Commit Graph

62789 Commits

Author SHA1 Message Date
Elijah Newren
ec59da6015 merge-ort: record the reason that we want a rename for a file
There are two different reasons we might want a rename for a file -- for
three-way content merging or as part of directory rename detection.
Record the reason.  diffcore-rename will potentially be able to filter
some of the ones marked as needed only for directory rename detection,
if it can determine those directory renames based solely on renames
found via exact rename detection and basename-guided rename detection.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
bf238b7137 diffcore-rename: add computation of number of unknown renames
The previous commit can only be effective if we have a computation of
the number of paths under a given directory which are still have pending
renames, and expected this number to be recorded in the dir_rename_count
map under the key UNKNOWN_DIR.  Add the code necessary to compute these
values.

Note that this change means dir_rename_count might have a directory
whose only entry (for UNKNOWN_DIR) was removed by the time merge-ort
goes to check it.  To account for this, merge-ort needs to check for the
case where the max count is 0.

With this change we are now computing the necessary value for each
directory in dirs_removed, but are not using that value anywhere.  The
next two commits will make use of the values stored in dirs_removed in
order to compute whether each relevant_source (that is needed only for
directory rename detection) has become unnecessary.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
0491d39297 diffcore-rename: check if we have enough renames for directories early on
As noted in the past few commits, if we can determine that a directory
already has enough renames to determine how directory rename detection
will be decided for that directory, then we can mark that directory as
no longer needing any more renames detected for files underneath it.
For such directories, we change the value in the dirs_removed map from
RELEVANT_TO_SELF to RELEVANT_FOR_ANCESTOR.

A subsequent patch will use this information while iterating over the
remaining potential rename sources to mark ones that were only
location_relevant as unneeded if no containing directory is still marked
as RELEVANT_TO_SELF.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:56 -07:00
Elijah Newren
e54385b97a diffcore-rename: only compute dir_rename_count for relevant directories
When one side adds files to a directory that the other side renamed,
directory rename detection is used to either move the new paths to the
newer directory or warn the user about the fact that another path
location might be better.

If a parent of the given directory had new files added to it, any
renames in the current directory are also part of determining where the
parent directory is renamed to.  Thus, naively, we need to record each
rename N times for a path at depth N.  However, we can use the
additional information added to dirs_removed in the last commit to avoid
traversing all N parent directories in many cases.  Let's use an example
to explain how this works.  If we have a path named
   src/old_dir/a/b/file.c
and src/old_dir doesn't exist on one side of history, but the other
added a file named src/old_dir/newfile.c, then if one side renamed
   src/old_dir/a/b/file.c => source/new_dir/a/b/file.c
then this file would affect potential directory rename detection counts
for
   src/old_dir/a/b => source/new_dir/a/b
   src/old_dir/a   => source/new_dir/a
   src/old_dir     => source/new_dir
   src             => source
adding a weight of 1 to each in dir_rename_counts.  However, if src/
exists on both sides of history, then we don't need to track any entries
for it in dir_rename_counts.  That was implemented previously.  What we
are adding now, is that if no new files were added to src/old_dir/a or
src/old_dir/b, then we don't need to have counts in dir_rename_count
for those directories either.

In short, we only need to track counts in dir_rename_count for
directories whose dirs_removed value is RELEVANT_FOR_SELF.  And as soon
as we reach a directory that isn't in dirs_removed (signalled by
returning the default value of NOT_RELEVANT from strintmap_get()), we
can stop looking any further up the directory hierarchy.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Elijah Newren
fb52938eec merge-ort: record the reason that we want a rename for a directory
When one side of history renames a directory, and the other side of
history added files to the old directory, directory rename detection is
used to warn about the location of the added files so the user can
move them to the old directory or keep them with the new one.

This sets up three different types of directories:
  * directories that had new files added to them
  * directories underneath a directory that had new files added to them
  * directories where no new files were added to it or any leading path

Save this information in dirs_removed; the next several commits will
make use of this information.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Elijah Newren
a49b55d52e merge-ort, diffcore-rename: tweak dirs_removed and relevant_source type
As noted in the previous commit, we want to be able to take advantage of
the "majority rules" portion of directory rename detection to avoid
detecting more renames than necessary.  However, for diffcore-rename to
take advantage of that, it needs to know whether a rename source file
was needed for just directory rename detection reasons, or if it is
wanted for potential three-way content merging.  Modify relevant_sources
from a strset to a strintmap, so we can encode additional information.

We also modify dirs_removed from a strset to a strintmap at the same
time because trying to determine what files are needed for directory
rename detection will require us tracking a bit more information for
each directory.

