The final leg of SHA-256 transition.
* bc/sha-256-part-3: (39 commits)
t: remove test_oid_init in tests
docs: add documentation for extensions.objectFormat
ci: run tests with SHA-256
t: make SHA1 prerequisite depend on default hash
t: allow testing different hash algorithms via environment
t: add test_oid option to select hash algorithm
repository: enable SHA-256 support by default
setup: add support for reading extensions.objectformat
bundle: add new version for use with SHA-256
builtin/verify-pack: implement an --object-format option
http-fetch: set up git directory before parsing pack hashes
t0410: mark test with SHA1 prerequisite
t5308: make test work with SHA-256
t9700: make hash size independent
t9500: ensure that algorithm info is preserved in config
t9350: make hash size independent
t9301: make hash size independent
t9300: use $ZERO_OID instead of hard-coded object ID
t9300: abstract away SHA-1-specific constants
t8011: make hash size independent
...
Update "git help guides" documentation organization.
* pb/guide-docs:
git.txt: add list of guides
Documentation: don't hardcode command categories twice
help: drop usage of 'common' and 'useful' for guides
command-list.txt: add missing 'gitcredentials' and 'gitremote-helpers'
All "mergy" operations that internally use the merge-recursive
machinery should honor the merge.renormalize configuration, but
many of them didn't.
* en/eol-attrs-gotchas:
checkout: support renormalization with checkout -m <paths>
merge: make merge.renormalize work for all uses of merge machinery
t6038: remove problematic test
t6038: make tests fail for the right reason
The argv_array API is useful for not just managing argv but any
"vector" (NULL-terminated array) of strings, and has seen adoption
to a certain degree. It has been renamed to "strvec" to reduce the
barrier to adoption.
* jk/strvec:
strvec: rename struct fields
strvec: drop argv_array compatibility layer
strvec: update documention to avoid argv_array
strvec: fix indentation in renamed calls
strvec: convert remaining callers away from argv_array name
strvec: convert more callers away from argv_array name
strvec: convert builtin/ callers away from argv_array name
quote: rename sq_dequote_to_argv_array to mention strvec
strvec: rename files from argv-array to strvec
argv-array: rename to strvec
argv-array: use size_t for count and alloc
Since 1b81d8cb19 (help: use command-list.txt for the source of guides,
2018-05-20), all man5/man7 guides listed in command-list.txt appear in
the output of 'git help -g'.
However, 'git help -g' still prefixes this list with "The common Git
guides are:", which makes one wonder if there are others!
In the same spirit, the man page for 'git help' describes the '--guides'
option as listing 'useful' guides, which is not false per se but can
also be taken to mean that there are other guides that exist but are not
useful.
Instead of 'common' and 'useful', use 'Git concept guides' in both
places. To keep the code in line with this change, rename
help.c::list_common_guides_help to list_guides_help.
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While packing many objects in a repository with a promissor remote,
lazily fetching missing objects from the promissor remote one by
one may be inefficient---the code now attempts to fetch all the
missing objects in batch (obviously this won't work for a lazy
clone that lazily fetches tree objects as you cannot even enumerate
what blobs are missing until you learn which trees are missing).
* jt/pack-objects-prefetch-in-batch:
pack-objects: prefetch objects to be packed
pack-objects: refactor to oid_object_info_extended
The 'merge' command is not the only one that does merges; other commands
like checkout -m or rebase do as well. Unfortunately, the only area of
the code that checked for the "merge.renormalize" config setting was in
builtin/merge.c, meaning it could only affect merges performed by the
"merge" command. Move the handling of this config setting to
merge_recursive_config() so that other commands can benefit from it as
well. Fixes a few tests in t6038.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").
Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git mv src dst", when src is an unmerged path, errored out
correctly but with an incorrect error message to claim that src is
not tracked, which has been clarified.
* ct/mv-unmerged-path-error:
git-mv: improve error message for conflicted file
Preliminary clean-up of the refs API in preparation for adding a
new refs backend "reftable".
* hn/reftable:
reflog: cleanse messages in the refs.c layer
bisect: treat BISECT_HEAD as a pseudo ref
t3432: use git-reflog to inspect the reflog for HEAD
lib-t6000.sh: write tag using git-update-ref
"git clone --separate-git-dir=$elsewhere" used to stomp on the
contents of the existing directory $elsewhere, which has been
taught to fail when $elsewhere is not an empty directory.
