bug#62333: 30.0.50; Issue with tree-sitter syntax tree during certain changes

[Yuan Fu]

> On Mar 23, 2023, at 12:13 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> Date: Thu, 23 Mar 2023 06:20:19 +0200
>> Cc: Wilhelm Kirschbaum <wkirschbaum@gmail.com>, 62333@debbugs.gnu.org,
>> Eli Zaretskii <eliz@gnu.org>
>> From: Dmitry Gutov <dgutov@yandex.ru>
>> 
>> On 23/03/2023 05:03, Yuan Fu wrote:
>>> I suspect this has to do with the narrowed fontification we added for 
>>> dealing with long lines.
>> 
>> I'm pretty sure that one should only get used when the buffer contains a 
>> line longer than 10000 characters.
> 
> Yes (but I believe the threshold is 50K characters).
> 
> The narrowing must come from somewhere else.  Yuan, how did you see
> that ZV was changed?  Can you run with a breakpoint in
> Fnarrow_to_region, and see which Lisp code does that?

I did that, some observations:

1. This doesn’t reproduce on Linux (it does on Mac).
2. The function that narrowed the region is blink-matching-open
3. If I (advice-add 'blink-matching-open :around #’ignore) on my Mac, it 
“solves” the problem

I guess the question now is why redisplay is triggered in blink-matching-open 
on Mac?

Yuan