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

From: Gregory Heytings <[email-masked]>
Date: Tue, 16 Aug 2022 08:12:55 +0000

>>>> There have been many more complaints about being unable to edit a 
>>>> file with a 5000+ line comfortably, than about editing 100+ MB files.
>>>
>>> Also because we have things like so-long to handle the large file 
>>> case.
>>
>> These things are expedients for want of anything better, aren't they?
>
> Yes, just like the narrowing your use in your long lines patch.
>

That's... unfair.  These things turn off everything (in particular, the 
major mode and font locking) and provide a bare-bones editing experience. 
What we'd like now is to provide Emacs users a near-complete editing 
experience in all buffers.

>
> They're slightly different in that they don't try to prevent replacing 
> those solutions with something better (or worse), tho.
>

When one looks at things from far enough, everything is indeed "slightly 
different" from everything else.  For example, the Statue of Liberty is 
"slightly different" from Empire State Building.