A "git fetch" from the superproject going down to a submodule used
a wrong remote when the default remote names are set differently
between them.
* db/submodule-fetch-with-remote-name-fix:
submodule: correct remote name with fetch
Fail gracefully instead of crashing when attempting to write the
contents of a corrupt in-core index as a tree object.
* ps/cache-tree-w-broken-index-entry:
unpack-trees: detect mismatching number of cache-tree/index entries
cache-tree: detect mismatching number of index entries
cache-tree: refactor verification to return error codes
"git maintenance start" crashed due to an uninitialized variable
reference, which has been corrected.
* ps/maintenance-start-crash-fix:
builtin/gc: fix crash when running `git maintenance start`
Use after free and double freeing at the end in "git log -L... -p"
had been identified and fixed.
* ds/line-log-asan-fix:
line-log: protect inner strbuf from free
It was reported on the mailing list that running `git maintenance start`
immediately segfaults starting with b6c3f8e12c (builtin/maintenance: fix
leak in `get_schedule_cmd()`, 2024-09-26). And indeed, this segfault is
trivial to reproduce up to a point where one is scratching their head
why we didn't catch this regression in our test suite.
The root cause of this error is `get_schedule_cmd()`, which does not
populate the `out` parameter in all cases anymore starting with the
mentioned commit. Callers do assume it to always be populated though and
will e.g. call `strvec_split()` on the returned value, which will of
course segfault when the variable is uninitialized.
So why didn't we catch this trivial regression? The reason is that our
tests always set up the "GIT_TEST_MAINT_SCHEDULER" environment variable
via "t/test-lib.sh", which allows us to override the scheduler command
with a custom one so that we don't accidentally modify the developer's
system. But the faulty code where we don't set the `out` parameter will
only get hit in case that environment variable is _not_ set, which is
never the case when executing our tests.
Fix the regression by again unconditionally allocating the value in the
`out` parameter, if provided. Add a test that unsets the environment
variable to catch future regressions in this area.
Reported-by: Shubham Kanodia <shubham.kanodia10@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code fetches the submodules remote based on the superproject remote name
instead of the submodule remote name[1].
Instead of grabbing the default remote of the superproject repository, ask
the default remote of the submodule we are going to run 'git fetch' in.
1. https://lore.kernel.org/git/ZJR5SPDj4Wt_gmRO@pweza/
Signed-off-by: Daniel Black <daniel@mariadb.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Same as the preceding commit, we unconditionally dereference the index's
cache entries depending on the number of cache-tree entries, which can
lead to a segfault when the cache-tree is corrupted. Fix this bug.
This also makes t4058 pass with the leak sanitizer enabled.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In t4058 we have some tests that exercise git-read-tree(1) when used
with a tree that contains duplicate entries. While the expectation is
that we fail, we ideally should fail gracefully without a segfault.
But that is not the case: we never check that the number of entries in
the cache-tree is less than or equal to the number of entries in the
index. This can lead to an out-of-bounds read as we unconditionally
access `istate->cache[idx]`, where `idx` is controlled by the number of
cache-tree entries and the current position therein. The result is a
segfault.
Fix this segfault by adding a sanity check for the number of index
entries before dereferencing them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
macOS with fsmonitor daemon can hang forever when a submodule is
involved, which has been corrected.
* kn/osx-fsmonitor-with-submodules-fix:
fsmonitor OSX: fix hangs for submodules
Usability improvements for running tests in leak-checking mode.
* jk/test-lsan-improvements:
test-lib: check for leak logs after every test
test-lib: show leak-sanitizer logs on --immediate failure
test-lib: stop showing old leak logs
In 6241ce2170 (refs/reftable: reload locked stack when preparing
transaction, 2024-09-24) we have introduced a new test that exercises
how the reftable backend behaves with many concurrent writers all racing
with each other. This test was introduced after a couple of fixes in
this context that should make concurrent writes behave gracefully. As it
turns out though, Windows systems do not yet handle concurrent writes
properly, as we've got two reports for Cygwin and MinGW failing in this
newly added test.
