Commit Graph

70885 Commits (e7e03ef9950df84d60b093ab925ccf34a8453369)

Author SHA1 Message Date
Johannes Schindelin e7e03ef995 ci: avoid running the test suite _twice_
This is a late amendment of 4a6e4b9602 (CI: remove Travis CI support,
2021-11-23), whereby the `.prove` file (being written by the `prove`
command that is used to run the test suite) is no longer retained
between CI builds: This feature was only ever used in the Travis CI
builds, we tried for a while to do the same in Azure Pipelines CI runs
(but I gave up on it after a while), and we never used that feature in
GitHub Actions (nor does the new GitLab CI code use it).

Retaining the Prove cache has been fragile from the start, even though
the idea seemed good at the time, the idea being that the `.prove` file
caches information about previous `prove` runs (`save`) and uses them
(`slow`) to run the tests in the order from longer-running to shorter
ones, making optimal use of the parallelism implied by `--jobs=<N>`.

However, using a Prove cache can cause some surprising behavior: When
the `prove` caches information about a test script it has run,
subsequent `prove` runs (with `--state=slow`) will run the same test
script again even if said script is not specified on the `prove`
command-line!

So far, this bug did not matter. Right until d8f416bbb8 (ci: run unit
tests in CI, 2023-11-09) did it not matter.

But starting with that commit, we invoke `prove` _twice_ in CI, once to
run the regular test suite of regression test scripts, and once to run
the unit tests. Due to the bug, the second invocation re-runs all of the
tests that were already run as part of the first invocation. This not
only wastes build minutes, it also frequently causes the `osx-*` jobs to
fail because they already take a long time and now are likely to run
into a timeout.

The worst part about it is that there is actually no benefit to keep
running with `--state=slow,save`, ever since we decided no longer to
try to reuse the Prove cache between CI runs.

So let's just drop that Prove option and live happily ever after.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-14 09:24:23 +09:00
Patrick Steinhardt 0e3b67e2aa ci: add support for GitLab CI
We already support Azure Pipelines and GitHub Workflows in the Git
project, but until now we do not have support for GitLab CI. While it is
arguably not in the interest of the Git project to maintain a ton of
different CI platforms, GitLab has recently ramped up its efforts and
tries to contribute to the Git project more regularly.

Part of a problem we hit at GitLab rather frequently is that our own,
custom CI setup we have is so different to the setup that the Git
project has. More esoteric jobs like "linux-TEST-vars" that also set a
couple of environment variables do not exist in GitLab's custom CI
setup, and maintaining them to keep up with what Git does feels like
wasted time. The result is that we regularly send patch series upstream
that fail to compile or pass tests in GitHub Workflows. We would thus
like to integrate the GitLab CI configuration into the Git project to
help us send better patch series upstream and thus reduce overhead for
the maintainer. Results of these pipeline runs will be made available
(at least) in GitLab's mirror of the Git project at [1].

This commit introduces the integration into our regular CI scripts so
that most of the setup continues to be shared across all of the CI
solutions. Note that as the builds on GitLab CI run as unprivileged
user, we need to pull in both sudo and shadow packages to our Alpine
based job to set this up.

[1]: https://gitlab.com/gitlab-org/git

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:10 +09:00
Patrick Steinhardt 0d3911ad73 ci: install test dependencies for linux-musl
The linux-musl CI job executes tests on Alpine Linux, which is based on
musl libc instead of glibc. We're missing some test dependencies though,
which causes us to skip a subset of tests.

Install these test dependencies to increase our test coverage on this
platform. There are still some missing test dependecies, but these do
not have a corresponding package in the Alpine repositories:

    - p4 and p4d, both parts of the Perforce version control system.

    - cvsps, which generates patch sets for CVS.

    - Subversion and the SVN::Core Perl library, the latter of which is
      not available in the Alpine repositories. While the tool itself is
      available, all Subversion-related tests are skipped without the
      SVN::Core Perl library anyway.

The Apache2-based tests require a bit more care though. For one, the
module path is different on Alpine Linux, which requires us to add it to
the list of known module paths to detect it. But second, the WebDAV
module on Alpine Linux is broken because it does not bundle the default
database backend [1]. We thus need to skip the WebDAV-based tests on
Alpine Linux for now.

