bug#56682: Fix the long lines font locking related slowdowns

[Eli Zaretskii]

> Date: Thu, 04 Aug 2022 10:33:48 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: gerd.moellmann@gmail.com, 56682@debbugs.gnu.org, 
> monnier@iro.umontreal.ca, 
>     dgutov@yandex.ru
> 
> I know next to nothing about bidi, so it's very well possible indeed that 
> I confused "bidi" and "composition" (or "bidi composition"?).  Anyway, 
> navigating through the locales.json file was slow (at some positions) 
> before the change and is now reasonably fast (but alas not instantaneous).
> 
> >
> > Are you saying that if you replace the Arabic text there with some other 
> > script that also requires composition processing (like one of the Indic 
> > scripts, see lisp/language/indian.el), editing this file is 
> > significantly faster?
> >
> 
> I think the locales.json file contains samples of pretty much all 
> available scripts.  Devanagari for example is around position 3260000. 
> As far as I can tell, navigating in that part of the file is not 
> significantly faster with the change.  It is only in the parts of the file 
> that contain e.g. Arabic text that the speedup is visible, around position 
> 70000 for example.

OK, I will take a look.

> > Btw, I'm unable to edit that file on the branch, because 
> > show-paren--default causes an assertion violation.  I'm pretty sure 
> > that's due to the issues in narrow-to-region that were already fixed on 
> > master.
> 
> I just merged master into the feature branch.

Thanks.