This commit only changes the types of the two variables from strset to
strintmap; it does not actually store any special values yet and for now
only checks for presence of entries in the strintmap.  Thus, the code is
functionally identical to how it behaved before.  Future commits will
start associating values with each key for these two maps.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Elijah Newren
ae1db7b31c diffcore-rename: take advantage of "majority rules" to skip more renames
In directory rename detection (when a directory is removed on one side
of history and the other side adds new files to that directory), we work
to find where the greatest number of files within that directory were
renamed to so that the new files can be moved with the majority of the
files.

Naively, we can just do this by detecting renames for *all* files within
the removed/renamed directory, looking at all the destination
directories where files within that directory were moved, and if there
is more than one such directory then taking the one with the greatest
number of files as the directory where the old directory was renamed to.

However, sometimes there are enough renames from exact rename detection
or basename-guided rename detection that we have enough information to
determine the majority winner already.  Add a function meant to compute
whether particular renames are still needed based on this majority rules
check.  The next several commits will then add the necessary
infrastructure to get the information we need to compute which
additional rename sources we can skip.

An important side note for future further optimization:

There is a possible improvement to this optimization that I have not yet
attempted and will not be included in this series of patches: we could
first check whether exact renames provide enough information for us to
determine directory renames, and avoid doing basename-guided rename
detection on some or all of the RELEVANT_LOCATION files within those
directories.  In effect, this variant would mean doing the
handle_early_known_dir_renames() both after exact rename detection and
again after basename-guided rename detection, though it would also mean
decrementing the number of "unknown" renames for each rename we found
from basename-guided rename detection.  Adding this additional check for
skippable renames right after exact rename detection might turn out to
be valuable, especially for partial clones where it might allow us to
download certain source files entirely.  However, this particular
optimization was actually the last one I did in original implementation
order, and by the time I implemented this idea, every testcase I had was
sufficiently fast that further optimization was unwarranted.  If future
testcases arise that tax rename detection more heavily (or perhaps
partial clones can benefit from avoiding loading more objects), it may
be worth implementing this more involved variant.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:32:55 -07:00
Jeff King
27d578d904 t: annotate !PTHREADS tests with !FAIL_PREREQS
Some tests in t5300 and t7810 expect us to complain about a "--threads"
argument when Git is compiled without pthread support. Running these
under GIT_TEST_FAIL_PREREQS produces a confusing failure: we pretend to
the tests that there is no pthread support, so they expect the warning,
but of course the actual build is perfectly happy to respect the
--threads argument.

We never noticed before the recent a926c4b904 (tests: remove most uses
of C_LOCALE_OUTPUT, 2021-02-11), because the tests also were marked as
requiring the C_LOCALE_OUTPUT prerequisite. Which means they'd never
have run in FAIL_PREREQS mode, since it would always pretend that the
locale prereq was not satisfied.

These tests can't possibly work in this mode; it is a mismatch between
what the tests expect and what the build was told to do. So let's just
mark them to be skipped, using the special prereq introduced by
dfe1a17df9 (tests: add a special setup where prerequisites fail,
2019-05-13).

Reported-by: Son Luong Ngoc <sluongng@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 14:17:30 -07:00
Jeff Hostetler
f59d15bb42 convert: add classification for conv_attrs struct
Create `enum conv_attrs_classification` to express the different ways
that attributes are handled for a blob during checkout.

This will be used in a later commit when deciding whether to add a file
to the parallel or delayed queue during checkout. For now, we can also
use it in get_stream_filter_ca() to simplify the function (as the
classifying logic is the same).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Jeff Hostetler
3e9e82c0d8 convert: add get_stream_filter_ca() variant
Like the previous patch, we will also need to call get_stream_filter()
with a precomputed `struct conv_attrs`, when we add support for parallel
checkout workers. So add the _ca() variant which takes the conversion
attributes struct as a parameter.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Jeff Hostetler
55b4ad0ead convert: add [async_]convert_to_working_tree_ca() variants
Separate the attribute gathering from the actual conversion by adding
_ca() variants of the conversion functions. These variants receive a
precomputed 'struct conv_attrs', not relying, thus, on an index state.
They will be used in a future patch adding parallel checkout support,
for two reasons:

- We will already load the conversion attributes in checkout_entry(),
  before conversion, to decide whether a path is eligible for parallel
  checkout. Therefore, it would be wasteful to load them again later,
  for the actual conversion.

- The parallel workers will be responsible for reading, converting and
  writing blobs to the working tree. They won't have access to the main
  process' index state, so they cannot load the attributes. Instead,
  they will receive the preloaded ones and call the _ca() variant of
  the conversion functions. Furthermore, the attributes machinery is
  optimized to handle paths in sequential order, so it's better to leave
  it for the main process, anyway.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Jeff Hostetler
38e95844e8 convert: make convert_attrs() and convert structs public
Move convert_attrs() declaration from convert.c to convert.h, together
with the conv_attrs struct and the crlf_action enum. This function and
the data structures will be used outside convert.c in the upcoming
parallel checkout implementation. Note that crlf_action is renamed to
convert_crlf_action, which is more appropriate for the global namespace.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:56:40 -07:00
Nipunn Koorapati
7e5aa13d2c fsmonitor: add perf test for git diff HEAD
Update the xargs call so that if your large repo contains
symlinks, test-tool chmtime failure does not end the script.

