On Cygwin, t0301 fails because "git credential-cache exit" returns a
non-zero exit code. What's supposed to happen here is:
1. The client (the "credential-cache" invocation above) connects to a
previously-spawned credential-cache--daemon.
2. The client sends an "exit" command to the daemon.
3. The daemon unlinks the socket and then exits, closing the
descriptor back to the client.
4. The client sees EOF on the descriptor and exits successfully.
That works on most platforms, and even _used_ to work on Cygwin. But
that changed in Cygwin's ef95c03522 (Cygwin: select: Fix FD_CLOSE
handling, 2021-04-06). After that commit, the client sees a read error
with errno set to ECONNABORTED, and it reports the error and dies.
It's not entirely clear if this is a Cygwin bug. It seems that calling
fclose() on the filehandles pointing to the sockets is sufficient to
avoid this error return, even though exiting should in general look the
same from the client's perspective.
However, we can't just call fclose() here. It's important in step 3
above to unlink the socket before closing the descriptor to avoid the
race mentioned by 7d5e9c9849 (credential-cache--daemon: clarify "exit"
action semantics, 2016-03-18). The client will exit as soon as it sees
the descriptor close, and the daemon may or may not have actually
unlinked the socket by then. That makes test code like this:
git credential exit &&
test_path_is_missing .git-credential-cache
racy.
So we probably _could_ fix this by calling:
delete_tempfile(&socket_file);
fclose(in);
fclose(out);
before we exit(). Or by replacing the exit() with a return up the stack,
in which case the fclose() happens as we unwind. But in that case we'd
still need to call delete_tempfile() here to avoid the race.
But simpler still is that we can notice that we already special-case
ECONNRESET on the client side, courtesy of 1f180e5eb9 (credential-cache:
interpret an ECONNRESET as an EOF, 2017-07-27). We can just do the same
thing here (I suspect that prior to the Cygwin commit that introduced
this problem, we were really just seeing ECONNRESET instead of
ECONNABORTED, so the "new" problem is just the switch of the errno
values).
There's loads more debugging in this thread:
https://lore.kernel.org/git/9dc3e85f-a532-6cff-de11-1dfb2e4bc6b6@ramsayjones.plus.com/
but I've tried to summarize the useful bits in this commit message.
[jk: commit message]
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email to git+subscribe@vger.kernel.org (see https://subspace.kernel.org/subscribing.html for details). The mailing list archives are available at https://lore.kernel.org/git/, https://marc.info/?l=git and other archival sites.
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks