In our CI systems we can observe that t0610 fails rather frequently.
This testcase races a bunch of git-update-ref(1) processes with one
another which are all trying to update a unique reference, where we
expect that all processes succeed and end up updating the reftable
stack. The error message in this case looks like the following:
fatal: update_ref failed for ref 'refs/heads/branch-88': reftable: transaction prepare: I/O error
Instrumenting the code with a couple of calls to `BUG()` in relevant
sites where we return `REFTABLE_IO_ERROR` quickly leads one to discover
that this error is caused when calling `flock_acquire()`, which is a
thin wrapper around our lockfile API. Curiously, the error code we get
in such cases is `EACCESS`, indicating that we are not allowed to access
the file.
The root cause of this is an oddity of `CreateFileW()`, which is what
`_wopen()` uses internally. Quoting its documentation [1]:
If you call CreateFile on a file that is pending deletion as a
result of a previous call to DeleteFile, the function fails. The
operating system delays file deletion until all handles to the file
are closed. GetLastError returns ERROR_ACCESS_DENIED.
This behaviour is triggered quite often in the above testcase because
all the processes race with one another trying to acquire the lock for
the "tables.list" file. This is due to how locking works in the reftable
library when compacting a stack:
1. Lock the "tables.list" file and reads its contents.
2. Decide which tables to compact.
3. Lock each of the individual tables that we are about to compact.
4. Unlock the "tables.list" file.
5. Compact the individual tables into one large table.
6. Re-lock the "tables.list" file.
7. Write the new list of tables into it.
8. Commit the "tables.list" file.
The important step is (4): we don't commit the file directly by renaming
it into place, but instead we delete the lockfile so that concurrent
processes can continue to append to the reftable stack while we compact
the tables. And because we use `DeleteFileW()` to do so, we may now race
with another process that wants to acquire that lockfile. So if we are
unlucky, we would now see `ERROR_ACCESS_DENIED` instead of the expected
`ERROR_FILE_EXISTS`, which the lockfile subsystem isn't prepared to
handle and thus it will bail out without retrying to acquire the lock.
In theory, the issue is not limited to the reftable library and can be
triggered by every other user of the lockfile subsystem, as well. My gut
feeling tells me it's rather unlikely to surface elsewhere though.
Fix the issue by translating the error to `EEXIST`. This makes the
lockfile subsystem handle the error correctly: in case a timeout is set
it will now retry acquiring the lockfile until the timeout has expired.
With this, t0610 is now always passing on my machine whereas it was
previously failing in around 20-30% of all test runs.
[1]: https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In our compat library we have both "msvc.c" and "mingw.c". The former is
mostly a thin wrapper around the latter as it directly includes it, but
it has a couple of extra headers that aren't included in "mingw.c" and
is expected to be used with the Visual Studio compiler toolchain.
While our Makefile knows to pick up the correct file depending on
whether or not the Visual Studio toolchain is used, we don't do the same
with Meson. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git version --build-options" stopped showing zlib version by
mistake due to recent refactoring, which has been corrected.
* tc/zlib-ng-fix:
help: print zlib-ng version number
help: include git-zlib.h to print zlib version
Commit bc26f7690a (clone: make it possible to specify --tags,
2025-02-06) added a new paragraph in the middle of this list item. By
adding an empty line rather than using a list continuation, we broke the
list continuation, with the new paragraph ending up funnily indented.
Restore the chain of list continuations.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 3f763ddf28 (fetch: set remote/HEAD if it does not exist, 2024-11-22),
unconditionally adds "HEAD" to the list of ref prefixes we send to the
server.
This breaks a core assumption that the list of prefixes we send to the
server is complete. We must either send all prefixes we care about, or
none at all (in the latter case the server then advertises everything).
The tag following code is careful to only add "refs/tags/" to the list
of prefixes if there are already entries in the prefix list. But because
the new code from 3f763ddf28 runs after the tag code, and because it
unconditionally adds to the prefix list, we may end up with a prefix
list that _should_ have "refs/tags/" in it, but doesn't.