The root cause of this is how we update the "tables.list" file: when
writing a new stack of tables we first write the data into a lockfile
and then rename that file into place. But Windows forbids us from doing
that rename when the target path is open for reading by another process.
And as the test races both readers and writers with each other we are
quite likely to hit this edge case.
This is not a regression: the logic didn't work before the mentioned
commit, and after the commit it performs well on Linux and macOS, and
the situation on Windows should have at least improved a bit. But the
test shows that we need to put more thought into how to make this work
properly there.
Work around the issue by disabling the test on Windows for now. While at
it, increase the locking timeout to address reported timeouts when using
either the address or memory sanitizer, which also tend to significantly
extend the runtime of this test.
This should be revisited after Git v2.47 is out.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsmonitor_classify_path_absolute() expects state->path_gitdir_watch.buf
has no trailing '/' or '.' For a submodule, fsmonitor_run_daemon() sets
the value with trailing "/." (as repo_get_git_dir(the_repository) on
Darwin returns ".") so that fsmonitor_classify_path_absolute() returns
IS_OUTSIDE_CONE.
In this case, fsevent_callback() doesn't update cookie_list so that
fsmonitor_publish() does nothing and with_lock__mark_cookies_seen() is
not invoked.
As with_lock__wait_for_cookie() infinitely waits for state->cookies_cond
that with_lock__mark_cookies_seen() should unlock, the whole daemon
hangs.
Remove trailing "/." from state->path_gitdir_watch.buf for submodules
and add a corresponding test in t7527-builtin-fsmonitor.sh. The test is
disabled for MINGW because hangs treated with this patch occur only for
Darwin and there is no simple way to terminate the win32 fsmonitor
daemon that hangs.
Suggested-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Koji Nakamaru <koji.nakamaru@gree.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The output_prefix() method in line-log.c may call a function pointer via
the diff_options struct. This function pointer returns a strbuf struct
and then its buffer is passed back. However, that implies that the
consumer is responsible to free the string. This is especially true
because the default behavior is to duplicate the empty string.
The existing functions used in the output_prefix pointer include:
1. idiff_prefix_cb() in diff-lib.c. This returns the data pointer, so
the value exists across multiple calls.
2. diff_output_prefix_callback() in graph.c. This uses a static strbuf
struct, so it reuses buffers across calls. These should not be
freed.
3. output_prefix_cb() in range-diff.c. This is similar to the
diff-lib.c case.
In each case, we should not be freeing this buffer. We can convert the
output_prefix() function to return a const char pointer and stop freeing
the result.
This choice is essentially the opposite of what was done in 394affd46d
(line-log: always allocate the output prefix, 2024-06-07).
This was discovered via 'valgrind' while investigating a public report
of a bug in 'git log --graph -L' [1].
[1] https://github.com/git-for-windows/git/issues/5185
This issue would have been caught by the new test, when Git is compiled
with ASan to catch these double frees.
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The checksum at the tail of files are now computed without
collision detection protection. This is safe as the consumer of
the information to protect itself from replay attacks checks for
hash collisions independently.
* tb/weak-sha1-for-tail-sum:
csum-file.c: use unsafe SHA-1 implementation when available
Makefile: allow specifying a SHA-1 for non-cryptographic uses
hash.h: scaffolding for _unsafe hashing variants
sha1: do not redefine `platform_SHA_CTX` and friends
pack-objects: use finalize_object_file() to rename pack/idx/etc
finalize_object_file(): implement collision check
finalize_object_file(): refactor unlink_or_warn() placement
finalize_object_file(): check for name collision before renaming
Leakfixes.
