On 2021-01-31 21:49:49 +0100, Ævar Arnfjörð Bjarmason wrote:
> On Sun, Jan 31 2021, Vincent Lefevre wrote:
> > FYI, I already have the exit status already in my prompt (the above
> > commands were just for the example). Still, the git behavior is
> > disturbing.
> >
> > Moreover, this doesn't solve the issue when doing something like
> >
> > git log && some_other_command
>
> What issue? That we're returning an exit code per getting a SIGHUP here
> is a feature. Consider:
>
> git -c core.pager=/bin/false log && echo showed you the output
If the pager exists with a non-zero exit status, it is normal to
return a non-zero exit status. This was not the bug I reported.
> > No! I want to be warned about real SIGPIPEs.
>
> Not being able to write "git log" output is a real SIGPIPE.
Which is not the case here, because the full output has never been
requested by the user.
> Is it because in your mind it's got something to do with the "|" shell
> piping construct? The SIGPIPE is sent by the kernel, so it's no less
> expected in cases like:
>
> git log && echo foo
>
> Than:
>
> git log | cat
See the difference (without the patch) between
$ git log && echo foo; echo $?
141
and
$ git log | head; echo $?
[...]
0
[...]
> Maybe we have users who'd like to work around zsh's "setopt
> PRINT_EXIT_VALUE" mode (would you want this patch if you could make zsh
> ignore 141?).
zsh is working as expected, and as I've already said, I ***WANT***
SIGPIPE to be reported by the shell, as it may indicate a real failure
in a script. BTW, I even have a script using git that relies on that:
{ git rev-list --author "$@[-1]" HEAD &&
git rev-list --grep "$@[-1]" HEAD } | \
git "${@[1,-2]:-lv}" --no-walk --stdin
return $((pipestatus[2] ? pipestatus[2] : pipestatus[1]))
Here it is important not to lose any information. No pager is
involved, the full output is needed. If for some reason, the
LHS of the pipe fails due to a SIGPIPE but the right hand side
succeeds, the error will be reported.
The fact is that with a pager, the SIGPIPE with a pager is normal.
Thus with a pager, git is reporting a spurious SIGPIPE, and this
is disturbing.
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