When that is the case, the server does not advertise any tags, and our
auto-following breaks because we never learned about any tags in the
first place.
Fix this by only adding "HEAD" to the ref prefixes when we know that we
are already limiting the advertisement. In either case we'll learn about
HEAD (either through the limited advertisement, or implicitly through a
full advertisement).
Reported-by: Igor Todorovski <itodorov@ca.ibm.com>
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 building against zlib-ng, the header file `zlib.h` is not included,
but `zlib-ng.h` is included instead. It's `zlib.h` that defines
`ZLIB_VERSION` and that macro is used to print out zlib version in
`git-version(1)` with `--build-options`. But when it's not defined, no
version is printed.
`zlib-ng.h` defines another macro: `ZLIBNG_VERSION`. Use that macro to
print the zlib-ng version in `git version --build-options` when it's
set. Otherwise fallback to `ZLIB_VERSION`.
Signed-off-by: Toon Claes <toon@iotcl.com>
Helped-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 41f1a8435a (git-compat-util: move include of "compat/zlib.h" into
"git-zlib.h", 2025-01-28) some code was refactored to enable easier
linking against zlib-ng.
This removed `zlib.h` being indirectly included in `help.c`. As this
file uses `ZLIB_VERSION` to print the version number of zlib when
running git-version(1) with `--build-options`, this resulted in a
regression.
Include `git-zlib.h` directly into `help.c` to print zlib version
information. This brings back the zlib version in the output of
`git version --build-options`.
Signed-off-by: Toon Claes <toon@iotcl.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Hotfix to help building Git-for-Windows.
* js/win-2.49-build-fixes:
cmake: generalize the handling of the `CLAR_TEST_OBJS` list
meson: fix sorting
ident: stop assuming that `gw_gecos` is writable
Some future breaking changes would remove certain parts of the
default repository, which were still described even when the
documents were built for the future with WITH_BREAKING_CHANGES.
* pw/repo-layout-doc-update:
docs: fix repository-layout when building with breaking changes
A late-comer to the v2.49.0 party, `sk/unit-test-oid`, added yet another
array item to `CLAR_TEST_OBJS`, causing the `win+VS build` job to fail
with symptoms like this one:
unit-tests-lib.lib(u-oid-array.obj) : error LNK2019: unresolved
external symbol cl_parse_any_oid referenced in function fill_array
This is a similar scenario to the one that forced me to write
8afda42fce (cmake: generalize the handling of the `UNIT_TEST_OBJS`
list, 2024-09-18): The hard-coded echo of `CLAR_TEST_OBJS` in
`CMakeLists.txt` that recapitulates faithfully what was already
hard-coded in `Makefile` would either have to be updated whack-a-mole
style, or generalized.
Just like I chose the latter option for `UNIT_TEST_OBJS`, I now do the
same for `CLAR_TEST_OBJS`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 904339edbd (Introduce support for the Meson build system,
2024-12-06) the `meson.build` file was introduced, adding also a
Windows-specific list of source files. This list was obviously meant to
be sorted alphabetically, but there is one mistake. Let's fix that.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 590e081dea (ident: add NO_GECOS_IN_PWENT for systems without
pw_gecos in struct passwd, 2011-05-19), code was introduced to iterate
over the `gw_gecos` field; The loop variable is of type `char *`, which
assumes that `gw_gecos` is writable.
However, it is not necessarily writable (and it is a bad idea to have it
writable in the first place), so let's switch the loop variable type to
`const char *`.
