Fix macros that can silently inject unintended null-statements.
* rs/avoid-null-statement-after-macro-call:
mem-pool: drop trailing semicolon from macro definition
block-sha1: drop trailing semicolon from macro definition
Junio C Hamano [Fri, 19 Mar 2021 22:25:37 +0000 (15:25 -0700)]
Merge branch 'jk/bisect-peel-tag-fix'
"git bisect" reimplemented more in C during 2.30 timeframe did not
take an annotated tag as a good/bad endpoint well. This regression
has been corrected.
* jk/bisect-peel-tag-fix:
bisect: peel annotated tags to commits
Taylor Blau [Fri, 19 Mar 2021 15:40:52 +0000 (11:40 -0400)]
builtin/pack-objects.c: ignore missing links with --stdin-packs
When 'git pack-objects --stdin-packs' encounters a commit in a pack, it
marks it as a starting point of a best-effort reachability traversal
that is used to populate the name-hash of the objects listed in the
given packs.
The traversal expects that it should be able to walk the ancestors of
all commits in a pack without issue. Ordinarily this is the case, but it
is possible to having missing parents from an unreachable part of the
repository. In that case, we'd consider any missing objects in the
unreachable portion of the graph to be junk.
This should be handled gracefully: since the traversal is best-effort
(i.e., we don't strictly need to fill in all of the name-hash fields),
we should simply ignore any missing links.
This patch does that (by setting the 'ignore_missing_links' bit on the
rev_info struct), and ensures we don't regress in the future by adding a
test which demonstrates this case.
It is a little over-eager, since it will also ignore missing links in
reachable parts of the packs (which would indicate a corrupted
repository), but '--stdin-packs' is explicitly *not* about reachability.
So this step isn't making anything worse for a repository which contains
packs missing reachable objects (since we never drop objects with
'--stdin-packs').
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Sat, 13 Mar 2021 22:22:08 +0000 (22:22 +0000)]
diffcore-rename: determine which relevant_sources are no longer relevant
As noted a few commits ago ("diffcore-rename: only compute
dir_rename_count for relevant directories"), when a source file rename
is used as part of directory rename detection, we need to increment
counts for each ancestor directory in dirs_removed with value
RELEVANT_FOR_SELF. However, a few commits ago ("diffcore-rename: check
if we have enough renames for directories early on"), we may have
downgraded all relevant ancestor directories from RELEVANT_FOR_SELF to
RELEVANT_FOR_ANCESTOR.
For a given file, if no ancestor directory is found in dirs_removed with
a value of RELEVANT_FOR_SELF, then we can downgrade
relevant_source[PATH] from RELEVANT_LOCATION to RELEVANT_NO_MORE. This
means we can skip detecting a rename for that particular path (and any
other paths in the same directory).
For the testcases mentioned in commit 557ac0350d ("merge-ort: begin
performance work; instrument with trace2_region_* calls", 2020-10-28),
this change improves the performance as follows:
Before After
no-renames: 5.680 s ± 0.096 s 5.665 s ± 0.129 s
mega-renames: 13.812 s ± 0.162 s 11.435 s ± 0.158 s
just-one-mega: 506.0 ms ± 3.9 ms 494.2 ms ± 6.1 ms
While this improvement looks rather modest for these testcases (because
all the previous optimizations were sufficient to nearly remove all time
spent in rename detection already), consider this alternative testcase
tweaked from the ones in commit 557ac0350d as follows
For this testcase, we see the following improvement:
Before After
pick-empty: 1.936 s ± 0.024 s 688.1 ms ± 4.2 ms
So roughly a factor of 3 speedup. At $DAYJOB, there was a particular
repository and cherry-pick that inspired this optimization; for that
case I saw a speedup factor of 7 with this optimization.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Sat, 13 Mar 2021 22:22:07 +0000 (22:22 +0000)]
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>
Elijah Newren [Sat, 13 Mar 2021 22:22:06 +0000 (22:22 +0000)]
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>
Elijah Newren [Sat, 13 Mar 2021 22:22:05 +0000 (22:22 +0000)]
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>
Elijah Newren [Sat, 13 Mar 2021 22:22:04 +0000 (22:22 +0000)]
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>
Elijah Newren [Sat, 13 Mar 2021 22:22:03 +0000 (22:22 +0000)]
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>
Elijah Newren [Sat, 13 Mar 2021 22:22:02 +0000 (22:22 +0000)]
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>
Elijah Newren [Sat, 13 Mar 2021 22:22:01 +0000 (22:22 +0000)]
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>
Jeff King [Wed, 17 Mar 2021 22:47:03 +0000 (18:47 -0400)]
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>
Jeff Hostetler [Wed, 16 Dec 2020 14:50:33 +0000 (11:50 -0300)]
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>
Jeff Hostetler [Wed, 16 Dec 2020 14:50:32 +0000 (11:50 -0300)]
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>
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>
Jeff Hostetler [Wed, 16 Dec 2020 14:50:30 +0000 (11:50 -0300)]
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>
Matheus Tavares [Thu, 18 Mar 2021 18:43:47 +0000 (15:43 -0300)]
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>
Matheus Tavares [Thu, 18 Mar 2021 18:43:46 +0000 (15:43 -0300)]
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>
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>
fsmonitor: do not forget to release the token in `discard_index()`
In 56c6910028a (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>
fsmonitor: fix memory corruption in some corner cases
In 56c6910028a (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 679f2f9fdd2
(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>
Jeff King [Tue, 16 Mar 2021 15:15:55 +0000 (11:15 -0400)]
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).
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>
Jonathan Tan [Wed, 17 Mar 2021 15:42:00 +0000 (08:42 -0700)]
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>
René Scharfe [Sat, 13 Mar 2021 16:17:37 +0000 (17:17 +0100)]
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>
René Scharfe [Sat, 13 Mar 2021 16:17:30 +0000 (17:17 +0100)]
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>
Andrzej Hunt [Mon, 15 Mar 2021 16:39:23 +0000 (16:39 +0000)]
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>
Junio C Hamano [Tue, 16 Mar 2021 00:56:07 +0000 (17:56 -0700)]
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.
Jeff Hostetler [Mon, 15 Mar 2021 21:08:27 +0000 (21:08 +0000)]
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>
Jeff Hostetler [Mon, 15 Mar 2021 21:08:26 +0000 (21:08 +0000)]
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>
Jeff Hostetler [Mon, 15 Mar 2021 21:08:24 +0000 (21:08 +0000)]
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>
Jeff Hostetler [Mon, 15 Mar 2021 21:08:22 +0000 (21:08 +0000)]
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>
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>
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>
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>
Jeff Hostetler [Mon, 15 Mar 2021 21:08:18 +0000 (21:08 +0000)]
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>
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>
`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>
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>
Andrzej Hunt [Sun, 14 Mar 2021 18:47:39 +0000 (18:47 +0000)]
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>
Andrzej Hunt [Sun, 14 Mar 2021 18:47:38 +0000 (18:47 +0000)]
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>
Andrzej Hunt [Sun, 14 Mar 2021 18:47:37 +0000 (18:47 +0000)]
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>
Andrzej Hunt [Sun, 14 Mar 2021 18:47:36 +0000 (18:47 +0000)]
clone: free or UNLEAK further pointers when finished
Most of these pointers can safely be freed when cmd_clone() completes,
therefore we make sure to free them. The one exception is that we
have to UNLEAK(repo) because it can point either to argv[0], or a
malloc'd string returned by absolute_pathdup().
We also have to free(path) in the middle of cmd_clone(): later during
cmd_clone(), path is unconditionally overwritten with a different path,
triggering a leak. Freeing the first path immediately after use (but
only in the case where it contains data) seems like the cleanest
solution, as opposed to freeing it unconditionally before path is reused
for another path. This leak appears to have been introduced in: f38aa83f9a (use local cloning if insteadOf makes a local URL, 2014-07-17)
These leaks were found when running t0001 with LSAN, see also an excerpt
of the LSAN output below (the full list is omitted because it's far too
long, and mostly consists of indirect leakage of members of the refs we
are freeing).
Direct leak of 178 byte(s) in 1 object(s) allocated from:
#0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
#2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
#3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
#4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
#5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
#6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 165 byte(s) in 1 object(s) allocated from:
#0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
#2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
#3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
#4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21
#5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17
#6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 178 byte(s) in 1 object(s) allocated from:
#0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8
#2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9
#3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8
#4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10
#5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4
#6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 165 byte(s) in 1 object(s) allocated from:
#0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
#1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
#2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
#3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
#4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
#5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
#6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
#7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
#8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
#9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
#10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 105 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 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8
#2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2
#3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3
#4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4
#5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2
#6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10
#7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#12 0x7f6a459d5349 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>
Andrzej Hunt [Sun, 14 Mar 2021 18:47:35 +0000 (18:47 +0000)]
reset: free instead of leaking unneeded ref
dwim_ref() allocs a new string into ref. Instead of setting to NULL to
discard it, we can FREE_AND_NULL.
