bug#61091: 30.0.50; y-or-n-p clobbers match data

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Cc: rms@gnu.org,  61091@debbugs.gnu.org
> Date: Fri, 27 Jan 2023 15:38:14 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > y-or-n-p originally was implemented in C and was relatively simple.
> > Since then it was moved to Lisp and became a monster, see subr.el.  It
> > is anyone's guess where in that code we clobber the match data.
> 
> I see that the code calls `substitute-command-keys' which potentially
> changes match data.

Yes, that's also my prime suspect.