[1]: https://gitlab.alpinelinux.org/alpine/aports/-/issues/13112

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:10 +09:00
Patrick Steinhardt dd02c3b68c ci: squelch warnings when testing with unusable Git repo
Our CI jobs that run on Docker also use mostly the same architecture to
build and test Git via the "ci/run-build-and-tests.sh" script. These
scripts also provide some functionality to massage the Git repository
we're supposedly operating in.

In our Docker-based infrastructure we may not even have a Git repository
available though, which leads to warnings when those functions execute.
Make the helpers exit gracefully in case either there is no Git in our
PATH, or when not running in a Git repository.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:10 +09:00
Patrick Steinhardt 9f17bef9a6 ci: unify setup of some environment variables
Both GitHub Actions and Azure Pipelines set up the environment variables
GIT_TEST_OPTS, GIT_PROVE_OPTS and MAKEFLAGS. And while most values are
actually the same, the setup is completely duplicate. With the upcoming
support for GitLab CI this duplication would only extend even further.

Unify the setup of those environment variables so that only the uncommon
parts are separated. While at it, we also perform some additional small
improvements:

    - We now always pass `--state=failed,slow,save` via GIT_PROVE_OPTS.
      It doesn't hurt on platforms where we don't persist the state, so
      this further reduces boilerplate.

    - When running on Windows systems we set `--no-chain-lint` and
      `--no-bin-wrappers`. Interestingly though, we did so _after_
      already having exported the respective environment variables.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:09 +09:00
Patrick Steinhardt e624f206bc ci: split out logic to set up failed test artifacts
We have some logic in place to create a directory with the output from
failed tests, which will then subsequently be uploaded as CI artifacts.
We're about to add support for GitLab CI, which will want to reuse the
logic.

Split the logic into a separate function so that it is reusable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:09 +09:00
Patrick Steinhardt 412847ced4 ci: group installation of Docker dependencies
The output of CI jobs tends to be quite long-winded and hard to digest.
To help with this, many CI systems provide the ability to group output
into collapsible sections, and we're also doing this in some of our
scripts.

One notable omission is the script to install Docker dependencies.
Address it to bring more structure to the output for Docker-based jobs.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:09 +09:00
Patrick Steinhardt a7d499cb93 ci: make grouping setup more generic
Make the grouping setup more generic by always calling `begin_group ()`
and `end_group ()` regardless of whether we have stubbed those functions
or not. This ensures we can more readily add support for additional CI
platforms.

Furthermore, the `group ()` function is made generic so that it is the
same for both GitHub Actions and for other platforms. There is a
semantic conflict here though: GitHub Actions used to call `set +x` in
`group ()` whereas the non-GitHub case unconditionally uses `set -x`.
The latter would get overriden if we kept the `set +x` in the generic
version of `group ()`. To resolve this conflict, we simply drop the `set
+x` in the generic variant of this function. As `begin_group ()` calls
`set -x` anyway this is not much of a change though, as the only
commands that aren't printed anymore now are the ones between the
beginning of `group ()` and the end of `begin_group ()`.

Last, this commit changes `end_group ()` to also accept a parameter that
indicates _which_ group should end. This will be required by a later
commit that introduces support for GitLab CI.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:09 +09:00
Patrick Steinhardt a4761b605c ci: reorder definitions for grouping functions
We define a set of grouping functions that are used to group together
output in our CI, where these groups then end up as collapsible sections
in the respective pipeline platform. The way these functions are defined
is not easily extensible though as we have an up front check for the CI
_not_ being GitHub Actions, where we define the non-stub logic in the
else branch.

Reorder the conditional branches such that we explicitly handle GitHub
Actions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-09 18:56:08 +09:00
Junio C Hamano 43c8a30d15 Git 2.42
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-21 09:34:58 -07:00
Junio C Hamano 915e51b74e Merge branch 'jk/function-pointer-mismatches-fix' (early part)
Fix a minor regression that some compiler might notice.