This leak appears to have been introduced in: 4cf76f6bbf (builtin/reset: compute checkout metadata for reset, 2020-03-16)
This leak was found when running t0001 with LSAN, see also LSAN output below:
Direct leak of 5 byte(s) in 1 object(s) allocated from:
#0 0x486514 in strdup /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3
#1 0x9a7108 in xstrdup /home/ahunt/oss-fuzz/git/wrapper.c:29:14
#2 0x8add6b in expand_ref /home/ahunt/oss-fuzz/git/refs.c:670:12
#3 0x8ad777 in repo_dwim_ref /home/ahunt/oss-fuzz/git/refs.c:644:22
#4 0x6394af in dwim_ref /home/ahunt/oss-fuzz/git/./refs.h:162:9
#5 0x637e5c in cmd_reset /home/ahunt/oss-fuzz/git/builtin/reset.c:426:4
#6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#10 0x69c5ce in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#11 0x7f57ebb9d349 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>
Andrzej Hunt [Sun, 14 Mar 2021 18:47:34 +0000 (18:47 +0000)]
symbolic-ref: don't leak shortened refname in check_symref()
shorten_unambiguous_ref() returns an allocated string. We have to
track it separately from the const refname.
This leak has existed since: 9ab55daa55 (git symbolic-ref --delete $symref, 2012-10-21)
This leak was found when running t0001 with LSAN, see also LSAN output
below:
Direct leak of 19 byte(s) in 1 object(s) allocated from:
#0 0x486514 in strdup /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3
#1 0x9ab048 in xstrdup /home/ahunt/oss-fuzz/git/wrapper.c:29:14
#2 0x8b452f in refs_shorten_unambiguous_ref /home/ahunt/oss-fuzz/git/refs.c
#3 0x8b47e8 in shorten_unambiguous_ref /home/ahunt/oss-fuzz/git/refs.c:1287:9
#4 0x679fce in check_symref /home/ahunt/oss-fuzz/git/builtin/symbolic-ref.c:28:14
#5 0x679ad8 in cmd_symbolic_ref /home/ahunt/oss-fuzz/git/builtin/symbolic-ref.c:70:9
#6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
#7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
#8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
#9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
#10 0x69cc6e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
#11 0x7f98388a4349 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>
René Scharfe [Sat, 13 Mar 2021 16:17:22 +0000 (17:17 +0100)]
use CALLOC_ARRAY
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
René Scharfe [Sat, 13 Mar 2021 16:10:47 +0000 (17:10 +0100)]
git-compat-util.h: drop trailing semicolon from macro definition
Make CALLOC_ARRAY usable like a function by requiring callers to supply
the trailing semicolon, which all of the current ones already do. With
the extra semicolon e.g. the following code wouldn't compile because it
disconnects the "else" from the "if":
if (condition)
CALLOC_ARRAY(ptr, n);
else
whatever();
Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the EXAMPLES section, git-push(1) says that 'git push origin' pushes
the current branch to the value of the 'remote.origin.merge'
configuration.
This wording (which dates back to b2ed944af7 (push: switch default from
"matching" to "simple", 2013-01-04)) is incorrect. There is no such
configuration as 'remote.<name>.merge'. This likely was originally
intended to read "branch.<name>.merge" instead.
Indeed, when 'push.default' is 'simple' (which is the default value, and
is applicable in this scenario per "without additional configuration"),
setup_push_upstream() dies if the branch's local name does not match
'branch.<name>.merge'.
Correct this long-standing typo to resolve some recent confusion on the
intended behavior of this example.
Reported-by: Adam Sharafeddine <adam.shrfdn@gmail.com> Reported-by: Fabien Terrani <terranifabien@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Nieder [Sat, 13 Mar 2021 08:41:33 +0000 (00:41 -0800)]
doc: describe mergetool configuration in git-mergetool(1)
In particular, this describes mergetool.hideResolved, which can help
users discover this setting (either because it may be useful to them
or in order to understand mergetool's behavior if they have forgotten
setting it in the past).
Tested by running
make -C Documentation git-mergetool.1
man Documentation/git-mergetool.1
and reading through the page.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jonathan Nieder [Sat, 13 Mar 2021 08:38:48 +0000 (00:38 -0800)]
mergetool: do not enable hideResolved by default
When 98ea309b3f (mergetool: add hideResolved configuration,
2021-02-09) introduced the mergetool.hideResolved setting to reduce
the clutter in viewing non-conflicted sections of files in a
mergetool, it enabled it by default, explaining:
No adverse effects were noted in a small survey of popular mergetools[1]
so this behavior defaults to `true`.
In practice, alas, adverse effects do appear. A few issues:
1. No indication is shown in the UI that the base, local, and remote
versions shown have been modified by additional resolution. This
is inherent in the design: the idea of mergetool.hideResolved is to
convince a mergetool that expects pristine local, base, and remote
files to show partially resolved verisons of those files instead;
there is no additional source of information accessible to the
mergetool to see where the resolution has happened.
(By contrast, a mergetool generating the partial resolution from
conflict markers for itself would be able to hilight the resolved
sections with a different color.)
A user accustomed to seeing the files without partial resolution
gets no indication that this behavior has changed when they upgrade
Git.
2. If the computed merge did not line up the files correctly (for
example due to repeated sections in the file), the partially
resolved files can be misleading and do not have enough information
to reconstruct what happened and compute the correct merge result.
3. Resolving a conflict can involve information beyond the textual
conflict. For example, if the local and remote versions added
overlapping functionality in different ways, seeing the full
unresolved versions of each alongside the base gives information
about each side's intent that makes it possible to come up with a
resolution that combines those two intents. By contrast, when
starting with partially resolved versions of those files, one can
produce a subtly wrong resolution that includes redundant extra
code added by one side that is not needed in the approach taken
on the other.
All that said, a user wanting to focus on textual conflicts with
reduced clutter can still benefit from mergetool.hideResolved=true as
a way to deemphasize sections of the code that resolve cleanly without
requiring any changes to the invoked mergetool. The caveats described
above are reduced when the user has explicitly turned this on, because
then the user is aware of them.
Flip the default to 'false'.
Reported-by: Dana Dahlstrom <dahlstrom@google.com> Helped-by: Seth House <seth@eseth.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
John Szakmeister [Fri, 12 Mar 2021 02:40:26 +0000 (21:40 -0500)]
http: store credential when PKI auth is used
We already looked for the PKI credentials in the credential store, but
failed to approve it on success. Meaning, the PKI certificate password
was never stored and git would request it on every connection to the
remote. Let's complete the chain by storing the certificate password on
success.
Likewise, we also need to reject the credential when there is a failure.
Curl appears to report client-related certificate issues are reported
with the CURLE_SSL_CERTPROBLEM error. This includes not only a bad
password, but potentially other client certificate related problems.
Since we cannot get more information from curl, we'll go ahead and
reject the credential upon receiving that error, just to be safe and
avoid caching or saving a bad password.
Signed-off-by: John Szakmeister <john@szakmeister.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
René Scharfe [Sun, 28 Feb 2021 11:22:47 +0000 (12:22 +0100)]
archive: expand only a single %(describe) per archive
Every %(describe) placeholder in $Format:...$ strings in files with the
attribute export-subst is expanded by calling git describe. This can
potentially result in a lot of such calls per archive. That's OK for
local repositories under control of the user of git archive, but could
be a problem for hosted repositories.
Expand only a single %(describe) placeholder per archive for now to
avoid denial-of-service attacks. We can make this limit configurable
later if needed, but let's start out simple.
Reported-by: Jeff King <peff@peff.net> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:31 +0000 (00:38 +0000)]
diffcore-rename: avoid doing basename comparisons for irrelevant sources
The basename comparison optimization implemented in
find_basename_matches() is very beneficial since it allows a source to
sometimes only be compared with one other file instead of N other files.
When a match is found, both a source and destination can be removed from
the matrix of inexact rename comparisons. In contrast, the irrelevant
source optimization only allows us to remove a source from the matrix of
inexact rename comparisons...but it has the advantage of allowing a
source file to not even be loaded into memory at all and be compared to
0 other files. Generally, not even comparing is a bigger performance
win, so when both optimizations could apply, prefer to use the
irrelevant-source optimization.
