Re: Is it ok to sort a list of overlays destructively?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 29 Jul 2021 09:20:21 -0700
> From: 2QdxY4RzWzUUiLuE@potatochowder.com
> 
> > Because anything else is a bug, for the same reason that you
> > rightfully expect Emacs not to crash when some Lisp program does
> > something silly.
> 
> That's very thought provoking.  Thank you.
> 
> If I believe (and maybe I'm old!) that "Emacs is the extensible,
> customizable, self-documenting, real-time display editor," then I
> wouldn't be surprised at all if some Lisp program caused Emacs to crash.
> After all, those Lisp programs have [a great deal of] access to Emacs'
> internals.

Access to the internals is protected by validity checks that signal
Lisp-level errors instead of letting Emacs crash.  Emacs crashing is a
bad problem because you lose your editing session, so Emacs strives to
avoid crashing.

About the only thing I know of that a Lisp program can do to crash
Emacs is to trigger infinite recursion, and even that has protection
in Emacs, albeit not 100% reliable.