On Linux
Test                                                          this tree           upstream/master
---------------------------------------------------------------------------------------------------------
7519.4: status (fsmonitor=fsmonitor-watchman)                 0.52(0.43+0.10)     0.53(0.49+0.05) +1.9%
7519.5: status -uno (fsmonitor=fsmonitor-watchman)            0.21(0.15+0.07)     0.22(0.13+0.09) +4.8%
7519.6: status -uall (fsmonitor=fsmonitor-watchman)           1.65(0.93+0.71)     1.69(1.03+0.65) +2.4%
7519.7: status (dirty) (fsmonitor=fsmonitor-watchman)         11.99(11.34+1.58)   11.95(11.02+1.79) -0.3%
7519.8: diff (fsmonitor=fsmonitor-watchman)                   0.25(0.17+0.26)     0.25(0.18+0.26) +0.0%
7519.9: diff HEAD (fsmonitor=fsmonitor-watchman)              0.39(0.25+0.34)     0.89(0.35+0.74) +128.2%
7519.10: diff -- 0_files (fsmonitor=fsmonitor-watchman)       0.16(0.13+0.04)     0.16(0.12+0.05) +0.0%
7519.11: diff -- 10_files (fsmonitor=fsmonitor-watchman)      0.16(0.12+0.05)     0.16(0.12+0.05) +0.0%
7519.12: diff -- 100_files (fsmonitor=fsmonitor-watchman)     0.16(0.12+0.05)     0.16(0.12+0.05) +0.0%
7519.13: diff -- 1000_files (fsmonitor=fsmonitor-watchman)    0.16(0.11+0.06)     0.16(0.12+0.05) +0.0%
7519.14: diff -- 10000_files (fsmonitor=fsmonitor-watchman)   0.18(0.13+0.06)     0.17(0.10+0.08) -5.6%
7519.15: add (fsmonitor=fsmonitor-watchman)                   2.25(1.53+0.68)     2.25(1.47+0.74) +0.0%
7519.18: status (fsmonitor=disabled)                          0.88(0.73+1.03)     0.89(0.67+1.08) +1.1%
7519.19: status -uno (fsmonitor=disabled)                     0.45(0.43+0.89)     0.45(0.34+0.98) +0.0%
7519.20: status -uall (fsmonitor=disabled)                    1.88(1.16+1.58)     1.88(1.22+1.51) +0.0%
7519.21: status (dirty) (fsmonitor=disabled)                  7.53(7.05+2.11)     7.53(6.98+2.04) +0.0%
7519.22: diff (fsmonitor=disabled)                            0.42(0.37+0.92)     0.42(0.38+0.91) +0.0%
7519.23: diff HEAD (fsmonitor=disabled)                       0.44(0.41+0.90)     0.44(0.40+0.91) +0.0%
7519.24: diff -- 0_files (fsmonitor=disabled)                 0.13(0.09+0.05)     0.13(0.09+0.05) +0.0%
7519.25: diff -- 10_files (fsmonitor=disabled)                0.13(0.10+0.04)     0.13(0.10+0.04) +0.0%
7519.26: diff -- 100_files (fsmonitor=disabled)               0.13(0.09+0.05)     0.13(0.10+0.04) +0.0%
7519.27: diff -- 1000_files (fsmonitor=disabled)              0.13(0.09+0.06)     0.13(0.09+0.05) +0.0%
7519.28: diff -- 10000_files (fsmonitor=disabled)             0.14(0.11+0.05)     0.14(0.10+0.05) +0.0%
7519.29: add (fsmonitor=disabled)                             2.43(1.61+1.64)     2.43(1.69+1.57) +0.0%

On linux (2.29.2 vs w/ this patch):
nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff 2>&1 | grep lstat
  0.04    0.000063           3        20         6 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff HEAD 2>&1 | grep lstat
 94.98    5.242262          10    523783        13 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff 2>&1 | grep lstat
  0.38    0.000032           5         7         3 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep lstat
 99.44    0.741892           9     81634        10 lstat

On mac (2.29.2 vs w/ this patch):
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff 2>&1 | grep "^lstat64 "
lstat64                                         8
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff HEAD 2>&1 | grep "^lstat64 "
lstat64                                    120242
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff 2>&1 | grep "^lstat64 "
lstat64                                         4
nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep "^lstat64 "
lstat64                                      4497

There are still a bunch of lstats - on directories, but not every file. Progress!

