From: Jeff King <peff@peff.net>
Date: Tue, 30 Mar 2010 22:56:29 GMT
Subject: Re: [PATCH] diff: fix textconv error zombies
Message-ID: <20100330225628.GB608@coredump.intra.peff.net>
In-Reply-To: <201003310017.24979.j6t@kdbg.org>

On Wed, Mar 31, 2010 at 12:17:24AM +0200, Johannes Sixt wrote:

> This could deadlock in the theoretical case that the read() in the parent 
> returns an error even though the child is still writing data; the child would 
> hang while waiting for the pipe being drained by the parent; but the parent 
> would wait for the child to exit, which never happens. Doing the close() 
> before finish_command() avoids this situation because the child dies of 
> SIGPIPE.

Yeah, I actually thought about that while writing the error case for
strbuf_read (I do close(child.out) before finish_command). But I didn't
consider it in the success case. I don't think it matters here because
we will already have gotten EOF from child.out, which should mean the
child is no longer writing and will not block.

So I am not sure there is any deadlock, but I am fine with your version
of the patch.

-Peff