* jk/http-leakfixes: (28 commits)
http-push: clean up local_refs at exit
http-push: clean up loose request when falling back to packed
http-push: clean up objects list
http-push: free xml_ctx.cdata after use
http-push: free remote_ls_ctx.dentry_name
http-push: free transfer_request strbuf
http-push: free transfer_request dest field
http-push: free curl header lists
http-push: free repo->url string
http-push: clear refspecs before exiting
http-walker: free fake packed_git list
remote-curl: free HEAD ref with free_one_ref()
http: stop leaking buffer in http_get_info_packs()
http: call git_inflate_end() when releasing http_object_request
http: fix leak of http_object_request struct
http: fix leak when redacting cookies from curl trace
transport-helper: fix leak of dummy refs_list
fetch-pack: clear pack lockfiles list
fetch: free "raw" string when shrinking refspec
transport-helper: fix strbuf leak in push_refs_with_push()
...
When "git sparse-checkout disable" turns a sparse checkout into a
regular checkout, the index is fully expanded. This totally
expected behaviour however had an "oops, we are expanding the
index" advice message, which has been corrected.
* ds/sparse-checkout-expansion-advice:
sparse-checkout: disable advice in 'disable'
"git --git-dir=nowhere cmd" failed to properly notice that it
wasn't in any repository while processing includeIf.onbranch
configuration and instead crashed.
* ps/includeif-onbranch-cornercase-fix:
config: fix evaluating "onbranch" with nonexistent git dir
t1305: exercise edge cases of "onbranch" includes
Background tasks "git maintenance" runs may need to use credential
information when going over the network, but a credential helper
may work only in an interactive environment, and end up blocking a
scheduled task waiting for UI. Credential helpers can now behave
differently when they are not running interactively.
* ds/background-maintenance-with-credential:
scalar: configure maintenance during 'reconfigure'
maintenance: add custom config to background jobs
credential: add new interactive config option
"git archive" with pathspec magic that uses the attribute
information did not work well, which has been corrected.
* rs/archive-with-attr-pathspec-fix:
archive: load index before pathspec checks
When a subprocess to work in a submodule spawned by "git submodule"
fails with SIGPIPE, the parent Git process caught the death of it,
but gave a generic "failed to work in that submodule", which was
misleading. We now behave as if the parent got SIGPIPE and die.
* pw/submodule-process-sigpipe:
submodule status: propagate SIGPIPE
Give timeout to the locking code to write to reftable.
* ps/reftable-concurrent-writes:
refs/reftable: reload locked stack when preparing transaction
reftable/stack: allow locking of outdated stacks
refs/reftable: introduce "reftable.lockTimeout"
In most places that write files to the object database (even packfiles
via index-pack or fast-import), we use finalize_object_file(). This
prefers link()/unlink() over rename(), because it means we will prefer
data that is already in the repository to data that we are newly
writing.
We should do the same thing in pack-objects. Even though we don't think
of it as accepting outside data (and thus not being susceptible to
collision attacks), in theory a determined attacker could present just
the right set of objects to cause an incremental repack to generate
a pack with their desired hash.
This has some test and real-world fallout, as seen in the adjustment to
t5303 below. That test script assumes that we can "fix" corruption by
repacking into a good state, including when the pack generated by that
repack operation collides with a (corrupted) pack with the same hash.
This violates our assumption from the previous adjustments to
finalize_object_file() that if we're moving a new file over an existing
one, that since their checksums match, so too must their contents.
This makes "fixing" corruption like this a more explicit operation,
since the test (and users, who may fix real-life corruption using a
similar technique) must first move the broken contents out of the way.
Note also that we now call adjust_shared_perm() twice. We already call
adjust_shared_perm() in stage_tmp_packfiles(), and now call it again in
finalize_object_file(). This is somewhat wasteful, but cleaning up the
existing calls to adjust_shared_perm() is tricky (because sometimes
we're writing to a tmpfile, and sometimes we're writing directly into
the final destination), so let's tolerate some minor waste until we can
more carefully clean up the now-redundant calls.
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When merging file pairs after they have been broken up we queue a new
file pair and discard the broken-up ones. The newly-queued file pair
reuses one filespec of the broken up pairs each, where the respective
other filespec gets discarded. But we only end up freeing the filespec's
data, not the filespec itself, and thus leak memory.