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:31:14 -07:00
Nipunn Koorapati
0ec9949f78 fsmonitor: add assertion that fsmonitor is valid to check_removed
Validate that fsmonitor is valid to futureproof against bugs where
check_removed might be called from places that haven't refreshed.

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:31:13 -07:00
Nipunn Koorapati
4f3d6d0261 fsmonitor: skip lstat deletion check during git diff-index
Teach git to honor fsmonitor rather than issuing an lstat
when checking for dirty local deletes. Eliminates O(files)
lstats during `git diff HEAD`

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 13:31:11 -07:00
Matheus Tavares
fab78a0c3d checkout: don't follow symlinks when removing entries
At 1d718a5108 ("do not overwrite untracked symlinks", 2011-02-20),
symlink.c:check_leading_path() started returning different codes for
FL_ENOENT and FL_SYMLINK. But one of its callers, unlink_entry(), was
not adjusted for this change, so it started to follow symlinks on the
leading path of to-be-removed entries. Fix that and add a regression
test.

Note that since 1d718a5108 check_leading_path() no longer differentiates
the case where it found a symlink in the path's leading components from
the cases where it found a regular file or failed to lstat() the
component. So, a side effect of this current patch is that
unlink_entry() now returns early in all of these three cases. And
because we no longer try to unlink such paths, we also don't get the
warning from remove_or_warn().

For the regular file and symlink cases, it's questionable whether the
warning was useful in the first place: unlink_entry() removes tracked
paths that should no longer be present in the state we are checking out
to. If the path had its leading dir replaced by another file, it means
that the basename already doesn't exist, so there is no need for a
warning. Sure, we are leaving a regular file or symlink behind at the
path's dirname, but this file is either untracked now (so again, no
need to warn), or it will be replaced by a tracked file during the next
phase of this checkout operation.

As for failing to lstat() one of the leading components, the basename
might still exist only we cannot unlink it (e.g. due to the lack of the
required permissions). Since the user expect it to be removed
(especially with checkout's --no-overlay option), add back the warning
in this more relevant case.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 12:58:10 -07:00
Matheus Tavares
462b4e8dfd symlinks: update comment on threaded_check_leading_path()
Since 1d718a5108 ("do not overwrite untracked symlinks", 2011-02-20),
the comment on top of threaded_check_leading_path() is outdated and no
longer reflects the behavior of this function. Let's updated it to avoid
confusions. While we are here, also remove some duplicated comments to
avoid similar maintenance problems.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 12:58:08 -07:00
Ævar Arnfjörð Bjarmason
fb79f5bff7 fsck.c: refactor and rename common config callback
Refactor code I recently changed in 1f3299fda9 (fsck: make
fsck_config() re-usable, 2021-01-05) so that I could use fsck's config
callback in mktag in 1f3299fda9 (fsck: make fsck_config() re-usable,
2021-01-05).

I don't know what I was thinking in structuring the code this way, but
it clearly makes no sense to have an fsck_config_internal() at all
just so it can get a fsck_options when git_config() already supports
passing along some void* data.

Let's just make use of that instead, which gets us rid of the two
wrapper functions, and brings fsck's common config callback in line
with other such reusable config callbacks.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 14:02:43 -07:00
Johannes Schindelin
4abc57848d fsmonitor: do not forget to release the token in discard_index()
In 56c6910028 (fsmonitor: change last update timestamp on the
index_state to opaque token, 2020-01-07), we forgot to adjust
`discard_index()` to release the "last-update" token: it is no longer a
64-bit number, but a free-form string that has been allocated.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 12:19:28 -07:00
Johannes Schindelin
3dfd30598b fsmonitor: fix memory corruption in some corner cases
In 56c6910028 (fsmonitor: change last update timestamp on the
index_state to opaque token, 2020-01-07), we forgot to adjust the part
of `unpack_trees()` that copies the FSMonitor "last-update" information
that we copy from the source index to the result index since 679f2f9fdd
(unpack-trees: skip stat on fsmonitor-valid files, 2019-11-20).

Since the "last-update" information is no longer a 64-bit number, but a
free-form string that has been allocated, we need to duplicate it rather
than just copying it.

This is important because there _are_ cases when `unpack_trees()` will
perform a oneway merge that implicitly calls `refresh_fsmonitor()`
(which will allocate that "last-update" token). This happens _after_
that token was copied into the result index. However, we _then_ call
`check_updates()` on that index, which will _also_ call
`refresh_fsmonitor()`, accessing the "last-update" string, which by now
would be released already.

In the instance that lead to this patch, this caused a segmentation
fault during a lengthy, complicated rebase involving the todo command
`reset` that (crucially) had to updated many files. Unfortunately, it
seems very hard to trigger that crash, therefore this patch is not
accompanied by a regression test.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 12:19:26 -07:00
Kyle Meyer
cfd409ed09 config.txt: add missing period
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 11:25:15 -07:00
Jeff King
7730f85594 bisect: peel annotated tags to commits
This patch fixes a bug where git-bisect doesn't handle receiving
annotated tags as "git bisect good <tag>", etc. It's a regression in
27257bc466 (bisect--helper: reimplement `bisect_state` & `bisect_head`
shell functions in C, 2020-10-15).