* 'jk/function-pointer-mismatches-fix' (early part):
  fsck: use enum object_type for fsck_walk callback
2023-08-21 09:27:44 -07:00
Junio C Hamano 5a50dd7eda l10n-2.42.0-rnd2
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE37vMEzKDqYvVxs51k24VDd1FMtUFAmTinJwACgkQk24VDd1F
 MtXNfw/9Hn8LCB7MXV0FGvS7BYcijWuXZxGa+3o4mxKREwmHe3R7AYVTcVKADw03
 YE77oHVCcG6EiVldfUDOdwIO3bgKTlp8On4LpLzGAoB8+oT4dLntQvIQK+W0vw8A
 zCgTR5c0IMahdUxJgFMoYsTxN3bScTMJgdrQZ6OLJ8OaP4nTOhrzyoGIPWKE7QMt
 zQ058zUJi+OA/Z7arKJG72IiwB6u+/xSdnf94+qjIbvCaQf1HDs2E/eniNMKY/do
 u4ETO5mgqnAZdowWvp18uBwStkGZTmucYb5D9aq1lUDeUKGXEIRZlYCIz8h7g318
 9ZYVJlj8L2y/vCw4C/jdpcjGvZeIWQYibIHPItWLGo3HgKXp41phCsGPi4TkBi61
 dwpizSkCXpUMr7EVj4ngBiqCLvjqIrX/WPU3KrAgUYLvsUwPtczAHsCrT1EA7gXR
 Wbpv6yEDRjdvqgId4oL2UvJK6EANIug6ZJt29LdkegAH9lCB4Q13ULeHgS9CsWpZ
 xwmmR8ybxoSmjsjvpcMFKfBLuB/kc9JjqGx852w2GQMDOTtVGxLMTPGrkMWr2pfw
 WpbQ/HImNG6UEFpstW7/pEP/0OQV/oUZjGD39/NJBEcIImS89LUV+MXeZj+3DwbO
 TqZ+Q5eF+ScgCD32CNM/CU7x2o5xs+42dYk09r8cGdqzB4NUBQc=
 =bnqd
 -----END PGP SIGNATURE-----

Merge tag 'l10n-2.42.0-rnd2' of https://github.com/git-l10n/git-po

l10n-2.42.0-rnd2

* tag 'l10n-2.42.0-rnd2' of https://github.com/git-l10n/git-po:
  l10n: zh_TW.po: Git 2.42
  l10n: zh_CN: 2.42.0 round 2
  l10n: zh_CN: v2.42.0 round 1
  l10n: Update German translation
  l10n: Update Catalan translation
  l10n: tr: git 2.42.0
  l10n: fr v2.42.0 rnd 2
  l10n: fr v2.42.0 rnd 1
  l10n: sv.po: Update Swedish translation 5549t0f0u
  l10n: uk: update translation (2.42.0)
  l10n: po-id for 2.42 (round 1)
  l10n: ru.po: update Russian translation
2023-08-21 08:43:46 -07:00
Jiang Xin d1f87c2148 Merge branch 'po-id' of github.com:bagasme/git-po
* 'po-id' of github.com:bagasme/git-po:
  l10n: po-id for 2.42 (round 1)
2023-08-21 07:05:38 +08:00
Yi-Jyun Pan 5e2dff212a
l10n: zh_TW.po: Git 2.42
Co-authored-by: Lumynous <lumynou5.tw@gmail.com>
Signed-off-by: Yi-Jyun Pan <pan93412@gmail.com>
2023-08-20 22:01:37 +08:00
Jeff King 2bbeddee5d fsck: use enum object_type for fsck_walk callback
We switched the function interface for fsck callbacks in a1aad71601
(fsck.h: use "enum object_type" instead of "int", 2021-03-28). However,
we accidentally flipped the type back to "int" as part of 0b4e9013f1
(fsck: mark unused parameters in various fsck callbacks, 2023-07-03).
The mistake happened because that commit was written before a1aad71601
and rebased forward, and I screwed up while resolving the conflict.

