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_48_0_bit|DV_II_49_0_bit))
+		mask &= ((0-(((W[53]^W[56])>>29)&1)) | ~(DV_I_52_0_bit|DV_II_48_0_bit|DV_II_49_0_bit));
+	if (mask & (DV_I_50_0_bit|DV_II_46_0_bit|DV_II_47_0_bit))
+		mask &= ((0-(((W[51]^W[54])>>29)&1)) | ~(DV_I_50_0_bit|DV_II_46_0_bit|DV_II_47_0_bit));
+	if (mask & (DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit))
+		mask &= ((0-(((W[50]^W[52])>>29)&1)) | ~(DV_I_49_0_bit|DV_I_51_0_bit|DV_II_45_0_bit));
+	if (mask & (DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit))
+		mask &= ((0-(((W[49]^W[51])>>29)&1)) | ~(DV_I_48_0_bit|DV_I_50_0_bit|DV_I_52_0_bit));
+	if (mask & (DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit))
+		mask &= ((0-(((W[48]^W[50])>>29)&1)) | ~(DV_I_47_0_bit|DV_I_49_0_bit|DV_I_51_0_bit));
+	if (mask & (DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit))
+		mask &= ((0-(((W[47]^W[49])>>29)&1)) | ~(DV_I_46_0_bit|DV_I_48_0_bit|DV_I_50_0_bit));
+	if (mask & (DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit))
+		mask &= ((0-(((W[46]^W[48])>>29)&1)) | ~(DV_I_45_0_bit|DV_I_47_0_bit|DV_I_49_0_bit));
+	mask &= ((((W[45]^W[47])&(1<<6))-(1<<6)) | ~(DV_I_47_2_bit|DV_I_49_2_bit|DV_I_51_2_bit));
+	if (mask & (DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit))
+		mask &= ((0-(((W[45]^W[47])>>29)&1)) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_I_48_0_bit));
+	mask &= (((((W[44]^W[46])>>6)&1)-1) | ~(DV_I_46_2_bit|DV_I_48_2_bit|DV_I_50_2_bit));
+	if (mask & (DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit))
+		mask &= ((0-(((W[44]^W[46])>>29)&1)) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_I_47_0_bit));
+	mask &= ((0-((W[41]^(W[42]>>5))&(1<<1))) | ~(DV_I_48_2_bit|DV_II_46_2_bit|DV_II_51_2_bit));
+	mask &= ((0-((W[40]^(W[41]>>5))&(1<<1))) | ~(DV_I_47_2_bit|DV_I_51_2_bit|DV_II_50_2_bit));
+	if (mask & (DV_I_44_0_bit|DV_I_46_0_bit|DV_II_56_0_bit))
+		mask &= ((0-(((W[40]^W[42])>>4)&1)) | ~(DV_I_44_0_bit|DV_I_46_0_bit|DV_II_56_0_bit));
+	mask &= ((0-((W[39]^(W[40]>>5))&(1<<1))) | ~(DV_I_46_2_bit|DV_I_50_2_bit|DV_II_49_2_bit));
+	if (mask & (DV_I_43_0_bit|DV_I_45_0_bit|DV_II_55_0_bit))
+		mask &= ((0-(((W[39]^W[41])>>4)&1)) | ~(DV_I_43_0_bit|DV_I_45_0_bit|DV_II_55_0_bit));
+	if (mask & (DV_I_44_0_bit|DV_II_54_0_bit|DV_II_56_0_bit))
+		mask &= ((0-(((W[38]^W[40])>>4)&1)) | ~(DV_I_44_0_bit|DV_II_54_0_bit|DV_II_56_0_bit));
+	if (mask & (DV_I_43_0_bit|DV_II_53_0_bit|DV_II_55_0_bit))
+		mask &= ((0-(((W[37]^W[39])>>4)&1)) | ~(DV_I_43_0_bit|DV_II_53_0_bit|DV_II_55_0_bit));
+	mask &= ((0-((W[36]^(W[37]>>5))&(1<<1))) | ~(DV_I_47_2_bit|DV_I_50_2_bit|DV_II_46_2_bit));
+	if (mask & (DV_I_45_0_bit|DV_I_48_0_bit|DV_II_47_0_bit))
+		mask &= (((((W[35]>>4)^(W[39]>>29))&1)-1) | ~(DV_I_45_0_bit|DV_I_48_0_bit|DV_II_47_0_bit));
+	if (mask & (DV_I_48_0_bit|DV_II_48_0_bit))
+		mask &= ((0-((W[63]^(W[64]>>5))&(1<<0))) | ~(DV_I_48_0_bit|DV_II_48_0_bit));
+	if (mask & (DV_I_45_0_bit|DV_II_45_0_bit))
+		mask &= ((0-((W[63]^(W[64]>>5))&(1<<1))) | ~(DV_I_45_0_bit|DV_II_45_0_bit));
+	if (mask & (DV_I_47_0_bit|DV_II_47_0_bit))
+		mask &= ((0-((W[62]^(W[63]>>5))&(1<<0))) | ~(DV_I_47_0_bit|DV_II_47_0_bit));
+	if (mask & (DV_I_46_0_bit|DV_II_46_0_bit))
+		mask &= ((0-((W[61]^(W[62]>>5))&(1<<0))) | ~(DV_I_46_0_bit|DV_II_46_0_bit));
+	mask &= ((0-((W[61]^(W[62]>>5))&(1<<2))) | ~(DV_I_46_2_bit|DV_II_46_2_bit));
+	if (mask & (DV_I_45_0_bit|DV_II_45_0_bit))
+		mask &= ((0-((W[60]^(W[61]>>5))&(1<<0))) | ~(DV_I_45_0_bit|DV_II_45_0_bit));
+	if (mask & (DV_II_51_0_bit|DV_II_54_0_bit))
+		mask &= (((((W[58]^W[59])>>29)&1)-1) | ~(DV_II_51_0_bit|DV_II_54_0_bit));
+	if (mask & (DV_II_50_0_bit|DV_II_53_0_bit))
+		mask &= (((((W[57]^W[58])>>29)&1)-1) | ~(DV_II_50_0_bit|DV_II_53_0_bit));
+	if (mask & (DV_II_52_0_bit|DV_II_54_0_bit))
+		mask &= ((((W[56]^(W[59]>>25))&(1<<4))-(1<<4)) | ~(DV_II_52_0_bit|DV_II_54_0_bit));
+	if (mask & (DV_II_51_0_bit|DV_II_52_0_bit))
+		mask &= ((0-(((W[56]^W[59])>>29)&1)) | ~(DV_II_51_0_bit|DV_II_52_0_bit));
+	if (mask & (DV_II_49_0_bit|DV_II_52_0_bit))
+		mask &= (((((W[56]^W[57])>>29)&1)-1) | ~(DV_II_49_0_bit|DV_II_52_0_bit));
+	if (mask & (DV_II_51_0_bit|DV_II_53_0_bit))
+		mask &= ((((W[55]^(W[58]>>25))&(1<<4))-(1<<4)) | ~(DV_II_51_0_bit|DV_II_53_0_bit));
+	if (mask & (DV_II_50_0_bit|DV_II_52_0_bit))
+		mask &= ((((W[54]^(W[57]>>25))&(1<<4))-(1<<4)) | ~(DV_II_50_0_bit|DV_II_52_0_bit));
+	if (mask & (DV_II_49_0_bit|DV_II_51_0_bit))
+		mask &= ((((W[53]^(W[56]>>25))&(1<<4))-(1<<4)) | ~(DV_II_49_0_bit|DV_II_51_0_bit));
+	mask &= ((((W[51]^(W[50]>>5))&(1<<1))-(1<<1)) | ~(DV_I_50_2_bit|DV_II_46_2_bit));
+	mask &= ((((W[48]^W[50])&(1<<6))-(1<<6)) | ~(DV_I_50_2_bit|DV_II_46_2_bit));
+	if (mask & (DV_I_51_0_bit|DV_I_52_0_bit))
+		mask &= ((0-(((W[48]^W[55])>>29)&1)) | ~(DV_I_51_0_bit|DV_I_52_0_bit));
+	mask &= ((((W[47]^W[49])&(1<<6))-(1<<6)) | ~(DV_I_49_2_bit|DV_I_51_2_bit));
+	mask &= ((((W[48]^(W[47]>>5))&(1<<1))-(1<<1)) | ~(DV_I_47_2_bit|DV_II_51_2_bit));
+	mask &= ((((W[46]^W[48])&(1<<6))-(1<<6)) | ~(DV_I_48_2_bit|DV_I_50_2_bit));
+	mask &= ((((W[47]^(W[46]>>5))&(1<<1))-(1<<1)) | ~(DV_I_46_2_bit|DV_II_50_2_bit));
+	mask &= ((0-((W[44]^(W[45]>>5))&(1<<1))) | ~(DV_I_51_2_bit|DV_II_49_2_bit));
+	mask &= ((((W[43]^W[45])&(1<<6))-(1<<6)) | ~(DV_I_47_2_bit|DV_I_49_2_bit));
+	mask &= (((((W[42]^W[44])>>6)&1)-1) | ~(DV_I_46_2_bit|DV_I_48_2_bit));
+	mask &= ((((W[43]^(W[42]>>5))&(1<<1))-(1<<1)) | ~(DV_II_46_2_bit|DV_II_51_2_bit));
+	mask &= ((((W[42]^(W[41]>>5))&(1<<1))-(1<<1)) | ~(DV_I_51_2_bit|DV_II_50_2_bit));
+	mask &= ((((W[41]^(W[40]>>5))&(1<<1))-(1<<1)) | ~(DV_I_50_2_bit|DV_II_49_2_bit));
+	if (mask & (DV_I_52_0_bit|DV_II_51_0_bit))
+		mask &= ((((W[39]^(W[43]>>25))&(1<<4))-(1<<4)) | ~(DV_I_52_0_bit|DV_II_51_0_bit));
+	if (mask & (DV_I_51_0_bit|DV_II_50_0_bit))
+		mask &= ((((W[38]^(W[42]>>25))&(1<<4))-(1<<4)) | ~(DV_I_51_0_bit|DV_II_50_0_bit));
+	if (mask & (DV_I_48_2_bit|DV_I_51_2_bit))
+		mask &= ((0-((W[37]^(W[38]>>5))&(1<<1))) | ~(DV_I_48_2_bit|DV_I_51_2_bit));
+	if (mask & (DV_I_50_0_bit|DV_II_49_0_bit))
+		mask &= ((((W[37]^(W[41]>>25))&(1<<4))-(1<<4)) | ~(DV_I_50_0_bit|DV_II_49_0_bit));
+	if (mask & (DV_II_52_0_bit|DV_II_54_0_bit))
+		mask &= ((0-((W[36]^W[38])&(1<<4))) | ~(DV_II_52_0_bit|DV_II_54_0_bit));
+	mask &= ((0-((W[35]^(W[36]>>5))&(1<<1))) | ~(DV_I_46_2_bit|DV_I_49_2_bit));
+	if (mask & (DV_I_51_0_bit|DV_II_47_0_bit))
+		mask &= ((((W[35]^(W[39]>>25))&(1<<3))-(1<<3)) | ~(DV_I_51_0_bit|DV_II_47_0_bit));
+if (mask) {
+
+	if (mask & DV_I_43_0_bit)
+		 if (
+			    !((W[61]^(W[62]>>5)) & (1<<1))
+			 || !(!((W[59]^(W[63]>>25)) & (1<<5)))
+			 || !((W[58]^(W[63]>>30)) & (1<<0))
+		 )  mask &= ~DV_I_43_0_bit;
+	if (mask & DV_I_44_0_bit)
+		 if (
+			    !((W[62]^(W[63]>>5)) & (1<<1))
+			 || !(!((W[60]^(W[64]>>25)) & (1<<5)))
+			 || !((W[59]^(W[64]>>30)) & (1<<0))
+		 )  mask &= ~DV_I_44_0_bit;
+	if (mask & DV_I_46_2_bit)
+		mask &= ((~((W[40]^W[42])>>2)) | ~DV_I_46_2_bit);
+	if (mask & DV_I_47_2_bit)
+		 if (
+			    !((W[62]^(W[63]>>5)) & (1<<2))
+			 || !(!((W[41]^W[43]) & (1<<6)))
+		 )  mask &= ~DV_I_47_2_bit;
+	if (mask & DV_I_48_2_bit)
+		 if (
+			    !((W[63]^(W[64]>>5)) & (1<<2))
+			 || !(!((W[48]^(W[49]<<5)) & (1<<6)))
+		 )  mask &= ~DV_I_48_2_bit;
+	if (mask & DV_I_49_2_bit)
+		 if (
+			    !(!((W[49]^(W[50]<<5)) & (1<<6)))
+			 || !((W[42]^W[50]) & (1<<1))
+			 || !(!((W[39]^(W[40]<<5)) & (1<<6)))
+			 || !((W[38]^W[40]) & (1<<1))
+		 )  mask &= ~DV_I_49_2_bit;
+	if (mask & DV_I_50_0_bit)
+		mask &= ((((W[36]^W[37])<<7)) | ~DV_I_50_0_bit);
+	if (mask & DV_I_50_2_bit)
+		mask &= ((((W[43]^W[51])<<11)) | ~DV_I_50_2_bit);
+	if (mask & DV_I_51_0_bit)
+		mask &= ((((W[37]^W[38])<<9)) | ~DV_I_51_0_bit);
+	if (mask & DV_I_51_2_bit)
+		 if (
+			    !(!((W[51]^(W[52]<<5)) & (1<<6)))
+			 || !(!((W[49]^W[51]) & (1<<6)))
+			 || !(!((W[37]^(W[37]>>5)) & (1<<1)))
+			 || !(!((W[35]^(W[39]>>25)) & (1<<5)))
+		 )  mask &= ~DV_I_51_2_bit;
+	if (mask & DV_I_52_0_bit)
+		mask &= ((((W[38]^W[39])<<11)) | ~DV_I_52_0_bit);
+	if (mask & DV_II_46_2_bit)
+		mask &= ((((W[47]^W[51])<<17)) | ~DV_II_46_2_bit);
+	if (mask & DV_II_48_0_bit)
+		 if (
+			    !(!((W[36]^(W[40]>>25)) & (1<<3)))
+			 || !((W[35]^(W[40]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_48_0_bit;
+	if (mask & DV_II_49_0_bit)
+		 if (
+			    !(!((W[37]^(W[41]>>25)) & (1<<3)))
+			 || !((W[36]^(W[41]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_49_0_bit;
+	if (mask & DV_II_49_2_bit)
+		 if (
+			    !(!((W[53]^(W[54]<<5)) & (1<<6)))
+			 || !(!((W[51]^W[53]) & (1<<6)))
+			 || !((W[50]^W[54]) & (1<<1))
+			 || !(!((W[45]^(W[46]<<5)) & (1<<6)))
+			 || !(!((W[37]^(W[41]>>25)) & (1<<5)))
+			 || !((W[36]^(W[41]>>30)) & (1<<0))
+		 )  mask &= ~DV_II_49_2_bit;
+	if (mask & DV_II_50_0_bit)
+		 if (
+			    !((W[55]^W[58]) & (1<<29))
+			 || !(!((W[38]^(W[42]>>25)) & (1<<3)))
+			 || !((W[37]^(W[42]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_50_0_bit;
+	if (mask & DV_II_50_2_bit)
+		 if (
+			    !(!((W[54]^(W[55]<<5)) & (1<<6)))
+			 || !(!((W[52]^W[54]) & (1<<6)))
+			 || !((W[51]^W[55]) & (1<<1))
+			 || !((W[45]^W[47]) & (1<<1))
+			 || !(!((W[38]^(W[42]>>25)) & (1<<5)))
+			 || !((W[37]^(W[42]>>30)) & (1<<0))
+		 )  mask &= ~DV_II_50_2_bit;
+	if (mask & DV_II_51_0_bit)
+		 if (
+			    !(!((W[39]^(W[43]>>25)) & (1<<3)))
+			 || !((W[38]^(W[43]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_51_0_bit;
+	if (mask & DV_II_51_2_bit)
+		 if (
+			    !(!((W[55]^(W[56]<<5)) & (1<<6)))
+			 || !(!((W[53]^W[55]) & (1<<6)))
+			 || !((W[52]^W[56]) & (1<<1))
+			 || !((W[46]^W[48]) & (1<<1))
+			 || !(!((W[39]^(W[43]>>25)) & (1<<5)))
+			 || !((W[38]^(W[43]>>30)) & (1<<0))
+		 )  mask &= ~DV_II_51_2_bit;
+	if (mask & DV_II_52_0_bit)
+		 if (
+			    !(!((W[59]^W[60]) & (1<<29)))
+			 || !(!((W[40]^(W[44]>>25)) & (1<<3)))
+			 || !(!((W[40]^(W[44]>>25)) & (1<<4)))
+			 || !((W[39]^(W[44]<<2)) & (1<<30))
+		 )  mask &= ~DV_II_52_0_bit;
+	if (mask & DV_II_53_0_bit)
+		 if (
+			    !((W[58]^W[61]) & (1<<29))
+			 || !(!((W[57]^(W[61]>>25)) & (1<<4)))
+			 || !(!((W[41]^(W[45]>>25)) & (1<<3)))
+			 || !(!((W[41]^(W[45]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_53_0_bit;
+	if (mask & DV_II_54_0_bit)
+		 if (
+			    !(!((W[58]^(W[62]>>25)) & (1<<4)))
+			 || !(!((W[42]^(W[46]>>25)) & (1<<3)))
+			 || !(!((W[42]^(W[46]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_54_0_bit;
+	if (mask & DV_II_55_0_bit)
+		 if (
+			    !(!((W[59]^(W[63]>>25)) & (1<<4)))
+			 || !(!((W[57]^(W[59]>>25)) & (1<<4)))
+			 || !(!((W[43]^(W[47]>>25)) & (1<<3)))
+			 || !(!((W[43]^(W[47]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_55_0_bit;
+	if (mask & DV_II_56_0_bit)
+		 if (
+			    !(!((W[60]^(W[64]>>25)) & (1<<4)))
+			 || !(!((W[44]^(W[48]>>25)) & (1<<3)))
+			 || !(!((W[44]^(W[48]>>25)) & (1<<4)))
+		 )  mask &= ~DV_II_56_0_bit;
+}
+
+	dvmask[0]=mask;
+}
diff --git a/sha1dc/ubc_check.h b/sha1dc/ubc_check.h
new file mode 100644
index 0000000..b64c306
--- /dev/null
+++ b/sha1dc/ubc_check.h
@@ -0,0 +1,44 @@
+/***
+* Copyright 2017 Marc Stevens <marc@marc-stevens.nl>, Dan Shumow <danshu@microsoft.com>
+* Distributed under the MIT Software License.
+* See accompanying file LICENSE.txt or copy at
+* https://opensource.org/licenses/MIT
+***/
+
+/*
+// this file was generated by the 'parse_bitrel' program in the tools section
+// using the data files from directory 'tools/data/3565'
+//
+// sha1_dvs contains a list of SHA-1 Disturbance Vectors (DV) to check
+// dvType, dvK and dvB define the DV: I(K,B) or II(K,B) (see the paper)
+// dm[80] is the expanded message block XOR-difference defined by the DV
+// testt is the step to do the recompression from for collision detection
+// maski and maskb define the bit to check for each DV in the dvmask returned by ubc_check
+//
+// ubc_check takes as input an expanded message block and verifies the unavoidable bitconditions for all listed DVs
+// it returns a dvmask where each bit belonging to a DV is set if all unavoidable bitconditions for that DV have been met
+// thus one needs to do the recompression check for each DV that has its bit set
+*/
+
+#ifndef UBC_CHECK_H
+#define UBC_CHECK_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#define DVMASKSIZE 1
+typedef struct { int dvType; int dvK; int dvB; int testt; int maski; int maskb; uint32_t dm[80]; } dv_info_t;
+extern dv_info_t sha1_dvs[];
+void ubc_check(const uint32_t W[80], uint32_t dvmask[DVMASKSIZE]);
+
+#define DOSTORESTATE58
+#define DOSTORESTATE65
+
+#define CHECK_DVMASK(_DVMASK) (0 != _DVMASK[0])
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* UBC_CHECK_H */
diff --git a/split-index.c b/split-index.c
index 615f4ca..f519e60 100644
--- a/split-index.c
+++ b/split-index.c
@@ -317,3 +317,25 @@
 		istate->split_index->base->cache[new->index - 1] = new;
 	}
 }
+
+void add_split_index(struct index_state *istate)
+{
+	if (!istate->split_index) {
+		init_split_index(istate);
+		istate->cache_changed |= SPLIT_INDEX_ORDERED;
+	}
+}
+
+void remove_split_index(struct index_state *istate)
+{
+	if (istate->split_index) {
+		/*
+		 * can't discard_split_index(&the_index); because that
+		 * will destroy split_index->base->cache[], which may
+		 * be shared with the_index.cache[]. So yeah we're
+		 * leaking a bit here.
+		 */
+		istate->split_index = NULL;
+		istate->cache_changed |= SOMETHING_CHANGED;
+	}
+}
diff --git a/split-index.h b/split-index.h
index c1324f5..df91c1b 100644
--- a/split-index.h
+++ b/split-index.h
@@ -31,5 +31,7 @@
 void prepare_to_write_split_index(struct index_state *istate);
 void finish_writing_split_index(struct index_state *istate);
 void discard_split_index(struct index_state *istate);
+void add_split_index(struct index_state *istate);
+void remove_split_index(struct index_state *istate);
 
 #endif
diff --git a/submodule-config.c b/submodule-config.c
index bb069bc..4f58491 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -234,6 +234,26 @@
 	return parse_fetch_recurse(opt, arg, 1);
 }
 
+static int parse_update_recurse(const char *opt, const char *arg,
+				int die_on_error)
+{
+	switch (git_config_maybe_bool(opt, arg)) {
+	case 1:
+		return RECURSE_SUBMODULES_ON;
+	case 0:
+		return RECURSE_SUBMODULES_OFF;
+	default:
+		if (die_on_error)
+			die("bad %s argument: %s", opt, arg);
+		return RECURSE_SUBMODULES_ERROR;
+	}
+}
+
+int parse_update_recurse_submodules_arg(const char *opt, const char *arg)
+{
+	return parse_update_recurse(opt, arg, 1);
+}
+
 static int parse_push_recurse(const char *opt, const char *arg,
 			       int die_on_error)
 {
diff --git a/submodule-config.h b/submodule-config.h
index 70f1936..d434ecd 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -22,16 +22,17 @@
 	int recommend_shallow;
 };
 
-int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
-int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
-int parse_submodule_config_option(const char *var, const char *value);
-const struct submodule *submodule_from_name(const unsigned char *commit_or_tree,
-		const char *name);
-const struct submodule *submodule_from_path(const unsigned char *commit_or_tree,
-		const char *path);
+extern int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
+extern int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
+extern int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
+extern int parse_submodule_config_option(const char *var, const char *value);
+extern const struct submodule *submodule_from_name(
+		const unsigned char *commit_or_tree, const char *name);
+extern const struct submodule *submodule_from_path(
+		const unsigned char *commit_or_tree, const char *path);
 extern int gitmodule_sha1_from_commit(const unsigned char *commit_sha1,
 				      unsigned char *gitmodules_sha1,
 				      struct strbuf *rev);
-void submodule_free(void);
+extern void submodule_free(void);
 
 #endif /* SUBMODULE_CONFIG_H */
diff --git a/submodule.c b/submodule.c
index 0a2831d..040f4c2 100644
--- a/submodule.c
+++ b/submodule.c
@@ -17,6 +17,7 @@
 #include "worktree.h"
 
 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
+static int config_update_recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
 static int parallel_jobs = 1;
 static struct string_list changed_submodule_paths = STRING_LIST_INIT_NODUP;
 static int initialized_fetch_ref_tips;
@@ -234,15 +235,12 @@
 	return ret;
 }
 
-/*
- * Determine if a submodule has been populated at a given 'path'
- */
-int is_submodule_populated(const char *path)
+int is_submodule_populated_gently(const char *path, int *return_error_code)
 {
 	int ret = 0;
 	char *gitdir = xstrfmt("%s/.git", path);
 
-	if (resolve_gitdir(gitdir))
+	if (resolve_gitdir_gently(gitdir, return_error_code))
 		ret = 1;
 
 	free(gitdir);
@@ -358,6 +356,23 @@
 	strbuf_release(&sb);
 }
 
+static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
+{
+	const char * const *var;
+
+	for (var = local_repo_env; *var; var++) {
+		if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
+			argv_array_push(out, *var);
+	}
+}
+
+void prepare_submodule_repo_env(struct argv_array *out)
+{
+	prepare_submodule_repo_env_no_git_dir(out);
+	argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
+			 DEFAULT_GIT_DIR_ENVIRONMENT);
+}
+
 /* Helper function to display the submodule header line prior to the full
  * summary output. If it can locate the submodule objects directory it will
  * attempt to lookup both the left and right commits and put them into the
@@ -545,6 +560,27 @@
 	config_fetch_recurse_submodules = value;
 }
 
+void set_config_update_recurse_submodules(int value)
+{
+	config_update_recurse_submodules = value;
+}
+
+int should_update_submodules(void)
+{
+	return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
+}
+
+const struct submodule *submodule_from_ce(const struct cache_entry *ce)
+{
+	if (!S_ISGITLINK(ce->ce_mode))
+		return NULL;
+
+	if (!should_update_submodules())
+		return NULL;
+
+	return submodule_from_path(null_sha1, ce->name);
+}
+
 static int has_remote(const char *refname, const struct object_id *oid,
 		      int flags, void *cb_data)
 {
@@ -1203,6 +1239,151 @@
 	return ret;
 }
 