The original shell code called:

  sha=$(git rev-parse --verify "$rev^{commit}") ||
          die "$(eval_gettext "Bad rev input: \$rev")"

which will peel the input to a commit (or complain if that's not
possible). But the C code just calls get_oid(), which will yield the oid
of the tag.

The fix is to peel to a commit. The error message here is a little
non-idiomatic for Git (since it starts with a capital). I've mostly left
it, as it matches the other converted messages (like the "Bad rev input"
we print when get_oid() fails), though I did add an indication that it
was the peeling that was the problem. It might be worth taking a pass
through this converted code to modernize some of the error messages.

Note also that the test does a bare "grep" (not i18ngrep) on the
expected "X is the first bad commit" output message. This matches the
rest of the test script.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 11:24:08 -07:00
Jonathan Tan
5f70859c15 t5606: run clone branch name test with protocol v2
4f37d45706 ("clone: respect remote unborn HEAD", 2021-02-05) introduces
a new feature (if the remote has an unborn HEAD, e.g. when the remote
repository is empty, use it as the name of the branch) that only works
in protocol v2, but did not ensure that one of its tests always uses
protocol v2, and thus that test would fail if
GIT_TEST_PROTOCOL_VERSION=0 (or 1) is used. Therefore, add "-c
protocol.version=2" to the appropriate test.

(The rest of the tests from that commit have "-c protocol.version=2"
already added.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 11:19:36 -07:00
René Scharfe
116affac3f mem-pool: drop trailing semicolon from macro definition
Allow BLOCK_GROWTH_SIZE to be used like an integer literal by removing
the trailing semicolon from its definition.  Also wrap the expression in
parentheses, to allow it to be used with operators without leading to
unexpected results.  It doesn't matter for the current use site, but
make it follow standard macro rules anyway to avoid future surprises.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 10:20:16 -07:00
René Scharfe
3d8cbbf2c3 block-sha1: drop trailing semicolon from macro definition
23119ffb4e (block-sha1: put expanded macro parameters in parentheses,
2012-07-22) added a trailing semicolon to the definition of SHA_MIX
without explanation.  It doesn't matter with the current code, but make
sure to avoid potential surprises by removing it again.

This allows the macro to be used almost like a function: Users can
combine it with operators of their choice, but still must not pass an
expression with side-effects as a parameter, as it would be evaluated
multiple times.

Signed-off-by: René Scharfe <l.s.r@web.de>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 10:20:01 -07:00
Andrzej Hunt
097ea2c848 fsmonitor: avoid global-buffer-overflow READ when checking trivial response
query_result can be be an empty strbuf (STRBUF_INIT) - in that case
trying to read 3 bytes triggers a buffer overflow read (as
query_result.buf = '\0').

Therefore we need to check query_result's length before trying to read 3
bytes.

This overflow was introduced in:
  940b94f35c (fsmonitor: log invocation of FSMonitor hook to trace2, 2021-02-03)
It was found when running the test-suite against ASAN, and can be most
easily reproduced with the following command:

make GIT_TEST_OPTS="-v" DEFAULT_TEST_TARGET="t7519-status-fsmonitor.sh" \
SANITIZE=address DEVELOPER=1 test

==2235==ERROR: AddressSanitizer: global-buffer-overflow on address 0x0000019e6e5e at pc 0x00000043745c bp 0x7fffd382c520 sp 0x7fffd382bcc8
READ of size 3 at 0x0000019e6e5e thread T0
    #0 0x43745b in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7
    #1 0x43786d in bcmp /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:887:10
    #2 0x80b146 in fsmonitor_is_trivial_response /home/ahunt/oss-fuzz/git/fsmonitor.c:192:10
    #3 0x80b146 in query_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:175:7
    #4 0x80a749 in refresh_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:267:21
    #5 0x80bad1 in tweak_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:429:4
    #6 0x90f040 in read_index_from /home/ahunt/oss-fuzz/git/read-cache.c:2321:3
    #7 0x8e5d08 in repo_read_index_preload /home/ahunt/oss-fuzz/git/preload-index.c:164:15
    #8 0x52dd45 in prepare_index /home/ahunt/oss-fuzz/git/builtin/commit.c:363:6
    #9 0x52a188 in cmd_commit /home/ahunt/oss-fuzz/git/builtin/commit.c:1588:15
    #10 0x4ce77e in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #11 0x4ccb18 in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #12 0x4cb01c in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #13 0x4cb01c in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #14 0x6aca8d in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #15 0x7fb027bf5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
    #16 0x4206b9 in _start /home/abuild/rpmbuild/BUILD/glibc-2.26/csu/../sysdeps/x86_64/start.S:120

