Subject: Re: 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 19:25:49 +0200

Paul Pogonyshev <[email-masked]> writes:

>> For instance, if the user hits `C-g' three times (and Emacs doesn't idle
>> in between), then we disable font-lock in that buffer.
>
> That sounds much better. I know that `C-g' is what to press when Emacs
> is stuck.

A single `C-g' wouldn't be quite the right thing, because the user may
hit `C-g' by accident while font-lock happens to run (and it's not
hanging), which is why I though a special key sequence like `C-g C-g
C-g' might make sense.

>> There's also `max-redisplay-ticks' -- but I'm not sure that would have
>> helped here?
>
> If I add `(setf max-redisplay-ticks 100)' right after entering
> `buggy-mode', it seems to have some effect, but not exactly what I'd
> hope on. I suggest you try and see for yourself, hard to describe
> them.

Doesn't seem to have any effect here...