+static const char *get_super_prefix_or_empty(void)
+{
+	const char *s = get_super_prefix();
+	if (!s)
+		s = "";
+	return s;
+}
+
+static int submodule_has_dirty_index(const struct submodule *sub)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+
+	prepare_submodule_repo_env_no_git_dir(&cp.env_array);
+
+	cp.git_cmd = 1;
+	argv_array_pushl(&cp.args, "diff-index", "--quiet",
+				   "--cached", "HEAD", NULL);
+	cp.no_stdin = 1;
+	cp.no_stdout = 1;
+	cp.dir = sub->path;
+	if (start_command(&cp))
+		die("could not recurse into submodule '%s'", sub->path);
+
+	return finish_command(&cp);
+}
+
+static void submodule_reset_index(const char *path)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+	prepare_submodule_repo_env_no_git_dir(&cp.env_array);
+
+	cp.git_cmd = 1;
+	cp.no_stdin = 1;
+	cp.dir = path;
+
+	argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
+				   get_super_prefix_or_empty(), path);
+	argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
+
+	argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
+
+	if (run_command(&cp))
+		die("could not reset submodule index");
+}
+
+/**
+ * Moves a submodule at a given path from a given head to another new head.
+ * For edge cases (a submodule coming into existence or removing a submodule)
+ * pass NULL for old or new respectively.
+ */
+int submodule_move_head(const char *path,
+			 const char *old,
+			 const char *new,
+			 unsigned flags)
+{
+	int ret = 0;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	const struct submodule *sub;
+
+	sub = submodule_from_path(null_sha1, path);
+
+	if (!sub)
+		die("BUG: could not get submodule information for '%s'", path);
+
+	if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
+		/* Check if the submodule has a dirty index. */
+		if (submodule_has_dirty_index(sub))
+			return error(_("submodule '%s' has dirty index"), path);
+	}
+
+	if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
+		if (old) {
+			if (!submodule_uses_gitfile(path))
+				absorb_git_dir_into_superproject("", path,
+					ABSORB_GITDIR_RECURSE_SUBMODULES);
+		} else {
+			struct strbuf sb = STRBUF_INIT;
+			strbuf_addf(&sb, "%s/modules/%s",
+				    get_git_common_dir(), sub->name);
+			connect_work_tree_and_git_dir(path, sb.buf);
+			strbuf_release(&sb);
+
+			/* make sure the index is clean as well */
+			submodule_reset_index(path);
+		}
+	}
+
+	prepare_submodule_repo_env_no_git_dir(&cp.env_array);
+
+	cp.git_cmd = 1;
+	cp.no_stdin = 1;
+	cp.dir = path;
+
+	argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
+			get_super_prefix_or_empty(), path);
+	argv_array_pushl(&cp.args, "read-tree", NULL);
+
+	if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
+		argv_array_push(&cp.args, "-n");
+	else
+		argv_array_push(&cp.args, "-u");
+
+	if (flags & SUBMODULE_MOVE_HEAD_FORCE)
+		argv_array_push(&cp.args, "--reset");
+	else
+		argv_array_push(&cp.args, "-m");
+
+	argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
+	argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
+
+	if (run_command(&cp)) {
+		ret = -1;
+		goto out;
+	}
+
+	if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
+		if (new) {
+			struct child_process cp1 = CHILD_PROCESS_INIT;
+			/* also set the HEAD accordingly */
+			cp1.git_cmd = 1;
+			cp1.no_stdin = 1;
+			cp1.dir = path;
+
+			argv_array_pushl(&cp1.args, "update-ref", "HEAD",
+					 new ? new : EMPTY_TREE_SHA1_HEX, NULL);
+
+			if (run_command(&cp1)) {
+				ret = -1;
+				goto out;
+			}
+		} else {
+			struct strbuf sb = STRBUF_INIT;
+
+			strbuf_addf(&sb, "%s/.git", path);
+			unlink_or_warn(sb.buf);
+			strbuf_release(&sb);
+
+			if (is_empty_dir(path))
+				rmdir_or_warn(path);
+		}
+	}
+out:
+	return ret;
+}
+
 static int find_first_merges(struct object_array *result, const char *path,
 		struct commit *a, struct commit *b)
 {
@@ -1371,18 +1552,6 @@
 	return parallel_jobs;
 }
 
-void prepare_submodule_repo_env(struct argv_array *out)
-{
-	const char * const *var;
-
-	for (var = local_repo_env; *var; var++) {
-		if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
-			argv_array_push(out, *var);
-	}
-	argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
-			 DEFAULT_GIT_DIR_ENVIRONMENT);
-}
-
 /*
  * Embeds a single submodules git directory into the superprojects git dir,
  * non recursively.
@@ -1414,11 +1583,8 @@
 		die(_("could not create directory '%s'"), new_git_dir);
 	real_new_git_dir = real_pathdup(new_git_dir, 1);
 
-	if (!prefix)
-		prefix = get_super_prefix();
-
 	fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
-		prefix ? prefix : "", path,
+		get_super_prefix_or_empty(), path,
 		real_old_git_dir, real_new_git_dir);
 
 	relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
@@ -1445,8 +1611,6 @@
 
 	/* Not populated? */
 	if (!sub_git_dir) {
-		char *real_new_git_dir;
-		const char *new_git_dir;
 		const struct submodule *sub;
 
 		if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
@@ -1469,13 +1633,8 @@
 		sub = submodule_from_path(null_sha1, path);
 		if (!sub)
 			die(_("could not lookup name for submodule '%s'"), path);
-		new_git_dir = git_path("modules/%s", sub->name);
-		if (safe_create_leading_directories_const(new_git_dir) < 0)
-			die(_("could not create directory '%s'"), new_git_dir);
-		real_new_git_dir = real_pathdup(new_git_dir, 1);
-		connect_work_tree_and_git_dir(path, real_new_git_dir);
-
-		free(real_new_git_dir);
+		connect_work_tree_and_git_dir(path,
+			git_path("modules/%s", sub->name));
 	} else {
 		/* Is it already absorbed into the superprojects git dir? */
 		char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
@@ -1496,8 +1655,7 @@
 		if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
 			die("BUG: we don't know how to pass the flags down?");
 
-		if (get_super_prefix())
-			strbuf_addstr(&sb, get_super_prefix());
+		strbuf_addstr(&sb, get_super_prefix_or_empty());
 		strbuf_addstr(&sb, path);
 		strbuf_addch(&sb, '/');
 
@@ -1514,3 +1672,85 @@
 		strbuf_release(&sb);
 	}
 }
+
+const char *get_superproject_working_tree(void)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+	struct strbuf sb = STRBUF_INIT;
+	const char *one_up = real_path_if_valid("../");
+	const char *cwd = xgetcwd();
+	const char *ret = NULL;
+	const char *subpath;
+	int code;
+	ssize_t len;
+
+	if (!is_inside_work_tree())
+		/*
+		 * FIXME:
+		 * We might have a superproject, but it is harder
+		 * to determine.
+		 */
+		return NULL;
+
+	if (!one_up)
+		return NULL;
+
+	subpath = relative_path(cwd, one_up, &sb);
+
+	prepare_submodule_repo_env(&cp.env_array);
+	argv_array_pop(&cp.env_array);
+
+	argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
+			"ls-files", "-z", "--stage", "--full-name", "--",
+			subpath, NULL);
+	strbuf_reset(&sb);
+
+	cp.no_stdin = 1;
+	cp.no_stderr = 1;
+	cp.out = -1;
+	cp.git_cmd = 1;
+
+	if (start_command(&cp))
+		die(_("could not start ls-files in .."));
+
+	len = strbuf_read(&sb, cp.out, PATH_MAX);
+	close(cp.out);
+
+	if (starts_with(sb.buf, "160000")) {
+		int super_sub_len;
+		int cwd_len = strlen(cwd);
+		char *super_sub, *super_wt;
+
+		/*
+		 * There is a superproject having this repo as a submodule.
+		 * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
+		 * We're only interested in the name after the tab.
+		 */
+		super_sub = strchr(sb.buf, '\t') + 1;
+		super_sub_len = sb.buf + sb.len - super_sub - 1;
+
+		if (super_sub_len > cwd_len ||
+		    strcmp(&cwd[cwd_len - super_sub_len], super_sub))
+			die (_("BUG: returned path string doesn't match cwd?"));
+
+		super_wt = xstrdup(cwd);
+		super_wt[cwd_len - super_sub_len] = '\0';
+
+		ret = real_path(super_wt);
+		free(super_wt);
+	}
+	strbuf_release(&sb);
+
+	code = finish_command(&cp);
+
+	if (code == 128)
+		/* '../' is not a git repository */
+		return NULL;
+	if (code == 0 && len == 0)
+		/* There is an unrelated git repository at '../' */
+		return NULL;
+	if (code)
+		die(_("ls-tree returned unexpected return code %d"), code);
+
+	return ret;
+}
diff --git a/submodule.h b/submodule.h
index 05ab674..8a8bc49 100644
--- a/submodule.h
+++ b/submodule.h
@@ -41,7 +41,13 @@
 extern void gitmodules_config(void);
 extern void gitmodules_config_sha1(const unsigned char *commit_sha1);
 extern int is_submodule_initialized(const char *path);
-extern int is_submodule_populated(const char *path);
+/*
+ * Determine if a submodule has been populated at a given 'path' by checking if
+ * the <path>/.git resolves to a valid git repository.
+ * If return_error_code is NULL, die on error.
+ * Otherwise the return error code is the same as of resolve_gitdir_gently.
+ */
+extern int is_submodule_populated_gently(const char *path, int *return_error_code);
 extern int parse_submodule_update_strategy(const char *value,
 		struct submodule_update_strategy *dst);
 extern const char *submodule_strategy_to_string(const struct submodule_update_strategy *s);
@@ -58,6 +64,14 @@
 		const char *del, const char *add, const char *reset,
 		const struct diff_options *opt);
 extern void set_config_fetch_recurse_submodules(int value);
+extern void set_config_update_recurse_submodules(int value);
+/* Check if we want to update any submodule.*/
+extern int should_update_submodules(void);
+/*
+ * Returns the submodule struct if the given ce entry is a submodule
+ * and it should be updated. Returns NULL otherwise.
+ */
+extern const struct submodule *submodule_from_ce(const struct cache_entry *ce);
 extern void check_for_new_submodule_commits(unsigned char new_sha1[20]);
 extern int fetch_populated_submodules(const struct argv_array *options,
 			       const char *prefix, int command_line_option,
@@ -82,6 +96,13 @@
 extern void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir);
 extern int parallel_submodules(void);
 
+#define SUBMODULE_MOVE_HEAD_DRY_RUN (1<<0)
+#define SUBMODULE_MOVE_HEAD_FORCE   (1<<1)
+extern int submodule_move_head(const char *path,
+			       const char *old,
+			       const char *new,
+			       unsigned flags);
+
 /*
  * Prepare the "env_array" parameter of a "struct child_process" for executing
  * a submodule by clearing any repo-specific envirionment variables, but
@@ -93,4 +114,12 @@
 extern void absorb_git_dir_into_superproject(const char *prefix,
 					     const char *path,
 					     unsigned flags);
+
+/*
+ * Return the absolute path of the working tree of the superproject, which this
+ * project is a submodule of. If this repository is not a submodule of
+ * another repository, return NULL.
+ */
+extern const char *get_superproject_working_tree(void);
+
 #endif
diff --git a/t/helper/.gitignore b/t/helper/.gitignore
index d6e8b36..758ed2e 100644
--- a/t/helper/.gitignore
+++ b/t/helper/.gitignore
@@ -11,6 +11,7 @@
 /test-genrandom
 /test-hashmap
 /test-index-version
+/test-lazy-init-name-hash
 /test-line-buffer
 /test-match-trees
 /test-mergesort
diff --git a/t/helper/test-config.c b/t/helper/test-config.c
index 83a4f2a..8e3ed6a 100644
--- a/t/helper/test-config.c
+++ b/t/helper/test-config.c
@@ -66,6 +66,16 @@
 	return 0;
 }
 
+static int early_config_cb(const char *var, const char *value, void *vdata)
+{
+	const char *key = vdata;
+
+	if (!strcmp(key, var))
+		printf("%s\n", value);
+
+	return 0;
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	int i, val;
@@ -73,6 +83,11 @@
 	const struct string_list *strptr;
 	struct config_set cs;
 
+	if (argc == 3 && !strcmp(argv[1], "read_early_config")) {
+		read_early_config(early_config_cb, (void *)argv[2]);
+		return 0;
+	}
+
 	setup_git_directory();
 
 	git_configset_init(&cs);
diff --git a/t/helper/test-lazy-init-name-hash.c b/t/helper/test-lazy-init-name-hash.c
new file mode 100644
index 0000000..6368a89
--- /dev/null
+++ b/t/helper/test-lazy-init-name-hash.c
@@ -0,0 +1,264 @@
+#include "cache.h"
+#include "parse-options.h"
+
+static int single;
+static int multi;
+static int count = 1;
+static int dump;
+static int perf;
+static int analyze;
+static int analyze_step;
+
+/*
+ * Dump the contents of the "dir" and "name" hash tables to stdout.
+ * If you sort the result, you can compare it with the other type
+ * mode and verify that both single and multi produce the same set.
+ */
+static void dump_run(void)
+{
+	struct hashmap_iter iter_dir;
+	struct hashmap_iter iter_cache;
+
+	/* Stolen from name-hash.c */
+	struct dir_entry {
+		struct hashmap_entry ent;
+		struct dir_entry *parent;
+		int nr;
+		unsigned int namelen;
+		char name[FLEX_ARRAY];
+	};
+
+	struct dir_entry *dir;
+	struct cache_entry *ce;
+
+	read_cache();
+	if (single) {
+		test_lazy_init_name_hash(&the_index, 0);
+	} else {
+		int nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
+		if (!nr_threads_used)
+			die("non-threaded code path used");
+	}
+
+	dir = hashmap_iter_first(&the_index.dir_hash, &iter_dir);
+	while (dir) {
+		printf("dir %08x %7d %s\n", dir->ent.hash, dir->nr, dir->name);
+		dir = hashmap_iter_next(&iter_dir);
+	}
+
+	ce = hashmap_iter_first(&the_index.name_hash, &iter_cache);
+	while (ce) {
+		printf("name %08x %s\n", ce->ent.hash, ce->name);
+		ce = hashmap_iter_next(&iter_cache);
+	}
+
+	discard_cache();
+}
+
+/*
+ * Run the single or multi threaded version "count" times and
+ * report on the time taken.
+ */
+static uint64_t time_runs(int try_threaded)
+{
+	uint64_t t0, t1, t2;
+	uint64_t sum = 0;
+	uint64_t avg;
+	int nr_threads_used;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		t0 = getnanotime();
+		read_cache();
+		t1 = getnanotime();
+		nr_threads_used = test_lazy_init_name_hash(&the_index, try_threaded);
+		t2 = getnanotime();
+
+		sum += (t2 - t1);
+
+		if (try_threaded && !nr_threads_used)
+			die("non-threaded code path used");
+
+		if (nr_threads_used)
+			printf("%f %f %d multi %d\n",
+				   ((double)(t1 - t0))/1000000000,
+				   ((double)(t2 - t1))/1000000000,
+				   the_index.cache_nr,
+				   nr_threads_used);
+		else
+			printf("%f %f %d single\n",
+				   ((double)(t1 - t0))/1000000000,
+				   ((double)(t2 - t1))/1000000000,
+				   the_index.cache_nr);
+		fflush(stdout);
+
+		discard_cache();
+	}
+
+	avg = sum / count;
+	if (count > 1)
+		printf("avg %f %s\n",
+			   (double)avg/1000000000,
+			   (try_threaded) ? "multi" : "single");
+
+	return avg;
+}
+
+/*
+ * Try a series of runs varying the "istate->cache_nr" and
+ * try to find a good value for the multi-threaded criteria.
+ */
+static void analyze_run(void)
+{
+	uint64_t t1s, t1m, t2s, t2m;
+	int cache_nr_limit;
+	int nr_threads_used;
+	int i;
+	int nr;
+
+	read_cache();
+	cache_nr_limit = the_index.cache_nr;
+	discard_cache();
+
+	nr = analyze;
+	while (1) {
+		uint64_t sum_single = 0;
+		uint64_t sum_multi = 0;
+		uint64_t avg_single;
+		uint64_t avg_multi;
+
+		if (nr > cache_nr_limit)
+			nr = cache_nr_limit;
+
+		for (i = 0; i < count; i++) {
+			read_cache();
+			the_index.cache_nr = nr; /* cheap truncate of index */
+			t1s = getnanotime();
+			test_lazy_init_name_hash(&the_index, 0);
+			t2s = getnanotime();
+			sum_single += (t2s - t1s);
+			the_index.cache_nr = cache_nr_limit;
+			discard_cache();
+
+			read_cache();
+			the_index.cache_nr = nr; /* cheap truncate of index */
+			t1m = getnanotime();
+			nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
+			t2m = getnanotime();
+			sum_multi += (t2m - t1m);
+			the_index.cache_nr = cache_nr_limit;
+			discard_cache();
+
+			if (!nr_threads_used)
+				printf("    [size %8d] [single %f]   non-threaded code path used\n",
+					   nr, ((double)(t2s - t1s))/1000000000);
+			else
+				printf("    [size %8d] [single %f] %c [multi %f %d]\n",
+					   nr,
+					   ((double)(t2s - t1s))/1000000000,
+					   (((t2s - t1s) < (t2m - t1m)) ? '<' : '>'),
+					   ((double)(t2m - t1m))/1000000000,
+					   nr_threads_used);
+			fflush(stdout);
+		}
+		if (count > 1) {
+			avg_single = sum_single / count;
+			avg_multi = sum_multi / count;
+			if (!nr_threads_used)
+				printf("avg [size %8d] [single %f]\n",
+					   nr,
+					   (double)avg_single/1000000000);
+			else
+				printf("avg [size %8d] [single %f] %c [multi %f %d]\n",
+					   nr,
+					   (double)avg_single/1000000000,
+					   (avg_single < avg_multi ? '<' : '>'),
+					   (double)avg_multi/1000000000,
+					   nr_threads_used);
+			fflush(stdout);
+		}
+
+		if (nr >= cache_nr_limit)
+			return;
+		nr += analyze_step;
+	}
+}
+
+int cmd_main(int argc, const char **argv)
+{
+	const char *usage[] = {
+		"test-lazy-init-name-hash -d (-s | -m)",
+		"test-lazy-init-name-hash -p [-c c]",
+		"test-lazy-init-name-hash -a a [--step s] [-c c]",
+		"test-lazy-init-name-hash (-s | -m) [-c c]",
+		"test-lazy-init-name-hash -s -m [-c c]",
+		NULL
+	};
+	struct option options[] = {
+		OPT_BOOL('s', "single", &single, "run single-threaded code"),
+		OPT_BOOL('m', "multi", &multi, "run multi-threaded code"),
+		OPT_INTEGER('c', "count", &count, "number of passes"),
+		OPT_BOOL('d', "dump", &dump, "dump hash tables"),
+		OPT_BOOL('p', "perf", &perf, "compare single vs multi"),
+		OPT_INTEGER('a', "analyze", &analyze, "analyze different multi sizes"),
+		OPT_INTEGER(0, "step", &analyze_step, "analyze step factor"),
+		OPT_END(),
+	};
+	const char *prefix;
+	uint64_t avg_single, avg_multi;
+
+	prefix = setup_git_directory();
+
+	argc = parse_options(argc, argv, prefix, options, usage, 0);
+
+	/*
+	 * istate->dir_hash is only created when ignore_case is set.
+	 */
+	ignore_case = 1;
+
+	if (dump) {
+		if (perf || analyze > 0)
+			die("cannot combine dump, perf, or analyze");
+		if (count > 1)
+			die("count not valid with dump");
+		if (single && multi)
+			die("cannot use both single and multi with dump");
+		if (!single && !multi)
+			die("dump requires either single or multi");
+		dump_run();
+		return 0;
+	}
+
+	if (perf) {
+		if (analyze > 0)
+			die("cannot combine dump, perf, or analyze");
+		if (single || multi)
+			die("cannot use single or multi with perf");
+		avg_single = time_runs(0);
+		avg_multi = time_runs(1);
+		if (avg_multi > avg_single)
+			die("multi is slower");
+		return 0;
+	}
+
+	if (analyze) {
+		if (analyze < 500)
+			die("analyze must be at least 500");
+		if (!analyze_step)
+			analyze_step = analyze;
+		if (single || multi)
+			die("cannot use single or multi with analyze");
+		analyze_run();
+		return 0;
+	}
+
+	if (!single && !multi)
+		die("require either -s or -m or both");
+
+	if (single)
+		time_runs(0);
+	if (multi)
+		time_runs(1);
+
+	return 0;
+}
diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
index 915eb4a..fb4f7b0 100755
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -4,6 +4,7 @@
 # - New submodule (no_submodule => add_sub1)
 # - Removed submodule (add_sub1 => remove_sub1)
 # - Updated submodule (add_sub1 => modify_sub1)
+# - Updated submodule recursively (add_nested_sub => modify_sub1_recursively)
 # - Submodule updated to invalid commit (add_sub1 => invalid_sub1)
 # - Submodule updated from invalid commit (invalid_sub1 => valid_sub1)
 # - Submodule replaced by tracked files in directory (add_sub1 =>
@@ -15,23 +16,50 @@
 # - Tracked file replaced by submodule (replace_sub1_with_file =>
 #   replace_file_with_sub1)
 #
-#                   --O-----O
-#                  /  ^     replace_directory_with_sub1
-#                 /   replace_sub1_with_directory
-#                /----O
-#               /     ^
-#              /      modify_sub1
-#      O------O-------O
-#      ^      ^\      ^
-#      |      | \     remove_sub1
-#      |      |  -----O-----O
-#      |      |   \   ^     replace_file_with_sub1
-#      |      |    \  replace_sub1_with_file
-#      |   add_sub1 --O-----O
-# no_submodule        ^     valid_sub1
-#                     invalid_sub1
+#                     ----O
+#                    /    ^
+#                   /     remove_sub1
+#                  /
+#       add_sub1  /-------O---------O--------O  modify_sub1_recursively
+#             |  /        ^         add_nested_sub
+#             | /         modify_sub1
+#             v/
+#      O------O-----------O---------O
+#      ^       \          ^         replace_directory_with_sub1
+#      |        \         replace_sub1_with_directory
+# no_submodule   \
+#                 --------O---------O
+#                  \      ^         replace_file_with_sub1
+#                   \     replace_sub1_with_file
+#                    \
+#                     ----O---------O
+#                         ^         valid_sub1
+#                         invalid_sub1
 #
+
 create_lib_submodule_repo () {
+	git init submodule_update_sub1 &&
+	(
+		cd submodule_update_sub1 &&
+		echo "expect" >>.gitignore &&
+		echo "actual" >>.gitignore &&
+		echo "x" >file1 &&
+		echo "y" >file2 &&
+		git add .gitignore file1 file2 &&
+		git commit -m "Base inside first submodule" &&
+		git branch "no_submodule"
+	) &&
+	git init submodule_update_sub2 &&
+	(
+		cd submodule_update_sub2
+		echo "expect" >>.gitignore &&
+		echo "actual" >>.gitignore &&
+		echo "x" >file1 &&
+		echo "y" >file2 &&
+		git add .gitignore file1 file2 &&
+		git commit -m "nested submodule base" &&
+		git branch "no_submodule"
+	) &&
 	git init submodule_update_repo &&
 	(
 		cd submodule_update_repo &&
@@ -44,15 +72,16 @@
 		git branch "no_submodule" &&
 
 		git checkout -b "add_sub1" &&
-		git submodule add ./. sub1 &&
+		git submodule add ../submodule_update_sub1 sub1 &&
 		git config -f .gitmodules submodule.sub1.ignore all &&
 		git config submodule.sub1.ignore all &&
 		git add .gitmodules &&
 		git commit -m "Add sub1" &&
-		git checkout -b remove_sub1 &&
+
+		git checkout -b remove_sub1 add_sub1 &&
 		git revert HEAD &&
 
-		git checkout -b "modify_sub1" "add_sub1" &&
+		git checkout -b modify_sub1 add_sub1 &&
 		git submodule update &&
 		(
 			cd sub1 &&
@@ -67,7 +96,27 @@
 		git add sub1 &&
 		git commit -m "Modify sub1" &&
 