0x0000019e6e5e is located 2 bytes to the left of global variable 'strbuf_slopbuf' defined in 'strbuf.c:51:6' (0x19e6e60) of size 1
  'strbuf_slopbuf' is ascii string ''
0x0000019e6e5e is located 126 bytes to the right of global variable 'signals' defined in 'sigchain.c:11:31' (0x19e6be0) of size 512
SUMMARY: AddressSanitizer: global-buffer-overflow /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long)
Shadow bytes around the buggy address:
  0x000080334d70: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x000080334d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x000080334db0: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
=>0x000080334dc0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9[f9]01 f9 f9 f9
  0x000080334dd0: f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9 02 f9 f9 f9
  0x000080334de0: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9
  0x000080334df0: f9 f9 f9 f9 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x000080334e00: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 01 f9 f9 f9
  0x000080334e10: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Acked-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 10:00:20 -07:00
Junio C Hamano
1c57cc70ec cocci: allow xcalloc(1, size)
Allocating a pre-cleared single element is quite common and it is
misleading to use CALLOC_ARRAY(); these allocations that would be
affected without this change are not allocating an array.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 17:56:07 -07:00
Junio C Hamano
486f4bd183 xcalloc: use CALLOC_ARRAY() when applicable
These are for codebase before Git 2.31

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 17:51:10 -07:00
Jeff Hostetler
9fd1902762 unix-stream-server: create unix domain socket under lock
Create a wrapper class for `unix_stream_listen()` that uses a ".lock"
lockfile to create the unix domain socket in a race-free manner.

Unix domain sockets have a fundamental problem on Unix systems because
they persist in the filesystem until they are deleted.  This is
independent of whether a server is actually listening for connections.
Well-behaved servers are expected to delete the socket when they
shutdown.  A new server cannot easily tell if a found socket is
attached to an active server or is leftover cruft from a dead server.
The traditional solution used by `unix_stream_listen()` is to force
delete the socket pathname and then create a new socket.  This solves
the latter (cruft) problem, but in the case of the former, it orphans
the existing server (by stealing the pathname associated with the
socket it is listening on).

We cannot directly use a .lock lockfile to create the socket because
the socket is created by `bind(2)` rather than the `open(2)` mechanism
used by `tempfile.c`.

As an alternative, we hold a plain lockfile ("<path>.lock") as a
mutual exclusion device.  Under the lock, we test if an existing
socket ("<path>") is has an active server.  If not, we create a new
socket and begin listening.  Then we use "rollback" to delete the
lockfile in all cases.

This wrapper code conceptually exists at a higher-level than the core
unix_stream_connect() and unix_stream_listen() routines that it
consumes.  It is isolated in a wrapper class for clarity.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:51 -07:00
Jeff Hostetler
77e522caae unix-socket: disallow chdir() when creating unix domain sockets
Calls to `chdir()` are dangerous in a multi-threaded context.  If
`unix_stream_listen()` or `unix_stream_connect()` is given a socket
pathname that is too long to fit in a `sockaddr_un` structure, it will
`chdir()` to the parent directory of the requested socket pathname,
create the socket using a relative pathname, and then `chdir()` back.
This is not thread-safe.

Teach `unix_sockaddr_init()` to not allow calls to `chdir()` when this
flag is set.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:51 -07:00
Jeff Hostetler
55144ccb0a unix-socket: add backlog size option to unix_stream_listen()
Update `unix_stream_listen()` to take an options structure to override
default behaviors.  This commit includes the size of the `listen()` backlog.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:51 -07:00
Jeff Hostetler
4f98ce5865 unix-socket: eliminate static unix_stream_socket() helper function
The static helper function `unix_stream_socket()` calls `die()`.  This
is not appropriate for all callers.  Eliminate the wrapper function
and make the callers propagate the error.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:51 -07:00
Jeff Hostetler
59c7b88198 simple-ipc: add win32 implementation
Create Windows implementation of "simple-ipc" using named pipes.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Jeff Hostetler
066d5234d0 simple-ipc: design documentation for new IPC mechanism
Brief design documentation for new IPC mechanism allowing
foreground Git client to talk with an existing daemon process
at a known location using a named pipe or unix domain socket.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Johannes Schindelin
8c2efa5d76 pkt-line: add options argument to read_packetized_to_strbuf()
Update the calling sequence of `read_packetized_to_strbuf()` to take
an options argument and not assume a fixed set of options.  Update the
only existing caller accordingly to explicitly pass the
formerly-assumed flags.

The `read_packetized_to_strbuf()` function calls `packet_read()` with
a fixed set of assumed options (`PACKET_READ_GENTLE_ON_EOF`).  This
assumption has been fine for the single existing caller
`apply_multi_file_filter()` in `convert.c`.

