Replace open-coded reallocation with ALLOC_GROW() macro.
* dd/use-alloc-grow:
sha1_file.c: use ALLOC_GROW() in pretend_sha1_file()
read-cache.c: use ALLOC_GROW() in add_index_entry()
builtin/mktree.c: use ALLOC_GROW() in append_to_tree()
attr.c: use ALLOC_GROW() in handle_attr_line()
dir.c: use ALLOC_GROW() in create_simplify()
reflog-walk.c: use ALLOC_GROW()
replace_object.c: use ALLOC_GROW() in register_replace_object()
patch-ids.c: use ALLOC_GROW() in add_commit()
diffcore-rename.c: use ALLOC_GROW()
diff.c: use ALLOC_GROW()
commit.c: use ALLOC_GROW() in register_commit_graft()
cache-tree.c: use ALLOC_GROW() in find_subtree()
bundle.c: use ALLOC_GROW() in add_to_ref_list()
builtin/pack-objects.c: use ALLOC_GROW() in check_pbase_path()
Updates transport-helper, fast-import and fast-export to allow the
ref mapping and ref deletion in a way similar to the natively
supported transports.
* fc/transport-helper-fixes:
remote-bzr: support the new 'force' option
test-hg.sh: tests are now expected to pass
transport-helper.c: do not overwrite forced bit
transport-helper: check for 'forced update' message
transport-helper: add 'force' to 'export' helpers
transport-helper: don't update refs in dry-run
transport-helper: mismerge fix
add: use struct argv_array in run_add_interactive()
run_add_interactive() in builtin/add.c manually computes array bounds
and allocates a static args array to build the add--interactive command
line, which is error-prone. Use the argv-array helper functions instead.
Signed-off-by: Fabian Ruch <bafain@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
test-lib.sh: do not "echo" caller-supplied strings
In some places we "echo" a string that is supplied by the calling
test script and may contain backslash sequences. The echo command
of some shells, most notably "dash", interprets these backslash
sequences (POSIX.1 allows this) which may scramble the test
output.
Signed-off-by: Uwe Storbeck <uwe@ibr.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
- update 'no editor' hook test and add 'editor' hook test
- make sure the tree is reset to a clean state after running a test
(using test_when_finished) so later tests are not impacted
Signed-off-by: Benoit Pierre <benoit.pierre@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add (failing) tests: with commit changing the environment to let hooks
know that no editor will be used (by setting GIT_EDITOR to ":"), the
"edit hunk" functionality does not work (no editor is launched and the
whole hunk is committed).
Signed-off-by: Benoit Pierre <benoit.pierre@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We parse the "--prefix" command-line option into the
"$prefix" shell variable. However, if we do not see such an
option, the variable is left with whatever value it had in
the environment. We should initialize it to a known value,
like we do for other variables.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before writing the shallow file, we stat() the existing file
to make sure it has not been updated since our operation
began. However, we do not do so under a lock, so there is a
possible race:
1. Process A takes the lock.
2. Process B calls check_shallow_file_for_update and finds
no update.
3. Process A commits the lockfile.
4. Process B takes the lock, then overwrite's process A's
changes.
We can fix this by doing our check while we hold the lock.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-objects: turn off bitmaps when skipping objects
The pack bitmap format requires that we have a single bit
for each object in the pack, and that each object's bitmap
represents its complete set of reachable objects. Therefore
we have no way to represent the bitmap of an object which
references objects outside the pack.
We notice this problem while generating the bitmaps, as we
try to find the offset of a particular object and realize
that we do not have it. In this case we die, and neither the
bitmap nor the pack is generated. This is correct, but
perhaps a little unfriendly. If you have bitmaps turned on
in the config, many repacks will fail which would otherwise
succeed. E.g., incremental repacks, repacks with "-l" when
you have alternates, ".keep" files.
Instead, this patch notices early that we are omitting some
objects from the pack and turns off bitmaps (with a
warning). Note that this is not strictly correct, as it's
possible that the object being omitted is not reachable from
any other object in the pack. In practice, this is almost
never the case, and there are two advantages to doing it
this way:
1. The code is much simpler, as we do not have to cleanly
abort the bitmap-generation process midway through.
2. We do not waste time partially generating bitmaps only
to find out that some object deep in the history is not
being packed.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The first line shows that we are reusing a large chunk of
objects, and then we further count any objects not included
in the reused portion with an actual traversal.
These are all implementation details that the user does not
need to care about. Instead, we can show the reused objects
in the normal "counting..." progress meter (which will
simply go much faster than normal), and then continue to add
to it as we traverse.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the "--all-progress" option is in effect, pack-objects
shows a progress report for the "writing" phase. If the
repository has bitmaps and we are reusing a packfile, the
user sees no progress update until the whole packfile is
sent. Since this is typically the bulk of what is being
written, it can look like git hangs during this phase, even
though the transfer is proceeding.
This generally only happens with "git push" from a
repository with bitmaps. We do not use "--all-progress" for
fetch (since the result is going to index-pack on the
client, which takes care of progress reporting). And for
regular repacks to disk, we do not reuse packfiles.
We already have the progress meter setup during
write_reused_pack; we just need to call display_progress
whiel we are writing out the pack. The progress meter is
attached to our output descriptor, so it automatically
handles the throughput measurements.
However, we need to update the object count as we go, since
that is what feeds the percentage we show. We aren't
actually parsing the packfile as we send it, so we have no
idea how many objects we have sent; we only know that at the
end of N bytes, we will have sent M objects. So we cheat a
little and assume each object is M/N bytes (i.e., the mean
of the objects we are sending). While this isn't strictly
true, it actually produces a more pleasing progress meter
for the user, as it moves smoothly and predictably (and
nobody really cares about the object count; they care about
the percentage, and the object count is a proxy for that).
One alternative would be to actually show two progress
meters: one for the reused pack, and one for the rest of the
objects. That would more closely reflect the data we have
(the first would be measured in bytes, and the second
measured in objects). But it would also be more complex and
annoying to the user; rather than seeing one progress meter
counting up to 100%, they would finish one meter, then start
another one at zero.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
rebase -i: do not "echo" random user-supplied strings
In some places we "echo" a string that comes from a commit log
message, which may have a backslash sequence that is interpreted by
the command (POSIX.1 allows this), most notably "dash"'s built-in
'echo'.
A commit message which contains the string '\n' (or ends with the
string '\c') may result in a garbage line in the todo list of an
interactive rebase which causes the rebase to fail.
To reproduce the behavior (with dash as /bin/sh):
mkdir test && cd test && git init
echo 1 >foo && git add foo
git commit -m"this commit message ends with '\n'"
echo 2 >foo && git commit -a --fixup HEAD
git rebase -i --autosquash --root
Now the editor opens with garbage in line 3 which has to be
removed or the rebase fails.
Signed-off-by: Uwe Storbeck <uwe@ibr.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
We shrink the source and destination arrays, but not the modes or
submodule_gitfile arrays, resulting in potentially mismatched data. Shrink
all the arrays at the same time to prevent this. Add tests to ensure the
problem does not recur.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When lib-terminal.sh is sourced by a test script, we
immediately set up the TTY prerequisite. We do so inside a
test_expect_success, because that nicely isolates any
generated output.
However, this early test can interfere with a script that
later wants to skip all tests (e.g., t5541 then goes on to
set up the httpd server, and wants to skip_all if that
fails). TAP output doesn't let us skip everything after we
have already run at least one test.
We could fix this by reordering the inclusion of
lib-terminal.sh in t5541 to go after the httpd setup. That
solves this case, but we might eventually hit a case with
circular dependencies, where either lib-*.sh include might
want to skip_all after the other has run a test. So
instead, let's just remove the ordering constraint entirely
by doing the setup inside a test_lazy_prereq construct,
rather than in a regular test. We never cared about the
test outcome anyway (it was written to always succeed).
Note that in addition to setting up the prerequisite, the
current test also defines test_terminal. Since we can't
affect the environment from a lazy_prereq, we have to hoist
that out. We previously depended on it _not_ being defined
when the TTY prereq isn't set as a way to ensure that tests
properly declare their dependency on TTY. However, we still
cover the case (see the in-code comment for details).
Reported-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* sr/add--interactive-term-readkey:
git-add--interactive: warn if module for interactive.singlekey is missing
git-config: document interactive.singlekey requires Term::ReadKey
* mh/replace-refs-variable-rename:
Document some functions defined in object.c
Add docstrings for lookup_replace_object() and do_lookup_replace_object()
rename read_replace_refs to check_replace_refs
"git difftool" misbehaved when the repository is bound to the
working tree with the ".git file" mechanism, where a textual
file ".git" tells us where it is.