-		git checkout -b "replace_sub1_with_directory" "add_sub1" &&
+		git checkout -b add_nested_sub modify_sub1 &&
+		git -C sub1 checkout -b "add_nested_sub" &&
+		git -C sub1 submodule add --branch no_submodule ../submodule_update_sub2 sub2 &&
+		git -C sub1 commit -a -m "add a nested submodule" &&
+		git add sub1 &&
+		git commit -a -m "update submodule, that updates a nested submodule" &&
+		git checkout -b modify_sub1_recursively &&
+		git -C sub1 checkout -b modify_sub1_recursively &&
+		git -C sub1/sub2 checkout -b modify_sub1_recursively &&
+		echo change >sub1/sub2/file3 &&
+		git -C sub1/sub2 add file3 &&
+		git -C sub1/sub2 commit -m "make a change in nested sub" &&
+		git -C sub1 add sub2 &&
+		git -C sub1 commit -m "update nested sub" &&
+		git add sub1 &&
+		git commit -m "update sub1, that updates nested sub" &&
+		git -C sub1 push origin modify_sub1_recursively &&
+		git -C sub1/sub2 push origin modify_sub1_recursively &&
+		git -C sub1 submodule deinit -f --all &&
+
+		git checkout -b replace_sub1_with_directory add_sub1 &&
 		git submodule update &&
 		git -C sub1 checkout modifications &&
 		git rm --cached sub1 &&
@@ -75,22 +124,25 @@
 		git config -f .gitmodules --remove-section "submodule.sub1" &&
 		git add .gitmodules sub1/* &&
 		git commit -m "Replace sub1 with directory" &&
+
 		git checkout -b replace_directory_with_sub1 &&
 		git revert HEAD &&
 
-		git checkout -b "replace_sub1_with_file" "add_sub1" &&
+		git checkout -b replace_sub1_with_file add_sub1 &&
 		git rm sub1 &&
 		echo "content" >sub1 &&
 		git add sub1 &&
 		git commit -m "Replace sub1 with file" &&
+
 		git checkout -b replace_file_with_sub1 &&
 		git revert HEAD &&
 
-		git checkout -b "invalid_sub1" "add_sub1" &&
+		git checkout -b invalid_sub1 add_sub1 &&
 		git update-index --cacheinfo 160000 0123456789012345678901234567890123456789 sub1 &&
 		git commit -m "Invalid sub1 commit" &&
 		git checkout -b valid_sub1 &&
 		git revert HEAD &&
+
 		git checkout master
 	)
 }
@@ -130,6 +182,15 @@
 	)
 }
 
+test_git_directory_exists() {
+	test -e ".git/modules/$1" &&
+	if test -f sub1/.git
+	then
+		# does core.worktree point at the right place?
+		test "$(git -C .git/modules/$1 config core.worktree)" = "../../../$1"
+	fi
+}
+
 # Helper function to be executed at the start of every test below, it sets up
 # the submodule repo if it doesn't exist and configures the most problematic
 # settings for diff.ignoreSubmodules.
@@ -151,15 +212,36 @@
 		git checkout -f "$1" &&
 		git status -u -s >actual &&
 		test_must_be_empty actual &&
-		sha1=$(git rev-parse --revs-only HEAD:sub1) &&
-		if test -n "$sha1" &&
-		   test $(cd "sub1" && git rev-parse --verify "$sha1^{commit}")
+		hash=$(git rev-parse --revs-only HEAD:sub1) &&
+		if test -n "$hash" &&
+		   test $(cd "../submodule_update_sub1" && git rev-parse --verify "$hash^{commit}")
 		then
 			git submodule update --init --recursive "sub1"
 		fi
 	)
 }
 
+reset_work_tree_to_interested () {
+	reset_work_tree_to $1 &&
+	# make the submodule git dirs available
+	if ! test -d submodule_update/.git/modules/sub1
+	then
+		mkdir -p submodule_update/.git/modules &&
+		cp -r submodule_update_repo/.git/modules/sub1 submodule_update/.git/modules/sub1
+		GIT_WORK_TREE=. git -C submodule_update/.git/modules/sub1 config --unset core.worktree
+	fi &&
+	if ! test -d submodule_update/.git/modules/sub1/modules/sub2
+	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
+	fi &&
+	# indicate we are interested in the submodule:
+	git -C submodule_update config submodule.sub1.url "bogus" &&
+	# sub1 might not be checked out, so use the git dir
+	git -C submodule_update/.git/modules/sub1 config submodule.sub2.url "bogus"
+}
+
 # Test that the superproject contains the content according to commit "$1"
 # (the work tree must match the index for everything but submodules but the
 # index must exactly match the given commit including any submodule SHA-1s).
@@ -173,6 +255,11 @@
 # Test that the given submodule at path "$1" contains the content according
 # to the submodule commit recorded in the superproject's commit "$2"
 test_submodule_content () {
+	if test x"$1" = "x-C"
+	then
+		cd "$2"
+		shift; shift;
+	fi
 	if test $# != 2
 	then
 		echo "test_submodule_content needs two arguments"
@@ -675,3 +762,464 @@
 		)
 	'
 }
+
+# Test that submodule contents are correctly updated when switching
+# between commits that change a submodule.
+# Test that the following transitions are correctly handled:
+# (These tests are also above in the case where we expect no change
+#  in the submodule)
+# - Updated submodule
+# - New submodule
+# - Removed submodule
+# - Directory containing tracked files replaced by submodule
+# - Submodule replaced by tracked files in directory
+# - Submodule replaced by tracked file with the same name
+# - tracked file replaced by submodule
+#
+# New test cases
+# - Removing a submodule with a git directory absorbs the submodules
+#   git directory first into the superproject.
+
+test_submodule_switch_recursing () {
+	command="$1"
+	RESULTDS=success
+	if test "$KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS" = 1
+	then
+		RESULTDS=failure
+	fi
+	RESULTR=success
+	if test "$KNOWN_FAILURE_SUBMODULE_RECURSIVE_NESTED" = 1
+	then
+		RESULTR=failure
+	fi
+	RESULTOI=success
+	if test "$KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED" = 1
+	then
+		RESULTOI=failure
+	fi
+	######################### Appearing submodule #########################
+	# Switching to a commit letting a submodule appear checks it out ...
+	test_expect_success "$command: added submodule is checked out" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			$command add_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# ... ignoring an empty existing directory ...
+	test_expect_success "$command: added submodule is checked out in empty dir" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			mkdir sub1 &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			$command add_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# ... unless there is an untracked file in its place.
+	test_expect_success "$command: added submodule doesn't remove untracked file with same name" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			: >sub1 &&
+			test_must_fail $command add_sub1 &&
+			test_superproject_content origin/no_submodule &&
+			test_must_be_empty sub1
+		)
+	'
+	# ... but an ignored file is fine.
+	test_expect_$RESULTOI "$command: added submodule removes an untracked ignored file" '
+		test_when_finished "rm submodule_update/.git/info/exclude" &&
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			: >sub1 &&
+			echo sub1 >.git/info/exclude
+			$command add_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# Replacing a tracked file with a submodule produces a checked out submodule
+	test_expect_success "$command: replace tracked file with submodule checks out submodule" '
+		prolog &&
+		reset_work_tree_to_interested replace_sub1_with_file &&
+		(
+			cd submodule_update &&
+			git branch -t replace_file_with_sub1 origin/replace_file_with_sub1 &&
+			$command replace_file_with_sub1 &&
+			test_superproject_content origin/replace_file_with_sub1 &&
+			test_submodule_content sub1 origin/replace_file_with_sub1
+		)
+	'
+	# ... as does removing a directory with tracked files with a submodule.
+	test_expect_success "$command: replace directory with submodule" '
+		prolog &&
+		reset_work_tree_to_interested replace_sub1_with_directory &&
+		(
+			cd submodule_update &&
+			git branch -t replace_directory_with_sub1 origin/replace_directory_with_sub1 &&
+			$command replace_directory_with_sub1 &&
+			test_superproject_content origin/replace_directory_with_sub1 &&
+			test_submodule_content sub1 origin/replace_directory_with_sub1
+		)
+	'
+
+	######################## Disappearing submodule #######################
+	# Removing a submodule removes its work tree ...
+	test_expect_success "$command: removed submodule removes submodules working tree" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t remove_sub1 origin/remove_sub1 &&
+			$command remove_sub1 &&
+			test_superproject_content origin/remove_sub1 &&
+			! test -e sub1
+		)
+	'
+	# ... absorbing a .git directory along the way.
+	test_expect_success "$command: removed submodule absorbs submodules .git directory" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t remove_sub1 origin/remove_sub1 &&
+			replace_gitfile_with_git_dir sub1 &&
+			rm -rf .git/modules &&
+			$command remove_sub1 &&
+			test_superproject_content origin/remove_sub1 &&
+			! test -e sub1 &&
+			test_git_directory_exists sub1
+		)
+	'
+	# Replacing a submodule with files in a directory must succeeds
+	# when the submodule is clean
+	test_expect_$RESULTDS "$command: replace submodule with a directory" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
+			$command replace_sub1_with_directory &&
+			test_superproject_content origin/replace_sub1_with_directory &&
+			test_submodule_content sub1 origin/replace_sub1_with_directory
+		)
+	'
+	# ... absorbing a .git directory.
+	test_expect_$RESULTDS "$command: replace submodule containing a .git directory with a directory must absorb the git dir" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
+			replace_gitfile_with_git_dir sub1 &&
+			rm -rf .git/modules &&
+			$command replace_sub1_with_directory &&
+			test_superproject_content origin/replace_sub1_with_directory &&
+			test_git_directory_exists sub1
+		)
+	'
+
+	# Replacing it with a file ...
+	test_expect_success "$command: replace submodule with a file" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			$command replace_sub1_with_file &&
+			test_superproject_content origin/replace_sub1_with_file &&
+			test -f sub1
+		)
+	'
+
+	# ... must check its local work tree for untracked files
+	test_expect_$RESULTDS "$command: replace submodule with a file must fail with untracked files" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			: >sub1/untrackedfile &&
+			test_must_fail $command replace_sub1_with_file &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+
+	# ... and ignored files are ignored
+	test_expect_success "$command: replace submodule with a file works ignores ignored files in submodule" '
+		test_when_finished "rm submodule_update/.git/modules/sub1/info/exclude" &&
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			: >sub1/ignored &&
+			$command replace_sub1_with_file &&
+			test_superproject_content origin/replace_sub1_with_file &&
+			test -f sub1
+		)
+	'
+
+	########################## Modified submodule #########################
+	# Updating a submodule sha1 updates the submodule's work tree
+	test_expect_success "$command: modified submodule updates submodule work tree" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t modify_sub1 origin/modify_sub1 &&
+			$command modify_sub1 &&
+			test_superproject_content origin/modify_sub1 &&
+			test_submodule_content sub1 origin/modify_sub1
+		)
+	'
+
+	# Updating a submodule to an invalid sha1 doesn't update the
+	# superproject nor the submodule's work tree.
+	test_expect_success "$command: updating to a missing submodule commit fails" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t invalid_sub1 origin/invalid_sub1 &&
+			test_must_fail $command invalid_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+
+	# recursing deeper than one level doesn't work yet.
+	test_expect_$RESULTR "$command: modified submodule updates submodule recursively" '
+		prolog &&
+		reset_work_tree_to_interested add_nested_sub &&
+		(
+			cd submodule_update &&
+			git branch -t modify_sub1_recursively origin/modify_sub1_recursively &&
+			$command modify_sub1_recursively &&
+			test_superproject_content origin/modify_sub1_recursively &&
+			test_submodule_content sub1 origin/modify_sub1_recursively &&
+			test_submodule_content -C sub1 sub2 origin/modify_sub1_recursively
+		)
+	'
+}
+
+# Test that submodule contents are updated when switching between commits
+# that change a submodule, but throwing away local changes in
+# the superproject as well as the submodule is allowed.
+test_submodule_forced_switch_recursing () {
+	command="$1"
+	RESULT=success
+	if test "$KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS" = 1
+	then
+		RESULT=failure
+	fi
+	######################### Appearing submodule #########################
+	# Switching to a commit letting a submodule appear creates empty dir ...
+	test_expect_success "$command: added submodule is checked out" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			$command add_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# ... and doesn't care if it already exists ...
+	test_expect_success "$command: added submodule ignores empty directory" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			mkdir sub1 &&
+			$command add_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# ... not caring about an untracked file either
+	test_expect_success "$command: added submodule does remove untracked unignored file with same name when forced" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t add_sub1 origin/add_sub1 &&
+			>sub1 &&
+			$command add_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# Replacing a tracked file with a submodule checks out the submodule
+	test_expect_success "$command: replace tracked file with submodule populates the submodule" '
+		prolog &&
+		reset_work_tree_to_interested replace_sub1_with_file &&
+		(
+			cd submodule_update &&
+			git branch -t replace_file_with_sub1 origin/replace_file_with_sub1 &&
+			$command replace_file_with_sub1 &&
+			test_superproject_content origin/replace_file_with_sub1 &&
+			test_submodule_content sub1 origin/replace_file_with_sub1
+		)
+	'
+	# ... as does removing a directory with tracked files with a
+	# submodule.
+	test_expect_success "$command: replace directory with submodule" '
+		prolog &&
+		reset_work_tree_to_interested replace_sub1_with_directory &&
+		(
+			cd submodule_update &&
+			git branch -t replace_directory_with_sub1 origin/replace_directory_with_sub1 &&
+			$command replace_directory_with_sub1 &&
+			test_superproject_content origin/replace_directory_with_sub1 &&
+			test_submodule_content sub1 origin/replace_directory_with_sub1
+		)
+	'
+
+	######################## Disappearing submodule #######################
+	# Removing a submodule doesn't remove its work tree ...
+	test_expect_success "$command: removed submodule leaves submodule directory and its contents in place" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t remove_sub1 origin/remove_sub1 &&
+			$command remove_sub1 &&
+			test_superproject_content origin/remove_sub1 &&
+			! test -e sub1
+		)
+	'
+	# ... especially when it contains a .git directory.
+	test_expect_success "$command: removed submodule leaves submodule containing a .git directory alone" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t remove_sub1 origin/remove_sub1 &&
+			replace_gitfile_with_git_dir sub1 &&
+			rm -rf .git/modules/sub1 &&
+			$command remove_sub1 &&
+			test_superproject_content origin/remove_sub1 &&
+			test_git_directory_exists sub1 &&
+			! test -e sub1
+		)
+	'
+	# Replacing a submodule with files in a directory ...
+	test_expect_success "$command: replace submodule with a directory" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
+			$command replace_sub1_with_directory &&
+			test_superproject_content origin/replace_sub1_with_directory
+		)
+	'
+	# ... absorbing a .git directory.
+	test_expect_success "$command: replace submodule containing a .git directory with a directory must fail" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
+			replace_gitfile_with_git_dir sub1 &&
+			rm -rf .git/modules/sub1 &&
+			$command replace_sub1_with_directory &&
+			test_superproject_content origin/replace_sub1_with_directory &&
+			test_submodule_content sub1 origin/modify_sub1
+			test_git_directory_exists sub1
+		)
+	'
+	# Replacing it with a file
+	test_expect_success "$command: replace submodule with a file" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			$command replace_sub1_with_file &&
+			test_superproject_content origin/replace_sub1_with_file
+		)
+	'
+
+	# ... even if the submodule contains ignored files
+	test_expect_success "$command: replace submodule with a file ignoring ignored files" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			: >sub1/expect &&
+			$command replace_sub1_with_file &&
+			test_superproject_content origin/replace_sub1_with_file
+		)
+	'
+
+	# ... but stops for untracked files that would be lost
+	test_expect_$RESULT "$command: replace submodule with a file stops for untracked files" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
+			: >sub1/untracked_file &&
+			test_must_fail $command replace_sub1_with_file &&
+			test_superproject_content origin/add_sub1 &&
+			test -f sub1/untracked_file
+		)
+	'
+
+	########################## Modified submodule #########################
+	# Updating a submodule sha1 updates the submodule's work tree
+	test_expect_success "$command: modified submodule updates submodule work tree" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t modify_sub1 origin/modify_sub1 &&
+			$command modify_sub1 &&
+			test_superproject_content origin/modify_sub1 &&
+			test_submodule_content sub1 origin/modify_sub1
+		)
+	'
+	# Updating a submodule to an invalid sha1 doesn't update the
+	# submodule's work tree, subsequent update will fail
+	test_expect_success "$command: modified submodule does not update submodule work tree to invalid commit" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t invalid_sub1 origin/invalid_sub1 &&
+			test_must_fail $command invalid_sub1 &&
+			test_superproject_content origin/add_sub1 &&
+			test_submodule_content sub1 origin/add_sub1
+		)
+	'
+	# Updating a submodule from an invalid sha1 updates
+	test_expect_success "$command: modified submodule does not update submodule work tree from invalid commit" '
+		prolog &&
+		reset_work_tree_to_interested invalid_sub1 &&
+		(
+			cd submodule_update &&
+			git branch -t valid_sub1 origin/valid_sub1 &&
+			test_must_fail $command valid_sub1 &&
+			test_superproject_content origin/invalid_sub1
+		)
+	'
+}
diff --git a/t/perf/p0004-lazy-init-name-hash.sh b/t/perf/p0004-lazy-init-name-hash.sh
new file mode 100644
index 0000000..5afa8c8
--- /dev/null
+++ b/t/perf/p0004-lazy-init-name-hash.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+test_description='Tests multi-threaded lazy_init_name_hash'
+. ./perf-lib.sh
+
+test_perf_large_repo
+test_checkout_worktree
+
+test_expect_success 'verify both methods build the same hashmaps' '
+	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --dump --single | sort >out.single &&
+	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --dump --multi  | sort >out.multi  &&
+	test_cmp out.single out.multi
+'
+
+test_expect_success 'multithreaded should be faster' '
+	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --perf >out.perf
+'
+
+test_done
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index f0fbb42..f19ae4f 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -13,10 +13,31 @@
 	test_line_count = 0 err
 }
 
+attr_check_quote () {
+
+	path="$1"
+	quoted_path="$2"
+	expect="$3"
+
+	git check-attr test -- "$path" >actual &&
+	echo "\"$quoted_path\": test: $expect" >expect &&
+	test_cmp expect actual
+
+}
+
+test_expect_success 'open-quoted pathname' '
+	echo "\"a test=a" >.gitattributes &&
+	test_must_fail attr_check a a
+'
+
+
 test_expect_success 'setup' '
 	mkdir -p a/b/d a/c b &&
 	(
 		echo "[attr]notest !test"
+		echo "\" d \"	test=d"
+		echo " e	test=e"
+		echo " e\"	test=e"
 		echo "f	test=f"
 		echo "a/i test=a/i"
 		echo "onoff test -test"
@@ -69,6 +90,11 @@
 '
 
 test_expect_success 'attribute test' '
+
+	attr_check " d " d &&
+	attr_check e e &&
+	attr_check_quote e\" e\\\" e &&
+
 	attr_check f f &&
 	attr_check a/f f &&
 	attr_check a/c/f f &&
diff --git a/t/t0013-sha1dc.sh b/t/t0013-sha1dc.sh
new file mode 100755
index 0000000..6d655cb
--- /dev/null
+++ b/t/t0013-sha1dc.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+test_description='test sha1 collision detection'
+. ./test-lib.sh
+TEST_DATA="$TEST_DIRECTORY/t0013"
+
+if test -z "$DC_SHA1"
+then
+	skip_all='skipping sha1 collision tests, DC_SHA1 not set'
+	test_done
+fi
+
+test_expect_success 'test-sha1 detects shattered pdf' '
+	test_must_fail test-sha1 <"$TEST_DATA/shattered-1.pdf" 2>err &&
+	test_i18ngrep collision err &&
+	grep 38762cf7f55934b34d179ae6a4c80cadccbb7f0a err
+'
+
+test_done
diff --git a/t/t0013/shattered-1.pdf b/t/t0013/shattered-1.pdf
new file mode 100644
index 0000000..ba9aaa1
--- /dev/null
+++ b/t/t0013/shattered-1.pdf
Binary files differ
diff --git a/t/t0301-credential-cache.sh b/t/t0301-credential-cache.sh
index 82c8411..fd92533 100755
--- a/t/t0301-credential-cache.sh
+++ b/t/t0301-credential-cache.sh
@@ -12,7 +12,100 @@
 # don't leave a stale daemon running
 trap 'code=$?; git credential-cache exit; (exit $code); die' EXIT
 
+# test that the daemon works with no special setup
 helper_test cache
+
+test_expect_success 'socket defaults to ~/.cache/git/credential/socket' '
+	test_when_finished "
+		git credential-cache exit &&
+		rmdir -p .cache/git/credential/
+	" &&
+	test_path_is_missing "$HOME/.git-credential-cache" &&
+	test -S "$HOME/.cache/git/credential/socket"
+'
+
+XDG_CACHE_HOME="$HOME/xdg"
+export XDG_CACHE_HOME
+# test behavior when XDG_CACHE_HOME is set
+helper_test cache
+
+test_expect_success "use custom XDG_CACHE_HOME if set and default sockets are not created" '
+	test_when_finished "git credential-cache exit" &&
+	test -S "$XDG_CACHE_HOME/git/credential/socket" &&
+	test_path_is_missing "$HOME/.git-credential-cache/socket" &&
+	test_path_is_missing "$HOME/.cache/git/credential/socket"
+'
+unset XDG_CACHE_HOME
+
+test_expect_success 'credential-cache --socket option overrides default location' '
+	test_when_finished "
+		git credential-cache exit --socket \"\$HOME/dir/socket\" &&
+		rmdir \"\$HOME/dir\"
+	" &&
+	check approve "cache --socket \"\$HOME/dir/socket\"" <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/dir/socket"
+'
+
+test_expect_success "use custom XDG_CACHE_HOME even if xdg socket exists" '
+	test_when_finished "
+		git credential-cache exit &&
+		sane_unset XDG_CACHE_HOME
+	" &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/.cache/git/credential/socket" &&
+	XDG_CACHE_HOME="$HOME/xdg" &&
+	export XDG_CACHE_HOME &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$XDG_CACHE_HOME/git/credential/socket"
+'
+
+test_expect_success 'use user socket if user directory exists' '
+	test_when_finished "
+		git credential-cache exit &&
+		rmdir \"\$HOME/.git-credential-cache/\"
+	" &&
+	mkdir -p -m 700 "$HOME/.git-credential-cache/" &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/.git-credential-cache/socket"
+'
+
+test_expect_success SYMLINKS 'use user socket if user directory is a symlink to a directory' '
+	test_when_finished "
+		git credential-cache exit &&
+		rmdir \"\$HOME/dir/\" &&
+		rm \"\$HOME/.git-credential-cache\"
+	" &&
+	mkdir -p -m 700 "$HOME/dir/" &&
+	ln -s "$HOME/dir" "$HOME/.git-credential-cache" &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/.git-credential-cache/socket"
+'
+
 helper_test_timeout cache --timeout=1
 
 # we can't rely on our "trap" above working after test_done,
diff --git a/t/t1007-hash-object.sh b/t/t1007-hash-object.sh
index c5245c5..532682f 100755
--- a/t/t1007-hash-object.sh
+++ b/t/t1007-hash-object.sh
@@ -134,6 +134,16 @@
 	)
 '
 
+test_expect_success '--path works in a subdirectory' '
+	(
+		cd subdir &&
+		path1_sha=$(git hash-object --path=../file1 ../file0) &&
+		path0_sha=$(git hash-object --path=../file0 ../file1) &&
+		test "$file0_sha" = "$path0_sha" &&
+		test "$file1_sha" = "$path1_sha"
+	)
+'
+
 test_expect_success 'check that --no-filters option works' '
 	nofilters_file1=$(git hash-object --no-filters file1) &&
 	test "$file0_sha" = "$nofilters_file1" &&
diff --git a/t/t1013-read-tree-submodule.sh b/t/t1013-read-tree-submodule.sh
index 20526ae..de1ba02 100755
--- a/t/t1013-read-tree-submodule.sh
+++ b/t/t1013-read-tree-submodule.sh
@@ -5,6 +5,14 @@
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
+KNOWN_FAILURE_SUBMODULE_RECURSIVE_NESTED=1
+KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS=1
+KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED=1
+
+test_submodule_switch_recursing "git read-tree --recurse-submodules -u -m"
+
+test_submodule_forced_switch_recursing "git read-tree --recurse-submodules -u --reset"
+
 test_submodule_switch "git read-tree -u -m"
 
 test_submodule_forced_switch "git read-tree -u --reset"
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index ea37102..afcca0d 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -1239,6 +1239,111 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'urlmatch favors more specific URLs' '
+	cat >.git/config <<-\EOF &&
+	[http "https://example.com/"]
+		cookieFile = /tmp/root.txt
+	[http "https://example.com/subdirectory"]
+		cookieFile = /tmp/subdirectory.txt
+	[http "https://user@example.com/"]
+		cookieFile = /tmp/user.txt
+	[http "https://averylonguser@example.com/"]
+		cookieFile = /tmp/averylonguser.txt
+	[http "https://preceding.example.com"]
+		cookieFile = /tmp/preceding.txt
+	[http "https://*.example.com"]
+		cookieFile = /tmp/wildcard.txt
+	[http "https://*.example.com/wildcardwithsubdomain"]
+		cookieFile = /tmp/wildcardwithsubdomain.txt
+	[http "https://trailing.example.com"]
+		cookieFile = /tmp/trailing.txt
+	[http "https://user@*.example.com/"]
+		cookieFile = /tmp/wildcardwithuser.txt
+	[http "https://sub.example.com/"]
+		cookieFile = /tmp/sub.txt
+	EOF
+
+	echo http.cookiefile /tmp/root.txt >expect &&
+	git config --get-urlmatch HTTP https://example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/subdirectory.txt >expect &&
+	git config --get-urlmatch HTTP https://example.com/subdirectory >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/subdirectory.txt >expect &&
+	git config --get-urlmatch HTTP https://example.com/subdirectory/nested >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/user.txt >expect &&
+	git config --get-urlmatch HTTP https://user@example.com/ >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/subdirectory.txt >expect &&
+	git config --get-urlmatch HTTP https://averylonguser@example.com/subdirectory >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/preceding.txt >expect &&
+	git config --get-urlmatch HTTP https://preceding.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/wildcard.txt >expect &&
+	git config --get-urlmatch HTTP https://wildcard.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/sub.txt >expect &&
+	git config --get-urlmatch HTTP https://sub.example.com/wildcardwithsubdomain >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/trailing.txt >expect &&
+	git config --get-urlmatch HTTP https://trailing.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/sub.txt >expect &&
+	git config --get-urlmatch HTTP https://user@sub.example.com >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'urlmatch with wildcard' '
+	cat >.git/config <<-\EOF &&
+	[http]
+		sslVerify
+	[http "https://*.example.com"]
+		sslVerify = false
+		cookieFile = /tmp/cookie.txt
+	EOF
+
+	test_expect_code 1 git config --bool --get-urlmatch doesnt.exist https://good.example.com >actual &&
+	test_must_be_empty actual &&
+
+	echo true >expect &&
+	git config --bool --get-urlmatch http.SSLverify https://example.com >actual &&
+	test_cmp expect actual &&
+
+	echo true >expect &&
+	git config --bool --get-urlmatch http.SSLverify https://good-example.com >actual &&
+	test_cmp expect actual &&
+
+	echo true >expect &&
+	git config --bool --get-urlmatch http.sslverify https://deep.nested.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo false >expect &&
+	git config --bool --get-urlmatch http.sslverify https://good.example.com >actual &&
+	test_cmp expect actual &&
+
+	{
+		echo http.cookiefile /tmp/cookie.txt &&
+		echo http.sslverify false
+	} >expect &&
+	git config --get-urlmatch HTTP https://good.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.sslverify >expect &&
+	git config --get-urlmatch HTTP https://more.example.com.au >actual &&
+	test_cmp expect actual
+'
+
 # good section hygiene
 test_expect_failure 'unsetting the last key in a section removes header' '
 	cat >.git/config <<-\EOF &&
diff --git a/t/t1305-config-include.sh b/t/t1305-config-include.sh
index 9ba2ba1..e833939 100755
--- a/t/t1305-config-include.sh
+++ b/t/t1305-config-include.sh
@@ -102,7 +102,7 @@
 
 test_expect_success 'missing include files are ignored' '
 	cat >.gitconfig <<-\EOF &&
-	[include]path = foo
+	[include]path = non-existent
 	[test]value = yes
 	EOF
 	echo yes >expect &&
@@ -152,6 +152,62 @@
 	test_must_fail git config --file - test.one
 '
 
