bug#18438: 24.4.50; assertion failed in bidi.c

[Eli Zaretskii]

> Date: Wed, 24 Sep 2014 12:40:31 -0400
> From: Ken Brown <kbrown@cornell.edu>
> CC: aidalgol@amuri.net, 18438@debbugs.gnu.org,
>         Daniel Colascione <dancol@dancol.org>
> 
> > What is the backtrace of the other threads?
> 
> Attached.

Nothing stands out.

> I have one thought: You've mentioned before the possibility that this 
> problem is caused by interference from other threads.  The one thread 
> that exists in the Cygwin-w32 build but not in other Cygwin builds is 
> the one used for the Windows message queue. (Thread 5 in the attached 
> backtrace).  I'm not familiar with the code involving the message queue, 
> but is it possible that this code is not thread safe in the 64-bit 
> Cygwin build?

I will try to look at that code, although I'm not very familiar with
it.

Also note that if there's some problem with that code, I'd expect the
users of the native MinGW64 build to bump into it.