bug#24811: 26.0.50; backtrace

[Eli Zaretskii <eliz@gnu.org>]

> From: Mark Oteiza <mvoteiza@udel.edu>
> Date: Thu, 27 Oct 2016 21:16:56 -0400
> 
> 
> >From -Q:
> 
> 1. M-x eww RET https://marmalade-repo.org RET
> 
> The certificate is signed by Comodo, which is an untrusted CA on my
> system.  At this point, NSM pops up asking how I want to proceed.
> 
> 2. Wait for a while. A minute here is sufficient.
> 3. Hit s to allow the cert for the session only.
> 
> Emacs has now crashed:
> 
> #0  0x00007f8dc27ba04f in raise () at /usr/lib/libc.so.6
> #1  0x00007f8dc27bb47a in abort () at /usr/lib/libc.so.6
> #2  0x00007f8dc27f7c50 in __libc_message () at /usr/lib/libc.so.6
> #3  0x00007f8dc287ff17 in __fortify_fail () at /usr/lib/libc.so.6
> #4  0x00007f8dc287e050 in __readonly_area () at /usr/lib/libc.so.6
> #5  0x00007f8dc287fe8a in  () at /usr/lib/libc.so.6
> #6  0x0000000000595a43 in fd_ISSET (set=0xbfa8e0 <connect_wait_mask>, fd=-1)
>     at sysselect.h:72
> #7  0x0000000000595a43 in finish_after_tls_connection (proc=proc@entry=65073861)
>     at process.c:3102

Some async code doesn't make sure the TLS negotiation succeeded before
proceeding?  Look at "fd=-1" part in frame #6 above: it means the file
descriptor is invalid.

Thanks.