+test_expect_success 'conditional include, both unanchored' '
+	git init foo &&
+	(
+		cd foo &&
+		echo "[includeIf \"gitdir:foo/\"]path=bar" >>.git/config &&
+		echo "[test]one=1" >.git/bar &&
+		echo 1 >expect &&
+		git config test.one >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'conditional include, $HOME expansion' '
+	(
+		cd foo &&
+		echo "[includeIf \"gitdir:~/foo/\"]path=bar2" >>.git/config &&
+		echo "[test]two=2" >.git/bar2 &&
+		echo 2 >expect &&
+		git config test.two >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'conditional include, full pattern' '
+	(
+		cd foo &&
+		echo "[includeIf \"gitdir:**/foo/**\"]path=bar3" >>.git/config &&
+		echo "[test]three=3" >.git/bar3 &&
+		echo 3 >expect &&
+		git config test.three >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'conditional include, relative path' '
+	echo "[includeIf \"gitdir:./foo/.git\"]path=bar4" >>.gitconfig &&
+	echo "[test]four=4" >bar4 &&
+	(
+		cd foo &&
+		echo 4 >expect &&
+		git config test.four >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'conditional include, both unanchored, icase' '
+	(
+		cd foo &&
+		echo "[includeIf \"gitdir/i:FOO/\"]path=bar5" >>.git/config &&
+		echo "[test]five=5" >.git/bar5 &&
+		echo 5 >expect &&
+		git config test.five >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_expect_success 'include cycles are detected' '
 	cat >.gitconfig <<-\EOF &&
 	[test]value = gitconfig
diff --git a/t/t1309-early-config.sh b/t/t1309-early-config.sh
new file mode 100755
index 0000000..b97357b
--- /dev/null
+++ b/t/t1309-early-config.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+test_description='Test read_early_config()'
+
+. ./test-lib.sh
+
+test_expect_success 'read early config' '
+	test_config early.config correct &&
+	test-config read_early_config early.config >output &&
+	test correct = "$(cat output)"
+'
+
+test_expect_success 'in a sub-directory' '
+	test_config early.config sub &&
+	mkdir -p sub &&
+	(
+		cd sub &&
+		test-config read_early_config early.config
+	) >output &&
+	test sub = "$(cat output)"
+'
+
+test_expect_success 'ceiling' '
+	test_config early.config ceiling &&
+	mkdir -p sub &&
+	(
+		GIT_CEILING_DIRECTORIES="$PWD" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd sub &&
+		test-config read_early_config early.config
+	) >output &&
+	test -z "$(cat output)"
+'
+
+test_expect_success 'ceiling #2' '
+	mkdir -p xdg/git &&
+	git config -f xdg/git/config early.config xdg &&
+	test_config early.config ceiling &&
+	mkdir -p sub &&
+	(
+		XDG_CONFIG_HOME="$PWD"/xdg &&
+		GIT_CEILING_DIRECTORIES="$PWD" &&
+		export GIT_CEILING_DIRECTORIES XDG_CONFIG_HOME &&
+		cd sub &&
+		test-config read_early_config early.config
+	) >output &&
+	test xdg = "$(cat output)"
+'
+
+test_with_config () {
+	rm -rf throwaway &&
+	git init throwaway &&
+	(
+		cd throwaway &&
+		echo "$*" >.git/config &&
+		test-config read_early_config early.config
+	)
+}
+
+test_expect_success 'ignore .git/ with incompatible repository version' '
+	test_with_config "[core]repositoryformatversion = 999999" 2>err &&
+	grep "warning:.* Expected git repo version <= [1-9]" err
+'
+
+test_expect_failure 'ignore .git/ with invalid repository version' '
+	test_with_config "[core]repositoryformatversion = invalid"
+'
+
+
+test_expect_failure 'ignore .git/ with invalid config' '
+	test_with_config "["
+'
+
+test_done
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index b0ffc0b..a23cd7b 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -40,7 +40,7 @@
 	"git update-ref $m $A &&
 	 test $A"' = $(cat .git/'"$m"')'
 test_expect_success \
-	"create $m" \
+	"create $m with oldvalue verification" \
 	"git update-ref $m $B $A &&
 	 test $B"' = $(cat .git/'"$m"')'
 test_expect_success "fail to delete $m with stale ref" '
@@ -48,31 +48,31 @@
 	test $B = "$(cat .git/$m)"
 '
 test_expect_success "delete $m" '
+	test_when_finished "rm -f .git/$m" &&
 	git update-ref -d $m $B &&
-	! test -f .git/$m
+	test_path_is_missing .git/$m
 '
-rm -f .git/$m
 
-test_expect_success "delete $m without oldvalue verification" "
+test_expect_success "delete $m without oldvalue verification" '
+	test_when_finished "rm -f .git/$m" &&
 	git update-ref $m $A &&
-	test $A = \$(cat .git/$m) &&
+	test $A = $(cat .git/$m) &&
 	git update-ref -d $m &&
-	! test -f .git/$m
-"
-rm -f .git/$m
+	test_path_is_missing .git/$m
+'
 
-test_expect_success \
-	"fail to create $n" \
-	"touch .git/$n_dir &&
-	 test_must_fail git update-ref $n $A >out 2>err"
-rm -f .git/$n_dir out err
+test_expect_success "fail to create $n" '
+	test_when_finished "rm -f .git/$n_dir" &&
+	touch .git/$n_dir &&
+	test_must_fail git update-ref $n $A
+'
 
 test_expect_success \
 	"create $m (by HEAD)" \
 	"git update-ref HEAD $A &&
 	 test $A"' = $(cat .git/'"$m"')'
 test_expect_success \
-	"create $m (by HEAD)" \
+	"create $m (by HEAD) with oldvalue verification" \
 	"git update-ref HEAD $B $A &&
 	 test $B"' = $(cat .git/'"$m"')'
 test_expect_success "fail to delete $m (by HEAD) with stale ref" '
@@ -80,10 +80,28 @@
 	test $B = $(cat .git/$m)
 '
 test_expect_success "delete $m (by HEAD)" '
+	test_when_finished "rm -f .git/$m" &&
 	git update-ref -d HEAD $B &&
-	! test -f .git/$m
+	test_path_is_missing .git/$m
 '
-rm -f .git/$m
+
+test_expect_success "deleting current branch adds message to HEAD's log" '
+	test_when_finished "rm -f .git/$m" &&
+	git update-ref $m $A &&
+	git symbolic-ref HEAD $m &&
+	git update-ref -m delete-$m -d $m &&
+	test_path_is_missing .git/$m &&
+	grep "delete-$m$" .git/logs/HEAD
+'
+
+test_expect_success "deleting by HEAD adds message to HEAD's log" '
+	test_when_finished "rm -f .git/$m" &&
+	git update-ref $m $A &&
+	git symbolic-ref HEAD $m &&
+	git update-ref -m delete-by-head -d HEAD &&
+	test_path_is_missing .git/$m &&
+	grep "delete-by-head$" .git/logs/HEAD
+'
 
 test_expect_success 'update-ref does not create reflogs by default' '
 	test_when_finished "git update-ref -d $outside" &&
@@ -170,28 +188,29 @@
 	"git update-ref HEAD $B $A &&
 	 test $B"' = $(cat .git/'"$m"')'
 test_expect_success "delete $m (by HEAD) should remove both packed and loose $m" '
+	test_when_finished "rm -f .git/$m" &&
 	git update-ref -d HEAD $B &&
 	! grep "$m" .git/packed-refs &&
-	! test -f .git/$m
+	test_path_is_missing .git/$m
 '
-rm -f .git/$m
 
 cp -f .git/HEAD .git/HEAD.orig
 test_expect_success "delete symref without dereference" '
+	test_when_finished "cp -f .git/HEAD.orig .git/HEAD" &&
 	git update-ref --no-deref -d HEAD &&
-	! test -f .git/HEAD
+	test_path_is_missing .git/HEAD
 '
-cp -f .git/HEAD.orig .git/HEAD
 
 test_expect_success "delete symref without dereference when the referred ref is packed" '
+	test_when_finished "cp -f .git/HEAD.orig .git/HEAD" &&
 	echo foo >foo.c &&
 	git add foo.c &&
 	git commit -m foo &&
 	git pack-refs --all &&
 	git update-ref --no-deref -d HEAD &&
-	! test -f .git/HEAD
+	test_path_is_missing .git/HEAD
 '
-cp -f .git/HEAD.orig .git/HEAD
+
 git update-ref -d $m
 
 test_expect_success 'update-ref -d is not confused by self-reference' '
@@ -223,10 +242,10 @@
 test_expect_success '(not) create HEAD with old sha1' "
 	test_must_fail git update-ref HEAD $A $B
 "
-test_expect_success "(not) prior created .git/$m" "
-	! test -f .git/$m
-"
-rm -f .git/$m
+test_expect_success "(not) prior created .git/$m" '
+	test_when_finished "rm -f .git/$m" &&
+	test_path_is_missing .git/$m
+'
 
 test_expect_success \
 	"create HEAD" \
@@ -234,56 +253,84 @@
 test_expect_success '(not) change HEAD with wrong SHA1' "
 	test_must_fail git update-ref HEAD $B $Z
 "
-test_expect_success "(not) changed .git/$m" "
-	! test $B"' = $(cat .git/'"$m"')
+test_expect_success "(not) changed .git/$m" '
+	test_when_finished "rm -f .git/$m" &&
+	! test $B = $(cat .git/$m)
 '
-rm -f .git/$m
 
 rm -f .git/logs/refs/heads/master
 test_expect_success \
 	"create $m (logged by touch)" \
-	'GIT_COMMITTER_DATE="2005-05-26 23:30" \
+	'test_config core.logAllRefUpdates false &&
+	 GIT_COMMITTER_DATE="2005-05-26 23:30" \
 	 git update-ref --create-reflog HEAD '"$A"' -m "Initial Creation" &&
 	 test '"$A"' = $(cat .git/'"$m"')'
 test_expect_success \
 	"update $m (logged by touch)" \
-	'GIT_COMMITTER_DATE="2005-05-26 23:31" \
+	'test_config core.logAllRefUpdates false &&
+	 GIT_COMMITTER_DATE="2005-05-26 23:31" \
 	 git update-ref HEAD'" $B $A "'-m "Switch" &&
 	 test '"$B"' = $(cat .git/'"$m"')'
 test_expect_success \
 	"set $m (logged by touch)" \
-	'GIT_COMMITTER_DATE="2005-05-26 23:41" \
+	'test_config core.logAllRefUpdates false &&
+	 GIT_COMMITTER_DATE="2005-05-26 23:41" \
 	 git update-ref HEAD'" $A &&
 	 test $A"' = $(cat .git/'"$m"')'
 
+test_expect_success "empty directory removal" '
+	git branch d1/d2/r1 HEAD &&
+	git branch d1/r2 HEAD &&
+	test_path_is_file .git/refs/heads/d1/d2/r1 &&
+	test_path_is_file .git/logs/refs/heads/d1/d2/r1 &&
+	git branch -d d1/d2/r1 &&
+	test_path_is_missing .git/refs/heads/d1/d2 &&
+	test_path_is_missing .git/logs/refs/heads/d1/d2 &&
+	test_path_is_file .git/refs/heads/d1/r2 &&
+	test_path_is_file .git/logs/refs/heads/d1/r2
+'
+
+test_expect_success "symref empty directory removal" '
+	git branch e1/e2/r1 HEAD &&
+	git branch e1/r2 HEAD &&
+	git checkout e1/e2/r1 &&
+	test_when_finished "git checkout master" &&
+	test_path_is_file .git/refs/heads/e1/e2/r1 &&
+	test_path_is_file .git/logs/refs/heads/e1/e2/r1 &&
+	git update-ref -d HEAD &&
+	test_path_is_missing .git/refs/heads/e1/e2 &&
+	test_path_is_missing .git/logs/refs/heads/e1/e2 &&
+	test_path_is_file .git/refs/heads/e1/r2 &&
+	test_path_is_file .git/logs/refs/heads/e1/r2 &&
+	test_path_is_file .git/logs/HEAD
+'
+
 cat >expect <<EOF
 $Z $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	Initial Creation
 $A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150260 +0000	Switch
 $B $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150860 +0000
 EOF
-test_expect_success \
-	"verifying $m's log" \
-	"test_cmp expect .git/logs/$m"
-rm -rf .git/$m .git/logs expect
-
-test_expect_success \
-	'enable core.logAllRefUpdates' \
-	'git config core.logAllRefUpdates true &&
-	 test true = $(git config --bool --get core.logAllRefUpdates)'
+test_expect_success "verifying $m's log (logged by touch)" '
+	test_when_finished "rm -rf .git/$m .git/logs expect" &&
+	test_cmp expect .git/logs/$m
+'
 
 test_expect_success \
 	"create $m (logged by config)" \
-	'GIT_COMMITTER_DATE="2005-05-26 23:32" \
+	'test_config core.logAllRefUpdates true &&
+	 GIT_COMMITTER_DATE="2005-05-26 23:32" \
 	 git update-ref HEAD'" $A "'-m "Initial Creation" &&
 	 test '"$A"' = $(cat .git/'"$m"')'
 test_expect_success \
 	"update $m (logged by config)" \
-	'GIT_COMMITTER_DATE="2005-05-26 23:33" \
+	'test_config core.logAllRefUpdates true &&
+	 GIT_COMMITTER_DATE="2005-05-26 23:33" \
 	 git update-ref HEAD'" $B $A "'-m "Switch" &&
 	 test '"$B"' = $(cat .git/'"$m"')'
 test_expect_success \
 	"set $m (logged by config)" \
-	'GIT_COMMITTER_DATE="2005-05-26 23:43" \
+	'test_config core.logAllRefUpdates true &&
+	 GIT_COMMITTER_DATE="2005-05-26 23:43" \
 	 git update-ref HEAD '"$A &&
 	 test $A"' = $(cat .git/'"$m"')'
 
@@ -293,9 +340,9 @@
 $B $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150980 +0000
 EOF
 test_expect_success \
-	"verifying $m's log" \
-	'test_cmp expect .git/logs/$m'
-rm -f .git/$m .git/logs/$m expect
+	"verifying $m's log (logged by config)" \
+	'test_when_finished "rm -f .git/$m .git/logs/$m expect" &&
+	 test_cmp expect .git/logs/$m'
 
 git update-ref $m $D
 cat >.git/logs/$m <<EOF
@@ -311,55 +358,55 @@
 ld="Thu, 26 May 2005 18:43:00 -0500"
 test_expect_success \
 	'Query "master@{May 25 2005}" (before history)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{May 25 2005}" >o 2>e &&
 	 test '"$C"' = $(cat o) &&
 	 test "warning: Log for '\'master\'' only goes back to $ed." = "$(cat e)"'
 test_expect_success \
 	"Query master@{2005-05-25} (before history)" \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify master@{2005-05-25} >o 2>e &&
 	 test '"$C"' = $(cat o) &&
 	 echo test "warning: Log for '\'master\'' only goes back to $ed." = "$(cat e)"'
 test_expect_success \
 	'Query "master@{May 26 2005 23:31:59}" (1 second before history)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{May 26 2005 23:31:59}" >o 2>e &&
 	 test '"$C"' = $(cat o) &&
 	 test "warning: Log for '\''master'\'' only goes back to $ed." = "$(cat e)"'
 test_expect_success \
 	'Query "master@{May 26 2005 23:32:00}" (exactly history start)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{May 26 2005 23:32:00}" >o 2>e &&
 	 test '"$C"' = $(cat o) &&
 	 test "" = "$(cat e)"'
 test_expect_success \
 	'Query "master@{May 26 2005 23:32:30}" (first non-creation change)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{May 26 2005 23:32:30}" >o 2>e &&
 	 test '"$A"' = $(cat o) &&
 	 test "" = "$(cat e)"'
 test_expect_success \
 	'Query "master@{2005-05-26 23:33:01}" (middle of history with gap)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{2005-05-26 23:33:01}" >o 2>e &&
 	 test '"$B"' = $(cat o) &&
 	 test "warning: Log for ref '"$m has gap after $gd"'." = "$(cat e)"'
 test_expect_success \
 	'Query "master@{2005-05-26 23:38:00}" (middle of history)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{2005-05-26 23:38:00}" >o 2>e &&
 	 test '"$Z"' = $(cat o) &&
 	 test "" = "$(cat e)"'
 test_expect_success \
 	'Query "master@{2005-05-26 23:43:00}" (exact end of history)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{2005-05-26 23:43:00}" >o 2>e &&
 	 test '"$E"' = $(cat o) &&
 	 test "" = "$(cat e)"'
 test_expect_success \
 	'Query "master@{2005-05-28}" (past end of history)' \
-	'rm -f o e &&
+	'test_when_finished "rm -f o e" &&
 	 git rev-parse --verify "master@{2005-05-28}" >o 2>e &&
 	 test '"$D"' = $(cat o) &&
 	 test "warning: Log for ref '"$m unexpectedly ended on $ld"'." = "$(cat e)"'
@@ -369,7 +416,8 @@
 
 test_expect_success \
     'creating initial files' \
-    'echo TEST >F &&
+    'test_when_finished rm -f M &&
+     echo TEST >F &&
      git add F &&
 	 GIT_AUTHOR_DATE="2005-05-26 23:30" \
 	 GIT_COMMITTER_DATE="2005-05-26 23:30" git commit -m add -a &&
@@ -387,8 +435,7 @@
 	 echo $h_TEST >.git/MERGE_HEAD &&
 	 GIT_AUTHOR_DATE="2005-05-26 23:45" \
 	 GIT_COMMITTER_DATE="2005-05-26 23:45" git commit -F M &&
-	 h_MERGED=$(git rev-parse --verify HEAD) &&
-	 rm -f M'
+	 h_MERGED=$(git rev-parse --verify HEAD)'
 
 cat >expect <<EOF
 $Z $h_TEST $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	commit (initial): add
diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh
index 038e24c..03d3c7f 100755
--- a/t/t1500-rev-parse.sh
+++ b/t/t1500-rev-parse.sh
@@ -3,7 +3,7 @@
 test_description='test git rev-parse'
 . ./test-lib.sh
 
-# usage: [options] label is-bare is-inside-git is-inside-work prefix git-dir
+# usage: [options] label is-bare is-inside-git is-inside-work prefix git-dir absolute-git-dir
 test_rev_parse () {
 	d=
 	bare=
@@ -29,7 +29,8 @@
 		 --is-inside-git-dir \
 		 --is-inside-work-tree \
 		 --show-prefix \
-		 --git-dir
+		 --git-dir \
+		 --absolute-git-dir
 	do
 		test $# -eq 0 && break
 		expect="$1"
@@ -62,29 +63,71 @@
 	cp -R .git repo.git
 '
 
-test_rev_parse toplevel false false true '' .git
+test_rev_parse toplevel false false true '' .git "$ROOT/.git"
 
-test_rev_parse -C .git .git/ false true false '' .
-test_rev_parse -C .git/objects .git/objects/ false true false '' "$ROOT/.git"
+test_rev_parse -C .git .git/ false true false '' . "$ROOT/.git"
+test_rev_parse -C .git/objects .git/objects/ false true false '' "$ROOT/.git" "$ROOT/.git"
 
-test_rev_parse -C sub/dir subdirectory false false true sub/dir/ "$ROOT/.git"
+test_rev_parse -C sub/dir subdirectory false false true sub/dir/ "$ROOT/.git" "$ROOT/.git"
 
 test_rev_parse -b t 'core.bare = true' true false false
 
 test_rev_parse -b u 'core.bare undefined' false false true
 
 
-test_rev_parse -C work -g ../.git -b f 'GIT_DIR=../.git, core.bare = false' false false true ''
+test_rev_parse -C work -g ../.git -b f 'GIT_DIR=../.git, core.bare = false' false false true '' "../.git" "$ROOT/.git"
 
 test_rev_parse -C work -g ../.git -b t 'GIT_DIR=../.git, core.bare = true' true false false ''
 
 test_rev_parse -C work -g ../.git -b u 'GIT_DIR=../.git, core.bare undefined' false false true ''
 
 
-test_rev_parse -C work -g ../repo.git -b f 'GIT_DIR=../repo.git, core.bare = false' false false true ''
+test_rev_parse -C work -g ../repo.git -b f 'GIT_DIR=../repo.git, core.bare = false' false false true '' "../repo.git" "$ROOT/repo.git"
 
 test_rev_parse -C work -g ../repo.git -b t 'GIT_DIR=../repo.git, core.bare = true' true false false ''
 
 test_rev_parse -C work -g ../repo.git -b u 'GIT_DIR=../repo.git, core.bare undefined' false false true ''
 
+test_expect_success 'git-common-dir from worktree root' '
+	echo .git >expect &&
+	git rev-parse --git-common-dir >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-common-dir inside sub-dir' '
+	mkdir -p path/to/child &&
+	test_when_finished "rm -rf path" &&
+	echo "$(git -C path/to/child rev-parse --show-cdup).git" >expect &&
+	git -C path/to/child rev-parse --git-common-dir >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-path from worktree root' '
+	echo .git/objects >expect &&
+	git rev-parse --git-path objects >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-path inside sub-dir' '
+	mkdir -p path/to/child &&
+	test_when_finished "rm -rf path" &&
+	echo "$(git -C path/to/child rev-parse --show-cdup).git/objects" >expect &&
+	git -C path/to/child rev-parse --git-path objects >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'showing the superproject correctly' '
+	git rev-parse --show-superproject-working-tree >out &&
+	test_must_be_empty out &&
+
+	test_create_repo super &&
+	test_commit -C super test_commit &&
+	test_create_repo sub &&
+	test_commit -C sub test_commit &&
+	git -C super submodule add ../sub dir/sub &&
+	echo $(pwd)/super >expect  &&
+	git -C super/dir/sub rev-parse --show-superproject-working-tree >out &&
+	test_cmp expect out
+'
+
 test_done
diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh
index 292a072..af3ec0d 100755
--- a/t/t1700-split-index.sh
+++ b/t/t1700-split-index.sh
@@ -8,6 +8,7 @@
 sane_unset GIT_TEST_SPLIT_INDEX
 
 test_expect_success 'enable split index' '
+	git config splitIndex.maxPercentChange 100 &&
 	git update-index --split-index &&
 	test-dump-split-index .git/index >actual &&
 	indexversion=$(test-index-version <.git/index) &&
@@ -19,12 +20,12 @@
 		own=8299b0bcd1ac364e5f1d7768efb62fa2da79a339
 		base=39d890139ee5356c7ef572216cebcd27aa41f9df
 	fi &&
-	cat >expect <<EOF &&
-own $own
-base $base
-replacements:
-deletions:
-EOF
+	cat >expect <<-EOF &&
+	own $own
+	base $base
+	replacements:
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
@@ -32,51 +33,51 @@
 	: >one &&
 	git update-index --add one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-base $base
-100644 $EMPTY_BLOB 0	one
-replacements:
-deletions:
-EOF
+	cat >expect <<-EOF &&
+	base $base
+	100644 $EMPTY_BLOB 0	one
+	replacements:
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'disable split index' '
 	git update-index --no-split-index &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	BASE=$(test-dump-split-index .git/index | grep "^own" | sed "s/own/base/") &&
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-not a split index
-EOF
+	cat >expect <<-EOF &&
+	not a split index
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'enable split index again, "one" now belongs to base index"' '
 	git update-index --split-index &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-$BASE
-replacements:
-deletions:
-EOF
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
@@ -84,18 +85,18 @@
 	echo modified >one &&
 	git update-index one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	q_to_tab >expect <<EOF &&
-$BASE
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
-replacements: 0
-deletions:
-EOF
+	q_to_tab >expect <<-EOF &&
+	$BASE
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
+	replacements: 0
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
@@ -103,54 +104,54 @@
 	: >two &&
 	git update-index --add two &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
-100644 $EMPTY_BLOB 0	two
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
+	100644 $EMPTY_BLOB 0	two
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	q_to_tab >expect <<EOF &&
-$BASE
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
-100644 $EMPTY_BLOB 0	two
-replacements: 0
-deletions:
-EOF
+	q_to_tab >expect <<-EOF &&
+	$BASE
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
+	100644 $EMPTY_BLOB 0	two
+	replacements: 0
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'remove file not in base index' '
 	git update-index --force-remove two &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	q_to_tab >expect <<EOF &&
-$BASE
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
-replacements: 0
-deletions:
-EOF
+	q_to_tab >expect <<-EOF &&
+	$BASE
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
+	replacements: 0
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'remove file in base index' '
 	git update-index --force-remove one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-EOF
+	cat >ls-files.expect <<-EOF &&
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-$BASE
-replacements:
-deletions: 0
-EOF
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions: 0
+	EOF
 	test_cmp expect actual
 '
 