Curiously, the compiler does not warn about this mismatch, at least not
when using gcc and clang on Linux (nor in any of our CI environments).
Based on 28abf260a5 (builtin/fsck.c: don't conflate "int" and "enum" in
callback, 2021-06-01), I'd guess that this would cause the AIX xlc
compiler to complain. I noticed because clang-18's UBSan now identifies
mis-matched function calls at runtime, and does complain of this case
when running the test suite.

I'm not entirely clear on whether this mismatch is a problem in
practice. Compilers are certainly free to make enums smaller than "int"
if they don't need the bits, but I suspect that they have to promote
back to int for function calls (though I didn't dig in the standard, and
I won't be surprised if I'm simply wrong and the real-world impact would
depend on the ABI).

Regardless, switching it back to enum is obviously the right thing to do
here; the switch to "int" was simply a mistake.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-19 21:17:32 -07:00
Jiang Xin 3cf978718f Merge branch 'l10n-de-2.42' of github.com:ralfth/git
* 'l10n-de-2.42' of github.com:ralfth/git:
  l10n: Update German translation
2023-08-19 21:09:31 +08:00
Jiang Xin 6fb0e532d5 Merge branch 'catalan' of github.com:Softcatala/git-po
* 'catalan' of github.com:Softcatala/git-po:
  l10n: Update Catalan translation
2023-08-19 21:08:22 +08:00
Jiang Xin d731a52e4d Merge branch 'update-uk-l10n' of github.com:arkid15r/git-ukrainian-l10n
* 'update-uk-l10n' of github.com:arkid15r/git-ukrainian-l10n:
  l10n: uk: update translation (2.42.0)
2023-08-19 21:07:47 +08:00
Jiang Xin c04e26683f Merge branch 'tl/zh_CN_2.42.0_rnd1' of github.com:dyrone/git
* 'tl/zh_CN_2.42.0_rnd1' of github.com:dyrone/git:
  l10n: zh_CN: 2.42.0 round 2
  l10n: zh_CN: v2.42.0 round 1
2023-08-19 21:07:03 +08:00
Jiang Xin 7fdd36c22b Merge branch 'master' of github.com:nafmo/git-l10n-sv
* 'master' of github.com:nafmo/git-l10n-sv:
  l10n: sv.po: Update Swedish translation 5549t0f0u
2023-08-19 21:05:00 +08:00
Jiang Xin d0d403b8bc Merge branch 'l10n-tr' of github.com:bitigchi/git-po
* 'l10n-tr' of github.com:bitigchi/git-po:
  l10n: tr: git 2.42.0
2023-08-19 21:04:09 +08:00
Teng Long 9441efe212 l10n: zh_CN: 2.42.0 round 2
Signed-off-by: Teng Long <dyroneteng@gmail.com>
2023-08-18 19:30:03 +08:00
Teng Long bb9c886334 l10n: zh_CN: v2.42.0 round 1
Signed-off-by: Teng Long <dyroneteng@gmail.com>
2023-08-18 19:29:01 +08:00
Junio C Hamano f9972720e9 Merge branch 'ps/revision-stdin-with-options'
Typofix to documentation added during this cycle.

* ps/revision-stdin-with-options:
  rev-list-options: fix typo in `--stdin` documentation
2023-08-17 15:50:05 -07:00
Junio C Hamano 62ce3dcd67 Merge branch 'sa/doc-ls-remote'
Mark-up fix to documentation added during this cycle.

* sa/doc-ls-remote:
  show-ref doc: fix carets in monospace
2023-08-17 15:50:05 -07:00
Junio C Hamano fa43131a09 Merge branch 'tl/notes-separator'
Typo/grammofix to documentation added during this cycle.

