bug#18420: 24.3; interaction with external process hangs emacs

[Eli Zaretskii]

> From: Stephen Leake <stephen_leake@stephe-leake.org>
> Cc: 18420@debbugs.gnu.org
> Date: Tue, 09 Sep 2014 16:48:26 -0500
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Anyway, it turns out we can make our pipes non-blocking on write,
> > which then allows us to use the EWOULDBLOCK/EAGAIN handling in
> > send_process.  Please try the patch below, and if it gives good
> > results, I will install it shortly.  
> 
> Yes, it fixes the problem.

Thanks, I installed this on the emacs-24 branch.