For the testcases mentioned in commit 557ac0350d ("merge-ort: begin
performance work; instrument with trace2_region_* calls", 2020-10-28),
this change improves the performance as follows:
Before After
no-renames: 5.708 s ± 0.111 s 5.680 s ± 0.096 s
mega-renames: 102.171 s ± 0.440 s 13.812 s ± 0.162 s
just-one-mega: 3.471 s ± 0.015 s 506.0 ms ± 3.9 ms
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:30 +0000 (00:38 +0000)]
merge-ort: skip rename detection entirely if possible
diffcore_rename_extended() will do a bunch of setup, then check for
exact renames, then abort before inexact rename detection if there are
no more sources or destinations that need to be matched. It will
sometimes be the case, however, that either
* we start with neither any sources or destinations
* we start with no *relevant* sources
In the first of these two cases, the setup and exact rename detection
will be very cheap since there are 0 files to operate on. In the second
case, it is quite possible to have thousands of files with none of the
source ones being relevant. Avoid calling diffcore_rename_extended() or
even some of the setup before diffcore_rename_extended() when we can
determine that rename detection is unnecessary.
For the testcases mentioned in commit 557ac0350d ("merge-ort: begin
performance work; instrument with trace2_region_* calls", 2020-10-28),
this change improves the performance as follows:
Before After
no-renames: 6.003 s ± 0.048 s 5.708 s ± 0.111 s
mega-renames: 114.009 s ± 0.236 s 102.171 s ± 0.440 s
just-one-mega: 3.489 s ± 0.017 s 3.471 s ± 0.015 s
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:29 +0000 (00:38 +0000)]
merge-ort: use relevant_sources to filter possible rename sources
The past several commits determined conditions when rename sources might
be needed, and filled a relevant_sources strset with those paths. Pass
these along to diffcore_rename_extended() to use to limit the sources
that we need to detect renames for.
For the testcases mentioned in commit 557ac0350d ("merge-ort: begin
performance work; instrument with trace2_region_* calls", 2020-10-28),
this change improves the performance as follows:
Before After
no-renames: 12.596 s ± 0.061 s 6.003 s ± 0.048 s
mega-renames: 130.465 s ± 0.259 s 114.009 s ± 0.236 s
just-one-mega: 3.958 s ± 0.010 s 3.489 s ± 0.017 s
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:28 +0000 (00:38 +0000)]
merge-ort: precompute whether directory rename detection is needed
The point of directory rename detection is that if one side of history
renames a directory, and the other side adds new files under the old
directory, then the merge can move those new files into the new
directory. This leads to the following important observation:
* If the other side does not add any new files under the old
directory, we do not need to detect any renames for that directory.
Similarly, directory rename detection had an important requirement:
* If a directory still exists on one side of history, it has not been
renamed on that side of history. (See section 4 of t6423 or
Documentation/technical/directory-rename-detection.txt for more
details).
Using these two bits of information, we note that directory rename
detection is only needed in cases where (1) directories exist in the
merge base and on one side of history (i.e. dirmask == 3 or dirmask ==
5), and (2) where there is some new file added to that directory on the
side where it still exists (thus where the file has filemask == 2 or
filemask == 4, respectively). This has to be done in two steps, because
we have the dirmask when we are first considering the directory, and
won't get the filemasks for the files within it until we recurse into
that directory. So, we save
dir_rename_mask = dirmask - 1
when we hit a directory that is missing on one side, and then later look
for cases of
filemask == dir_rename_mask
One final note is that as soon as we hit a directory that needs
directory rename detection, we will need to detect renames in all
subdirectories of that directory as well due to the "majority rules"
decision when files are renamed into different directory hierarchies.
We arbitrarily use the special value of 0x07 to record when we've hit
such a directory.
The combination of all the above mean that we introduce a variable
named dir_rename_mask (couldn't think of a better name) which has one
of the following values as we traverse into a directory:
* 0x00: directory rename detection not needed
* 0x02 or 0x04: directory rename detection only needed if files added
* 0x07: directory rename detection definitely needed
We then pass this value through to add_pairs() so that it can mark
location_relevant as true only when dir_rename_mask is 0x07.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:27 +0000 (00:38 +0000)]
merge-ort: introduce wrappers for alternate tree traversal
Add traverse_trees_wrapper() and traverse_trees_wrapper_callback()
functions. The former runs traverse_trees() with info->fn set to
traverse_trees_wrapper_callback, in order to simply save all the entries
without processing or recursing into any of them. This step allows
extra computation to be done (e.g. checking some condition across all
files) that can be used later. Then, after that is completed, it
iterates over all the saved entries and calls the original info->fn
callback with the saved data.