@@ -158,18 +159,18 @@
 	: >one &&
 	git update-index --add one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-$BASE
-100644 $EMPTY_BLOB 0	one
-replacements:
-deletions: 0
-EOF
+	cat >expect <<-EOF &&
+	$BASE
+	100644 $EMPTY_BLOB 0	one
+	replacements:
+	deletions: 0
+	EOF
 	test_cmp expect actual
 '
 
@@ -177,27 +178,196 @@
 	: >two &&
 	git update-index --add two &&
 	git ls-files --stage >actual &&
-	cat >expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-100644 $EMPTY_BLOB 0	two
-EOF
+	cat >expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	100644 $EMPTY_BLOB 0	two
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'unify index, two files remain' '
 	git update-index --no-split-index &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-100644 $EMPTY_BLOB 0	two
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	100644 $EMPTY_BLOB 0	two
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-not a split index
-EOF
+	cat >expect <<-EOF &&
+	not a split index
+	EOF
 	test_cmp expect actual
 '
 
+test_expect_success 'rev-parse --shared-index-path' '
+	test_create_repo split-index &&
+	(
+		cd split-index &&
+		git update-index --split-index &&
+		echo .git/sharedindex* >expect &&
+		git rev-parse --shared-index-path >actual &&
+		test_cmp expect actual &&
+		mkdir subdirectory &&
+		cd subdirectory &&
+		echo ../.git/sharedindex* >expect &&
+		git rev-parse --shared-index-path >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'set core.splitIndex config variable to true' '
+	git config core.splitIndex true &&
+	: >three &&
+	git update-index --add three &&
+	git ls-files --stage >ls-files.actual &&
+	cat >ls-files.expect <<-EOF &&
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	one
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	three
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	two
+	EOF
+	test_cmp ls-files.expect ls-files.actual &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'set core.splitIndex config variable to false' '
+	git config core.splitIndex false &&
+	git update-index --force-remove three &&
+	git ls-files --stage >ls-files.actual &&
+	cat >ls-files.expect <<-EOF &&
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	one
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	two
+	EOF
+	test_cmp ls-files.expect ls-files.actual &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	not a split index
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'set core.splitIndex config variable to true' '
+	git config core.splitIndex true &&
+	: >three &&
+	git update-index --add three &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual &&
+	: >four &&
+	git update-index --add four &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	four
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check behavior with splitIndex.maxPercentChange unset' '
+	git config --unset splitIndex.maxPercentChange &&
+	: >five &&
+	git update-index --add five &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual &&
+	: >six &&
+	git update-index --add six &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	six
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check splitIndex.maxPercentChange set to 0' '
+	git config splitIndex.maxPercentChange 0 &&
+	: >seven &&
+	git update-index --add seven &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual &&
+	: >eight &&
+	git update-index --add eight &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'shared index files expire after 2 weeks by default' '
+	: >ten &&
+	git update-index --add ten &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	just_under_2_weeks_ago=$((5-14*86400)) &&
+	test-chmtime =$just_under_2_weeks_ago .git/sharedindex.* &&
+	: >eleven &&
+	git update-index --add eleven &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	just_over_2_weeks_ago=$((-1-14*86400)) &&
+	test-chmtime =$just_over_2_weeks_ago .git/sharedindex.* &&
+	: >twelve &&
+	git update-index --add twelve &&
+	test $(ls .git/sharedindex.* | wc -l) -le 2
+'
+
+test_expect_success 'check splitIndex.sharedIndexExpire set to 16 days' '
+	git config splitIndex.sharedIndexExpire "16.days.ago" &&
+	test-chmtime =$just_over_2_weeks_ago .git/sharedindex.* &&
+	: >thirteen &&
+	git update-index --add thirteen &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	just_over_16_days_ago=$((-1-16*86400)) &&
+	test-chmtime =$just_over_16_days_ago .git/sharedindex.* &&
+	: >fourteen &&
+	git update-index --add fourteen &&
+	test $(ls .git/sharedindex.* | wc -l) -le 2
+'
+
+test_expect_success 'check splitIndex.sharedIndexExpire set to "never" and "now"' '
+	git config splitIndex.sharedIndexExpire never &&
+	just_10_years_ago=$((-365*10*86400)) &&
+	test-chmtime =$just_10_years_ago .git/sharedindex.* &&
+	: >fifteen &&
+	git update-index --add fifteen &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	git config splitIndex.sharedIndexExpire now &&
+	just_1_second_ago=-1 &&
+	test-chmtime =$just_1_second_ago .git/sharedindex.* &&
+	: >sixteen &&
+	git update-index --add sixteen &&
+	test $(ls .git/sharedindex.* | wc -l) -le 2
+'
+
 test_done
diff --git a/t/t2013-checkout-submodule.sh b/t/t2013-checkout-submodule.sh
index 6847f75..e8f70b8 100755
--- a/t/t2013-checkout-submodule.sh
+++ b/t/t2013-checkout-submodule.sh
@@ -63,6 +63,12 @@
 	! test -s actual
 '
 
+KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS=1
+KNOWN_FAILURE_SUBMODULE_RECURSIVE_NESTED=1
+test_submodule_switch_recursing "git checkout --recurse-submodules"
+
+test_submodule_forced_switch_recursing "git checkout -f --recurse-submodules"
+
 test_submodule_switch "git checkout"
 
 test_submodule_forced_switch "git checkout -f"
diff --git a/t/t2027-worktree-list.sh b/t/t2027-worktree-list.sh
index 465eeea..848da5f 100755
--- a/t/t2027-worktree-list.sh
+++ b/t/t2027-worktree-list.sh
@@ -14,10 +14,18 @@
 	test_cmp expected actual &&
 	mkdir sub &&
 	git -C sub rev-parse --git-common-dir >actual2 &&
-	echo sub/.git >expected2 &&
+	echo ../.git >expected2 &&
 	test_cmp expected2 actual2
 '
 
+test_expect_success 'rev-parse --git-path objects linked worktree' '
+	echo "$(git rev-parse --show-toplevel)/.git/objects" >expect &&
+	test_when_finished "rm -rf linked-tree && git worktree prune" &&
+	git worktree add --detach linked-tree master &&
+	git -C linked-tree rev-parse --git-path objects >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success '"list" all worktrees from main' '
 	echo "$(git rev-parse --show-toplevel) $(git rev-parse --short HEAD) [$(git symbolic-ref --short HEAD)]" >expect &&
 	test_when_finished "rm -rf here && git worktree prune" &&
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 8a833f3..9f353c0 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -139,6 +139,12 @@
 	test $(git rev-parse --abbrev-ref HEAD) = bam
 '
 
+test_expect_success 'git branch -M baz bam should add entries to .git/logs/HEAD' '
+	msg="Branch: renamed refs/heads/baz to refs/heads/bam" &&
+	grep " 0\{40\}.*$msg$" .git/logs/HEAD &&
+	grep "^0\{40\}.*$msg$" .git/logs/HEAD
+'
+
 test_expect_success 'git branch -M baz bam should succeed when baz is checked out as linked working tree' '
 	git checkout master &&
 	git worktree add -b baz bazdir &&
@@ -207,6 +213,31 @@
 	test_path_is_missing .git/refs/heads/t
 '
 
+test_expect_success 'git branch --list -v with --abbrev' '
+	test_when_finished "git branch -D t" &&
+	git branch t &&
+	git branch -v --list t >actual.default &&
+	git branch -v --list --abbrev t >actual.abbrev &&
+	test_cmp actual.default actual.abbrev &&
+
+	git branch -v --list --no-abbrev t >actual.noabbrev &&
+	git branch -v --list --abbrev=0 t >actual.0abbrev &&
+	test_cmp actual.noabbrev actual.0abbrev &&
+
+	git branch -v --list --abbrev=36 t >actual.36abbrev &&
+	# how many hexdigits are used?
+	read name objdefault rest <actual.abbrev &&
+	read name obj36 rest <actual.36abbrev &&
+	objfull=$(git rev-parse --verify t) &&
+
+	# are we really getting abbreviations?
+	test "$obj36" != "$objdefault" &&
+	expr "$obj36" : "$objdefault" >/dev/null &&
+	test "$objfull" != "$obj36" &&
+	expr "$objfull" : "$obj36" >/dev/null
+
+'
+
 test_expect_success 'git branch --column' '
 	COLUMNS=81 git branch --column=column >actual &&
 	cat >expected <<\EOF &&
diff --git a/t/t3203-branch-output.sh b/t/t3203-branch-output.sh
index 52283df..5778c0a 100755
--- a/t/t3203-branch-output.sh
+++ b/t/t3203-branch-output.sh
@@ -194,7 +194,7 @@
 	git symbolic-ref refs/heads/ref-to-remote refs/remotes/origin/branch-one &&
 	cat >expect <<-\EOF &&
 	  ref-to-branch -> branch-one
-	  ref-to-remote -> refs/remotes/origin/branch-one
+	  ref-to-remote -> origin/branch-one
 	EOF
 	git branch >actual.raw &&
 	grep ref-to <actual.raw >actual &&
@@ -225,4 +225,18 @@
 	)
 '
 
+test_expect_success 'git branch --format option' '
+	cat >expect <<-\EOF &&
+	Refname is (HEAD detached from fromtag)
+	Refname is refs/heads/ambiguous
+	Refname is refs/heads/branch-one
+	Refname is refs/heads/branch-two
+	Refname is refs/heads/master
+	Refname is refs/heads/ref-to-branch
+	Refname is refs/heads/ref-to-remote
+	EOF
+	git branch --format="Refname is %(refname)" >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index e2f18d1..33d392b 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -556,7 +556,7 @@
 	echo "edited again" > file7 &&
 	git add file7 &&
 	test_must_fail git rebase --continue 2>error &&
-	test_i18ngrep "You have staged changes in your working tree." error
+	test_i18ngrep "you have staged changes in your working tree" error
 '
 
 test_expect_success 'rebase a detached HEAD' '
diff --git a/t/t3502-cherry-pick-merge.sh b/t/t3502-cherry-pick-merge.sh
index e37547f..b160271 100755
--- a/t/t3502-cherry-pick-merge.sh
+++ b/t/t3502-cherry-pick-merge.sh
@@ -31,6 +31,15 @@
 
 '
 
+test_expect_success 'cherry-pick -m complains of bogus numbers' '
+	# expect 129 here to distinguish between cases where
+	# there was nothing to cherry-pick
+	test_expect_code 129 git cherry-pick -m &&
+	test_expect_code 129 git cherry-pick -m foo b &&
+	test_expect_code 129 git cherry-pick -m -1 b &&
+	test_expect_code 129 git cherry-pick -m 0 b
+'
+
 test_expect_success 'cherry-pick a non-merge with -m should fail' '
 
 	git reset --hard &&
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index aaa258d..f9528fa 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -412,4 +412,47 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'add -p handles globs' '
+	git reset --hard &&
+
+	mkdir -p subdir &&
+	echo base >one.c &&
+	echo base >subdir/two.c &&
+	git add "*.c" &&
+	git commit -m base &&
+
+	echo change >one.c &&
+	echo change >subdir/two.c &&
+	git add -p "*.c" <<-\EOF &&
+	y
+	y
+	EOF
+
+	cat >expect <<-\EOF &&
+	one.c
+	subdir/two.c
+	EOF
+	git diff --cached --name-only >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'add -p does not expand argument lists' '
+	git reset --hard &&
+
+	echo content >not-changed &&
+	git add not-changed &&
+	git commit -m "add not-changed file" &&
+
+	echo change >file &&
+	GIT_TRACE=$(pwd)/trace.out git add -p . <<-\EOF &&
+	y
+	EOF
+
+	# we know that "file" must be mentioned since we actually
+	# update it, but we want to be sure that our "." pathspec
+	# was not expanded into the argument list of any command.
+	# So look only for "not-changed".
+	! grep not-changed trace.out
+'
+
 test_done
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 2de3e18..b71d1e6 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -274,9 +274,7 @@
 	git add file2 &&
 	test_must_fail git stash --invalid-option &&
 	test_must_fail git stash save --invalid-option &&
-	test bar5,bar6 = $(cat file),$(cat file2) &&
-	git stash -- -message-starting-with-dash &&
-	test bar,bar2 = $(cat file),$(cat file2)
+	test bar5,bar6 = $(cat file),$(cat file2)
 '
 
 test_expect_success 'stash an added file' '
@@ -665,7 +663,7 @@
 		sane_unset GIT_MERGE_VERBOSITY &&
 		git stash apply
 	) |
-	sed -e 1,2d >actual && # drop "Saved..." and "HEAD is now..."
+	sed -e 1d >actual && # drop "Saved..."
 	test_i18ncmp expect actual
 '
 
@@ -775,4 +773,152 @@
 	test_path_is_missing file
 '
 
+test_expect_success 'push -m shows right message' '
+	>foo &&
+	git add foo &&
+	git stash push -m "test message" &&
+	echo "stash@{0}: On master: test message" >expect &&
+	git stash list -1 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'create stores correct message' '
+	>foo &&
+	git add foo &&
+	STASH_ID=$(git stash create "create test message") &&
+	echo "On master: create test message" >expect &&
+	git show --pretty=%s -s ${STASH_ID} >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'create with multiple arguments for the message' '
+	>foo &&
+	git add foo &&
+	STASH_ID=$(git stash create test untracked) &&
+	echo "On master: test untracked" >expect &&
+	git show --pretty=%s -s ${STASH_ID} >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash -- <pathspec> stashes and restores the file' '
+	>foo &&
+	>bar &&
+	git add foo bar &&
+	git stash push -- foo &&
+	test_path_is_file bar &&
+	test_path_is_missing foo &&
+	git stash pop &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
+test_expect_success 'stash with multiple pathspec arguments' '
+	>foo &&
+	>bar &&
+	>extra &&
+	git add foo bar extra &&
+	git stash push -- foo bar &&
+	test_path_is_missing bar &&
+	test_path_is_missing foo &&
+	test_path_is_file extra &&
+	git stash pop &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	test_path_is_file extra
+'
+
+test_expect_success 'stash with file including $IFS character' '
+	>"foo bar" &&
+	>foo &&
+	>bar &&
+	git add foo* &&
+	git stash push -- "foo b*" &&
+	test_path_is_missing "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	git stash pop &&
+	test_path_is_file "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
+test_expect_success 'stash with pathspec matching multiple paths' '
+       echo original >file &&
+       echo original >other-file &&
+       git commit -m "two" file other-file &&
+       echo modified >file &&
+       echo modified >other-file &&
+       git stash push -- "*file" &&
+       echo original >expect &&
+       test_cmp expect file &&
+       test_cmp expect other-file &&
+       git stash pop &&
+       echo modified >expect &&
+       test_cmp expect file &&
+       test_cmp expect other-file
+'
+
+test_expect_success 'stash push -p with pathspec shows no changes only once' '
+	>foo &&
+	git add foo &&
+	git commit -m "tmp" &&
+	git stash push -p foo >actual &&
+	echo "No local changes to save" >expect &&
+	git reset --hard HEAD~ &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash push with pathspec shows no changes when there are none' '
+	>foo &&
+	git add foo &&
+	git commit -m "tmp" &&
+	git stash push foo >actual &&
+	echo "No local changes to save" >expect &&
+	git reset --hard HEAD~ &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash push with pathspec not in the repository errors out' '
+	>untracked &&
+	test_must_fail git stash push untracked &&
+	test_path_is_file untracked
+'
+
+test_expect_success 'untracked files are left in place when -u is not given' '
+	>file &&
+	git add file &&
+	>untracked &&
+	git stash push file &&
+	test_path_is_file untracked
+'
+
+test_expect_success 'stash without verb with pathspec' '
+	>"foo bar" &&
+	>foo &&
+	>bar &&
+	git add foo* &&
+	git stash -- "foo b*" &&
+	test_path_is_missing "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	git stash pop &&
+	test_path_is_file "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
+test_expect_success 'stash -k -- <pathspec> leaves unstaged files intact' '
+	git reset &&
+	>foo &&
+	>bar &&
+	git add foo bar &&
+	git commit -m "test" &&
+	echo "foo" >foo &&
+	echo "bar" >bar &&
+	git stash -k -- foo &&
+	test "",bar = $(cat foo),$(cat bar) &&
+	git stash pop &&
+	test foo,bar = $(cat foo),$(cat bar)
+'
+
 test_done
diff --git a/t/t3904-stash-patch.sh b/t/t3904-stash-patch.sh
index 38e7300..83744f8 100755
--- a/t/t3904-stash-patch.sh
+++ b/t/t3904-stash-patch.sh
@@ -77,6 +77,14 @@
 	verify_state dir/foo work index
 '
 
+test_expect_success 'stash -p --no-keep-index -- <pathspec> does not unstage other files' '
+	set_state HEAD HEADfile_work HEADfile_index &&
+	set_state dir/foo work index &&
+	echo y | git stash push -p --no-keep-index -- HEAD &&
+	verify_state HEAD committed committed &&
+	verify_state dir/foo work index
+'
+
 test_expect_success 'none of this moved HEAD' '
 	verify_saved_head
 '
diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
index f372fc8..193adc7 100755
--- a/t/t3905-stash-include-untracked.sh
+++ b/t/t3905-stash-include-untracked.sh
@@ -185,4 +185,30 @@
 	test -s .gitignore
 '
 
+test_expect_success 'stash push --include-untracked with pathspec' '
+	>foo &&
+	>bar &&
+	git stash push --include-untracked -- foo &&
+	test_path_is_file bar &&
+	test_path_is_missing foo &&
+	git stash pop &&
+	test_path_is_file bar &&
+	test_path_is_file foo
+'
+
+test_expect_success 'stash push with $IFS character' '
+	>"foo bar" &&
+	>foo &&
+	>bar &&
+	git add foo* &&
+	git stash push --include-untracked -- "foo b*" &&
+	test_path_is_missing "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	git stash pop &&
+	test_path_is_file "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
 test_done
diff --git a/t/t5400-send-pack.sh b/t/t5400-send-pack.sh
index 305ca7a..3331e0f 100755
--- a/t/t5400-send-pack.sh
+++ b/t/t5400-send-pack.sh
@@ -255,4 +255,42 @@
 	)
 '
 
+extract_ref_advertisement () {
+	perl -lne '
+		# \\ is there to skip capabilities after \0
+		/push< ([^\\]+)/ or next;
+		exit 0 if $1 eq "0000";
+		print $1;
+	'
+}
+
+test_expect_success 'receive-pack de-dupes .have lines' '
+	git init shared &&
+	git -C shared commit --allow-empty -m both &&
+	git clone -s shared fork &&
+	(
+		cd shared &&
+		git checkout -b only-shared &&
+		git commit --allow-empty -m only-shared &&
+		git update-ref refs/heads/foo HEAD
+	) &&
+
+	# Notable things in this expectation:
+	#  - local refs are not de-duped
+	#  - .have does not duplicate locals
+	#  - .have does not duplicate itself
+	local=$(git -C fork rev-parse HEAD) &&
+	shared=$(git -C shared rev-parse only-shared) &&
+	cat >expect <<-EOF &&
+	$local refs/heads/master
+	$local refs/remotes/origin/HEAD
+	$local refs/remotes/origin/master
+	$shared .have
+	EOF
+
+	GIT_TRACE_PACKET=$(pwd)/trace git push fork HEAD:foo &&
+	extract_ref_advertisement <trace >refs &&
+	test_cmp expect refs
+'
+
 test_done
diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index 3ea2710..a6c0178 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -744,7 +744,7 @@
 	(
 		cd four &&
 		git remote rename origin upstream &&
-		rmdir .git/refs/remotes/origin &&
+		test -z "$(git for-each-ref refs/remotes/origin)" &&
 		test "$(git symbolic-ref refs/remotes/upstream/HEAD)" = "refs/remotes/upstream/master" &&
 		test "$(git rev-parse upstream/master)" = "$(git rev-parse master)" &&
 		test "$(git config remote.upstream.fetch)" = "+refs/heads/*:refs/remotes/upstream/*" &&
diff --git a/t/t5545-push-options.sh b/t/t5545-push-options.sh
index 9a57a7d..97065e6 100755
--- a/t/t5545-push-options.sh
+++ b/t/t5545-push-options.sh
@@ -102,17 +102,46 @@
 	test_cmp expect upstream/.git/hooks/post-receive.push_options
 '
 
-test_expect_success 'push option denied properly by http remote helper' '\
+test_expect_success 'push option denied properly by http server' '
+	test_when_finished "rm -rf test_http_clone" &&
+	test_when_finished "rm -rf \"$HTTPD_DOCUMENT_ROOT_PATH\"/upstream.git" &&
 	mk_repo_pair &&
 	git -C upstream config receive.advertisePushOptions false &&
 	git -C upstream config http.receivepack true &&
 	cp -R upstream/.git "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git &&
 	git clone "$HTTPD_URL"/smart/upstream test_http_clone &&
 	test_commit -C test_http_clone one &&
-	test_must_fail git -C test_http_clone push --push-option=asdf origin master &&
+	test_must_fail git -C test_http_clone push --push-option=asdf origin master 2>actual &&
+	test_i18ngrep "the receiving end does not support push options" actual &&
 	git -C test_http_clone push origin master
 '
 
+test_expect_success 'push options work properly across http' '
+	test_when_finished "rm -rf test_http_clone" &&
+	test_when_finished "rm -rf \"$HTTPD_DOCUMENT_ROOT_PATH\"/upstream.git" &&
+	mk_repo_pair &&
+	git -C upstream config receive.advertisePushOptions true &&
+	git -C upstream config http.receivepack true &&
+	cp -R upstream/.git "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git &&
+	git clone "$HTTPD_URL"/smart/upstream test_http_clone &&
+
+	test_commit -C test_http_clone one &&
+	git -C test_http_clone push origin master &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git rev-parse --verify master >expect &&
+	git -C test_http_clone rev-parse --verify master >actual &&
+	test_cmp expect actual &&
+
+	test_commit -C test_http_clone two &&
+	git -C test_http_clone push --push-option=asdf --push-option="more structured text" origin master &&
+	printf "asdf\nmore structured text\n" >expect &&
+	test_cmp expect "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git/hooks/pre-receive.push_options &&
+	test_cmp expect "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git/hooks/post-receive.push_options &&
+
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH"/upstream.git rev-parse --verify master >expect &&
+	git -C test_http_clone rev-parse --verify master >actual &&
+	test_cmp expect actual
+'
+
 stop_httpd
 
 test_done
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 4241ea5..b52b8ac 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -386,6 +386,47 @@
 	expect_ssh "-batch -P 123" myhost src
 '
 
+test_expect_success 'double quoted plink.exe in GIT_SSH_COMMAND' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	GIT_SSH_COMMAND="\"$TRASH_DIRECTORY/plink.exe\" -v" \
+		git clone "[myhost:123]:src" ssh-bracket-clone-plink-3 &&
+	expect_ssh "-v -P 123" myhost src
+'
+
+SQ="'"
+test_expect_success 'single quoted plink.exe in GIT_SSH_COMMAND' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	GIT_SSH_COMMAND="$SQ$TRASH_DIRECTORY/plink.exe$SQ -v" \
+		git clone "[myhost:123]:src" ssh-bracket-clone-plink-4 &&
+	expect_ssh "-v -P 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink detection' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	GIT_SSH_VARIANT=ssh \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-1 &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'ssh.variant overrides plink detection' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	git -c ssh.variant=ssh \
+		clone "[myhost:123]:src" ssh-bracket-clone-variant-2 &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink detection to plink' '
+	GIT_SSH_VARIANT=plink \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-3 &&
+	expect_ssh "-P 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink to tortoiseplink' '
+	GIT_SSH_VARIANT=tortoiseplink \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-4 &&
+	expect_ssh "-batch -P 123" myhost src
+'
+
 # Reset the GIT_SSH environment variable for clone tests.
 setup_ssh_wrapper
 
diff --git a/t/t6007-rev-list-cherry-pick-file.sh b/t/t6007-rev-list-cherry-pick-file.sh
index 1408b60..2959745 100755
--- a/t/t6007-rev-list-cherry-pick-file.sh
+++ b/t/t6007-rev-list-cherry-pick-file.sh
@@ -99,6 +99,44 @@
 	test_cmp actual.named expect
 '
 