* bw/fail-cloning-into-non-empty:
git clone: don't clone into non-empty directory
Updates to the changed-paths bloom filter.
* ds/commit-graph-bloom-updates:
commit-graph: check all leading directories in changed path Bloom filters
revision: empty pathspecs should not use Bloom filters
revision.c: fix whitespace
commit-graph: check chunk sizes after writing
commit-graph: simplify chunk writes into loop
commit-graph: unify the signatures of all write_graph_chunk_*() functions
commit-graph: persist existence of changed-paths
bloom: fix logic in get_bloom_filter()
commit-graph: change test to die on parse, not load
commit-graph: place bloom_settings in context
Now that we have a complete SHA-256 implementation in Git, let's enable
it so people can use it. Remove the ENABLE_SHA256 define constant
everywhere it's used. Add tests for initializing a repository with
SHA-256.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently we detect the hash algorithm in use by the length of the
object ID. This is inelegant and prevents us from using a different
hash algorithm that is also 256 bits in length.
Since we cannot extend the v2 format in a backward-compatible way, let's
add a v3 format, which is identical, except for the addition of
capabilities, which are prefixed by an at sign. We add "object-format"
as the only capability and reject unknown capabilities, since we do not
have a network connection and therefore cannot negotiate with the other
side.
For compatibility, default to the v2 format for SHA-1 and require v3
for SHA-256.
In t5510, always use format v3 so we can be sure we produce consistent
results across hash algorithms. Since head -n N lists the top N lines
instead of the Nth line, let's run our output through sed to normalize
it and compare it against a fixed value, which will make sure we get
exactly what we're expecting.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A recently added test in t5702 started using git verify-pack outside of
a repository. While this poses no problems with SHA-1, with SHA-256 we
implicitly rely on the setup of the repository to initialize our hash
algorithm settings.
Since we're not in a repository here, we need to provide git verify-pack
help to set things up properly. git index-pack already knows an
--object-format option, so let's accept one as well and pass it down to
our git index-pack invocation. Since we're now dynamically adjusting
the elements in argv, let's switch to using struct argv_array to manage
them. Finally, let's make t5702 pass the proper argument on down to its
git verify-pack caller.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
parse_object_or_die() is passed an object ID and a name to show if the
object cannot be parsed. If the name is NULL then it shows the
hexadecimal object ID. Use that feature instead of preparing and
passing the hexadecimal representation to the function proactively.
That's shorter and a bit more efficient.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code which split an argv_array call across multiple lines, like:
argv_array_pushl(&args, "one argument",
"another argument", "and more",
NULL);
was recently mechanically renamed to use strvec, which results in
mis-matched indentation like:
strvec_pushl(&args, "one argument",
"another argument", "and more",
NULL);
Let's fix these up to align the arguments with the opening paren. I did
this manually by sifting through the results of:
git jump grep 'strvec_.*,$'
and liberally applying my editor's auto-format. Most of the changes are
of the form shown above, though I also normalized a few that had
originally used a single-tab indentation (rather than our usual style of
aligning with the open paren). I also rewrapped a couple of obvious
cases (e.g., where previously too-long lines became short enough to fit
on one), but I wasn't aggressive about it. In cases broken to three or
more lines, the grouping of arguments is sometimes meaningful, and it
wasn't worth my time or reviewer time to ponder each case individually.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).
This patch converts all of the files in builtin/ to keep the diff to a
manageable size.
The conversion was done purely mechanically with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe '
s/ARGV_ARRAY/STRVEC/g;
s/argv_array/strvec/g;
'
and then selectively staging files with "git add builtin/". We'll deal
with any indentation/style fallouts separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We want to eventually drop the use of the "argv_array" name in favor of
"strvec." Unlike most other uses of the name, this one is embedded in a
function name, so the definition and all of the callers need to be
updated at the same time.
We don't technically need to update the parameter types here (our
preprocessor compat macros make the two names interchangeable), but
let's do so to keep the site consistent for now.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:
git ls-files '*.c' '*.h' |
xargs perl -i -pe 's/argv-array.h/strvec.h/'
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When an object to be packed is noticed to be missing, prefetch all
to-be-packed objects in one batch.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use oid_object_info_extended() instead of oid_object_info() because a
subsequent commit needs to specify an additional flag here.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'git mv' has always complained about renaming a conflicted
file, as it cannot handle multiple index entries for one file.