Currently, this does nothing more than marginally slowing down the tree
traversal since we do not take advantage of the opportunity to compute
anything special in traverse_trees_wrapper_callback(), and thus the real
callback will be called identically as it would have been without this
extra wrapper. However, a subsequent commit will add some special
computation of some values that the real callback will be able to use.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:26 +0000 (00:38 +0000)]
merge-ort: add data structures for an alternate tree traversal
In order to determine whether directory rename detection is needed, we
as a pre-requisite need a way to traverse through all the files in a
given tree before visiting any directories within that tree.
traverse_trees() only iterates through the entries in the order they
appear, so add some data structures that will store all the entries as
we iterate through them in traverse_trees(), which will allow us to
re-traverse them in our desired order.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:25 +0000 (00:38 +0000)]
merge-ort: precompute subset of sources for which we need rename detection
rename detection works by trying to pair all file deletions (or
"sources") with all file additions (or "destinations"), checking
similarity, and then marking the sufficiently similar ones as renames.
This can be expensive if there are many sources and destinations on a
given side of history as it results in an N x M comparison matrix.
However, there are many cases where we can compute in advance that
detecting renames for some of the sources provides no useful information
and thus that we can exclude those sources from the matrix.
To see why, first note that the merge machinery uses detected renames in
two ways:
* directory rename detection: when one side of history renames a
directory, and the other side of history adds new files to that
directory, we want to be able to warn the user about the need to
chose whether those new files stay in the old directory or move
to the new one.
* three-way content merging: in order to do three-way content merging
of files, we need three different file versions. If one side of
history renamed a file, then some of the content for the file is
found under a different path than in the merge base or on the
other side of history.
Add a simple testcase showing the two kinds of reasons renames are
relevant; it's a testcase that will only pass if we detect both kinds of
needed renames.
Other than the testcase added above, this commit concentrates just on
the three-way content merging; it will punt and mark all sources as
needed for directory rename detection, and leave it to future commits to
narrow that down more.
The point of three-way content merging is to reconcile changes made on
*both* sides of history. What if the file wasn't modified on both
sides? There are two possibilities:
* If it wasn't modified on the renamed side:
-> then we get to do exact rename detection, which is cheap.
* If it wasn't modified on the unrenamed side:
-> then detection of a rename for that source file is irrelevant
That latter claim might be surprising at first, so let's walk through a
case to show why rename detection for that source file is irrelevant.
Let's use two filenames, old.c & new.c, with the following abbreviated
object ids (and where the value '000000' is used to denote that the file
is missing in that commit):
If the rename *isn't* detected:
then old.c looks like it was unmodified on one side and deleted on
the other and should thus be removed. new.c looks like a new file we
should keep as-is.
If the rename *is* detected:
then a three-way content merge is done. Since the version of the
file in MERGE_BASE and MERGE_SIDE1 are identical, the three-way merge
will produce exactly the version of the file whose abbreviated
object id is 5e1ec7. It will record that file at the path new.c,
while removing old.c from the directory.
Note that these two results are identical -- a single file named 'new.c'
with object id 5e1ec7. In other words, it doesn't matter if the rename
is detected in the case where the file is unmodified on the unrenamed
side.
Use this information to compute whether we need rename detection for
each source created in add_pair().