+test_expect_success 'name-rev multiple --refs combine inclusive' '
+	git rev-list --left-right --cherry-pick F...E -- bar >actual &&
+	git name-rev --stdin --name-only --refs="*tags/F" --refs="*tags/E" \
+		<actual >actual.named &&
+	test_cmp actual.named expect
+'
+
+cat >expect <<EOF
+<tags/F
+EOF
+
+test_expect_success 'name-rev --refs excludes non-matched patterns' '
+	git rev-list --left-right --right-only --cherry-pick F...E -- bar >>expect &&
+	git rev-list --left-right --cherry-pick F...E -- bar >actual &&
+	git name-rev --stdin --name-only --refs="*tags/F" \
+		<actual >actual.named &&
+	test_cmp actual.named expect
+'
+
+cat >expect <<EOF
+<tags/F
+EOF
+
+test_expect_success 'name-rev --exclude excludes matched patterns' '
+	git rev-list --left-right --right-only --cherry-pick F...E -- bar >>expect &&
+	git rev-list --left-right --cherry-pick F...E -- bar >actual &&
+	git name-rev --stdin --name-only --refs="*tags/*" --exclude="*E" \
+		<actual >actual.named &&
+	test_cmp actual.named expect
+'
+
+test_expect_success 'name-rev --no-refs clears the refs list' '
+	git rev-list --left-right --cherry-pick F...E -- bar >expect &&
+	git name-rev --stdin --name-only --refs="*tags/F" --refs="*tags/E" --no-refs --refs="*tags/G" \
+		<expect >actual &&
+	test_cmp actual expect
+'
+
 cat >expect <<EOF
 +tags/F
 =tags/D
diff --git a/t/t6040-tracking-info.sh b/t/t6040-tracking-info.sh
index 3d5c238..97a0765 100755
--- a/t/t6040-tracking-info.sh
+++ b/t/t6040-tracking-info.sh
@@ -44,7 +44,7 @@
 b2 [ahead 1, behind 1] d
 b3 [behind 1] b
 b4 [ahead 2] f
-b5 g
+b5 [gone] g
 b6 c
 EOF
 
diff --git a/t/t6045-merge-rename-delete.sh b/t/t6045-merge-rename-delete.sh
new file mode 100755
index 0000000..5d33577
--- /dev/null
+++ b/t/t6045-merge-rename-delete.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+test_description='Merge-recursive rename/delete conflict message'
+. ./test-lib.sh
+
+test_expect_success 'rename/delete' '
+	echo foo >A &&
+	git add A &&
+	git commit -m "initial" &&
+
+	git checkout -b rename &&
+	git mv A B &&
+	git commit -m "rename" &&
+
+	git checkout master &&
+	git rm A &&
+	git commit -m "delete" &&
+
+	test_must_fail git merge --strategy=recursive rename >output &&
+	test_i18ngrep "CONFLICT (rename/delete): A deleted in HEAD and renamed to B in rename. Version rename of B left in tree." output
+'
+
+test_done
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 85f2694..16952e4 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -182,6 +182,10 @@
 
 check_describe "test2-lightweight-*" --long --tags --match="test2-*" HEAD^
 
+check_describe "test1-lightweight-*" --long --tags --match="test1-*" --match="test2-*" HEAD^
+
+check_describe "test2-lightweight-*" --long --tags --match="test1-*" --no-match --match="test2-*" HEAD^
+
 test_expect_success 'name-rev with exact tags' '
 	echo A >expect &&
 	tag_object=$(git rev-parse refs/tags/A) &&
@@ -206,4 +210,47 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'describe --contains and --match' '
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	test_must_fail git describe --contains --match="B" $tagged_commit &&
+	git describe --contains --match="B" --match="A" $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --exclude' '
+	echo "c~1" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	test_must_fail git describe --contains --match="B" $tagged_commit &&
+	git describe --contains --match="?" --exclude="A" $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --contains and --no-match' '
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	git describe --contains --match="B" --no-match $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'setup and absorb a submodule' '
+	test_create_repo sub1 &&
+	test_commit -C sub1 initial &&
+	git submodule add ./sub1 &&
+	git submodule absorbgitdirs &&
+	git commit -a -m "add submodule" &&
+	git describe --dirty >expect &&
+	git describe --broken >out &&
+	test_cmp expect out
+'
+
+test_expect_success 'describe chokes on severly broken submodules' '
+	mv .git/modules/sub1/ .git/modules/sub_moved &&
+	test_must_fail git describe --dirty
+'
+test_expect_success 'describe ignoring a borken submodule' '
+	git describe --broken >out &&
+	grep broken out
+'
+
 test_done
diff --git a/t/t6132-pathspec-exclude.sh b/t/t6132-pathspec-exclude.sh
index d51595c..9dd5cde 100755
--- a/t/t6132-pathspec-exclude.sh
+++ b/t/t6132-pathspec-exclude.sh
@@ -25,8 +25,10 @@
 	test_cmp expect actual
 '
 
-test_expect_success 'exclude only should error out' '
-	test_must_fail git log --oneline --format=%s -- ":(exclude)sub"
+test_expect_success 'exclude only no longer errors out' '
+	git log --oneline --format=%s -- . ":(exclude)sub" >expect &&
+	git log --oneline --format=%s -- ":(exclude)sub" >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 't_e_i() exclude sub' '
diff --git a/t/t6135-pathspec-with-attrs.sh b/t/t6135-pathspec-with-attrs.sh
new file mode 100755
index 0000000..77b8cef
--- /dev/null
+++ b/t/t6135-pathspec-with-attrs.sh
@@ -0,0 +1,200 @@
+#!/bin/sh
+
+test_description='test labels in pathspecs'
+. ./test-lib.sh
+
+test_expect_success 'setup a tree' '
+	cat <<-\EOF >expect &&
+	fileA
+	fileAB
+	fileAC
+	fileB
+	fileBC
+	fileC
+	fileNoLabel
+	fileSetLabel
+	fileUnsetLabel
+	fileValue
+	fileWrongLabel
+	sub/fileA
+	sub/fileAB
+	sub/fileAC
+	sub/fileB
+	sub/fileBC
+	sub/fileC
+	sub/fileNoLabel
+	sub/fileSetLabel
+	sub/fileUnsetLabel
+	sub/fileValue
+	sub/fileWrongLabel
+	EOF
+	mkdir sub &&
+	while read path
+	do
+		: >$path &&
+		git add $path || return 1
+	done <expect &&
+	git commit -m "initial commit" &&
+	git ls-files >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'pathspec with no attr' '
+	test_must_fail git ls-files ":(attr:)"
+'
+
+test_expect_success 'pathspec with labels and non existent .gitattributes' '
+	git ls-files ":(attr:label)" >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'setup .gitattributes' '
+	cat <<-\EOF >.gitattributes &&
+	fileA labelA
+	fileB labelB
+	fileC labelC
+	fileAB labelA labelB
+	fileAC labelA labelC
+	fileBC labelB labelC
+	fileUnsetLabel -label
+	fileSetLabel label
+	fileValue label=foo
+	fileWrongLabel label☺
+	EOF
+	git add .gitattributes &&
+	git commit -m "add attributes"
+'
+
+test_expect_success 'check specific set attr' '
+	cat <<-\EOF >expect &&
+	fileSetLabel
+	sub/fileSetLabel
+	EOF
+	git ls-files ":(attr:label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check specific unset attr' '
+	cat <<-\EOF >expect &&
+	fileUnsetLabel
+	sub/fileUnsetLabel
+	EOF
+	git ls-files ":(attr:-label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check specific value attr' '
+	cat <<-\EOF >expect &&
+	fileValue
+	sub/fileValue
+	EOF
+	git ls-files ":(attr:label=foo)" >actual &&
+	test_cmp expect actual &&
+	git ls-files ":(attr:label=bar)" >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'check unspecified attr' '
+	cat <<-\EOF >expect &&
+	.gitattributes
+	fileA
+	fileAB
+	fileAC
+	fileB
+	fileBC
+	fileC
+	fileNoLabel
+	fileWrongLabel
+	sub/fileA
+	sub/fileAB
+	sub/fileAC
+	sub/fileB
+	sub/fileBC
+	sub/fileC
+	sub/fileNoLabel
+	sub/fileWrongLabel
+	EOF
+	git ls-files ":(attr:!label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check multiple unspecified attr' '
+	cat <<-\EOF >expect &&
+	.gitattributes
+	fileC
+	fileNoLabel
+	fileWrongLabel
+	sub/fileC
+	sub/fileNoLabel
+	sub/fileWrongLabel
+	EOF
+	git ls-files ":(attr:!labelB !labelA !label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check label with more labels but excluded path' '
+	cat <<-\EOF >expect &&
+	fileAB
+	fileB
+	fileBC
+	EOF
+	git ls-files ":(attr:labelB)" ":(exclude)sub/" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check label excluding other labels' '
+	cat <<-\EOF >expect &&
+	fileAB
+	fileB
+	fileBC
+	sub/fileAB
+	sub/fileB
+	EOF
+	git ls-files ":(attr:labelB)" ":(exclude,attr:labelC)sub/" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'fail on multiple attr specifiers in one pathspec item' '
+	test_must_fail git ls-files . ":(attr:labelB,attr:labelC)" 2>actual &&
+	test_i18ngrep "Only one" actual
+'
+
+test_expect_success 'fail if attr magic is used places not implemented' '
+	# The main purpose of this test is to check that we actually fail
+	# when you attempt to use attr magic in commands that do not implement
+	# attr magic. This test does not advocate git-add to stay that way,
+	# though, but git-add is convenient as it has its own internal pathspec
+	# parsing.
+	test_must_fail git add ":(attr:labelB)" 2>actual &&
+	test_i18ngrep "unsupported magic" actual
+'
+
+test_expect_success 'abort on giving invalid label on the command line' '
+	test_must_fail git ls-files . ":(attr:☺)"
+'
+
+test_expect_success 'abort on asking for wrong magic' '
+	test_must_fail git ls-files . ":(attr:-label=foo)" &&
+	test_must_fail git ls-files . ":(attr:!label=foo)"
+'
+
+test_expect_success 'check attribute list' '
+	cat <<-EOF >>.gitattributes &&
+	* whitespace=indent,trail,space
+	EOF
+	git ls-files ":(attr:whitespace=indent\,trail\,space)" >actual &&
+	git ls-files >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'backslash cannot be the last character' '
+	test_must_fail git ls-files ":(attr:label=foo\\ labelA=bar)" 2>actual &&
+	test_i18ngrep "not allowed as last character in attr value" actual
+'
+
+test_expect_success 'backslash cannot be used as a value' '
+	test_must_fail git ls-files ":(attr:label=f\\\oo)" 2>actual &&
+	test_i18ngrep "for value matching" actual
+'
+
+test_done
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index a468041..834a9ed 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -38,6 +38,7 @@
 	case "$1" in
 		head) ref=refs/heads/master ;;
 		 tag) ref=refs/tags/testtag ;;
+		 sym) ref=refs/heads/sym ;;
 		   *) ref=$1 ;;
 	esac
 	printf '%s\n' "$3" >expected
@@ -50,16 +51,40 @@
 
 test_atom head refname refs/heads/master
 test_atom head refname:short master
+test_atom head refname:lstrip=1 heads/master
+test_atom head refname:lstrip=2 master
+test_atom head refname:lstrip=-1 master
+test_atom head refname:lstrip=-2 heads/master
+test_atom head refname:rstrip=1 refs/heads
+test_atom head refname:rstrip=2 refs
+test_atom head refname:rstrip=-1 refs
+test_atom head refname:rstrip=-2 refs/heads
 test_atom head refname:strip=1 heads/master
 test_atom head refname:strip=2 master
+test_atom head refname:strip=-1 master
+test_atom head refname:strip=-2 heads/master
 test_atom head upstream refs/remotes/origin/master
 test_atom head upstream:short origin/master
+test_atom head upstream:lstrip=2 origin/master
+test_atom head upstream:lstrip=-2 origin/master
+test_atom head upstream:rstrip=2 refs/remotes
+test_atom head upstream:rstrip=-2 refs/remotes
+test_atom head upstream:strip=2 origin/master
+test_atom head upstream:strip=-2 origin/master
 test_atom head push refs/remotes/myfork/master
 test_atom head push:short myfork/master
+test_atom head push:lstrip=1 remotes/myfork/master
+test_atom head push:lstrip=-1 master
+test_atom head push:rstrip=1 refs/remotes/myfork
+test_atom head push:rstrip=-1 refs
+test_atom head push:strip=1 remotes/myfork/master
+test_atom head push:strip=-1 master
 test_atom head objecttype commit
 test_atom head objectsize 171
 test_atom head 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)
+test_atom head objectname:short=10 $(git rev-parse --short=10 refs/heads/master)
 test_atom head tree $(git rev-parse refs/heads/master^{tree})
 test_atom head parent ''
 test_atom head numparent 0
@@ -99,6 +124,8 @@
 test_atom tag objectsize 154
 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)
+test_atom head objectname:short=10 $(git rev-parse --short=10 refs/heads/master)
 test_atom tag tree ''
 test_atom tag parent ''
 test_atom tag numparent ''
@@ -134,16 +161,6 @@
 	test_must_fail git for-each-ref --format="%(INVALID)" refs/heads
 '
 
-test_expect_success 'arguments to :strip must be positive integers' '
-	test_must_fail git for-each-ref --format="%(refname:strip=0)" &&
-	test_must_fail git for-each-ref --format="%(refname:strip=-1)" &&
-	test_must_fail git for-each-ref --format="%(refname:strip=foo)"
-'
-
-test_expect_success 'stripping refnames too far gives an error' '
-	test_must_fail git for-each-ref --format="%(refname:strip=3)"
-'
-
 test_expect_success 'Check format specifiers are ignored in naming date atoms' '
 	git for-each-ref --format="%(authordate)" refs/heads &&
 	git for-each-ref --format="%(authordate:default) %(authordate)" refs/heads &&
@@ -164,6 +181,12 @@
 	test_must_fail git for-each-ref --format="%(authordate:INVALID)" refs/heads
 '
 
+test_expect_success 'arguments to %(objectname:short=) must be positive integers' '
+	test_must_fail git for-each-ref --format="%(objectname:short=0)" &&
+	test_must_fail git for-each-ref --format="%(objectname:short=-1)" &&
+	test_must_fail git for-each-ref --format="%(objectname:short=foo)"
+'
+
 test_date () {
 	f=$1 &&
 	committer_date=$2 &&
@@ -362,6 +385,8 @@
 
 test_atom head upstream:track '[ahead 1]'
 test_atom head upstream:trackshort '>'
+test_atom head upstream:track,nobracket 'ahead 1'
+test_atom head upstream:nobracket,track 'ahead 1'
 test_atom head push:track '[ahead 1]'
 test_atom head push:trackshort '>'
 
@@ -372,7 +397,7 @@
 
 test_expect_success 'Check that :track[short] works when upstream is invalid' '
 	cat >expected <<-\EOF &&
-
+	[gone]
 
 	EOF
 	test_when_finished "git config branch.master.merge refs/heads/master" &&
@@ -554,6 +579,7 @@
 	test_cmp expected actual
 '
 
+
 test_expect_success 'do not dereference NULL upon %(HEAD) on unborn branch' '
 	test_when_finished "git checkout master" &&
 	git for-each-ref --format="%(HEAD) %(refname:short)" refs/heads/ >actual &&
@@ -588,4 +614,52 @@
 	test_cmp expect actual.clean
 '
 
+test_expect_success 'Add symbolic ref for the following tests' '
+	git symbolic-ref refs/heads/sym refs/heads/master
+'
+
+cat >expected <<EOF
+refs/heads/master
+EOF
+
+test_expect_success 'Verify usage of %(symref) atom' '
+	git for-each-ref --format="%(symref)" refs/heads/sym >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+heads/master
+EOF
+
+test_expect_success 'Verify usage of %(symref:short) atom' '
+	git for-each-ref --format="%(symref:short)" refs/heads/sym >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+master
+heads/master
+EOF
+
+test_expect_success 'Verify usage of %(symref:lstrip) atom' '
+	git for-each-ref --format="%(symref:lstrip=2)" refs/heads/sym > actual &&
+	git for-each-ref --format="%(symref:lstrip=-2)" refs/heads/sym >> actual &&
+	test_cmp expected actual &&
+
+	git for-each-ref --format="%(symref:strip=2)" refs/heads/sym > actual &&
+	git for-each-ref --format="%(symref:strip=-2)" refs/heads/sym >> actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+refs
+refs/heads
+EOF
+
+test_expect_success 'Verify usage of %(symref:rstrip) atom' '
+	git for-each-ref --format="%(symref:rstrip=2)" refs/heads/sym > actual &&
+	git for-each-ref --format="%(symref:rstrip=-2)" refs/heads/sym >> actual &&
+	test_cmp expected actual
+'
+
 test_done
diff --git a/t/t6302-for-each-ref-filter.sh b/t/t6302-for-each-ref-filter.sh
index d0ab09f..a09a1a4 100755
--- a/t/t6302-for-each-ref-filter.sh
+++ b/t/t6302-for-each-ref-filter.sh
@@ -327,4 +327,98 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'improper usage of %(if), %(then), %(else) and %(end) atoms' '
+	test_must_fail git for-each-ref --format="%(if)" &&
+	test_must_fail git for-each-ref --format="%(then) %(end)" &&
+	test_must_fail git for-each-ref --format="%(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(then) %(then) %(end)" &&
+	test_must_fail git for-each-ref --format="%(then) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(then) %(else)" &&
+	test_must_fail git for-each-ref --format="%(if) %(else) %(then) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(then) %(else) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(end)"
+'
+
+test_expect_success 'check %(if)...%(then)...%(end) atoms' '
+	git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Author: %(authorname)%(end)" >actual &&
+	cat >expect <<-\EOF &&
+	refs/heads/master Author: A U Thor
+	refs/heads/side Author: A U Thor
+	refs/odd/spot Author: A U Thor
+	refs/tags/annotated-tag
+	refs/tags/doubly-annotated-tag
+	refs/tags/doubly-signed-tag
+	refs/tags/foo1.10 Author: A U Thor
+	refs/tags/foo1.3 Author: A U Thor
+	refs/tags/foo1.6 Author: A U Thor
+	refs/tags/four Author: A U Thor
+	refs/tags/one Author: A U Thor
+	refs/tags/signed-tag
+	refs/tags/three Author: A U Thor
+	refs/tags/two Author: A U Thor
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check %(if)...%(then)...%(else)...%(end) atoms' '
+	git for-each-ref --format="%(if)%(authorname)%(then)%(authorname)%(else)No author%(end): %(refname)" >actual &&
+	cat >expect <<-\EOF &&
+	A U Thor: refs/heads/master
+	A U Thor: refs/heads/side
+	A U Thor: refs/odd/spot
+	No author: refs/tags/annotated-tag
+	No author: refs/tags/doubly-annotated-tag
+	No author: refs/tags/doubly-signed-tag
+	A U Thor: refs/tags/foo1.10
+	A U Thor: refs/tags/foo1.3
+	A U Thor: refs/tags/foo1.6
+	A U Thor: refs/tags/four
+	A U Thor: refs/tags/one
+	No author: refs/tags/signed-tag
+	A U Thor: refs/tags/three
+	A U Thor: refs/tags/two
+	EOF
+	test_cmp expect actual
+'
+test_expect_success 'ignore spaces in %(if) atom usage' '
+	git for-each-ref --format="%(refname:short): %(if)%(HEAD)%(then)Head ref%(else)Not Head ref%(end)" >actual &&
+	cat >expect <<-\EOF &&
+	master: Head ref
+	side: Not Head ref
+	odd/spot: Not Head ref
+	annotated-tag: Not Head ref
+	doubly-annotated-tag: Not Head ref
+	doubly-signed-tag: Not Head ref
+	foo1.10: Not Head ref
+	foo1.3: Not Head ref
+	foo1.6: Not Head ref
+	four: Not Head ref
+	one: Not Head ref
+	signed-tag: Not Head ref
+	three: Not Head ref
+	two: Not Head ref
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check %(if:equals=<string>)' '
+	git for-each-ref --format="%(if:equals=master)%(refname:short)%(then)Found master%(else)Not master%(end)" refs/heads/ >actual &&
+	cat >expect <<-\EOF &&
+	Found master
+	Not master
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check %(if:notequals=<string>)' '
+	git for-each-ref --format="%(if:notequals=master)%(refname:short)%(then)Not master%(else)Found master%(end)" refs/heads/ >actual &&
+	cat >expect <<-\EOF &&
+	Found master
+	Not master
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index b8ad076..772dc9e 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -81,9 +81,25 @@
 '
 
 test_expect_success 'creating a tag with --create-reflog should create reflog' '
+	git log -1 \
+		--format="format:tag: tagging %h (%s, %cd)%n" \
+		--date=format:%Y-%m-%d >expected &&
 	test_when_finished "git tag -d tag_with_reflog" &&
 	git tag --create-reflog tag_with_reflog &&
-	git reflog exists refs/tags/tag_with_reflog
+	git reflog exists refs/tags/tag_with_reflog &&
+	sed -e "s/^.*	//" .git/logs/refs/tags/tag_with_reflog >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'annotated tag with --create-reflog has correct message' '
+	git log -1 \
+		--format="format:tag: tagging %h (%s, %cd)%n" \
+		--date=format:%Y-%m-%d >expected &&
+	test_when_finished "git tag -d tag_with_reflog" &&
+	git tag -m "annotated tag" --create-reflog tag_with_reflog &&
+	git reflog exists refs/tags/tag_with_reflog &&
+	sed -e "s/^.*	//" .git/logs/refs/tags/tag_with_reflog >actual &&
+	test_cmp expected actual
 '
 
 test_expect_success '--create-reflog does not create reflog on failure' '
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index c8dc665..4f3794d 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -360,27 +360,37 @@
 test_default_pager        expect_success 'git -p aliasedlog'
 test_PAGER_overrides      expect_success 'git -p aliasedlog'
 test_core_pager_overrides expect_success 'git -p aliasedlog'
-test_core_pager_subdir    expect_failure 'git -p aliasedlog'
+test_core_pager_subdir    expect_success 'git -p aliasedlog'
 test_GIT_PAGER_overrides  expect_success 'git -p aliasedlog'
 
 test_default_pager        expect_success 'git -p true'
 test_PAGER_overrides      expect_success 'git -p true'
 test_core_pager_overrides expect_success 'git -p true'
-test_core_pager_subdir    expect_failure 'git -p true'
+test_core_pager_subdir    expect_success 'git -p true'
 test_GIT_PAGER_overrides  expect_success 'git -p true'
 
 test_default_pager        expect_success test_must_fail 'git -p request-pull'
 test_PAGER_overrides      expect_success test_must_fail 'git -p request-pull'
 test_core_pager_overrides expect_success test_must_fail 'git -p request-pull'
-test_core_pager_subdir    expect_failure test_must_fail 'git -p request-pull'
+test_core_pager_subdir    expect_success test_must_fail 'git -p request-pull'
 test_GIT_PAGER_overrides  expect_success test_must_fail 'git -p request-pull'
 
 test_default_pager        expect_success test_must_fail 'git -p'
 test_PAGER_overrides      expect_success test_must_fail 'git -p'
 test_local_config_ignored expect_failure test_must_fail 'git -p'
-test_no_local_config_subdir expect_success test_must_fail 'git -p'
 test_GIT_PAGER_overrides  expect_success test_must_fail 'git -p'
 
+test_expect_success TTY 'core.pager in repo config works and retains cwd' '
+	sane_unset GIT_PAGER &&
+	test_config core.pager "cat >cwd-retained" &&
+	(
+		cd sub &&
+		rm -f cwd-retained &&
+		test_terminal git -p rev-parse HEAD &&
+		test_path_is_file cwd-retained
+	)
+'
+
 test_doesnt_paginate      expect_failure test_must_fail 'git -p nonsense'
 
 test_pager_choices                       'git shortlog'
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 25241f4..0e7f30d 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -428,7 +428,7 @@
 		git difftool --dir-diff $symlinks --extcmd ls branch >output &&
 		# "sub" must only exist in "right"
 		# "file" and "file2" must be listed in both "left" and "right"
-		grep sub output > sub-output &&
+		grep sub output >sub-output &&
 		test_line_count = 1 sub-output &&
 		grep file"$" output >file-output &&
 		test_line_count = 2 file-output &&
@@ -591,6 +591,7 @@
 '
 
 test_expect_success 'difftool properly honors gitlink and core.worktree' '
+	test_when_finished rm -rf submod/ule &&
 	git submodule add ./. submod/ule &&
 	test_config -C submod/ule diff.tool checktrees &&
 	test_config -C submod/ule difftool.checktrees.cmd '\''
@@ -600,11 +601,13 @@
 		cd submod/ule &&
 		echo good >expect &&
 		git difftool --tool=checktrees --dir-diff HEAD~ >actual &&
-		test_cmp expect actual
+		test_cmp expect actual &&
+		rm -f expect actual
 	)
 '
 
 test_expect_success SYMLINKS 'difftool --dir-diff symlinked directories' '
+	test_when_finished git reset --hard &&
 	git init dirlinks &&
 	(
 		cd dirlinks &&
@@ -623,4 +626,64 @@
 	)
 '
 