However, the error message it uses has been the same as the
one for an untracked file:
fatal: not under version control, src=...
which is patently wrong. Distinguish the two cases and
add a test to make sure we produce the correct message.
Signed-off-by: Chris Torek <chris.torek@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix to the code to produce progress bar, which is new in the
upcoming release.
* tb/commit-graph-no-check-oids:
commit-graph: fix "Collecting commits from input" progress line
To display a progress line while reading commits from standard input
and looking them up, 5b6653e523 (builtin/commit-graph.c: dereference
tags in builtin, 2020-05-13) should have added a pair of
start_delayed_progress() and stop_progress() calls around the loop
reading stdin. Alas, the stop_progress() call ended up at the wrong
place, after write_commit_graph(), which does all the commit-graph
computation and writing, and has several progress lines of its own.
Consequently, that new
Collecting commits from input: 1234
progress line is overwritten by the first progress line shown by
write_commit_graph(), and its final "done" line is shown last, after
everything is finished:
$ { sleep 3 ; git rev-list -3 HEAD ; sleep 1 ; } | ~/src/git/git commit-graph write --stdin-commits
Expanding reachable commits in commit graph: 873402, done.
Writing out commit graph in 4 passes: 100% (3493608/3493608), done.
Collecting commits from input: 3, done.
Furthermore, that stop_progress() call was added after the 'cleanup'
label, where that loop reading stdin jumps in case of an error. In
case of invalid input this then results in the "done" line shown after
the error message:
$ { sleep 3 ; git rev-list -3 HEAD ; echo junk ; } | ~/src/git/git commit-graph write --stdin-commits
error: unexpected non-hex object ID: junk
Collecting commits from input: 3, done.
Move that stop_progress() call to the right place.
While at it, drop the unnecessary 'if (progress)' condition protecting
the stop_progress() call, because that function is prepared to handle
a NULL progress struct.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both the git-bisect.sh as bisect--helper inspected the file system
directly.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using git clone with --separate-git-dir realgitdir and
realgitdir already exists, it's content is destroyed.
So, make sure we don't clone into an existing non-empty directory.
When d45420c1 (clone: do not clean up directories we didn't create,
2018-01-02) tightened the clean-up procedure after a failed cloning
into an empty directory, it assumed that the existing directory
given is an empty one so it is OK to keep that directory, while
running the clean-up procedure that is designed to remove everything
in it (since there won't be any, anyway). Check and make sure that
the $GIT_DIR is empty even cloning into an existing repository.
Signed-off-by: Ben Wijen <ben@wijen.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recent update to "git diff" meant as a code clean-up introduced a
bug in its error handling code, which has been corrected.
* ct/diff-with-merge-base-clarification:
diff: check for merge bases before assigning sym->base
In symdiff_prepare(), we iterate over the set of parsed objects to pick
out any symmetric differences, including the left, right, and base
elements. We assign the results into pointers in a "struct symdiff", and
then complain if we didn't find a base, like so:
sym->left = rev->pending.objects[lpos].name;
sym->right = rev->pending.objects[rpos].name;
sym->base = rev->pending.objects[basepos].name;
if (basecount == 0)
die(_("%s...%s: no merge base"), sym->left, sym->right);
But the least lines are backwards. If basecount is 0, then basepos will
be -1, and we will access memory outside of the pending array. This
isn't usually that big a deal, since we don't do anything besides a
single pointer-sized read before exiting anyway, but it does violate the
C standard, and of course memory-checking tools like ASan complain.
Let's put the basecount check first. Note that we haveto split it from
the other assignments, since the die() relies on sym->left and
sym->right having been assigned (this isn't strictly necessary, but is
easier to read than dereferencing the pending array again).
Reported-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git fast-export --anonymize" learned to take customized mapping to
allow its users to tweak its output more usable for debugging.
* jk/fast-export-anonym-alt:
fast-export: use local array to store anonymized oid
fast-export: anonymize "master" refname
fast-export: allow seeding the anonymized mapping
fast-export: add a "data" callback parameter to anonymize_str()
fast-export: move global "idents" anonymize hashmap into function
fast-export: use a flex array to store anonymized entries
fast-export: stop storing lengths in anonymized hashmaps
fast-export: tighten anonymize_mem() interface to handle only strings
fast-export: store anonymized oids as hex strings
fast-export: use xmemdupz() for anonymizing oids
t9351: derive anonymized tree checks from original repo
The name of the primary branch in existing repositories, and the
default name used for the first branch in newly created
repositories, is made configurable, so that we can eventually wean
ourselves off of the hardcoded 'master'.