It's probably worth noting that there used to be a few other edge or
corner cases besides three-way content merges and directory rename
detection where lack of rename detection could have affected the result,
but those cases actually highlighted where conflict resolution methods
were not consistent with each other. Fixing those inconsistencies were
thus critically important to enabling this optimization. That work
involved the following:
* bringing consistency to add/add, rename/add, and rename/rename
conflict types, as done back in the topic merged at commit ac193e0e0a ("Merge branch 'en/merge-path-collision'", 2019-01-04),
and further extended in commits 2a7c16c980 ("t6422, t6426: be more
flexible for add/add conflicts involving renames", 2020-08-10) and e8eb99d4a6 ("t642[23]: be more flexible for add/add conflicts
involving pair renames", 2020-08-10)
* making rename/delete more consistent with modify/delete
as done in commits 1f3c9ba707 ("t6425: be more flexible with
rename/delete conflict messages", 2020-08-10) and 727c75b23f
("t6404, t6423: expect improved rename/delete handling in ort
backend", 2020-10-26)
Since the set of relevant_sources we compute has not yet been narrowed
down for directory rename detection, we do not pass it to
diffcore_rename_extended() yet. That will be done after subsequent
commits narrow down the list of relevant_sources needed for directory
rename detection reasons.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren [Thu, 11 Mar 2021 00:38:24 +0000 (00:38 +0000)]
diffcore-rename: enable filtering possible rename sources
Add the ability to diffcore_rename_extended() to allow external callers
to declare that they only need renames detected for a subset of source
files, and use that information to skip detecting renames for them.
There are two important pieces to this optimization that may not be
obvious at first glance:
* We do not require callers to just filter the filepairs out
to remove the non-relevant sources, because exact rename detection
is fast and when it finds a match it can remove both a source and a
destination whereas the relevant_sources filter can only remove a
source.
* We need to filter out the source pairs in a preliminary pass instead
of adding a
strset_contains(relevant_sources, one->path)
check within the nested matrix loop. The reason for that is if we
have 30k renames, doing 30k * 30k = 900M strset_contains() calls
becomes extraordinarily expensive and defeats the performance gains
from this change; we only want to do 30k such calls instead.
If callers pass NULL for relevant_sources, that is special cases to
treat all sources as relevant. Since all callers currently pass NULL,
this optimization does not yet have any effect. Subsequent commits will
have merge-ort compute a set of relevant_sources to restrict which
sources we detect renames for, and have merge-ort pass that set of
relevant_sources to diffcore_rename_extended().
A note about filtering order:
Some may be curious why we don't filter out irrelevant sources at the
same time we filter out exact renames. While that technically could be
done at this point, there are two reasons to defer it:
First, was to reinforce a lesson that was too easy to forget. As I
mentioned above, in the past I filtered irrelevant sources out before
exact rename checking, and then discovered that exact renames' ability
to remove both sources and destinations was an important consideration
and thus doing the filtering after exact rename checking would speed
things up. Then at some point I realized that basename matching could
also remove both sources and destinations, and decided to put irrelevant
source filtering after basename filtering. That slowed things down a
lot. But, despite learning about this important ordering, in later
restructuring I forgot and made the same mistake of putting the
filtering after basename guided rename detection again. So, I have this
series of patches structured to do the irrelevant filtering last to
start to show how much extra it costs, and then add relevant filtering
in to find_basename_matches() to show how much it speeds things up.
Basically, it's a way to reinforce something that apparently was too
easy to forget, and make sure the commit messages record this lesson.
Second, the items in the "relevant_sources" in this patch series will
include all sources that *might be* relevant. It has to be conservative
and catch anything that might need a rename, but in the patch series
after this one we'll find ways to weed out more of the *might be*
relevant ones. Unfortunately, merge-ort does not have sufficient
information to weed those ones out, and there isn't enough information
at the time of filtering exact renames out to remove the extra ones
either. It has to be deferred. So the deferral is in part to simplify
some later additions.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson [Wed, 10 Mar 2021 01:11:20 +0000 (01:11 +0000)]
builtin/init-db: handle bare clones when core.bare set to false
In 552955ed7f ("clone: use more conventional config/option layering",
2020-10-01), clone learned to read configuration options earlier in its
execution, before creating the new repository. However, that led to a
problem: if the core.bare setting is set to false in the global config,
cloning a bare repository segfaults. This happens because the
repository is falsely thought to be non-bare, but clone has set the work
tree to NULL, which is then dereferenced.
The code to initialize the repository already considers the fact that a
user might want to override the --bare option for git init, but it
doesn't take into account clone, which uses a different option. Let's
just check that the work tree is not NULL, since that's how clone
indicates that the repository is bare. This is also the case for git
init, so we won't be regressing that case.
Reported-by: Joseph Vusich <jvusich@amazon.com> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 10 Mar 2021 17:07:37 +0000 (12:07 -0500)]
filter-branch: drop $_x40 glob
When checking whether a commit was rewritten to a single object id, we
use a glob that insists on a 40-hex result. This works for sha1, but
fails t7003 when run with GIT_TEST_DEFAULT_HASH=sha256.