* da/difftool-git-files:
t7800: add a difftool test for .git-files
difftool: support repositories with .git-files
* tg/index-v4-format:
read-cache: add index.version config variable
test-lib: allow setting the index format version
introduce GIT_INDEX_VERSION environment variable
* mh/object-code-cleanup:
sha1_file.c: document a bunch of functions defined in the file
sha1_file_name(): declare to return a const string
find_pack_entry(): document last_found_pack
replace_object: use struct members instead of an array
"git push" did not pay attention to branch.*.pushremote if it is
defined earlier than remote.pushdefault; the order of these two
variables in the configuration file should not matter, but it did by
mistake.
* jk/remote-pushremote-config-reading:
remote: handle pushremote config in any order
Tighten codepaths that parse timestamps in commit objects.
* jk/commit-dates-parsing-fix:
show_ident_date: fix tz range check
log: do not segfault on gmtime errors
log: handle integer overflow in timestamps
date: check date overflow against time_t
fsck: report integer overflow in author timestamps
t4212: test bogus timestamps with git-log
"git diff --external-diff" incorrectly fed the submodule directory
in the working tree to the external diff driver when it knew it is
the same as one of the versions being compared.
* tr/diff-submodule-no-reuse-worktree:
diff: do not reuse_worktree_file for submodules
"git reset" needs to refresh the index when working in a working
tree (it can also be used to match the index to the HEAD in an
otherwise bare repository), but it failed to set up the working
tree properly, causing GIT_WORK_TREE to be ignored.
* nd/reset-setup-worktree:
reset: optionally setup worktree and refresh index on --mixed
"git config" learned to read from the standard input when "-" is
given as the value to its "--file" parameter (attempting an
operation to update the configuration in the standard input of
course is rejected).
* ks/config-file-stdin:
config: teach "git config --file -" to read from the standard input
config: change git_config_with_options() interface
builtin/config.c: rename check_blob_write() -> check_write()
config: disallow relative include paths from blobs
* jk/janitorial-fixes:
open_istream(): do not dereference NULL in the error case
builtin/mv: don't use memory after free
utf8: use correct type for values in interval table
utf8: fix iconv error detection
notes-utils: handle boolean notes.rewritemode correctly
Uses of curl's "multi" interface and "easy" interface do not mix
well when we attempt to reuse outgoing connections. Teach the RPC
over http code, used in the smart HTTP transport, not to use the
"easy" interface.
* jk/http-no-curl-easy:
http: never use curl_easy_perform
Trailing whitespaces in .gitignore files, unless they are quoted for
fnmatch(3), e.g. "path\ ", are warned and ignored.
Strictly speaking, this is a backward incompatible change, but very
unlikely to bite any sane user and adjusting should be obvious and
easy.
* nd/gitignore-trailing-whitespace:
t0008: skip trailing space test on Windows
dir: ignore trailing spaces in exclude patterns
dir: warn about trailing spaces in exclude patterns
"git check-attr" when (trying to) work on a repository with a
working tree did not work well when the working tree was specified
via --work-tree (and obviously with --git-dir).
The command also works in a bare repository but it reads from the
(possibly stale, irrelevant and/or nonexistent) index, which may
need to be fixed to read from HEAD, but that is a completely
separate issue. As a related tangent to this separate issue, we
may want to also fix "check-ignore", which refuses to work in a
bare repository, to also operate in a bare one.
* jc/check-attr-honor-working-tree:
check-attr: move to the top of working tree when in non-bare repository
t0003: do not chdir the whole test process
The original description talked only about what it does. Instead,
start it with the purpose of the command, i.e. what it is used for,
and then mention what it does to achieve that goal.
Clarify what <start>, <url> and <end> means in the context of the
overall purpose of the command.
Describe the extended syntax of <end> parameter that is used when
the local branch name is different from the branch name at the
repository the changes are published.
Helped-by: Eric Sunshine Signed-off-by: Junio C Hamano <gitster@pobox.com>
rev-list: disable object/refname ambiguity check with --stdin
This is the "rev-list" analogue to 25fba78 (cat-file:
disable object/refname ambiguity check for batch mode,
2013-07-12). Like cat-file, "rev-list --stdin" may read a
large number of sha1 object names, and the warning check
introduces a significant slow-down.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
cat-file: restore warn_on_object_refname_ambiguity flag
Commit 25fba78 turned off the object/refname ambiguity check
during "git cat-file --batch" operations. However, this is a
global flag, so let's restore it when we are done.