Fix these leaks by using `free_filespec()` instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When simplifying commits, e.g. because they are treesame with their
parents, we unset the commit's parent pointers but never free them. Plug
the resulting memory leaks.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `get_schedule_cmd()` function allows us to override the schedule
command with a specific test command such that we can verify the
underlying logic in a platform-independent way. Its memory management is
somewhat wild though, because it basically gives up and assigns an
allocated string to the string constant output pointer. While this part
is marked with `UNLEAK()` to mask this, we also leak the local string
lists.
Rework the function such that it has a separate out parameter. If set,
we will assign it the final allocated command. Plug the other memory
leaks and create a common exit path.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The partial clone filter of a promisor remote is never free'd, causing
memory leaks. Furthermore, in case multiple partial clone filters are
defined for the same remote, we'd overwrite previous values without
freeing them.
Fix these leaks.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are several leaking data structures in git-difftool(1). Plug them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When repacking, we assemble git-pack-objects(1) arguments both for the
"normal" pack and for the cruft pack. This configuration gets populated
with a bunch of `OPT_PASSTHRU` options that we end up passing to the
child process. These options are allocated, but never free'd.
Create a new `pack_objects_args_release()` function that releases the
memory for us and call it for both sets of options.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `prepare_order()` we parse an orderfile and assign it to a global
array. In order to save on some allocations, we replace newlines with
NUL characters and then assign pointers into the allocated buffer to
that array. This can cause the buffer to be completely unreferenced
though in some cases, e.g. because the order file is empty or because we
had to use `xmemdupz()` to copy the lines instead of NUL-terminating
them.
Refactor the code to always `xmemdupz()` the strings. This is a bit
simpler, and it is rather unlikely that saving a handful of allocations
really matters. This allows us to release the string buffer and thus
plug the memory leak.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `opt_ff` field gets populated either via `OPT_PASSTHRU` via
`config_get_ff()` or when `--rebase` is passed. So we sometimes end up
overriding the value in `opt_ff` with another value, but we do not free
the old value, causing a memory leak.
Adapt the type of the variable to be `char *` and consistently assign
allocated strings to it such that we can easily free it when it is being
overridden.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `treat_directory()` we perform some logic to handle ignored and
untracked entries. When populating a directory with entries we first
save the current number of ignored/untracked entries and then populate
new entries at the end of our arrays that keep track of those entries.
When we figure out that all entries have been ignored/are untracked we
then remove this tail of entries from those vectors again. But there is
an off by one error in both paths that causes us to not free the first
ignored and untracked entries, respectively.
Fix these off-by-one errors to plug the resulting leak. While at it,
massage the code a bit to match our modern code style.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When `update_submodule()` fails we return with `die_message()`, which
only causes us to print the same message as `die()` would without
actually causing the process to die. We don't free memory in that case
and thus leak memory.
Fix the leak by freeing the remote ref.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the "submodule-nested-repo-config" helper we create a submodule
repository and print its configuration. We do not clear the repo,
causing a memory leak. Plug it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix leaking error buffer when `compute_alternate_path()` fails.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `runcommand_in_submodule_cb()` we may end up not executing the child
command when `argv` is empty. But we still populate the command with
environment variables and other things, which needs cleanup. This leads
to a memory leak because we do not call `finish_command()`.
Fix this by clearing the child process when we don't execute it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're not freeing the submodule update strategy command. Provide a
helper function that does this for us and call it in
`update_data_release()`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `handle_builtin()` we may end up creating an ad-hoc argv array in
case we see that the command line contains the "--help" parameter. In
this case we observe two memory leaks though:
- We leak the `struct strvec` itself because we directly exit after
calling `run_builtin()`, without bothering about any cleanups.
- Even if we free'd that vector we'd end up leaking some of its
strings because `run_builtin()` will modify the array.
Plug both of these leaks.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff --exit-code" ignored modified binary files, which has
been corrected.
* rs/diff-exit-code-binary:
diff: report modified binary files as changes in builtin_diff()
The reftable backend learned to more efficiently handle exclude
patterns while enumerating the refs.
