Moving a submodule that itself has submodule in it with "git mv"
forgot to make necessary adjustment to the nested sub-submodules;
now the codepath learned to recurse into the submodules.
* sb/submodule-move-nested:
submodule: fixup nested submodules after moving the submodule
submodule-config: remove submodule_from_cache
submodule-config: add repository argument to submodule_from_{name, path}
submodule-config: allow submodule_free to handle arbitrary repositories
grep: remove "repo" arg from non-supporting funcs
submodule.h: drop declaration of connect_work_tree_and_git_dir
A build-time option has been added to allow Git to be told to refer
to its associated files relative to the main binary, in the same
way that has been possible on Windows for quite some time, for
Linux, BSDs and Darwin.
* dj/runtime-prefix:
Makefile: quote $INSTLIBDIR when passing it to sed
Makefile: remove unused @@PERLLIBDIR@@ substitution variable
mingw/msvc: use the new-style RUNTIME_PREFIX helper
exec_cmd: provide a new-style RUNTIME_PREFIX helper for Windows
exec_cmd: RUNTIME_PREFIX on some POSIX systems
Makefile: add Perl runtime prefix support
Makefile: generate Perl header from template file
Recent simplification of build procedure forgot a bit of tweak to
the build procedure of contrib/mw-to-git/
* ab/simplify-perl-makefile:
Makefile: mark perllibdir as a .PHONY target
perl: fix installing modules from contrib
The beginning of the next-gen transfer protocol.
* bw/protocol-v2: (35 commits)
remote-curl: don't request v2 when pushing
remote-curl: implement stateless-connect command
http: eliminate "# service" line when using protocol v2
http: don't always add Git-Protocol header
http: allow providing extra headers for http requests
remote-curl: store the protocol version the server responded with
remote-curl: create copy of the service name
pkt-line: add packet_buf_write_len function
transport-helper: introduce stateless-connect
transport-helper: refactor process_connect_service
transport-helper: remove name parameter
connect: don't request v2 when pushing
connect: refactor git_connect to only get the protocol version once
fetch-pack: support shallow requests
fetch-pack: perform a fetch using v2
upload-pack: introduce fetch server command
push: pass ref prefixes when pushing
fetch: pass ref prefixes when fetching
ls-remote: pass ref prefixes when requesting a remote's refs
transport: convert transport_get_remote_refs to take a list of ref prefixes
...
An earlier change, cdb6b5ac (".mailmap: Combine more (name, email) to
individual persons", 2013-08-12), noted that there were two name
spellings and two email addresses and mapped the crustytoothpaste.net
address to the crustytoothpaste.ath.cx address. The latter is an older,
obsolete address, while the former is current, so switch the order of
the addresses so that git log displays the correct address.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adding external subcommands to Git is as easy as to put an executable
file git-foo into PATH. Packaging such subcommands for a Linux
distribution can be achieved by unpacking the executable into /usr/bin
of the user's system. Adding system-wide completion scripts for new
subcommands, however, can be a bit tricky.
Since bash-completion started to use dynamical loading of completion
scripts since v1.90 (preview of v2.0), it is no longer sufficient to
drop a completion script of a subcommand into the standard completions
path, /usr/share/bash-completion/completions, since this script will not
be loaded if called as a git subcommand.
For example, look at https://bugs.gentoo.org/544722. To give a short
summary: The popular git-flow subcommand provides a completion script,
which gets installed as /usr/share/bash-completion/completions/git-flow.
If you now type into a Bash shell:
git flow <TAB>
You will not get any completions, because bash-completion only loads
completions for git and git has no idea that git-flow is defined in
another file. You have to load this script manually or trigger the
dynamic loader with:
git-flow <TAB> # Please notice the dash instead of whitespace
This will not complete anything either, because it only defines a Bash
function, without generating completions. But now the correct completion
script has been loaded and the first command can use the completions.
So, the goal is now to teach the git completion script to consider the
possibility of external completion scripts for subcommands, but of
course without breaking current workflows.
I think the easiest method is to use a function that was defined by
bash-completion v1.90, namely _completion_loader. It will take care of
loading the correct script if present. Afterwards, the git completion
script behaves as usual.
_completion_loader was introduced in commit 20c05b43 of bash-completion
(https://github.com/scop/bash-completion.git) back in 2011, so it should
be available in even older LTS distributions. This function searches for
external completion scripts not only in the default path
/usr/share/bash-completion/completions, but also in the user's home
directory via $XDG_DATA_HOME and in a user specified directory via
$BASH_COMPLETION_USER_DIR.