* tl/notes-separator:
  notes doc: tidy up `--no-stripspace` paragraph
  notes doc: split up run-on sentences
2023-08-17 15:50:05 -07:00
Ralf Thielow a1d7c65007 l10n: Update German translation
Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
2023-08-17 17:00:36 +02:00
Martin Ågren c81f1a1676 rev-list-options: fix typo in `--stdin` documentation
With `--stdin`, we read *from* standard input, not *for*.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-16 11:42:54 -07:00
Martin Ågren 18c4aac0dd show-ref doc: fix carets in monospace
When commit 00bf685975 (show-ref doc: update for internal consistency,
2023-05-19) switched from double quotes to backticks around our {caret}
macro, we started rendering "{caret}" literally. Fix this by replacing
by a "^" character.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-16 11:40:10 -07:00
Martin Ågren 3a6e1ad80b notes doc: tidy up `--no-stripspace` paragraph
Where we document the `--no-stripspace` option, remove a superfluous
"For" to fix the grammar. Mark option names and command names using
`backticks` to set them in monospace.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-16 11:37:25 -07:00
Martin Ågren 95b6ae9d74 notes doc: split up run-on sentences
When commit c4e2aa7d45 (notes.c: introduce "--[no-]stripspace" option,
2023-05-27) mentioned the new `--no-stripspace` in the documentation for
`-m` and `-F`, it created run-on sentences. It also used slightly
different language in the two sections for no apparent reason. Split the
sentences in two to improve readability, and while touching the two
sites, make them more similar.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-16 11:36:36 -07:00
Jordi Mas f8a7795b7a l10n: Update Catalan translation
Signed-off-by: Jordi Mas <jmas@softcatala.org>
2023-08-16 18:25:02 +02:00
Emir SARI d9dec13dde l10n: tr: git 2.42.0
Signed-off-by: Emir SARI <emir_sari@icloud.com>
2023-08-16 14:40:44 +03:00
Jean-Noël Avila 87afb88801 l10n: fr v2.42.0 rnd 2
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
2023-08-16 11:50:23 +02:00
Jean-Noël Avila f846e08312 l10n: fr v2.42.0 rnd 1
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
2023-08-16 11:48:16 +02:00
Peter Krefting b90a4a25e6 l10n: sv.po: Update Swedish translation 5549t0f0u
Signed-off-by: Peter Krefting <peter@softwolves.pp.se>
2023-08-16 07:42:51 +01:00
Arkadii Yakovets 5bf602fc3b
l10n: uk: update translation (2.42.0)
Co-authored-by: Kate Golovanova <kate@kgthreads.com>
Signed-off-by: Arkadii Yakovets <ark@cho.red>
Signed-off-by: Kate Golovanova <kate@kgthreads.com>
2023-08-15 18:55:13 -07:00
Jiang Xin 62a26b36bd Merge branch 'master' of github.com:git/git
* 'master' of github.com:git/git: (34 commits)
  Git 2.42-rc2
  t4053: avoid writing to unopened pipe
  t4053: avoid race when killing background processes
  Git 2.42-rc1
  git maintenance: avoid console window in scheduled tasks on Windows
  win32: add a helper to run `git.exe` without a foreground window
  t9001: remove excessive GIT_SEND_EMAIL_NOTTY=1
  mv: handle lstat() failure correctly
  parse-options: disallow negating OPTION_SET_INT 0
  repack: free geometry struct
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
  t0040: declare non-tab indentation to be okay in this script
  advice: handle "rebase" in error_resolve_conflict()
  A few more topics before -rc1
  mailmap: change primary address for Glen Choo
  gitignore: ignore clangd .cache directory
  docs: update when `git bisect visualize` uses `gitk`
  compat/mingw: implement a native locate_in_PATH()
  run-command: conditionally define locate_in_PATH()
  ...
2023-08-16 07:24:56 +08:00
Junio C Hamano f1ed9d7dc0 Git 2.42-rc2
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-15 10:20:02 -07:00
Junio C Hamano f9fe84b5a2 Merge branch 'pw/diff-no-index-from-named-pipes'
Test updates.

* pw/diff-no-index-from-named-pipes:
  t4053: avoid writing to unopened pipe
  t4053: avoid race when killing background processes
2023-08-15 10:19:47 -07:00
Junio C Hamano 8e12aaa7ce Merge branch 'st/mv-lstat-fix'
Correct use of lstat() that assumed a failing call would not
clobber the statbuf.

* st/mv-lstat-fix:
  mv: handle lstat() failure correctly
2023-08-15 10:19:47 -07:00
Junio C Hamano cecd6a5ffc Merge branch 'jc/send-email-pre-process-fix'
Test fix.

