bug#66732: tree-sitter fontification doesn't update multi-line syntax reliably

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: dmitry@gutov.dev,  66732@debbugs.gnu.org,  dominik@honnef.co,
>   casouri@gmail.com
> Date: Wed, 20 Dec 2023 15:50:21 -0500
> 
> >> I think Dmitry is talking about the case where the faces were change
> >> after the text was rendered (but before the end of the redisplay cycle).
> >> 
> >> I.e. the redisplay starts, renders up to position POS, then calls
> >> jit-lock because `fonfitied` is nil, and jit-lock modifies faces of text
> >> *before* POS.
> >
> > This can only happen if a function called from jit-lock doesn't comply
> > to the protocol wrt such changes, right?
> 
> I'm talking about a problem in the interaction between the redisplay
> a jit-lock itself.
> 
> Jit-lock is aware of it and uses `jit-lock-force-redisplay` as needed to
> account for it.
> 
> > Because otherwise the modified region would have been re-rendered on
> > the next redisplay cycle at the latest.
> 
> Yes, if the jit-lock client (e.g. font-lock) follows the protocol, then
> jit-lock should take care to re-render the regions when/where needed.
> 
> *Except* that the implementation of `jit-lock-force-redisplay` is
> not effective and needs a change like the one suggested by Dmitry.

So can we install that change and close this bug, then?