The only "drawback" (if it even can be called as such) is, that if
_completion_loader does not find a completion script, it automatically
registers a minimal function for basic path completion. In practice,
however, this will not matter, because in this case the given command is
a git command in its dashed form, e.g. 'git-diff-index', and those have
been deprecated for a long time.
This way we can leverage bash-completion's dynamic loading for git
subcommands and make it easier for developers to distribute custom
completion scripts.
Signed-off-by: Florian Gamböck <mail@floga.de>
Acked-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating a literal block from an indented block without any sort of
delimiters, Asciidoctor strips off all leading whitespace, resulting in
a misrendered chart. Use an explicit literal block to indicate to
Asciidoctor that we want to keep the leading whitespace.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Asciidoctor expands tabs at the beginning of a line. However, it does
not expand them into 8 spaces by default. Since we use 8-space tabs,
tell Asciidoctor that we want 8 spaces by setting the tabsize attribute.
This ensures that our ASCII art renders properly.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These were not caught by the previous commit, as they did not match the
regular expression.
While at it, remove the localization from one instance: we never want
BUG() messages to be translated, as they target Git developers, not the
end user (hence it would be quite unhelpful to not only burden the
translators, but then even end up with a bug report in a language that
no core Git contributor understands).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In d8193743e0 (usage.c: add BUG() function, 2017-05-12), a new macro
was introduced to use for reporting bugs instead of die(). It was then
subsequently used to convert one single caller in 588a538ae5
(setup_git_env: convert die("BUG") to BUG(), 2017-05-12).
The cover letter of the patch series containing this patch
(cf 20170513032414.mfrwabt4hovujde2@sigill.intra.peff.net) is not
terribly clear why only one call site was converted, or what the plan
is for other, similar calls to die() to report bugs.
Let's just convert all remaining ones in one fell swoop.
This trick was performed by this invocation:
sed -i 's/die("BUG: /BUG("/g' $(git grep -l 'die("BUG' \*.c)
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The slightly misleading name die_bug() of the function intended to
report a bug is actually called always, and only reports a bug if the
passed-in parameter `err` is non-zero.
It uses die_errno() to report the bug, to helpfully include the error
message corresponding to `err`.
However, as these messages indicate bugs, we really should use BUG().
And as BUG() is a macro to be able to report the exact file and line
number, we need to convert die_bug() to a macro instead of only
replacing the die_errno() by a call to BUG().
While at it, use a name more indicative of the purpose: CHECK_BUG().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we call BUG(), we signal via SIGABRT that something bad happened,
dumping cores if so configured. In some setups these coredumps are
redirected to some central place such as /proc/sys/kernel/core_pattern,
which is a good thing.
However, when we try to verify in our test suite that bugs are caught in
certain code paths, we do *not* want to clutter such a central place
with unnecessary coredumps.
So let's special-case the test helpers (which we use to verify such code
paths) so that the BUG() calls will *not* call abort() but exit with a
special-purpose exit code instead.
Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The correct name in git-send-email.perl is aliasfiletype [1]. There are
actually two instances of this misspelling. The other was found and
fixed in 6068ac8848 (completion: add missing configuration variables -
2010-12-20)
[1] 994d6c66d3 (send-email: address expansion for common mailers - 2006-05-14)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These options are added in [1] [2] [3]. All these depend on running
rev-list internally which is normally true since they are always used
with "--all --objects" which implies --revs. But let's keep this
dependency explicit.
While at there, add documentation for them. These are mostly used
internally by git-repack. But it's still good to not chase down the
right commit message to know how they work.
[1] ca11b212eb (let pack-objects do the writing of unreachable objects
as loose objects - 2008-05-14)
[2] 08cdfb1337 (pack-objects --keep-unreachable - 2007-09-16)
[3] e26a8c4721 (repack: extend --keep-unreachable to loose objects -
2016-06-13)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
SYNOPSIS and other manuals use [options] but DESCRIPTION
used [--options].
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The subcommand 'commit-diff' does not support the option
'--add-author-from'.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the missing `-o` shortcut for `--push-option` to the synopsis.
Add the missing `-d` shortcut for `--delete` in the main section.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Reviewed-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Explain that `git ls-files --ignored` requires at least one
of the `--exclude*` options to do its job.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the two '<path>' parameters in DESCRIPTION mandatory and
move the `--options` part to the same place where the other
variants show them. And finally make `--no-index` in SYNOPSIS
as mandatory as in DESCRIPTION.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Reviewed-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Typeset commands and similar things with as `git foo` instead of
'git foo' or 'git-foo' and add linkgit to the commands which run
the hooks.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Reviewed-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In this developer's earlier attempt to accelerate interactive rebases by
converting large parts from Unix shell script into portable, performant
C, the --root handling was specifically excluded (to simplify the task a
little bit; it still took over a year to get that reduced set of patches
into Git proper).