* ps/reftable-exclude:
refs/reftable: wire up support for exclude patterns
reftable/reader: make table iterator reseekable
t/unit-tests: introduce reftable library
Makefile: stop listing test library objects twice
builtin/receive-pack: fix exclude patterns when announcing refs
refs: properly apply exclude patterns to namespaced refs
"git apply" had custom buffer management code that predated before
use of strbuf got widespread, which has been updated to use strbuf,
which also plugged some memory leaks.
* ps/apply-leakfix:
apply: refactor `struct image` to use a `struct strbuf`
apply: rename members that track line count and allocation length
apply: refactor code to drop `line_allocated`
apply: introduce macro and function to init images
apply: rename functions operating on `struct image`
apply: reorder functions to move image-related things together
We allocate a list of ref structs from get_local_heads() but never clean
it up. We should do so before exiting to avoid complaints from the
leak-checker. Note that we have to initialize it to NULL, because
there's one code path that can jump to the cleanup label before we
assign to it.
Fixing this lets us mark t5540 as leak-free.
Curiously building with SANITIZE=leak and gcc does not seem to find this
problem, but switching to clang does. It seems like a fairly obvious
leak, though.
I was curious that the matching remote_refs did not have the same leak.
But that is because we store the list in a global variable, so it's
still reachable after we exit. Arguably we could treat it the same as
future-proofing, but I didn't bother (now that the script is marked
leak-free, anybody moving it to a stack variable will notice).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The dumb-http walker code creates a "fake" packed_git list representing
packs we've downloaded from the remote (I call it "fake" because
generally that struct is only used and managed by the local repository
struct). But during our cleanup phase we don't touch those at all,
causing a leak.
There's no support here from the rest of the object-database API, as
these structs are not meant to be freed, except when closing the object
store completely. But we can see that raw_object_store_clear() just
calls free() on them, and that's enough here to fix the leak.
I also added a call to close_pack() before each. In the regular code
this happens via close_object_store(), which we do as part of
raw_object_store_clear(). This is necessary to prevent leaking mmap'd
data (like the pack idx) or descriptors. The leak-checker won't catch
either of these itself, but I did confirm with some hacky warning()
calls and running t5550 that it's easy to leak at least index data.
This is all much more intimate with the packed_git struct than I'd like,
but I think fixing it would be a pretty big refactor. And it's just not
worth it for dumb-http code which is rarely used these days. If we can
silence the leak-checker without creating too much hassle, we should
just do that.
This lets us mark t5550 as leak-free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use http_get_strbuf() to fetch the remote info/packs content into a
strbuf, but never free it, causing a leak. There's no need to hold onto
it, as we've already parsed it completely.
This lets us mark t5619 as leak-free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new_http_object_request() function allocates a struct on the heap,
along with some fields inside the struct. But the matching function to
clean it up, release_http_object_request(), only frees the interior
fields without freeing the struct itself, causing a leak.
The related http_pack_request new/release pair gets this right, and at
first glance we should be able to do the same thing and just add a
single free() call. But there's a catch.
These http_object_request structs are typically embedded in the
object_request struct of http-walker.c. And when we clean up that parent
struct, it sanity-checks the embedded struct to make sure we are not
leaking descriptors. Which means a use-after-free if we simply free()
the embedded struct.
I have no idea how valuable that sanity-check is, or whether it can
simply be deleted. This all goes back to 5424bc557f (http*: add helper
methods for fetching objects (loose), 2009-06-06). But the obvious way
to make it all work is to be sure we set the pointer to NULL after
freeing it (and our freeing process closes the descriptor, so we know
there is no leak).
To make sure we do that consistently, we'll switch the pointer we take
in release_http_object_request() to a pointer-to-pointer, and we'll set
it to NULL ourselves. And then the compiler can help us find each caller
which needs to be updated.