Since the previous commit simplified the case statement here, we only
have two arms: an empty string or a single object id. We can just loosen
our glob to match anything, and still distinguish those cases (we lose
the ability to notice bogus input, but that's not a problem; we are the
one who wrote the map in the first place, and anyway update-ref will
complain loudly if the input isn't a valid hash).
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 10 Mar 2021 17:07:27 +0000 (12:07 -0500)]
filter-branch: drop multiple-ancestor warning
When a ref maps to a commit that is neither rewritten nor kept by
filter-branch (e.g., because it was eliminated by rev-list's pathspec
selection), we rewrite it to its nearest ancestor.
Since the initial commit in 6f6826c52b (Add git-filter-branch,
2007-06-03), we have warned when there are multiple such ancestors in
the map file. However, the warning code is impossible to trigger these
days. Since a0e46390d3 (filter-branch: fix ref rewriting with
--subdirectory-filter, 2008-08-12), we find the ancestor using "rev-list
-1", so it can only ever have a single value.
This code is made doubly confusing by the fact that we append to the map
file when mapping ancestors. However, this can never yield multiple
values because:
- we explicitly check whether the map already exists, and if so, do
nothing (so our "append" will always be to a file that does not
exist)
- even if we were to try mapping twice, the process to do so is
deterministic. I.e., we'd always end up with the same ancestor for a
given sha1. So warning about it would be pointless; there is no
ambiguity.
So swap out the warning code for a BUG (which we'll simplify further in
the next commit). And let's stop using the append operator to make the
ancestor-mapping code less confusing.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Wed, 10 Mar 2021 17:07:19 +0000 (12:07 -0500)]
t7003: test ref rewriting explicitly
After it has rewritten all of the commits, filter-branch will then
rewrite each of the input refs based on the resulting map of old/new
commits. But we don't have any explicit test coverage of this code.
Let's make sure we are covering each of those cases:
- deleting a ref when all of its commits were pruned
- rewriting a ref based on the mapping (this happens throughout the
script, but let's make sure we generate the correct messages)
- rewriting a ref whose tip was excluded, in which case we rewrite to
the nearest ancestor. Note in this case that we still insist that no
"warning" line is present (even though it looks like we'd trigger
the "... was rewritten into multiple commits" one). See the next
commit for more details.
Note these all pass currently, but the latter two will fail when run
with GIT_TEST_DEFAULT_HASH=sha256.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 9 Mar 2021 00:04:47 +0000 (16:04 -0800)]
Merge branch 'jt/transfer-fsck-across-packs-fix'
The code to fsck objects received across multiple packs during a
single git fetch session has been broken when the packfile URI
feature was in use. A workaround has been added by disabling the
codepath to avoid keeping a packfile that is too small.
* jt/transfer-fsck-across-packs-fix:
fetch-pack: do not mix --pack_header and packfile uri
Andrzej Hunt [Mon, 8 Mar 2021 17:14:42 +0000 (17:14 +0000)]
Makefile: update 'make fuzz-all' docs to reflect modern clang
Clang no longer produces a libFuzzer.a. Instead, you can include
libFuzzer by using -fsanitize=fuzzer. Therefore we should use that in
the example command for building fuzzers.
We also add -fsanitize=fuzzer-no-link to the CFLAGS to ensure that all
the required instrumentation is added when compiling git [1], and remove
-fsanitize-coverage=trace-pc-guard as it is deprecated.
I happen to have tested with LLVM 11 - however -fsanitize=fuzzer appears
to work in a wide range of reasonably modern clangs.
(On my system: what used to be libFuzzer.a now lives under the following
path, which is tricky albeit not impossible for a novice such as myself
to find:
/usr/lib64/clang/11.0.0/lib/linux/libclang_rt.fuzzer-x86_64.a )
René Scharfe [Sat, 6 Mar 2021 11:26:19 +0000 (12:26 +0100)]
fix xcalloc() argument order
Pass the number of elements first and ther size second, as expected
by xcalloc(). Provide a semantic patch, which was actually used to
generate the rest of this patch.
The semantic patch would generate flip-flop diffs if both arguments
are sizeofs. We don't have such a case, and it's hard to imagine
the usefulness of such an allocation. If it ever occurs then we
could deal with it by duplicating the rule in the semantic patch to
make it cancel itself out, or we could change the code to use
CALLOC_ARRAY.
Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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