* js/default-branch-name:
contrib: subtree: adjust test to change in fmt-merge-msg
testsvn: respect `init.defaultBranch`
remote: use the configured default branch name when appropriate
clone: use configured default branch name when appropriate
init: allow setting the default for the initial branch name via the config
init: allow specifying the initial branch name for the new repository
docs: add missing diamond brackets
submodule: fall back to remote's HEAD for missing remote.<name>.branch
send-pack/transport-helper: avoid mentioning a particular branch
fmt-merge-msg: stop treating `master` specially
API cleanup for get_worktrees()
* es/get-worktrees-unsort:
worktree: drop get_worktrees() unused 'flags' argument
worktree: drop get_worktrees() special-purpose sorting option
A few fields in "struct commit" that do not have to always be
present have been moved to commit slabs.
* ak/commit-graph-to-slab:
commit-graph: minimize commit_graph_data_slab access
commit: move members graph_pos, generation to a slab
commit-graph: introduce commit_graph_data_slab
object: drop parsed_object_pool->commit_count
SHA-256 migration work continues.
* bc/sha-256-part-2: (44 commits)
remote-testgit: adapt for object-format
bundle: detect hash algorithm when reading refs
t5300: pass --object-format to git index-pack
t5704: send object-format capability with SHA-256
t5703: use object-format serve option
t5702: offer an object-format capability in the test
t/helper: initialize the repository for test-sha1-array
remote-curl: avoid truncating refs with ls-remote
t1050: pass algorithm to index-pack when outside repo
builtin/index-pack: add option to specify hash algorithm
remote-curl: detect algorithm for dumb HTTP by size
builtin/ls-remote: initialize repository based on fetch
t5500: make hash independent
serve: advertise object-format capability for protocol v2
connect: parse v2 refs with correct hash algorithm
connect: pass full packet reader when parsing v2 refs
Documentation/technical: document object-format for protocol v2
t1302: expect repo format version 1 for SHA-256
builtin/show-index: provide options to determine hash algo
t5302: modernize test formatting
...
When displaying cat-file usage, the fact that a <format> can
be specified is only visible when lookling at the --batch and
--batch-check options which are shown like this:
--batch[=<format>] show info and content of objects fed from the standard input
--batch-check[=<format>]
show info about objects fed from the standard input
It seems more coherent and improves discovery to also show it
on the usage line.
In the documentation the DESCRIPTION tells us that "The output
format can be overridden using the optional <format> argument",
but we can't see the <format> argument in the SYNOPSIS above
the description which is confusing.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The changed-path Bloom filters were released in v2.27.0, but have a
significant drawback. A user can opt-in to writing the changed-path
filters using the "--changed-paths" option to "git commit-graph write"
but the next write will drop the filters unless that option is
specified.
This becomes even more important when considering the interaction with
gc.writeCommitGraph (on by default) or fetch.writeCommitGraph (part of
features.experimental). These config options trigger commit-graph writes
that the user did not signal, and hence there is no --changed-paths
option available.
Allow a user that opts-in to the changed-path filters to persist the
property of "my commit-graph has changed-path filters" automatically. A
user can drop filters using the --no-changed-paths option.
In the process, we need to be extremely careful to match the Bloom
filter settings as specified by the commit-graph. This will allow future
versions of Git to customize these settings, and the version with this
change will persist those settings as commit-graphs are rewritten on
top.
Use the trace2 API to signal the settings used during the write, and
check that output in a test after manually adjusting the correct bytes
in the commit-graph file.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff-files" has been taught to say paths that are marked as
intent-to-add are new files, not modified from an empty blob.
* sk/diff-files-show-i-t-a-as-new:
diff-files: treat "i-t-a" files as "not-in-index"
An in-code comment in "git diff" has been updated.
* dl/diff-usage-comment-update:
builtin/diff: fix botched update of usage comment
builtin/diff: update usage comment
Allow runtime upgrade of the repository format version, which needs
to be done carefully.