In a later commit we would like to add other callers to
`read_packetized_to_strbuf()` that need a different set of options.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Johannes Schindelin
c4ba579397 pkt-line: add PACKET_READ_GENTLE_ON_READ_ERROR option
Introduce PACKET_READ_GENTLE_ON_READ_ERROR option to help libify the
packet readers.

So far, the (possibly indirect) callers of `get_packet_data()` can ask
that function to return an error instead of `die()`ing upon end-of-file.
However, random read errors will still cause the process to die.

So let's introduce an explicit option to tell the packet reader
machinery to please be nice and only return an error on read errors.

This change prepares pkt-line for use by long-running daemon processes.
Such processes should be able to serve multiple concurrent clients and
and survive random IO errors.  If there is an error on one connection,
a daemon should be able to drop that connection and continue serving
existing and future connections.

This ability will be used by a Git-aware "Builtin FSMonitor" feature
in a later patch series.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Johannes Schindelin
3a63c6a48c pkt-line: do not issue flush packets in write_packetized_*()
Remove the `packet_flush_gently()` call in `write_packetized_from_buf() and
`write_packetized_from_fd()` and require the caller to call it if desired.
Rename both functions to `write_packetized_from_*_no_flush()` to prevent
later merge accidents.

`write_packetized_from_buf()` currently only has one caller:
`apply_multi_file_filter()` in `convert.c`.  It always wants a flush packet
to be written after writing the payload.

However, we are about to introduce a caller that wants to write many
packets before a final flush packet, so let's make the caller responsible
for emitting the flush packet.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Jeff Hostetler
7455e05e4e pkt-line: eliminate the need for static buffer in packet_write_gently()
Teach `packet_write_gently()` to write the pkt-line header and the actual
buffer in 2 separate calls to `write_in_full()` and avoid the need for a
static buffer, thread-safe scratch space, or an excessively large stack
buffer.

Change `write_packetized_from_fd()` to allocate a temporary buffer rather
than using a static buffer to avoid similar issues here.

These changes are intended to make it easier to use pkt-line routines in
a multi-threaded context with multiple concurrent writers writing to
different streams.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Charvi Mendiratta
00ea64ed7a doc/git-commit: add documentation for fixup=[amend|reword] options
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:36 -07:00
Charvi Mendiratta
8bedae4599 t3437: use --fixup with options to create amend! commit
We taught `git commit --fixup` to create "amend!" commit. Let's also
update the tests and use it to setup the rebase tests.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:36 -07:00
Charvi Mendiratta
3d1bda6b5b t7500: add tests for --fixup=[amend|reword] options
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:35 -07:00
Charvi Mendiratta
3270ae82ac commit: add a reword suboption to --fixup
`git commit --fixup=reword:<commit>` aliases
`--fixup=amend:<commit> --only`, where it creates an empty "amend!"
commit that will reword <commit> without changing its contents when
it is rebased with `--autosquash`.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:35 -07:00
Charvi Mendiratta
494d314a05 commit: add amend suboption to --fixup to create amend! commit
`git commit --fixup=amend:<commit>` will create an "amend!" commit.
The resulting commit message subject will be "amend! ..." where
"..." is the subject line of <commit> and the initial message
body will be <commit>'s message.

The "amend!" commit when rebased with --autosquash will fixup the
contents and replace the commit message of <commit> with the
"amend!" commit's message body.

In order to prevent rebase from creating commits with an empty
message we refuse to create an "amend!" commit if commit message
body is empty.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:35 -07:00
Charvi Mendiratta
6e0e288779 sequencer: export and rename subject_length()
This function can be used in other parts of git. Let's move the
function to commit.c and also rename it to make the name of the
function more generic.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:29:35 -07:00
Junio C Hamano
a5828ae6b5 Git 2.31
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 11:51:51 -07:00
Junio C Hamano
8775279891 Merge branch 'jn/mergetool-hideresolved-is-optional'
Disable the recent mergetool's hideresolved feature by default for
backward compatibility and safety.

* jn/mergetool-hideresolved-is-optional:
  doc: describe mergetool configuration in git-mergetool(1)
  mergetool: do not enable hideResolved by default
2021-03-14 16:01:41 -07:00
Junio C Hamano
074d162eff Merge branch 'tb/pack-revindex-on-disk'
Fix for a topic in 'master'.

* tb/pack-revindex-on-disk:
  pack-revindex.c: don't close unopened file descriptors
2021-03-14 16:01:41 -07:00
Andrzej Hunt
04fe4d75fa init-db: silence template_dir leak when converting to absolute path
template_dir starts off pointing to either argv or nothing. However if
the value supplied in argv is a relative path, absolute_pathdup() is
used to turn it into an absolute path. absolute_pathdup() allocates
a new string, and we then "leak" it when cmd_init_db() completes.

We don't bother to actually free the return value (instead we UNLEAK
it), because there's no significant advantage to doing so here.
Correctly freeing it would require more significant changes to code flow
which would be more noisy than beneficial.

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-14 15:58:00 -07:00
Andrzej Hunt
e4de4502e6 init: remove git_init_db_config() while fixing leaks
The primary goal of this change is to stop leaking init_db_template_dir.
This leak can happen because:
 1. git_init_db_config() allocates new memory into init_db_template_dir
    without first freeing the existing value.
 2. init_db_template_dir might already contain data, either because:
  2.1 git_config() can be invoked twice with this callback in a single
      process - at least 2 allocations are likely.
  2.2 A single git_config() allocation can invoke the callback multiple
      times for a given key (see further explanation in the function
      docs) - each of those calls will trigger another leak.

The simplest fix for the leak would be to free(init_db_template_dir)
before overwriting it. Instead we choose to convert to fetching
init.templatedir via git_config_get_value() as that is more explicit,
more efficient, and avoids allocations (the returned result is owned by
the config cache, so we aren't responsible for freeing it).

If we remove init_db_template_dir, git_init_db_config() ends up being
responsible only for forwarding core.* config values to
platform_core_config(). However platform_core_config() already ignores
non-core.* config values, so we can safely remove git_init_db_config()
and invoke git_config() directly with platform_core_config() as the
callback.

The platform_core_config forwarding was originally added in:
  287853392a (mingw: respect core.hidedotfiles = false in git-init again, 2019-03-11
And I suspect the potential for a leak existed since the original
implementation of git_init_db_config in:
  90b45187ba (Add `init.templatedir` configuration variable., 2010-02-17)

LSAN output from t0001:

Direct leak of 73 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9a7276 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x9362ad in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x936eaa in strbuf_add /home/ahunt/oss-fuzz/git/strbuf.c:295:2
    #4 0x868112 in strbuf_addstr /home/ahunt/oss-fuzz/git/./strbuf.h:304:2
    #5 0x86a8ad in expand_user_path /home/ahunt/oss-fuzz/git/path.c:758:2
    #6 0x720bb1 in git_config_pathname /home/ahunt/oss-fuzz/git/config.c:1287:10
    #7 0x5960e2 in git_init_db_config /home/ahunt/oss-fuzz/git/builtin/init-db.c:161:11
    #8 0x7255b8 in configset_iter /home/ahunt/oss-fuzz/git/config.c:1982:7
    #9 0x7253fc in repo_config /home/ahunt/oss-fuzz/git/config.c:2311:2
    #10 0x725ca7 in git_config /home/ahunt/oss-fuzz/git/config.c:2399:2
    #11 0x593e8d in create_default_files /home/ahunt/oss-fuzz/git/builtin/init-db.c:225:2
    #12 0x5935c6 in init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:449:11
    #13 0x59588e in cmd_init_db /home/ahunt/oss-fuzz/git/builtin/init-db.c:714:9
    #14 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #15 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #16 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #17 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #18 0x69c4de in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #19 0x7f23552d6349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-14 15:57:59 -07:00
Andrzej Hunt
aa1b63971a worktree: fix leak in dwim_branch()
Make sure that we release the temporary strbuf during dwim_branch() for
all codepaths (and not just for the early return).

This leak appears to have been introduced in:
  f60a7b763f (worktree: teach "add" to check out existing branches, 2018-04-24)

Note that UNLEAK(branchname) is still needed: the returned result is
used in add(), and is stored in a pointer which is used to point at one
of:
  - a string literal ("HEAD")
  - member of argv (whatever the user specified in their invocation)
  - or our newly allocated string returned from dwim_branch()
Fixing the branchname leak isn't impossible, but does not seem
worthwhile given that add() is called directly from cmd_main(), and
cmd_main() returns immediately thereafter - UNLEAK is good enough.

This leak was found when running t0001 with LSAN, see also LSAN output
below:

Direct leak of 60 byte(s) in 1 object(s) allocated from:
    #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
    #1 0x9ab076 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
    #2 0x939fcd in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
    #3 0x93af53 in strbuf_splice /home/ahunt/oss-fuzz/git/strbuf.c:239:3
    #4 0x83559a in strbuf_check_branch_ref /home/ahunt/oss-fuzz/git/object-name.c:1593:2
    #5 0x6988b9 in dwim_branch /home/ahunt/oss-fuzz/git/builtin/worktree.c:454:20
    #6 0x695f8f in add /home/ahunt/oss-fuzz/git/builtin/worktree.c:525:19
    #7 0x694a04 in cmd_worktree /home/ahunt/oss-fuzz/git/builtin/worktree.c:1036:10
    #8 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #9 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #10 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #11 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #12 0x69caee in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #13 0x7f7b7dd10349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-14 15:57:59 -07:00