Re: [PATCH 2/2] Check for IO errors after running a command

[Jim Meyering <jim@meyering.net>]

Junio C Hamano <gitster@pobox.com> wrote:
> Linus Torvalds <torvalds@linux-foundation.org> writes:
...
>> For example, then we could just do
>>
>> 	status = p->fn(...);
>> 	if (status)
>> 		return status;
>> 	/* Somebody closed stdout? */
>> 	if (fstat(fileno(stdout), &st))
>> 		return 0;
>> 	/* Ignore write errors for pipes and sockets.. */
>> 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
>> 		return 0;
>>
>> which makes it easy to explain what's going on, and avoids having any deep
>> indentation at all.
>
> I took the liberty of munging your two patches to follow your
> comments above

That has the disadvantage of ignoring *all* pipe and socket write errors.
IMHO, git would be better served if it didn't do that, since writing to
those can fail with EIO and even a new one: EACCES (though this latter
is only for sockets).  Also possible, according to POSIX: ENOBUFS.

Of course, one can probably argue that those are all unlikely.
They may be even less likely than an actual EPIPE, but the point is
that people and tools using git plumbing should be able to rely on
it to report such write failures, no matter how unusual they are.