Re: process_send_string blocks?

[Eli Zaretskii]

> From: Stephen Leake <address@hidden>
> Date: Sun, 07 Sep 2014 03:21:24 -0500
> 
> Eli Zaretskii <address@hidden> writes:
> 
> >> From: Stephen Leake <address@hidden>
> >>
> >> I have a reliable reproducer, which I can easily simplify.
> >
> > Please do simplify it and post it.  Having a way of debugging this by
> > several people will definitely make the process more efficient, and
> > probably produce a higher quality solution.
> 
> Posted bug#18420. Unfortunately, when I simplify the external process
> code, the hang goes away; I don't understand why, yet. 

Too bad it cannot be simplified.

> In general, nothing the external process does should hang Emacs, short
> of crashing the OS.

Not sure what you are saying here.  How can a crashing OS hang Emacs?

> > Btw, do you see the problem in "emacs -Q"?
> 
> Yes, but only with the full external process code and full Ada mode
> code.

So you are saying that sending text to the subprocess somehow depends
on the major mode?  That'd be surprising.

> I did manage to attach a debugger to the running processes; that's a
> first for me :). It was useful for the Ada code (compiled with debug
> info), but not for the Emacs process; it says the stack is corrupted.

See my response to the bug report: most probably, you are running an
optimized binary, where backtraces blatantly lie.