This shouldn't make any practical difference, as cat-file
exits immediately afterwards, but is good code hygeine and
would prevent an unnecessary surprise if somebody starts to
call cmd_cat_file later.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
entry.c: fix possible buffer overflow in remove_subtree()
remove_subtree() manipulated path in a fixed-size buffer even though
the length of the input, let alone the length of entries within the
directory, were not known in advance. Change the function to take a
strbuf argument and use that object as its scratch space.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
checkout_entry(): use the strbuf throughout the function
There is no need to break out the "buf" and "len" members into
separate temporary variables. Rename path_buf to path and use
path.buf and path.len directly. This makes it easier to reason about
the data flow in the function.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
This static function has no callers, nor has it had any since its
introduction in ba67aaf2d05d (git-sh-i18n--envsubst: our own envsubst(1)
for eval_gettext(), 2011-05-14). Remove it.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
wt-status: lift the artificual "at least 20 columns" floor
When we show unmerged paths, we had an artificial 20 columns floor
for the width of labels (e.g. "both deleted:") shown next to the
pathnames. Depending on the locale, this may result in a label that
is too wide when all the label strings are way shorter than 20
columns, or no-op when a label string is longer than 20 columns.
Just drop the artificial floor. The screen real estate is better
utilized this way when all the strings are shorter.
(1) the number of bytes written is the width of a string, so they
can line up;
(2) the "how" string is always <= 19 bytes.
Neither of which we should assume.
Using the same approach as the earlier 3651e45c (wt-status: take the
alignment burden off translators, 2013-11-05), compute the necessary
column width to hold the longest label and use that for alignment.
cf. http://bugs.debian.org/725777
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Helped-by: Sandy Carter Signed-off-by: Junio C Hamano <gitster@pobox.com>
wt-status: make full label string to be subject to l10n
Earlier in 3651e45c (wt-status: take the alignment burden off
translators, 2013-11-05), we assumed that it is OK to make the
string before the colon in a label string we give as the section
header of various kinds of changes (e.g. "new file:") translatable.
This assumption apparently does not hold for some languages,
e.g. ones that want to have spaces around the colon.
Also introduce a static label_width to avoid having to run
strlen(padding) over and over.
Some tests in t7810-grep.sh are in a loop that runs them against HEAD and
the work tree. In order for that to work the test code should use the
variables $L (display name), $H (HEAD or empty string) and $HC (revision
prefix for result lines); otherwise tests are just repeated with the same
target. Add the variables where they're missing and make sure the test
description is wrapped in double quotes (instead of single quotes) to
allow variables to be expanded.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When commit a88c915 (mv: move submodules using a gitfile, 2013-07-30)
added the submodule_gitfile array, it was not added to the block that
enlarges the arrays when we are moving a directory so that we do not
have to worry about it being a directory when we perform the actual
move. After this, the loop continues over the enlarged set of sources.
Since we assume that submodule_gitfile has size argc, if any of the
items in the source directory are submodules we are guaranteed to write
beyond the end of submodule_gitfile.
Fix this by realloc'ing submodule_gitfile at the same time as the other
arrays.
Reported-by: Guillaume Gelin <contact@ramnes.eu> Signed-off-by: John Keeping <john@keeping.me.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The --patch-format option has been supported for a while but it is not
mentioned in the man page and the short help cannot tell the user what
the supported formats are. Add the option to the man page along with the
supported options.
Signed-off-by: Chris Packham <judge.packham@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
configure.ac: link with -liconv for locale_charset()
On e.g. FreeBSD 10.x, the following situation is common:
- there's iconv implementation in libc, which has no locale_charset()
function
- there's GNU libiconv installed from Ports Collection
Git build process
- detects that iconv is in libc and thus -liconv is not needed for it
- detects locale_charset in -liconv, but for some reason doesn't add it
to CHARSET_LIB (as it would do with -lcharset if locale_charset() was
found there instead of -liconv)
- git doesn't build due to unresolved external locale_charset()
Fix this by adding -liconv to CHARSET_LIB if locale_charset() is
detected in this library.
Signed-off-by: Dmitry Marakasov <amdmi3@amdmi3.ru> Signed-off-by: Junio C Hamano <gitster@pobox.com>
upload-pack: send shallow info over stdin to pack-objects
Before cdab485 (upload-pack: delegate rev walking in shallow fetch to
pack-objects - 2013-08-16) upload-pack does not write to the source
repository. cdab485 starts to write $GIT_DIR/shallow_XXXXXX if it's a
shallow fetch, so the source repo must be writable.
git:// servers do not need write access to repos and usually don't
have it, which means cdab485 breaks shallow clone over git://
Instead of using a temporary file as the media for shallow points, we
can send them over stdin to pack-objects as well. Prepend shallow
SHA-1 with --shallow so pack-objects knows what is what.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we get a list of paths from read_directory, we further
prune it to create the final list of items to remove. The
code paths for directories and non-directories repeat the
same "add to list" code.
