Re: t5401-update-hooks test failure

> Junio C Hamano <gitster@pobox.com> wrote:
> > $ while sh t5401-*.sh -i; do :; done
> > ... wait for a while ...
> > * FAIL 12: send-pack stderr contains hook messages
> > 
> >                 grep ^remote: send.err | sed "s/ *\$//" >actual &&
> >                 test_cmp - actual <expect
> > 
> > $ t/(364643e...); cat trash\ directory.t5401-update-hooks/actual 
> > remote: STDOUT pre-receive
> > remote: STDERR pre-receive
> > remote: STDOUT update refs/heads/master
> > remote: STDERR update refs/heads/master
> > remote: STDOUT update refs/heads/tofail
> > remote: STDOUT post-receive
> > remote: STDERR post-receive
> > remote: STDOUT post-update
> > remote: STDERR post-update
> > $ t/(364643e...); cat trash\ directory.t5401-update-hooks/expect 
> > remote: STDOUT pre-receive
> > remote: STDERR pre-receive
> > remote: STDOUT update refs/heads/master
> > remote: STDERR update refs/heads/master
> > remote: STDOUT update refs/heads/tofail
> > remote: STDERR update refs/heads/tofail
> > remote: STDOUT post-receive
> > remote: STDERR post-receive
> > remote: STDOUT post-update
> > remote: STDERR post-update
> 
> A quick visual inspection shows that only the STDERR tofail message
> is missing here.  That sounds to me like a race condition in the
> recv_sideband decoder.  Or, a race condition in the hook code in
> builtin-receive-pack.c.
> 
> I doubt its in receive-pack. run_update_hook() directly calls the
> copy_to_sideband() function, and that reads until EOF on the hook's
> stderr stream before it returns and waits for the hook's exit status.
> So we should be pulling everything and dumping it into the sideband.
> 
> builtin-send-pack.c clearly isn't stopping early while processing
> the stream, since we see later messages from the post-receive and
> post-update hooks just fine.
> 
> So I think the only code that is in question is the case 2 arm of
> recv_sideband().  But to be honest, I can't find any fault with it.