+test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' '
+	test_when_finished git reset --hard &&
+	touch b &&
+	ln -s b c &&
+	git add b c &&
+	test_tick &&
+	git commit -m initial &&
+	touch d &&
+	rm c &&
+	ln -s d c &&
+	cat >expect <<-EOF &&
+		b
+		c
+
+		c
+	EOF
+	git difftool --symlinks --dir-diff --extcmd ls >output &&
+	grep -v ^/ output >actual &&
+	test_cmp expect actual &&
+
+	git difftool --no-symlinks --dir-diff --extcmd ls >output &&
+	grep -v ^/ output >actual &&
+	test_cmp expect actual &&
+
+	# The left side contains symlink "c" that points to "b"
+	test_config difftool.cat.cmd "cat \$LOCAL/c" &&
+	printf "%s\n" b >expect &&
+
+	git difftool --symlinks --dir-diff --tool cat >actual &&
+	test_cmp expect actual &&
+
+	git difftool --symlinks --no-symlinks --dir-diff --tool cat >actual &&
+	test_cmp expect actual &&
+
+	# The right side contains symlink "c" that points to "d"
+	test_config difftool.cat.cmd "cat \$REMOTE/c" &&
+	printf "%s\n" d >expect &&
+
+	git difftool --symlinks --dir-diff --tool cat >actual &&
+	test_cmp expect actual &&
+
+	git difftool --no-symlinks --dir-diff --tool cat >actual &&
+	test_cmp expect actual &&
+
+	# Deleted symlinks
+	rm -f c &&
+	cat >expect <<-EOF &&
+		b
+		c
+
+	EOF
+	git difftool --symlinks --dir-diff --extcmd ls >output &&
+	grep -v ^/ output >actual &&
+	test_cmp expect actual &&
+
+	git difftool --no-symlinks --dir-diff --extcmd ls >output &&
+	grep -v ^/ output >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index a34e55f..d711bef 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -98,7 +98,7 @@
 {
 	local -a COMPREPLY &&
 	sed -e 's/Z$//' >expected &&
-	cur="$1" &&
+	local cur="$1" &&
 	shift &&
 	__gitcomp "$@" &&
 	print_comp &&
@@ -113,7 +113,7 @@
 {
 	local -a COMPREPLY &&
 	sed -e 's/Z$//' >expected &&
-	cur="$1" &&
+	local cur="$1" &&
 	shift &&
 	__gitcomp_nl "$@" &&
 	print_comp &&
@@ -124,140 +124,280 @@
 
 actual="$TRASH_DIRECTORY/actual"
 
-test_expect_success 'setup for __gitdir tests' '
+if test_have_prereq MINGW
+then
+	ROOT="$(pwd -W)"
+else
+	ROOT="$(pwd)"
+fi
+
+test_expect_success 'setup for __git_find_repo_path/__gitdir tests' '
 	mkdir -p subdir/subsubdir &&
+	mkdir -p non-repo &&
 	git init otherrepo
 '
 
-test_expect_success '__gitdir - from command line (through $__git_dir)' '
-	echo "$TRASH_DIRECTORY/otherrepo/.git" >expected &&
+test_expect_success '__git_find_repo_path - from command line (through $__git_dir)' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	(
-		__git_dir="$TRASH_DIRECTORY/otherrepo/.git" &&
-		__gitdir >"$actual"
+		__git_dir="$ROOT/otherrepo/.git" &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - repo as argument' '
-	echo "otherrepo/.git" >expected &&
-	__gitdir "otherrepo" >"$actual" &&
-	test_cmp expected "$actual"
-'
-
-test_expect_success '__gitdir - remote as argument' '
-	echo "remote" >expected &&
-	__gitdir "remote" >"$actual" &&
-	test_cmp expected "$actual"
-'
-
-test_expect_success '__gitdir - .git directory in cwd' '
+test_expect_success '__git_find_repo_path - .git directory in cwd' '
 	echo ".git" >expected &&
-	__gitdir >"$actual" &&
+	(
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - .git directory in parent' '
-	echo "$(pwd -P)/.git" >expected &&
+test_expect_success '__git_find_repo_path - .git directory in parent' '
+	echo "$ROOT/.git" >expected &&
 	(
 		cd subdir/subsubdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - cwd is a .git directory' '
+test_expect_success '__git_find_repo_path - cwd is a .git directory' '
 	echo "." >expected &&
 	(
 		cd .git &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - parent is a .git directory' '
-	echo "$(pwd -P)/.git" >expected &&
+test_expect_success '__git_find_repo_path - parent is a .git directory' '
+	echo "$ROOT/.git" >expected &&
 	(
 		cd .git/refs/heads &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - $GIT_DIR set while .git directory in cwd' '
-	echo "$TRASH_DIRECTORY/otherrepo/.git" >expected &&
+test_expect_success '__git_find_repo_path - $GIT_DIR set while .git directory in cwd' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	(
-		GIT_DIR="$TRASH_DIRECTORY/otherrepo/.git" &&
+		GIT_DIR="$ROOT/otherrepo/.git" &&
 		export GIT_DIR &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - $GIT_DIR set while .git directory in parent' '
-	echo "$TRASH_DIRECTORY/otherrepo/.git" >expected &&
+test_expect_success '__git_find_repo_path - $GIT_DIR set while .git directory in parent' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	(
-		GIT_DIR="$TRASH_DIRECTORY/otherrepo/.git" &&
+		GIT_DIR="$ROOT/otherrepo/.git" &&
 		export GIT_DIR &&
 		cd subdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - non-existing $GIT_DIR' '
+test_expect_success '__git_find_repo_path - from command line while "git -C"' '
+	echo "$ROOT/.git" >expected &&
 	(
-		GIT_DIR="$TRASH_DIRECTORY/non-existing" &&
-		export GIT_DIR &&
-		test_must_fail __gitdir
-	)
+		__git_dir="$ROOT/.git" &&
+		__git_C_args=(-C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
 '
 
-function pwd_P_W () {
-	if test_have_prereq MINGW
-	then
-		pwd -W
-	else
-		pwd -P
-	fi
-}
+test_expect_success '__git_find_repo_path - relative dir from command line and "git -C"' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd subdir &&
+		__git_dir="otherrepo/.git" &&
+		__git_C_args=(-C ..) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
 
-test_expect_success '__gitdir - gitfile in cwd' '
-	echo "$(pwd_P_W)/otherrepo/.git" >expected &&
-	echo "gitdir: $(pwd_P_W)/otherrepo/.git" >subdir/.git &&
+test_expect_success '__git_find_repo_path - $GIT_DIR set while "git -C"' '
+	echo "$ROOT/.git" >expected &&
+	(
+		GIT_DIR="$ROOT/.git" &&
+		export GIT_DIR &&
+		__git_C_args=(-C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - relative dir in $GIT_DIR and "git -C"' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd subdir &&
+		GIT_DIR="otherrepo/.git" &&
+		export GIT_DIR &&
+		__git_C_args=(-C ..) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - "git -C" while .git directory in cwd' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		__git_C_args=(-C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - "git -C" while cwd is a .git directory' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd .git &&
+		__git_C_args=(-C .. -C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - "git -C" while .git directory in parent' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd subdir &&
+		__git_C_args=(-C .. -C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - non-existing path in "git -C"' '
+	(
+		__git_C_args=(-C non-existing) &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_find_repo_path - non-existing path in $__git_dir' '
+	(
+		__git_dir="non-existing" &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_find_repo_path - non-existing $GIT_DIR' '
+	(
+		GIT_DIR="$ROOT/non-existing" &&
+		export GIT_DIR &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_find_repo_path - gitfile in cwd' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	echo "gitdir: $ROOT/otherrepo/.git" >subdir/.git &&
 	test_when_finished "rm -f subdir/.git" &&
 	(
 		cd subdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - gitfile in parent' '
-	echo "$(pwd_P_W)/otherrepo/.git" >expected &&
-	echo "gitdir: $(pwd_P_W)/otherrepo/.git" >subdir/.git &&
+test_expect_success '__git_find_repo_path - gitfile in parent' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	echo "gitdir: $ROOT/otherrepo/.git" >subdir/.git &&
 	test_when_finished "rm -f subdir/.git" &&
 	(
 		cd subdir/subsubdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success SYMLINKS '__gitdir - resulting path avoids symlinks' '
-	echo "$(pwd -P)/otherrepo/.git" >expected &&
+test_expect_success SYMLINKS '__git_find_repo_path - resulting path avoids symlinks' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	mkdir otherrepo/dir &&
 	test_when_finished "rm -rf otherrepo/dir" &&
 	ln -s otherrepo/dir link &&
 	test_when_finished "rm -f link" &&
 	(
 		cd link &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - not a git repository' '
+	(
+		cd non-repo &&
+		GIT_CEILING_DIRECTORIES="$ROOT" &&
+		export GIT_CEILING_DIRECTORIES &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__gitdir - finds repo' '
+	echo "$ROOT/.git" >expected &&
+	(
+		cd subdir/subsubdir &&
 		__gitdir >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - not a git repository' '
-	nongit test_must_fail __gitdir
+
+test_expect_success '__gitdir - returns error when cant find repo' '
+	(
+		__git_dir="non-existing" &&
+		test_must_fail __gitdir >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__gitdir - repo as argument' '
+	echo "otherrepo/.git" >expected &&
+	(
+		__gitdir "otherrepo" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__gitdir - remote as argument' '
+	echo "remote" >expected &&
+	(
+		__gitdir "remote" >"$actual"
+	) &&
+	test_cmp expected "$actual"
 '
 
 test_expect_success '__gitcomp - trailing space - options' '
@@ -361,10 +501,286 @@
 	git remote add remote_in_config_1 git://remote_1 &&
 	test_when_finished "git remote remove remote_in_config_2" &&
 	git remote add remote_in_config_2 git://remote_2 &&
-	__git_remotes >actual &&
+	(
+		__git_remotes >actual
+	) &&
 	test_cmp expect actual
 '
 
+test_expect_success '__git_is_configured_remote' '
+	test_when_finished "git remote remove remote_1" &&
+	git remote add remote_1 git://remote_1 &&
+	test_when_finished "git remote remove remote_2" &&
+	git remote add remote_2 git://remote_2 &&
+	(
+		verbose __git_is_configured_remote remote_2 &&
+		test_must_fail __git_is_configured_remote non-existent
+	)
+'
+
+test_expect_success 'setup for ref completion' '
+	git commit --allow-empty -m initial &&
+	git branch matching-branch &&
+	git tag matching-tag &&
+	(
+		cd otherrepo &&
+		git commit --allow-empty -m initial &&
+		git branch -m master master-in-other &&
+		git branch branch-in-other &&
+		git tag tag-in-other
+	) &&
+	git remote add other "$ROOT/otherrepo/.git" &&
+	git fetch --no-tags other &&
+	rm -f .git/FETCH_HEAD &&
+	git init thirdrepo
+'
+
+test_expect_success '__git_refs - simple' '
+	cat >expected <<-EOF &&
+	HEAD
+	master
+	matching-branch
+	other/branch-in-other
+	other/master-in-other
+	matching-tag
+	EOF
+	(
+		cur= &&
+		__git_refs >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/master
+	refs/heads/matching-branch
+	EOF
+	(
+		cur=refs/heads/ &&
+		__git_refs >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - repo given on the command line' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	tag-in-other
+	EOF
+	(
+		__git_dir="$ROOT/otherrepo/.git" &&
+		cur= &&
+		__git_refs >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - remote on local file system' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	tag-in-other
+	EOF
+	(
+		cur= &&
+		__git_refs otherrepo >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - remote on local file system - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cur=refs/ &&
+		__git_refs otherrepo >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	EOF
+	(
+		cur= &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cur=refs/ &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - repo given on the command line' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	EOF
+	(
+		cd thirdrepo &&
+		__git_dir="$ROOT/.git" &&
+		cur= &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - full refs - repo given on the command line' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cd thirdrepo &&
+		__git_dir="$ROOT/.git" &&
+		cur=refs/ &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - remote name matches a directory' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	EOF
+	mkdir other &&
+	test_when_finished "rm -rf other" &&
+	(
+		cur= &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - URL remote' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	tag-in-other
+	EOF
+	(
+		cur= &&
+		__git_refs "file://$ROOT/otherrepo/.git" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - URL remote - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cur=refs/ &&
+		__git_refs "file://$ROOT/otherrepo/.git" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - non-existing remote' '
+	(
+		cur= &&
+		__git_refs non-existing >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - non-existing remote - full refs' '
+	(
+		cur=refs/ &&
+		__git_refs non-existing >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - non-existing URL remote' '
+	(
+		cur= &&
+		__git_refs "file://$ROOT/non-existing" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - non-existing URL remote - full refs' '
+	(
+		cur=refs/ &&
+		__git_refs "file://$ROOT/non-existing" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - not in a git repository' '
+	(
+		GIT_CEILING_DIRECTORIES="$ROOT" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd subdir &&
+		cur= &&
+		__git_refs >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - unique remote branches for git checkout DWIMery' '
+	cat >expected <<-EOF &&
+	HEAD
+	master
+	matching-branch
+	other/ambiguous
+	other/branch-in-other
+	other/master-in-other
+	remote/ambiguous
+	remote/branch-in-remote
+	matching-tag
+	branch-in-other
+	branch-in-remote
+	master-in-other
+	EOF
+	for remote_ref in refs/remotes/other/ambiguous \
+		refs/remotes/remote/ambiguous \
+		refs/remotes/remote/branch-in-remote
+	do
+		git update-ref $remote_ref master &&
+		test_when_finished "git update-ref -d $remote_ref"
+	done &&
+	(
+		cur= &&
+		__git_refs "" 1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'teardown after ref completion' '
+	git branch -d matching-branch &&
+	git tag -d matching-tag &&
+	git remote remove other
+'
+
 test_expect_success '__git_get_config_variables' '
 	cat >expect <<-EOF &&
 	name-1
@@ -475,7 +891,12 @@
 	test_completion "git --namespace=foo check" "checkout " &&
 	test_completion "git --paginate check" "checkout " &&
 	test_completion "git --info-path check" "checkout " &&
-	test_completion "git --no-replace-objects check" "checkout "
+	test_completion "git --no-replace-objects check" "checkout " &&
+	test_completion "git --git-dir some/path check" "checkout " &&
+	test_completion "git -c conf.var=value check" "checkout " &&
+	test_completion "git -C some/path check" "checkout " &&
+	test_completion "git --work-tree some/path check" "checkout " &&
+	test_completion "git --namespace name/space check" "checkout "
 '
 
 test_expect_success 'git --help completion' '
@@ -483,10 +904,10 @@
 	test_completion "git --help core" "core-tutorial "
 '
 
-test_expect_success 'setup for ref completion' '
+test_expect_success 'setup for integration tests' '
 	echo content >file1 &&
 	echo more >file2 &&
-	git add . &&
+	git add file1 file2 &&
 	git commit -m one &&
 	git branch mybranch &&
 	git tag mytag
@@ -500,6 +921,12 @@
 	EOF
 '
 
+test_expect_success 'git -C <path> checkout uses the right repo' '
+	test_completion "git -C subdir -C subsubdir -C .. -C ../otherrepo checkout b" <<-\EOF
+	branch-in-other Z
+	EOF
+'
+
 test_expect_success 'show completes all refs' '
 	test_completion "git show m" <<-\EOF
 	master Z
@@ -517,7 +944,7 @@
 
 test_expect_success 'complete tree filename with spaces' '
 	echo content >"name with spaces" &&
-	git add . &&
+	git add "name with spaces" &&
 	git commit -m spaces &&
 	test_completion "git show HEAD:nam" <<-\EOF
 	name with spaces Z
@@ -526,7 +953,7 @@
 
 test_expect_success 'complete tree filename with metacharacters' '
 	echo content >"name with \${meta}" &&
-	git add . &&
+	git add "name with \${meta}" &&
 	git commit -m meta &&
 	test_completion "git show HEAD:nam" <<-\EOF
 	name with ${meta} Z
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 23c29bc..13b5696 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -625,9 +625,9 @@
 		trace=
 		# 117 is magic because it is unlikely to match the exit
 		# code of other programs
-		test_eval_ "(exit 117) && $1"
-		if test "$?" != 117; then
-			error "bug in the test script: broken &&-chain: $1"
+		if test "OK-117" != "$(test_eval_ "(exit 117) && $1${LF}${LF}echo OK-\$?" 3>&1)"
+		then
+			error "bug in the test script: broken &&-chain or run-away HERE-DOC: $1"
 		fi
 		trace=$trace_tmp
 	fi
diff --git a/transport.c b/transport.c
index b58f5c8..417ed7f 100644
--- a/transport.c
+++ b/transport.c
@@ -303,7 +303,7 @@
 		if (verbose)
 			fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
 		if (ref->deletion) {
-			delete_ref(rs.dst, NULL, 0);
+			delete_ref(NULL, rs.dst, NULL, 0);
 		} else
 			update_ref("update by push", rs.dst,
 					ref->new_oid.hash, NULL, 0, 0);
@@ -471,11 +471,11 @@
 {
 	struct ref *ref;
 	int n = 0;
-	unsigned char head_sha1[20];
+	struct object_id head_oid;
 	char *head;
 	int summary_width = transport_summary_width(refs);
 
-	head = resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
+	head = resolve_refdup("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL);
 
 	if (verbose) {
 		for (ref = refs; ref; ref = ref->next)
@@ -1210,6 +1210,42 @@
 	return xstrdup(url);
 }
 
+static void read_alternate_refs(const char *path,
+				alternate_ref_fn *cb,
+				void *data)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct strbuf line = STRBUF_INIT;
+	FILE *fh;
+
+	cmd.git_cmd = 1;
+	argv_array_pushf(&cmd.args, "--git-dir=%s", path);
+	argv_array_push(&cmd.args, "for-each-ref");
+	argv_array_push(&cmd.args, "--format=%(objectname) %(refname)");
+	cmd.env = local_repo_env;
+	cmd.out = -1;
+
+	if (start_command(&cmd))
+		return;
+
+	fh = xfdopen(cmd.out, "r");
+	while (strbuf_getline_lf(&line, fh) != EOF) {
+		struct object_id oid;
+
+		if (get_oid_hex(line.buf, &oid) ||
+		    line.buf[GIT_SHA1_HEXSZ] != ' ') {
+			warning("invalid line while parsing alternate refs: %s",
+				line.buf);
+			break;
+		}
+
+		cb(line.buf + GIT_SHA1_HEXSZ + 1, &oid, data);
+	}
+
+	fclose(fh);
+	finish_command(&cmd);
+}
+
 struct alternate_refs_data {
 	alternate_ref_fn *fn;
 	void *data;
@@ -1218,34 +1254,26 @@
 static int refs_from_alternate_cb(struct alternate_object_database *e,
 				  void *data)
 {
-	char *other;
-	size_t len;
-	struct remote *remote;
-	struct transport *transport;
-	const struct ref *extra;
+	struct strbuf path = STRBUF_INIT;
+	size_t base_len;
 	struct alternate_refs_data *cb = data;
 
-	other = real_pathdup(e->path, 1);
-	len = strlen(other);
+	if (!strbuf_realpath(&path, e->path, 0))
+		goto out;
+	if (!strbuf_strip_suffix(&path, "/objects"))
+		goto out;
+	base_len = path.len;
 
-	while (other[len-1] == '/')
-		other[--len] = '\0';
-	if (len < 8 || memcmp(other + len - 8, "/objects", 8))
-		goto out;
 	/* Is this a git repository with refs? */
-	memcpy(other + len - 8, "/refs", 6);
-	if (!is_directory(other))
+	strbuf_addstr(&path, "/refs");
+	if (!is_directory(path.buf))
 		goto out;
-	other[len - 8] = '\0';
-	remote = remote_get(other);
-	transport = transport_get(remote, other);
-	for (extra = transport_get_remote_refs(transport);
-	     extra;
-	     extra = extra->next)
-		cb->fn(extra, cb->data);
-	transport_disconnect(transport);
+	strbuf_setlen(&path, base_len);
+
+	read_alternate_refs(path.buf, cb->fn, cb->data);
+
 out:
-	free(other);
+	strbuf_release(&path);
 	return 0;
 }
 
diff --git a/transport.h b/transport.h
index e597b31..bc55715 100644
--- a/transport.h
+++ b/transport.h
@@ -255,6 +255,6 @@
 void transport_print_push_status(const char *dest, struct ref *refs,
 		  int verbose, int porcelain, unsigned int *reject_reasons);
 
-typedef void alternate_ref_fn(const struct ref *, void *);
+typedef void alternate_ref_fn(const char *refname, const struct object_id *oid, void *);
 extern void for_each_alternate_ref(alternate_ref_fn, void *);
 #endif
diff --git a/unpack-trees.c b/unpack-trees.c
index 3a8ee19..8333da2 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -10,6 +10,8 @@
 #include "attr.h"
 #include "split-index.h"
 #include "dir.h"
+#include "submodule.h"
+#include "submodule-config.h"
 
 /*
  * Error messages expected by scripts out of plumbing commands such as
@@ -45,6 +47,9 @@
 
 	/* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
 	"Working tree file '%s' would be removed by sparse checkout update.",
+
+	/* ERROR_WOULD_LOSE_SUBMODULE */
+	"Submodule '%s' cannot checkout new HEAD.",
 };
 
 #define ERRORMSG(o,type) \
@@ -161,6 +166,8 @@
 		_("The following working tree files would be overwritten by sparse checkout update:\n%s");
 	msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
 		_("The following working tree files would be removed by sparse checkout update:\n%s");
+	msgs[ERROR_WOULD_LOSE_SUBMODULE] =
+		_("Submodule '%s' cannot checkout new HEAD");
 
 	opts->show_all_errors = 1;
 	/* rejected paths may not have a static buffer */
@@ -240,12 +247,75 @@
 		fprintf(stderr, _("Aborting\n"));
 }
 
+static int check_submodule_move_head(const struct cache_entry *ce,
+				     const char *old_id,
+				     const char *new_id,
+				     struct unpack_trees_options *o)
+{
+	const struct submodule *sub = submodule_from_ce(ce);
+	if (!sub)
+		return 0;
+
+	switch (sub->update_strategy.type) {
+	case SM_UPDATE_UNSPECIFIED:
+	case SM_UPDATE_CHECKOUT:
+		if (submodule_move_head(ce->name, old_id, new_id, SUBMODULE_MOVE_HEAD_DRY_RUN))
+			return o->gently ? -1 :
+				add_rejected_path(o, ERROR_WOULD_LOSE_SUBMODULE, ce->name);
+		return 0;
+	case SM_UPDATE_NONE:
+		return 0;
+	case SM_UPDATE_REBASE:
+	case SM_UPDATE_MERGE:
+	case SM_UPDATE_COMMAND:
+	default:
+		warning(_("submodule update strategy not supported for submodule '%s'"), ce->name);
+		return -1;
+	}
+}
+
+static void reload_gitmodules_file(struct index_state *index,
+				   struct checkout *state)
+{
+	int i;
+	for (i = 0; i < index->cache_nr; i++) {
+		struct cache_entry *ce = index->cache[i];
+		if (ce->ce_flags & CE_UPDATE) {
+			int r = strcmp(ce->name, ".gitmodules");
+			if (r < 0)
+				continue;
+			else if (r == 0) {
+				submodule_free();
+				checkout_entry(ce, state, NULL);
+				gitmodules_config();
+				git_config(submodule_config, NULL);
+			} else
+				break;
+		}
+	}
+}
+
 /*
  * Unlink the last component and schedule the leading directories for
  * removal, such that empty directories get removed.
  */
 static void unlink_entry(const struct cache_entry *ce)
 {
+	const struct submodule *sub = submodule_from_ce(ce);
+	if (sub) {
+		switch (sub->update_strategy.type) {
+		case SM_UPDATE_UNSPECIFIED:
+		case SM_UPDATE_CHECKOUT:
+		case SM_UPDATE_REBASE:
+		case SM_UPDATE_MERGE:
+			submodule_move_head(ce->name, "HEAD", NULL,
+					    SUBMODULE_MOVE_HEAD_FORCE);
+			break;
+		case SM_UPDATE_NONE:
+		case SM_UPDATE_COMMAND:
+			return; /* Do not touch the submodule. */
+		}
+	}
 	if (!check_leading_path(ce->name, ce_namelen(ce)))
 		return;
 	if (remove_or_warn(ce->ce_mode, ce->name))
@@ -301,6 +371,9 @@
 	remove_marked_cache_entries(index);
 	remove_scheduled_dirs();
 
+	if (should_update_submodules() && o->update && !o->dry_run)
+		reload_gitmodules_file(index, &state);
+
 	for (i = 0; i < index->cache_nr; i++) {
 		struct cache_entry *ce = index->cache[i];
 