There is a rather unpleasant backward compatibility worry with the
last step of this series, but it is the right thing to do in the
longer term.
* xl/upgrade-repo-format:
check_repository_format_gently(): refuse extensions for old repositories
sparse-checkout: upgrade repository to version 1 when enabling extension
fetch: allow adding a filter after initial clone
repository: add a helper function to perform repository format upgrade
Some older versions of gcc complain about this line:
builtin/fast-export.c:412:2: error: dereferencing type-punned pointer
will break strict-aliasing rules [-Werror=strict-aliasing]
put_be32(oid.hash + hashsz - 4, counter++);
^
This seems to be a false positive, as there's no type-punning at all
here. oid.hash is an array of unsigned char; when we pass it to a
function it decays to a pointer to unsigned char. We do take a void
pointer in put_be32(), but it's immediately aliased with another pointer
to unsigned char (and clearly the compiler is looking inside the inlined
put_be32(), since the warning doesn't happen with -O0).
This happens on gcc 4.8 and 4.9, but not later versions (I tested gcc 6,
7, 8, and 9).
We can work around it by using a local array instead of an object_id
struct. This is a little more intimate with the details of object_id,
but for whatever reason doesn't seem to trigger the compiler warning.
We can revert this patch once we decide that those gcc versions are too
old to care about for a warning like this (gcc 4.8 is the default
compiler for Ubuntu Trusty, which is out-of-support but not fully
end-of-life'd until April 2022).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running "fast-export --anonymize" will leave "refs/heads/master"
untouched in the output, for two reasons:
- it helped to have some known reference point between the original
and anonymized repository
- since it's historically the default branch name, it doesn't leak any
information
Now that we can ask fast-export to retain particular tokens, we have a
much better tool for the first one (because it works for any ref, not
just master).
For the second, the notion of "default branch name" is likely to become
configurable soon, at which point the name _does_ leak information.
Let's drop this special case in preparation.
Note that we have to adjust the test a bit, since it relied on using the
name "master" in the anonymized repos. We could just use
--anonymize-map=master to keep the same output, but then we wouldn't
know if it works because of our hard-coded master or because of the
explicit map.
So let's flip the test a bit, and confirm that we anonymize "master",
but keep "other" in the output.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After you anonymize a repository, it can be hard to find which commits
correspond between the original and the result, and thus hard to
reproduce commands that triggered bugs in the original.
Let's make it possible to seed the anonymization map. This lets users
either:
- mark names to be retained as-is, if they don't consider them secret
(in which case their original commands would just work)
- map names to new values, which lets them adapt the reproduction
recipe to the new names without revealing the originals
The implementation is fairly straight-forward. We already store each
anonymized token in a hashmap (so that the same token appearing twice is
converted to the same result). We can just introduce a new "seed"
hashmap which is consulted first.
This does make a few more promises to the user about how we'll anonymize
things (e.g., token-splitting pathnames). But it's unlikely that we'd
want to change those rules, even if the actual anonymization of a single
token changes. And it makes things much easier for the user, who can
unblind only a directory name without having to specify each path within
it.
One alternative to this approach would be to anonymize as we see fit,
and then dump the whole refname and pathname mappings to a file. This
does work, but it's a bit awkward to use (you have to manually dig the
items you care about out of the mapping).
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "fetch/clone" protocol has been updated to allow the server to
instruct the clients to grab pre-packaged packfile(s) in addition
to the packed object data coming over the wire.
* jt/cdn-offload:
upload-pack: fix a sparse '0 as NULL pointer' warning
upload-pack: send part of packfile response as uri
fetch-pack: support more than one pack lockfile
upload-pack: refactor reading of pack-objects out
Documentation: add Packfile URIs design doc
Documentation: order protocol v2 sections
http-fetch: support fetching packfiles by URL
http-fetch: refactor into function
http: refactor finish_http_pack_request()
http: use --stdin when indexing dumb HTTP pack
Rewrite of parts of the scripted "git submodule" Porcelain command
continues; this time it is "git submodule set-branch" subcommand's
turn.
* ss/submodule-set-branch-in-c:
submodule: port subcommand 'set-branch' from shell to C
Code clean-up around "git branch" with a minor bugfix.
* dl/branch-cleanup:
branch: don't mix --edit-description
t3200: test for specific errors
t3200: rename "expected" to "expect"
