bug#21602: 25.0.50; coding system seg fault

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: 21602@debbugs.gnu.org,  rms@gnu.org
> Date: Sat, 03 Oct 2015 14:48:26 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > In this case, we set it programmatically, so the user could rightfully
> > blame us.
> 
> The only one to blame is the one who sets coding-system-for-read.

Indeed.  But that one could be some Lisp about which the user has no
intimate knowledge.