@@ -1358,17 +1431,26 @@
 	if (!lstat(ce->name, &st)) {
 		int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
 		unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
+
+		if (submodule_from_ce(ce)) {
+			int r = check_submodule_move_head(ce,
+				"HEAD", oid_to_hex(&ce->oid), o);
+			if (r)
+				return o->gently ? -1 :
+					add_rejected_path(o, error_type, ce->name);
+			return 0;
+		}
+
 		if (!changed)
 			return 0;
 		/*
-		 * NEEDSWORK: the current default policy is to allow
-		 * submodule to be out of sync wrt the superproject
-		 * index.  This needs to be tightened later for
-		 * submodules that are marked to be automatically
-		 * checked out.
+		 * Historic default policy was to allow submodule to be out
+		 * of sync wrt the superproject index. If the submodule was
+		 * not considered interesting above, we don't care here.
 		 */
 		if (S_ISGITLINK(ce->ce_mode))
 			return 0;
+
 		errno = 0;
 	}
 	if (errno == ENOENT)
@@ -1407,11 +1489,16 @@
  * Currently, git does not checkout subprojects during a superproject
  * checkout, so it is not going to overwrite anything.
  */
-static int verify_clean_submodule(const struct cache_entry *ce,
+static int verify_clean_submodule(const char *old_sha1,
+				  const struct cache_entry *ce,
 				  enum unpack_trees_error_types error_type,
 				  struct unpack_trees_options *o)
 {
-	return 0;
+	if (!submodule_from_ce(ce))
+		return 0;
+
+	return check_submodule_move_head(ce, old_sha1,
+					 oid_to_hex(&ce->oid), o);
 }
 
 static int verify_clean_subdirectory(const struct cache_entry *ce,
@@ -1427,16 +1514,18 @@
 	struct dir_struct d;
 	char *pathbuf;
 	int cnt = 0;
-	unsigned char sha1[20];
 
-	if (S_ISGITLINK(ce->ce_mode) &&
-	    resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
-		/* If we are not going to update the submodule, then
+	if (S_ISGITLINK(ce->ce_mode)) {
+		unsigned char sha1[20];
+		int sub_head = resolve_gitlink_ref(ce->name, "HEAD", sha1);
+		/*
+		 * If we are not going to update the submodule, then
 		 * we don't care.
 		 */
-		if (!hashcmp(sha1, ce->oid.hash))
+		if (!sub_head && !hashcmp(sha1, ce->oid.hash))
 			return 0;
-		return verify_clean_submodule(ce, error_type, o);
+		return verify_clean_submodule(sub_head ? NULL : sha1_to_hex(sha1),
+					      ce, error_type, o);
 	}
 
 	/*
@@ -1575,9 +1664,15 @@
 		path = xmemdupz(ce->name, len);
 		if (lstat(path, &st))
 			ret = error_errno("cannot stat '%s'", path);
-		else
-			ret = check_ok_to_remove(path, len, DT_UNKNOWN, NULL,
-						 &st, error_type, o);
+		else {
+			if (submodule_from_ce(ce))
+				ret = check_submodule_move_head(ce,
+								oid_to_hex(&ce->oid),
+								NULL, o);
+			else
+				ret = check_ok_to_remove(path, len, DT_UNKNOWN, NULL,
+							 &st, error_type, o);
+		}
 		free(path);
 		return ret;
 	} else if (lstat(ce->name, &st)) {
@@ -1585,6 +1680,10 @@
 			return error_errno("cannot stat '%s'", ce->name);
 		return 0;
 	} else {
+		if (submodule_from_ce(ce))
+			return check_submodule_move_head(ce, oid_to_hex(&ce->oid),
+							 NULL, o);
+
 		return check_ok_to_remove(ce->name, ce_namelen(ce),
 					  ce_to_dtype(ce), ce, &st,
 					  error_type, o);
@@ -1640,6 +1739,15 @@
 			return -1;
 		}
 		invalidate_ce_path(merge, o);
+
+		if (submodule_from_ce(ce)) {
+			int ret = check_submodule_move_head(ce, NULL,
+							    oid_to_hex(&ce->oid),
+							    o);
+			if (ret)
+				return ret;
+		}
+
 	} else if (!(old->ce_flags & CE_CONFLICTED)) {
 		/*
 		 * See if we can re-use the old CE directly?
@@ -1660,6 +1768,14 @@
 			update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
 			invalidate_ce_path(old, o);
 		}
+
+		if (submodule_from_ce(ce)) {
+			int ret = check_submodule_move_head(ce, oid_to_hex(&old->oid),
+							    oid_to_hex(&ce->oid),
+							    o);
+			if (ret)
+				return ret;
+		}
 	} else {
 		/*
 		 * Previously unmerged entry left as an existence
diff --git a/unpack-trees.h b/unpack-trees.h
index 36a73a6..6c48117b 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -21,6 +21,7 @@
 	ERROR_SPARSE_NOT_UPTODATE_FILE,
 	ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN,
 	ERROR_WOULD_LOSE_ORPHANED_REMOVED,
+	ERROR_WOULD_LOSE_SUBMODULE,
 	NB_UNPACK_TREES_ERROR_TYPES
 };
 
diff --git a/urlmatch.c b/urlmatch.c
index 132d342..4bbde92 100644
--- a/urlmatch.c
+++ b/urlmatch.c
@@ -63,7 +63,50 @@
 	return 1;
 }
 
-char *url_normalize(const char *url, struct url_info *out_info)
+static const char *end_of_token(const char *s, int c, size_t n)
+{
+	const char *next = memchr(s, c, n);
+	if (!next)
+		next = s + n;
+	return next;
+}
+
+static int match_host(const struct url_info *url_info,
+		      const struct url_info *pattern_info)
+{
+	const char *url = url_info->url + url_info->host_off;
+	const char *pat = pattern_info->url + pattern_info->host_off;
+	int url_len = url_info->host_len;
+	int pat_len = pattern_info->host_len;
+
+	while (url_len && pat_len) {
+		const char *url_next = end_of_token(url, '.', url_len);
+		const char *pat_next = end_of_token(pat, '.', pat_len);
+
+		if (pat_next == pat + 1 && pat[0] == '*')
+			/* wildcard matches anything */
+			;
+		else if ((pat_next - pat) == (url_next - url) &&
+			 !memcmp(url, pat, url_next - url))
+			/* the components are the same */
+			;
+		else
+			return 0; /* found an unmatch */
+
+		if (url_next < url + url_len)
+			url_next++;
+		url_len -= url_next - url;
+		url = url_next;
+		if (pat_next < pat + pat_len)
+			pat_next++;
+		pat_len -= pat_next - pat;
+		pat = pat_next;
+	}
+
+	return (!url_len && !pat_len);
+}
+
+static char *url_normalize_1(const char *url, struct url_info *out_info, char allow_globs)
 {
 	/*
 	 * Normalize NUL-terminated url using the following rules:
@@ -104,7 +147,7 @@
 	struct strbuf norm;
 	size_t spanned;
 	size_t scheme_len, user_off=0, user_len=0, passwd_off=0, passwd_len=0;
-	size_t host_off=0, host_len=0, port_len=0, path_off, path_len, result_len;
+	size_t host_off=0, host_len=0, port_off=0, port_len=0, path_off, path_len, result_len;
 	const char *slash_ptr, *at_ptr, *colon_ptr, *path_start;
 	char *result;
 
@@ -191,7 +234,12 @@
 		strbuf_release(&norm);
 		return NULL;
 	}
-	spanned = strspn(url, URL_HOST_CHARS);
+
+	if (allow_globs)
+		spanned = strspn(url, URL_HOST_CHARS "*");
+	else
+		spanned = strspn(url, URL_HOST_CHARS);
+
 	if (spanned < colon_ptr - url) {
 		/* Host name has invalid characters */
 		if (out_info) {
@@ -258,6 +306,7 @@
 				return NULL;
 			}
 			strbuf_addch(&norm, ':');
+			port_off = norm.len;
 			strbuf_add(&norm, url, slash_ptr - url);
 			port_len = slash_ptr - url;
 		}
@@ -265,7 +314,7 @@
 		url = slash_ptr;
 	}
 	if (host_off)
-		host_len = norm.len - host_off;
+		host_len = norm.len - host_off - (port_len ? port_len + 1 : 0);
 
 
 	/*
@@ -373,6 +422,7 @@
 		out_info->passwd_len = passwd_len;
 		out_info->host_off = host_off;
 		out_info->host_len = host_len;
+		out_info->port_off = port_off;
 		out_info->port_len = port_len;
 		out_info->path_off = path_off;
 		out_info->path_len = path_len;
@@ -380,6 +430,11 @@
 	return result;
 }
 
+char *url_normalize(const char *url, struct url_info *out_info)
+{
+	return url_normalize_1(url, out_info, 0);
+}
+
 static size_t url_match_prefix(const char *url,
 			       const char *url_prefix,
 			       size_t url_prefix_len)
@@ -414,7 +469,7 @@
 
 static int match_urls(const struct url_info *url,
 		      const struct url_info *url_prefix,
-		      int *exactusermatch)
+		      struct urlmatch_item *match)
 {
 	/*
 	 * url_prefix matches url if the scheme, host and port of url_prefix
@@ -433,8 +488,8 @@
 	 * contained a user name or false if url_prefix did not have a
 	 * user name.  If there is no match *exactusermatch is left untouched.
 	 */
-	int usermatched = 0;
-	int pathmatchlen;
+	char usermatched = 0;
+	size_t pathmatchlen;
 
 	if (!url || !url_prefix || !url->url || !url_prefix->url)
 		return 0;
@@ -454,33 +509,53 @@
 		usermatched = 1;
 	}
 
-	/* check the host and port */
-	if (url_prefix->host_len != url->host_len ||
-	    strncmp(url->url + url->host_off,
-		    url_prefix->url + url_prefix->host_off, url->host_len))
-		return 0; /* host names and/or ports do not match */
+	/* check the host */
+	if (!match_host(url, url_prefix))
+		return 0; /* host names do not match */
+
+	/* check the port */
+	if (url_prefix->port_len != url->port_len ||
+	    strncmp(url->url + url->port_off,
+		    url_prefix->url + url_prefix->port_off, url->port_len))
+		return 0; /* ports do not match */
 
 	/* check the path */
 	pathmatchlen = url_match_prefix(
 		url->url + url->path_off,
 		url_prefix->url + url_prefix->path_off,
 		url_prefix->url_len - url_prefix->path_off);
+	if (!pathmatchlen)
+		return 0; /* paths do not match */
 
-	if (pathmatchlen && exactusermatch)
-		*exactusermatch = usermatched;
-	return pathmatchlen;
+	if (match) {
+		match->hostmatch_len = url_prefix->host_len;
+		match->pathmatch_len = pathmatchlen;
+		match->user_matched = usermatched;
+	}
+
+	return 1;
+}
+
+static int cmp_matches(const struct urlmatch_item *a,
+		       const struct urlmatch_item *b)
+{
+	if (a->hostmatch_len != b->hostmatch_len)
+		return a->hostmatch_len < b->hostmatch_len ? -1 : 1;
+	if (a->pathmatch_len != b->pathmatch_len)
+		return a->pathmatch_len < b->pathmatch_len ? -1 : 1;
+	if (a->user_matched != b->user_matched)
+		return b->user_matched ? -1 : 1;
+	return 0;
 }
 
 int urlmatch_config_entry(const char *var, const char *value, void *cb)
 {
 	struct string_list_item *item;
 	struct urlmatch_config *collect = cb;
-	struct urlmatch_item *matched;
+	struct urlmatch_item matched = {0};
 	struct url_info *url = &collect->url;
 	const char *key, *dot;
 	struct strbuf synthkey = STRBUF_INIT;
-	size_t matched_len = 0;
-	int user_matched = 0;
 	int retval;
 
 	if (!skip_prefix(var, collect->section, &key) || *(key++) != '.') {
@@ -494,13 +569,13 @@
 		struct url_info norm_info;
 
 		config_url = xmemdupz(key, dot - key);
-		norm_url = url_normalize(config_url, &norm_info);
+		norm_url = url_normalize_1(config_url, &norm_info, 1);
 		free(config_url);
 		if (!norm_url)
 			return 0;
-		matched_len = match_urls(url, &norm_info, &user_matched);
+		retval = match_urls(url, &norm_info, &matched);
 		free(norm_url);
-		if (!matched_len)
+		if (!retval)
 			return 0;
 		key = dot + 1;
 	}
@@ -510,24 +585,18 @@
 
 	item = string_list_insert(&collect->vars, key);
 	if (!item->util) {
-		matched = xcalloc(1, sizeof(*matched));
-		item->util = matched;
+		item->util = xcalloc(1, sizeof(matched));
 	} else {
-		matched = item->util;
-		/*
-		 * Is our match shorter?  Is our match the same
-		 * length, and without user while the current
-		 * candidate is with user?  Then we cannot use it.
-		 */
-		if (matched_len < matched->matched_len ||
-		    ((matched_len == matched->matched_len) &&
-		     (!user_matched && matched->user_matched)))
+		if (cmp_matches(&matched, item->util) < 0)
+			 /*
+			  * Our match is worse than the old one,
+			  * we cannot use it.
+			  */
 			return 0;
 		/* Otherwise, replace it with this one. */
 	}
 
-	matched->matched_len = matched_len;
-	matched->user_matched = user_matched;
+	memcpy(item->util, &matched, sizeof(matched));
 	strbuf_addstr(&synthkey, collect->section);
 	strbuf_addch(&synthkey, '.');
 	strbuf_addstr(&synthkey, key);
diff --git a/urlmatch.h b/urlmatch.h
index 528862a..37ee5da 100644
--- a/urlmatch.h
+++ b/urlmatch.h
@@ -18,11 +18,12 @@
 	size_t passwd_len;	/* length of passwd; if passwd_off != 0 but
 				   passwd_len == 0, an empty passwd was given */
 	size_t host_off;	/* offset into url to start of host name (0 => none) */
-	size_t host_len;	/* length of host name; this INCLUDES any ':portnum';
+	size_t host_len;	/* length of host name;
 				 * file urls may have host_len == 0 */
-	size_t port_len;	/* if a portnum is present (port_len != 0), it has
-				 * this length (excluding the leading ':') at the
-				 * end of the host name (always 0 for file urls) */
+	size_t port_off;	/* offset into url to start of port number (0 => none) */
+	size_t port_len;	/* if a portnum is present (port_off != 0), it has
+				 * this length (excluding the leading ':') starting
+				 * from port_off (always 0 for file urls) */
 	size_t path_off;	/* offset into url to the start of the url path;
 				 * this will always point to a '/' character
 				 * after the url has been normalized */
@@ -33,7 +34,8 @@
 extern char *url_normalize(const char *, struct url_info *);
 
 struct urlmatch_item {
-	size_t matched_len;
+	size_t hostmatch_len;
+	size_t pathmatch_len;
 	char user_matched;
 };
 
diff --git a/userdiff.c b/userdiff.c
index 2125d6d..8b732e4 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -262,25 +262,22 @@
 
 struct userdiff_driver *userdiff_find_by_path(const char *path)
 {
-	static struct git_attr *attr;
-	struct git_attr_check check;
+	static struct attr_check *check;
 
-	if (!attr)
-		attr = git_attr("diff");
-	check.attr = attr;
-
+	if (!check)
+		check = attr_check_initl("diff", NULL);
 	if (!path)
 		return NULL;
-	if (git_check_attr(path, 1, &check))
+	if (git_check_attr(path, check))
 		return NULL;
 
-	if (ATTR_TRUE(check.value))
+	if (ATTR_TRUE(check->items[0].value))
 		return &driver_true;
-	if (ATTR_FALSE(check.value))
+	if (ATTR_FALSE(check->items[0].value))
 		return &driver_false;
-	if (ATTR_UNSET(check.value))
+	if (ATTR_UNSET(check->items[0].value))
 		return NULL;
-	return userdiff_find_by_name(check.value);
+	return userdiff_find_by_name(check->items[0].value);
 }
 
 struct userdiff_driver *userdiff_get_textconv(struct userdiff_driver *driver)
diff --git a/worktree.c b/worktree.c
index fa7bc67..bae787c 100644
--- a/worktree.c
+++ b/worktree.c
@@ -250,16 +250,19 @@
 {
 	struct worktree *wt;
 	char *path;
+	char *to_free = NULL;
 
 	if ((wt = find_worktree_by_suffix(list, arg)))
 		return wt;
 
-	arg = prefix_filename(prefix, strlen(prefix), arg);
+	if (prefix)
+		arg = to_free = prefix_filename(prefix, arg);
 	path = real_pathdup(arg, 1);
 	for (; *list; list++)
 		if (!fspathcmp(path, real_path((*list)->path)))
 			break;
 	free(path);
+	free(to_free);
 	return *list;
 }
 
diff --git a/ws.c b/ws.c
index ea4b2b1..a07caed 100644
--- a/ws.c
+++ b/ws.c
@@ -71,24 +71,17 @@
 	return rule;
 }
 
-static void setup_whitespace_attr_check(struct git_attr_check *check)
-{
-	static struct git_attr *attr_whitespace;
-
-	if (!attr_whitespace)
-		attr_whitespace = git_attr("whitespace");
-	check[0].attr = attr_whitespace;
-}
-
 unsigned whitespace_rule(const char *pathname)
 {
-	struct git_attr_check attr_whitespace_rule;
+	static struct attr_check *attr_whitespace_rule;
 
-	setup_whitespace_attr_check(&attr_whitespace_rule);
-	if (!git_check_attr(pathname, 1, &attr_whitespace_rule)) {
+	if (!attr_whitespace_rule)
+		attr_whitespace_rule = attr_check_initl("whitespace", NULL);
+
+	if (!git_check_attr(pathname, attr_whitespace_rule)) {
 		const char *value;
 
-		value = attr_whitespace_rule.value;
+		value = attr_whitespace_rule->items[0].value;
 		if (ATTR_TRUE(value)) {
 			/* true (whitespace) */
 			unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
diff --git a/wt-status.c b/wt-status.c
index 4bb4678..308cf37 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -121,7 +121,7 @@
 
 void wt_status_prepare(struct wt_status *s)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	memset(s, 0, sizeof(*s));
 	memcpy(s->color_palette, default_wt_status_colors,
@@ -129,7 +129,7 @@
 	s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
 	s->use_color = -1;
 	s->relative_paths = 1;
-	s->branch = resolve_refdup("HEAD", 0, sha1, NULL);
+	s->branch = resolve_refdup("HEAD", 0, oid.hash, NULL);
 	s->reference = "HEAD";
 	s->fp = stdout;
 	s->index_file = get_index_file();
@@ -1115,16 +1115,16 @@
 
 	split = strbuf_split_max(line, ' ', 3);
 	if (split[0] && split[1]) {
-		unsigned char sha1[20];
+		struct object_id oid;
 
 		/*
 		 * strbuf_split_max left a space. Trim it and re-add
 		 * it after abbreviation.
 		 */
 		strbuf_trim(split[1]);
-		if (!get_sha1(split[1]->buf, sha1)) {
+		if (!get_oid(split[1]->buf, &oid)) {
 			strbuf_reset(split[1]);
-			strbuf_add_unique_abbrev(split[1], sha1,
+			strbuf_add_unique_abbrev(split[1], oid.hash,
 						 DEFAULT_ABBREV);
 			strbuf_addch(split[1], ' ');
 			strbuf_reset(line);
@@ -1340,7 +1340,7 @@
 static char *get_branch(const struct worktree *wt, const char *path)
 {
 	struct strbuf sb = STRBUF_INIT;
-	unsigned char sha1[20];
+	struct object_id oid;
 	const char *branch_name;
 
 	if (strbuf_read_file(&sb, worktree_git_path(wt, "%s", path), 0) <= 0)
@@ -1354,9 +1354,9 @@
 		strbuf_remove(&sb, 0, branch_name - sb.buf);
 	else if (starts_with(sb.buf, "refs/"))
 		;
-	else if (!get_sha1_hex(sb.buf, sha1)) {
+	else if (!get_oid_hex(sb.buf, &oid)) {
 		strbuf_reset(&sb);
-		strbuf_add_unique_abbrev(&sb, sha1, DEFAULT_ABBREV);
+		strbuf_add_unique_abbrev(&sb, oid.hash, DEFAULT_ABBREV);
 	} else if (!strcmp(sb.buf, "detached HEAD")) /* rebase */
 		goto got_nothing;
 	else			/* bisect */
@@ -1370,10 +1370,10 @@
 
 struct grab_1st_switch_cbdata {
 	struct strbuf buf;
-	unsigned char nsha1[20];
+	struct object_id noid;
 };
 
-static int grab_1st_switch(unsigned char *osha1, unsigned char *nsha1,
+static int grab_1st_switch(struct object_id *ooid, struct object_id *noid,
 			   const char *email, unsigned long timestamp, int tz,
 			   const char *message, void *cb_data)
 {
@@ -1387,13 +1387,13 @@
 		return 0;
 	target += strlen(" to ");
 	strbuf_reset(&cb->buf);
-	hashcpy(cb->nsha1, nsha1);
+	oidcpy(&cb->noid, noid);
 	end = strchrnul(target, '\n');
 	strbuf_add(&cb->buf, target, end - target);
 	if (!strcmp(cb->buf.buf, "HEAD")) {
 		/* HEAD is relative. Resolve it to the right reflog entry. */
 		strbuf_reset(&cb->buf);
-		strbuf_add_unique_abbrev(&cb->buf, nsha1, DEFAULT_ABBREV);
+		strbuf_add_unique_abbrev(&cb->buf, noid->hash, DEFAULT_ABBREV);
 	}
 	return 1;
 }
@@ -1402,7 +1402,7 @@
 {
 	struct grab_1st_switch_cbdata cb;
 	struct commit *commit;
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *ref = NULL;
 
 	strbuf_init(&cb.buf, 0);
@@ -1411,22 +1411,22 @@
 		return;
 	}
 
-	if (dwim_ref(cb.buf.buf, cb.buf.len, sha1, &ref) == 1 &&
+	if (dwim_ref(cb.buf.buf, cb.buf.len, oid.hash, &ref) == 1 &&
 	    /* sha1 is a commit? match without further lookup */
-	    (!hashcmp(cb.nsha1, sha1) ||
+	    (!oidcmp(&cb.noid, &oid) ||
 	     /* perhaps sha1 is a tag, try to dereference to a commit */
-	     ((commit = lookup_commit_reference_gently(sha1, 1)) != NULL &&
-	      !hashcmp(cb.nsha1, commit->object.oid.hash)))) {
+	     ((commit = lookup_commit_reference_gently(oid.hash, 1)) != NULL &&
+	      !oidcmp(&cb.noid, &commit->object.oid)))) {
 		const char *from = ref;
 		if (!skip_prefix(from, "refs/tags/", &from))
 			skip_prefix(from, "refs/remotes/", &from);
 		state->detached_from = xstrdup(from);
 	} else
 		state->detached_from =
-			xstrdup(find_unique_abbrev(cb.nsha1, DEFAULT_ABBREV));
-	hashcpy(state->detached_sha1, cb.nsha1);
-	state->detached_at = !get_sha1("HEAD", sha1) &&
-			     !hashcmp(sha1, state->detached_sha1);
+			xstrdup(find_unique_abbrev(cb.noid.hash, DEFAULT_ABBREV));
+	hashcpy(state->detached_sha1, cb.noid.hash);
+	state->detached_at = !get_oid("HEAD", &oid) &&
+			     !hashcmp(oid.hash, state->detached_sha1);
 
 	free(ref);
 	strbuf_release(&cb.buf);
@@ -1476,22 +1476,22 @@
 			 int get_detached_from)
 {
 	struct stat st;
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	if (!stat(git_path_merge_head(), &st)) {
 		state->merge_in_progress = 1;
 	} else if (wt_status_check_rebase(NULL, state)) {
 		;		/* all set */
 	} else if (!stat(git_path_cherry_pick_head(), &st) &&
-			!get_sha1("CHERRY_PICK_HEAD", sha1)) {
+			!get_oid("CHERRY_PICK_HEAD", &oid)) {
 		state->cherry_pick_in_progress = 1;
-		hashcpy(state->cherry_pick_head_sha1, sha1);
+		hashcpy(state->cherry_pick_head_sha1, oid.hash);
 	}
 	wt_status_check_bisect(NULL, state);
 	if (!stat(git_path_revert_head(), &st) &&
-	    !get_sha1("REVERT_HEAD", sha1)) {
+	    !get_oid("REVERT_HEAD", &oid)) {
 		state->revert_in_progress = 1;
-		hashcpy(state->revert_head_sha1, sha1);
+		hashcpy(state->revert_head_sha1, oid.hash);
 	}
 
 	if (get_detached_from)
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index 7389ce4..8c88dbd 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -183,16 +183,14 @@
 
 				/*
 				 * We don't need additional context if
-				 * a whole function was added, possibly
-				 * starting with empty lines.
+				 * a whole function was added.
 				 */
-				while (i2 < xe->xdf2.nrec &&
-				       is_empty_rec(&xe->xdf2, i2))
+				while (i2 < xe->xdf2.nrec) {
+					if (match_func_rec(&xe->xdf2, xecfg, i2,
+						dummy, sizeof(dummy)) >= 0)
+						goto post_context_calculation;
 					i2++;
-				if (i2 < xe->xdf2.nrec &&
-				    match_func_rec(&xe->xdf2, xecfg, i2,
-						   dummy, sizeof(dummy)) >= 0)
-					goto post_context_calculation;
+				}
 
 				/*
 				 * Otherwise get more context from the