bug#24201: 25.1.50; TLS connections sometimes hang

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: 24201@debbugs.gnu.org,  eggert@cs.ucla.edu
> Date: Thu, 27 Jun 2019 21:28:34 +0200
> 
> >>    (while (and (memq (process-status stream) '(open run))
> >>                (not (re-search-forward end-of-command nil t)))
> >>      (accept-process-output stream 0.05)
> >>      (goto-char start))
> >
> > Any idea why this loops?  Does the other end not respond or something?
> 
> I'm not sure -- I haven't been able to debug that at all.  Since C-g
> doesn't work (and it happens so rarely and I have to catch it before the
> peer hangs up), it makes it awkward...

You could try using debug-on-event in conjunction with SIGUSR1/SIGUSR2
to enter the debugger when you need.

> > Is inhibit-quit in fact nil or not inside this loop?
> 
> Looking at the code, I can't see any signs of it being inhibited here,
> but I'm waiting for the next time it happens so that I can inspect with
> gdb...

You could also add a call to 'message' in that loop to print the value
of the flag.