Re: git v2.49.0 - gitk regression on Cygwin

From: Johannes Sixt <j6t@kdbg.org>
Date: Mar 28, 2025, 17:30 UTC
Message-ID: <7b4149e1-44f8-44d4-89f8-647734f9e674@kdbg.org>
In-Reply-To: <23088b7d-ed98-4b78-bb9a-c3674da1117d@gmail.com>

Am 28.03.25 um 13:34 schrieb Mark Levedahl:

Show 6 quoted lines

> gitk no longer works on Cygwin. This commit is in Junio's tree as part
> of release v2.49.0, but I didn't trace to the specific merge commit.
> 
> The proximal issue is an endless loop caused by routine _which invoking
> exec, which is now a wrapper that invokes _which, while the builtin exec
> is renamed to real_exec.  This results in stack exhaustion.

Not good. Thanks for the report.

Show 11 quoted lines

> However, the above leaves code in place affecting path search on all
> platforms without justification. The commit message references the TCL
> man page for "exec", listing a number of directories (including the
> current working directory) and file suffixes searched on the Windows
> platform that could be problematic. However, that man page does not list
> any such issues for other platforms. So, it appears the patch does not
> address a known issue on Unix platforms, which includes Cygwin.
> 
> I believe the correct fix to 4cbe9e0e2 is limiting the override of exec
> and open to Windows, and I also have a patch to do that rather than what
> I show above. Let me know.

Indeed, it seems that this override is only needed on Windows. Dscho, is there a non-obvious reason that 'exec' and 'open' are overridden on all platforms?

-- Hannes