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

From: Gregory Heytings <[email-masked]>
Date: Mon, 15 Aug 2022 21:47:25 +0000

>>> FWIW, I strongly object to the addition of such a variable (unless it 
>>> is clearly stated that it is added temporarily and should not be used 
>>> except for testing purposes).
>>>
>>> Adding such a variable only two weeks after locked narrowing has been 
>>> introduced means that modes will have little incentive to adapt to 
>>> that stronger constraint, if they can "fix" whatever problems that 
>>> constraint might cause by setting that variable to nil in their 
>>> initialization hooks.
>>
>> I don't think major modes would take advantage of that var. I hope not, 
>> at least.
>
> I wouldn't mind because if things get slow, we get to point the finger 
> squarely at the culprit.
>

If it is clearly stated that it should only be used for testing/debugging 
purposes, yes.  Otherwise it's just another variable that anyone can use 
as they see fit.