From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shawn Pearce <spearce@spearce.org>
Subject: Re: [PATCH] http-backend: Don't infinite loop during die()
Date: Wed, 24 Mar 2010 13:25:36 -0700
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Cc: Junio C Hamano <gitster@pobox.com>,
	Brady Catherman <brady@catherman.org>,
	Git Mailing List <git@vger.kernel.org>
To: Nicolas Pitre <nico@fluxnic.net>
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On Wed, Mar 24, 2010 at 1:24 PM, Nicolas Pitre <nico@fluxnic.net> wrote=
:
> On Wed, 24 Mar 2010, Shawn O. Pearce wrote:
>
>> Junio C Hamano <gitster@pobox.com> wrote:
>> > "Shawn O. Pearce" <spearce@spearce.org> writes:
>> >
>> > > If stdout has already been closed by the CGI and die() gets call=
ed,
>> > > the CGI will fail to write the "Status: 500 Internal Server Erro=
r" to
>> > > the pipe, which results in die() being called again (via safe_wr=
ite).
>> > > This goes on in an infinite loop until the stack overflows and t=
he
>> > > process is killed by SIGSEGV.
>> > >
>> > > Instead set a flag on the first die() invocation and perform no
>> > > action during recursive die() calls. =A0This way failures to wri=
te the
>> > > error messages to the stdout pipe do not result in an infinite l=
oop.
>> >
>> > Hmm. =A0I would need something like this on top, but there must be=
 a better
>> > way. =A0Ideas?
>>
>> Ick.
>>
>> Just exit(0) if dead is true.
>
> Do you really want the exit code to be 0 if you're dying?

IIRC, yes.  If we exit non-zero Apache really freaked out.  That was a
big part of my motivation to write the die_webcgi handler.

--=20
Shawn.