This patch restructures the code so that we don't repeat
ourselves. Also, by following a "if (condition) continue"
pattern like the pathspec check above, it makes it more
obvious that the conditional is about excluding directories
under certain circumstances.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-clean uses read_directory to fill in a `struct dir` with
potential hits. However, read_directory does not actually
check against our pathspec. It uses a simplified version
that may turn up false positives. As a result, we need to
check that any hits match our pathspec. We do so reliably
for non-directories. For directories, if "-d" is not given
we check that the pathspec matched exactly (i.e., we are
even stricter, and require an explicit "git clean foo" to
clean "foo/"). But if "-d" is given, rather than relaxing
the exact match to allow a recursive match, we do not check
the pathspec at all.
This regression was introduced in 113f10f (Make git-clean a
builtin, 2007-11-11).
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Windows API does not preserve file names with trailing spaces (and
dots), but rather strips them. Our tools (MSYS bash, git) base the POSIX
emulation on the Windows API. As a consequence, it is impossible for bash
on Windows to allocate a file whose name has trailing spaces, and for git
to stat such a file. Both operate on a file whose name has the spaces
stripped. Skip the test that needs such a file name.
Note that we do not use (another incarnation of) prerequisite FUNNYNAMES.
The reason is that FUNNYNAMES is intended to represent a property of the
file system. But the inability to have trailing spaces in a file name is
a property of the Windows API. The file system (NTFS) does not have this
limitation.
Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Just like "git branch" can be told to list the branches that has the
named commit by "git branch --with <commit>", teach the same
short-hand to "git tag", so that "git tag --with <commit>" shows the
releases with the named commit.
Commit 1dca155fe3fa (log: handle integer overflow in
timestamps, 2014-02-24) tried to catch integer overflow
coming from strtol() on the timezone field by comparing against
LONG_MIN/LONG_MAX. However, the intermediate "tz" variable
is an "int", which means it can never be LONG_MAX on LP64
systems; we would truncate the output from strtol before the
comparison.
Clang's -Wtautological-constant-out-of-range-compare notices
this and rightly complains.
Let's instead store the result of strtol in a long, and then
compare it against INT_MIN/INT_MAX. This will catch overflow
from strtol, and also overflow when we pass the result as an
int to show_date.
Reported-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a bourne shell script, "VAR=VAL command" is sufficient to run
'command' with environment variable VAR set to value VAL without
affecting the environment of the shell itself; there is no need
to say "env VAR=VAL command".
We invented hashcpy() to keep the abstraction of "object name"
behind it. Use it instead of calling memcpy() with hard-coded
20-byte length when moving object names between pieces of memory.
Leave ppc/sha1.c as-is, because the function is about the SHA-1 hash
algorithm whose output is and will always be 20 bytes.
Helped-by: Michael Haggerty <mhagger@alum.mit.edu> Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Sun He <sunheehnus@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch: use skip_prefix() in install_branch_config()
The install_branch_config() function reimplemented the skip_prefix()
function inline.
Reported-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Brian Gesiak <modocache@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach combine-diff to honour the path-output-order imposed by
diffcore-order, and optimize how matching paths are found in
the N-way diffs made with parents.
* ks/combine-diff:
tests: add checking that combine-diff emits only correct paths
combine-diff: simplify intersect_paths() further
combine-diff: combine_diff_path.len is not needed anymore
combine-diff: optimize combine_diff_path sets intersection
diff test: add tests for combine-diff with orderfile
diffcore-order: export generic ordering interface
When pushing, we do not even look at our push refspecs until
after we have made contact with the remote receive-pack and
gotten its list of refs. This means that we may go to some
work, including asking the user to log in, before realizing
we have simple errors like "git push origin matser".
We cannot catch all refspec problems, since fully evaluating
the refspecs requires knowing what the remote side has. But
we can do a quick sanity check of the local side and catch a
few simple error cases.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The match_explicit_lhs function has all of the logic
necessary to verify the refspecs without actually doing any
work. This patch lets callers pass a NULL "match" pointer to
indicate they want a "verify only" operation.
For the most part, we just need to avoid writing to the NULL
pointer. However, we also have to refactor the
try_explicit_object_name sub-function; it indicates success by
allocating and returning a new ref. Instead, we give it an
"out" parameter for the match and return a numeric status.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>