Most cases will just pass "&obj_req->req", which will obviously do the
right thing. In a few cases, like http-push's finish_request(), we are
working with a copy of the pointer, so we don't NULL the original. But
it's OK because the next step is to free the struct containing the
original pointer anyway.
This lets us mark t5551 as leak-free. Ironically this is the "smart"
http test, and the leak here only affects dumb http. But there's a
single dumb-http invocation in there. The full dumb tests are in t5550,
which still has some more leaks.
This also makes t5559 leak-free, as it's just an HTTP/2 variant of
t5551. But we don't need to mark it as such, since it inherits the flag
from t5551.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "--prefetch" option to git-fetch modifies the default refspec,
including eliminating some entries entirely. When we drop an entry we
free the strings in the refspec_item, but we forgot to free the matching
string in the "raw" array of the refspec struct. There's no behavioral
bug here (since we correctly shrink the raw array, too), but we're
leaking the allocated string.
Let's add in the leak-fix, and while we're at it drop "const" from
the type of the raw string array. These strings are always allocated by
refspec_append(), etc, and this makes the memory ownership more clear.
This is all a bit more intimate with the refspec code than I'd like, and
I suspect it would be better if each refspec_item held on to its own raw
string, we had a single array, and we could use refspec_item_clear() to
clean up everything. But that's a non-trivial refactoring, since
refspec_item structs can be held outside of a "struct refspec", without
having a matching raw string at all. So let's leave that for now and
just fix the leak in the most immediate way.
This lets us mark t5582 as leak-free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We loop over the refs to push, building up a strbuf with the set of
"push" directives to send to the remote helper. But if the atomic-push
flag is set and we hit a rejected ref, we'll bail from the function
early. We clean up most things, but forgot to release the strbuf.
Fixing this lets us mark t5541 as leak-free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we parse a commit via repo_parse_commit_internal(), if
save_commit_buffer is set we'll stuff the buffer of the object contents
into a cache, overwriting any previous value.
This can result in a leak of that previously cached value, though it's
rare in practice. If we have a value in the cache it would have come
from a previous parse, and during that parse we'd set the object.parsed
flag, causing any subsequent parse attempts to exit without doing any
work.
But it's possible to "unparse" a commit, which we do when registering a
commit graft. And since shallow fetches are implemented using grafts,
the leak is triggered in practice by t5539.
There are a number of possible ways to address this:
1. the unparsing function could clear the cached commit buffer, too. I
think this would work for the case I found, but I'm not sure if
there are other ways to end up in the same state (an unparsed
commit with an entry in the commit buffer cache).
2. when we parse, we could check the buffer cache and prefer it to
reading the contents from the object database. In theory the
contents of a particular sha1 are immutable, but the code in
question is violating the immutability with grafts. So this
approach makes me a bit nervous, although I think it would work in
practice (the grafts are applied to what we parse, but we still
retain the original contents).
3. We could realize the cache is already populated and discard its
contents before overwriting. It's possible some other code could be
holding on to a pointer to the old cache entry (and we'd introduce
a use-after-free), but I think the risk of that is relatively low.
4. The reverse of (3): when the cache is populated, don't bother
saving our new copy. This is perhaps a little weird, since we'll
have just populated the commit struct based on a different buffer.
But the two buffers should be the same, even in the presence of
grafts (as in (2) above).
I went with option 4. It addresses the leak directly and doesn't carry
any risk of breaking other assumptions. And it's the same technique used
by parse_object_buffer() for this situation, though I'm not sure when it
would even come up there. The extra safety has been there since
bd1e17e245 (Make "parse_object()" also fill in commit message buffer
data., 2005-05-25).
This lets us mark t5539 as leak-free.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we call get_remote_heads() for protocol v0, that may populate the
"shallow" oid_array, which must be cleaned up to avoid a leak at the
program exit. The same problem exists for both fetch-pack and send-pack,
but not for the usual transport.c code paths, since we already do this
cleanup in disconnect_git().
Fixing this lets us mark t5542 as leak-free for the send-pack side, but
fetch-pack will need some more fixes before we can do the same for
t5539.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
