Subject: bug#57804: An infinite loop in a `fontify-region' function causes Emacs to hang indefinitely

From: Lars Ingebrigtsen <[email-masked]>
Date: Wed, 14 Sep 2022 19:46:15 +0200

Eli Zaretskii <[email-masked]> writes:

> While testing my code? sure.  But after testing, no, the loops are
> generally gone.

Of course.  This is a real problem while developing font locking methods
(and usually not afterwards).