* jc/send-email-pre-process-fix:
  t9001: remove excessive GIT_SEND_EMAIL_NOTTY=1
2023-08-15 10:19:47 -07:00
Junio C Hamano 32f4fa8d3b Merge branch 'ds/maintenance-on-windows-fix'
Windows updates.

* ds/maintenance-on-windows-fix:
  git maintenance: avoid console window in scheduled tasks on Windows
  win32: add a helper to run `git.exe` without a foreground window
2023-08-15 10:19:47 -07:00
Junio C Hamano fc6bba66bc Merge branch 'js/allow-t4000-to-be-indented-with-spaces'
File attribute update.

* js/allow-t4000-to-be-indented-with-spaces:
  t0040: declare non-tab indentation to be okay in this script
2023-08-14 13:26:41 -07:00
Junio C Hamano fc71d024ad Merge branch 'jk/send-email-with-new-readline'
Adjust to newer Term::ReadLine to prevent it from breaking
the interactive prompt code in send-email.

* jk/send-email-with-new-readline:
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2023-08-14 13:26:41 -07:00
Junio C Hamano 6df312ad31 Merge branch 'jk/repack-leakfix'
Leakfix.

* jk/repack-leakfix:
  repack: free geometry struct
2023-08-14 13:26:40 -07:00
Junio C Hamano aea6c0531c Merge branch 'rs/parse-opt-forbid-set-int-0-without-noneg'
Developer support to detect meaningless combination of options.

* rs/parse-opt-forbid-set-int-0-without-noneg:
  parse-options: disallow negating OPTION_SET_INT 0
2023-08-14 13:26:40 -07:00
Junio C Hamano f12cb5052d Merge branch 'ob/rebase-conflict-advice-i18n-fix'
i18n coverage improvement and avoidance of sentence lego.

* ob/rebase-conflict-advice-i18n-fix:
  advice: handle "rebase" in error_resolve_conflict()
2023-08-14 13:26:40 -07:00
Jeff King e5cb1e3f09 t4053: avoid writing to unopened pipe
This fixes an occasional hang I see when running t4053 with
--verbose-log using dash.

Commit 1e3f26542a (diff --no-index: support reading from named pipes,
2023-07-05) added a test that "diff --no-index" will complain when
comparing a named pipe and a directory. The minimum we need to test this
is to mkfifo the pipe, and then run "git diff --no-index pipe some_dir".
But the test does one thing more: it spawns a background shell process
that opens the pipe for writing, like this:

        {
                (>pipe) &
        } &&

This extra writer _could_ be useful if Git misbehaves and tries to open
the pipe for reading. Without the writer, Git would block indefinitely
and the test would never end. But since we do not have such a bug, Git
does not open the pipe and it is the writing process which will block
indefinitely, since there are no readers. The test addresses this by
running "kill $!" in a test_when_finished block. Since the writer should
be blocking forever, this kill command will reliably find it waiting.

However, this seems to be somewhat racy, in that the writing process
sometimes hangs around even after the "kill". In a normal run of the
test script without options, this doesn't have any effect; the
main test script completes anyway. But with --verbose-log, we spawn a
"tee" process that reads the script output, and it won't end until all
descriptors pointing to its input pipe are closed. And the background
process that is hanging around still has its stderr, etc, pointed into
that pipe.

You can reproduce the situation like this:

  cd t
  ./t4053-diff-no-index.sh --verbose-log --stress

Let that run for a few minutes, and then you'll find that some of the
runs have hung. For example, at 11:53, I ran:

  $ ps xk start o pid,start,command | grep tee | head
   713459 11:48:06 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-9.out
   713527 11:48:06 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-15.out
   719434 11:48:07 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-1.out
   728117 11:48:08 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-5.out
   738738 11:48:09 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-31.out
   739457 11:48:09 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-27.out
   744432 11:48:10 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-21.out
   744471 11:48:10 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-29.out
   761961 11:48:12 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-0.out
   812299 11:48:19 tee -a /home/peff/compile/git/t/test-results/t4053-diff-no-index.stress-8.out

All of these have been hung for several minutes. We can investigate one
and see that it's waiting to get EOF on its input:

  $ strace -p 713459
  strace: Process 713459 attached
  read(0,
  ^C

Who else has that descriptor open?