This patch ties up that loose end: now only --preserve-merges uses the
slow Unix shell script implementation to perform the interactive rebase.
As the rebase--helper reports progress to stderr (unlike the scripted
interactive rebase, which reports it to stdout, of all places), we have
to adjust a couple of tests that did not expect that for `git rebase -i
--root`.
This patch fixes -- at long last! -- the really old bug reported in
6a6bc5bdc4 (add tests for rebasing root, 2013-06-06) that rebasing with
--root *always* rewrote the root commit, even if there were no changes.
The bug still persists in --preserve-merges mode, of course, but that
mode will be deprecated as soon as the new --rebase-merges mode
stabilizes, anyway.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reported by Wink Saville: when rebasing with no-rebase-cousins, we
will want to refrain from rebasing all of them, even when they are
root commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When an interactive rebase wants to recreate a root commit, it
- first creates a new, empty root commit,
- checks it out,
- converts the next `pick` command so that it amends the empty root
commit
Introduce support in the sequencer to handle such an empty root commit,
by looking for the file <GIT_DIR>/rebase-merge/squash-onto; if it exists
and contains a commit name, the sequencer will compare the HEAD to said
root commit, and if identical, a new root commit will be created.
While converting scripted code into proper, portable C, we also do away
with the old "amend with an empty commit message, then cherry-pick
without committing, then amend again" dance and replace it with code
that uses the internal API properly to do exactly what we want: create a
new root commit.
To keep the implementation simple, we always spawn `git commit` to create
new root commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a user provides a todo list containing something like
reset [new root]
merge my-branch
let's do the same as if pulling into an orphan branch: simply
fast-forward.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the context of the new --rebase-merges mode, which was designed
specifically to allow for changing the existing branch topology
liberally, a user may want to extract commits into a completely fresh
branch that starts with a newly-created root commit.
This is now possible by inserting the command `reset [new root]` before
`pick`ing the commit that wants to become a root commit. Example:
reset [new root]
pick 012345 a commit that is about to become a root commit
pick 234567 this commit will have the previous one as parent
This does not conflict with other uses of the `reset` command because
`[new root]` is not (part of) a valid ref name: both the opening bracket
as well as the space are illegal in ref names.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch extracts the code from is_index_unchanged() to initialize or
update the index' cache tree (i.e. a tree object reflecting the current
index' top-level tree).
The new helper will be used in the upcoming code to support `git rebase
-i --root` via the sequencer.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The fetch-pack/upload-pack protocol v2 was developed independently of
the filter parameter (used in partial fetches), thus it did not include
support for it. Add support for the filter parameter.
Like in the legacy protocol, the server advertises and supports "filter"
only if uploadpack.allowfilter is configured.
Like in the legacy protocol, the client continues with a warning if
"--filter" is specified, but the server does not advertise it.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The upload-pack code paths never call git_config() with
upload_pack_config() when protocol v2 is used, causing options like
uploadpack.packobjectshook to not take effect. Ensure that this function
is called.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When bisecting a performance regression using a config file,
`./bisect_regression --config my_perf.conf` for example, the
config file can contain Codespeed configuration which would
instruct the 'aggregate.perl' script called by the 'run'
script to output results in the Codespeed format and maybe
to try to send this output to a Codespeed server.
This is unfortunate because the 'bisect_run_script' relies
on the regular output from 'aggregate.perl' to mesure
performance, so let's disable Codespeed output and sending
results to a Codespeed server.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you do something like
- git add .
- git status
- git commit
- git show (or git diff HEAD)
one would expect to have analogous output from git status and git show
(or similar diff-related programs). This is generally not the case, as
git status has hard coded values for diff related options.
With this commit the hard coded settings are dropped from the status
command in favour for values provided by git_diff_ui_config.
What follows are some remarks on the concrete options which were hard
coded in git status:
diffopt.detect_rename
Since the very beginning of git status in a3e870f2e2 ("Add "commit"
helper script", 2005-05-30), git status always used rename detection,
whereas with commands like show and log one had to activate it with a
command line option. After 5404c116aa ("diff: activate diff.renames by
default", 2016-02-25) the default behaves the same by coincidence, but
changing diff.renames to other values can break the consistency between
git status and other commands again. With this commit one control the
same default behaviour with diff.renames.
diffopt.rename_limit
Similarly one has the option diff.renamelimit to adjust this limit for
all commands but git status. With this commit git status will also honor
those.
diffopt.break_opt
Unlike the other two options this cannot be configured by a
configuration option yet. This commit will also change the default
behaviour to not use break rewrites. But as rename detection is most
likely on, this is dangerous to be activated anyway as one can see
here:
https://public-inbox.org/git/xmqqegqaahnh.fsf@gitster.dls.corp.google.com/
Signed-off-by: Eckhard S. Maaß <eckhard.s.maass@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When shown the email summary, an opportunity is presented for the user
to edit the email as if they had specified --annotate. This also permits
them to edit it multiple times.