This is not a new problem, but what is new is the Meson build. While it
does not trigger in CI builds, imitating the commands of
`ci/run-build-and-tests.sh` in a regular Git for Windows SDK (`meson
setup build . --fatal-meson-warnings --warnlevel 2 --werror --wrap-mode
nofallback -Dfuzzers=true` followed by `meson compile -C build --`
results in this beautiful error:
"cc" [...] -o libgit.a.p/ident.c.obj "-c" ../ident.c
../ident.c: In function 'copy_gecos':
../ident.c:68:18: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
68 | for (src = get_gecos(w); *src && *src != ','; src++) {
| ^
cc1.exe: all warnings being treated as errors
Now, why does this not trigger in CI? The answer is as simple as it is
puzzling: The `win+Meson` job completely side-steps Git for Windows'
development environment, opting instead to use the GCC that is on the
`PATH` in GitHub-hosted `windows-latest` runners. That GCC is pinned to
v12.2.0 and targets the UCRT (unlikely to change any time soon, see
https://github.com/actions/runner-images/blob/win25/20250303.1/images/windows/toolsets/toolset-2022.json#L132-L141).
That is in stark contrast to Git for Windows, which uses GCC v14.2.0 and
targets MSVCRT. Git for Windows' `Makefile`-based build also obviously
uses different compiler flags, otherwise this compile error would have
had plenty of opportunity in almost 14 years to surface.
In other words, contrary to my expectations, the `win+Meson` job is
ill-equipped to replace the `win build` job because it exercises a
completely different tool version/compiler flags vector than what Git
for Windows needs.
Nevertheless, there is currently this huge push, including breaking
changes after -rc1 and all, for switching to Meson. Therefore, we need
to make it work, somehow, even in Git for Windows' SDK, hence this
patch, at this point in time.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Meson-based build procedure forgot to build some docs, which has
been corrected.
* pw/build-meson-technical-and-howto-docs:
meson: fix building technical and howto docs
The editorconfig file is updated to tell us that bash scripts are
similar to general Bourne shell scripts.
* dm/editorconfig-bash-is-like-sh:
editorconfig: add .bash extension
Convert a few unit tests to the clar framework.
* sk/unit-test-oid:
t/unit-tests: convert oidtree test to use clar test framework
t/unit-tests: convert oidmap test to use clar test framework
t/unit-tests: convert oid-array test to use clar test framework
t/unit-tests: implement clar specific oid helper functions
The path.[ch] API takes an explicit repository parameter passed
throughout the callchain, instead of relying on the_repository
singleton instance.
* ps/path-sans-the-repository:
path: adjust last remaining users of `the_repository`
environment: move access to "core.sharedRepository" into repo settings
environment: move access to "core.hooksPath" into repo settings
repo-settings: introduce function to clear struct
path: drop `git_path()` in favor of `repo_git_path()`
rerere: let `rerere_path()` write paths into a caller-provided buffer
path: drop `git_common_path()` in favor of `repo_common_path()`
worktree: return allocated string from `get_worktree_git_dir()`
path: drop `git_path_buf()` in favor of `repo_git_path_replace()`
path: drop `git_pathdup()` in favor of `repo_git_path()`
path: drop unused `strbuf_git_path()` function
path: refactor `repo_submodule_path()` family of functions
submodule: refactor `submodule_to_gitdir()` to accept a repo
path: refactor `repo_worktree_path()` family of functions
path: refactor `repo_git_path()` family of functions
path: refactor `repo_common_path()` family of functions
Since commit 8ccc75c245 (remote: announce removal of "branches/" and
"remotes/", 2025-01-22) enabling WITH_BREAKING_CHANGES when building git
removes support for reading branches from ".git/branches" and remotes
from ".git/remotes". However those locations are still documented in
gitrepository-layout.adoc even though the build does not support them.
Rectify this by adding a new document attribute "with-breaking-changes"
and use it to make the inclusion of those sections of the documentation
conditional. Note that the name of the attribute does not match the test
prerequisite WITHOUT_BREAKING_CHANGES added in c5bc9a7f94 (Makefile:
wire up build option for deprecated features, 2025-01-22). This is to
avoid the awkward double negative ifndef::without_breaking_changes for
documentation that should be included when WITH_BREAKING_CHANGES is
enabled. The test prerequisite will be renamed to match the
documentation attribute in a future patch series.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If block_source_read_block() or parse_footer() fail, we leak the "name"
member of struct reftable_reader in reftable_reader_new(). Release it.
Reported by: H Z <shiyuyuranzh@gmail.com>
Helped-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>