  $ lsof -a -p 713459 -d 0 +E
  COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF    NODE NAME
  tee     713459 peff    0r  FIFO   0,13      0t0 3943636 pipe 719203,sh,5w 719203,sh,7w 719203,sh,12w 719203,sh,13w
  sh      719203 peff    5w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,7w 719203,sh,12w 719203,sh,13w
  sh      719203 peff    7w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,5w 719203,sh,12w 719203,sh,13w
  sh      719203 peff   12w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,5w 719203,sh,7w 719203,sh,13w
  sh      719203 peff   13w  FIFO   0,13      0t0 3943636 pipe 713459,tee,0r 719203,sh,5w 719203,sh,7w 719203,sh,12w

It's a shell, presumably a subshell spawned by the main script. Though
it may seem odd, having the same descriptor open several times is not
unreasonable (they're all basically the original stdout/stderr of the
script that has been copied). And they should all close when the process
exits. So what's it doing? Curiously, it will exit as soon as we strace
it:

  $ strace -s 64 -p 719203
  strace: Process 719203 attached
  openat(AT_FDCWD, "pipe", O_WRONLY|O_CREAT|O_TRUNC, 0666) = -1 ENOENT (No such file or directory)
  write(2, "./t4053-diff-no-index.sh: 7: eval: ", 35) = 35
  write(2, "cannot create pipe: Directory nonexistent", 41) = 41
  write(2, "\n", 1)                       = 1
  exit_group(2)                           = ?
  +++ exited with 2 +++

I think what happens is this:

  - it is blocking in the openat() call for the pipe, as we expect (so
    this is definitely the backgrounded subshell mentioned above)

  - strace sends signals (probably STOP/CONT); those cause the kernel to
    stop blocking, but libc will restart the system call automatically

  - by this time, the "pipe" fifo is gone, so we'll actually try to
    create a regular file. But of course the surrounding directory is
    gone, too! So we get ENOENT, and then exit as normal.

So the blocking is something we expect to happen. But what we didn't
expect is for the process to still exist at all! It should have been
killed earlier when the parent process called "kill", but it wasn't. And
we can't catch the race at this point, because it happened much earlier.

One can guess, though, that there is some race with the shell setting up
the signal handling in the backgrounded subshell, and possibly blocking
or ignoring signals at the time that the "kill" is received.  Curiously,
the race does not seem to happen if I use "bash" instead of "dash", so
presumably bash's setup here is more atomic.

One fix might be to try killing the subshell more aggressively, either
using SIGKILL, or looping on kill/wait. But that seems complex and
likely to introduce new problems/races. Instead, we can observe that the
writer is not needed at all. Git will notice the pipe via stat() before
it is ever opened. So we can simply drop the writer subshell entirely.

If we ever changed Git to open the path and fstat() it, this would
result in the test hanging. But we're not likely to do that. After all,
we have to stat() paths to see if they are openable at all (e.g., it
could be a directory), so this seems like a low risk. And anybody who
does make such a change will immediately see the issue, as Git would
hang consistently.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-13 16:30:36 -07:00
Phillip Wood 231e86c10c t4053: avoid race when killing background processes
The test 'diff --no-index reads from pipes' starts a couple of
background processes that write to the pipes that are passed to "diff
--no-index". If the test passes then we expect these processes to exit
as all their output will have been read. However if the test fails
then we want to make sure they do not hang about on the users machine
and the test remembers they should be killed by calling

      test_when_finished  "! kill $!"

after each background process is created. Unfortunately there is a
race where test_when_finished may run before the background process
exits even when all its output has been read resulting in the kill
command succeeding which causes the test to fail. Fix this by ignoring
the exit status of the kill command. If the diff is successful we
could instead wait for the background process to exit and check their
status but that feels like it is testing the platform's printf
implementation rather than git's code.

Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-10 09:16:27 -07:00