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Helped-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is possible to configure 'less', the pager, to use an alternate
screen to show the content, for example, by setting LESS=RS in the
environment. When it is closed in this configuration, it switches
back to the original screen, and all content is gone.
It is not uncommon to request that the output remains visible in
the terminal. For this, the option --no-pager can be used. But
it is a bit cumbersome to type, even when command completion is
available. Provide a short option, -P, to make the option more
easily accessible.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Take advantage of the recent addition of support for lazy loading functions[1]
on Windows to simplify the loading of NtSetSystemInformation.
[1] db2f7c48cb (Win32: simplify loading of DLL functions, 2017-09-25)
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a typo in an error message.
Also, this line was introduced in 3145ea957d ("upload-pack: introduce
fetch server command", 2018-03-15), which did not contain a test for the
case which causes this error to be printed, so introduce a test.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The beginning of the next-gen transfer protocol.
* bw/protocol-v2: (35 commits)
remote-curl: don't request v2 when pushing
remote-curl: implement stateless-connect command
http: eliminate "# service" line when using protocol v2
http: don't always add Git-Protocol header
http: allow providing extra headers for http requests
remote-curl: store the protocol version the server responded with
remote-curl: create copy of the service name
pkt-line: add packet_buf_write_len function
transport-helper: introduce stateless-connect
transport-helper: refactor process_connect_service
transport-helper: remove name parameter
connect: don't request v2 when pushing
connect: refactor git_connect to only get the protocol version once
fetch-pack: support shallow requests
fetch-pack: perform a fetch using v2
upload-pack: introduce fetch server command
push: pass ref prefixes when pushing
fetch: pass ref prefixes when fetching
ls-remote: pass ref prefixes when requesting a remote's refs
transport: convert transport_get_remote_refs to take a list of ref prefixes
...
When formatted as a man page, 1st section header is always in upper
case even if we write it otherwise. Make all 1st section headers
uppercase to keep it close to the final output.
This does affect html since case is kept there, but I still think it's
a good idea to maintain a consistent style for 1st section headers.
Some sections perhaps should become second sections instead, where
case is kept, and for better organization. I will update if anyone has
suggestions about this.
While at there I also make some header more consistent (e.g. examples
vs example) and fix a couple minor things here and there.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This script hard-codes the object ID of the empty blob. To avoid any
problems when changing hashes, compute this value by calling git
hash-object.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The interactive add script hard-codes the object ID of the empty tree.
To avoid any problems when changing hashes, compute this value when used
and cache it for any future uses.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Several of our shell scripts hard-code the object ID of the empty tree.
To avoid any problems when changing hashes, compute this value on
startup of the script. For performance, store the value in a variable
and reuse it throughout the life of the script.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There really isn't any case in which we want to expose the constants for
empty trees and blobs outside of using the hash algorithm abstraction.
Make these constants static and stop exposing the defines in cache.h.
Remove the constants which are no longer in use.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To ensure that we are hash algorithm agnostic, use the_hash_algo to look
up the object ID for the empty blob instead of using the empty_tree_oid
variable.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To ensure that we are hash algorithm agnostic, use the_hash_algo to look
up the object ID for the empty tree instead of using the empty_tree_oid
variable.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When comparing an object ID against that of the empty tree, use the
is_empty_tree_oid function to ensure that we abstract over the hash
algorithm properly. In addition, this is more readable than a plain
oidcmp.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the code that looks up cached objects to use struct object_id.
Adjust the lookup for empty trees to use the_hash_algo. Note that we
don't need to be concerned about the hard-coded object ID in the
empty_tree object since we never use it.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the last use of EMPTY_TREE_SHA1_BIN to use a direct copy from
the_hash_algo->empty_tree to avoid a dependency on a given hash
algorithm.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert one use of EMPTY_TREE_SHA1_HEX to use empty_tree_oid_hex to
avoid a dependency on a given hash algorithm.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert two uses of EMPTY_TREE_SHA1_HEX to use empty_tree_oid_hex to
avoid a dependency on a given hash algorithm.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert several uses of EMPTY_TREE_SHA1_HEX to use empty_tree_oid_hex to
avoid a dependency on a given hash algorithm.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert one use of EMPTY_TREE_SHA1_HEX to use empty_tree_oid_hex to
avoid a dependency on a given hash algorithm.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>