bug#69431: 30.0.50; Strange fontificaion behavior

[Eli Zaretskii]

> From: Andrea Corallo <acorallo@gnu.org>
> Cc: Björn Bidar <bjorn.bidar@thaodan.de>,
>   hirofumi@mail.parknet.co.jp,
>   69431@debbugs.gnu.org,  yantar92@posteo.net
> Date: Sun, 24 Mar 2024 05:12:17 -0400
> 
> >> Meanwhile Björn could you try reverting cf11fdfd8e46 and report if fixes
> >> for you as well?
> 
> I'm trying to progress on this but I've difficult time at getting a grip
> on this bug.  One of the reason why is that on my reproducer Emacs
> doesn't crash nor complain, the other reason is that I'm not really into
> our fontification.  I'll keep on looking into it but I'd appretiate any
> hint like: what should be happening to fontify the buffer that is not
> actually happening here?  With such info I could try investingating the
> issue from there comparing with the working case.

Maybe Stefan (CC'ed) could help in that matter?