bug#50339: master creashed in compact_small_strings

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Cc: 50339@debbugs.gnu.org
> Date: Mon, 06 Sep 2021 23:17:39 -0400
> 
>   > Yes, that's one thing that crossed my mind.  Did you have hardware
>   > problems on this machine in the past?
> 
> Yes, though I don't know if they involved incorrect execution on the CPU.
> I have no evidence for that specific kind of problem.

A memory-related problem could also explain that.