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

[Dmitry Gutov]

On 17/12/2023 03:16, Yuan Fu wrote:
> +(defun treesit--pre-syntax-ppss (&rest _)
> +  "Force reparse and consequently run all notifiers.
> +
> +Similar to font-lock, we want to update the `syntax' text
> +property before `syntax-ppss' starts working on the text."
> +  (treesit--pre-redisplay)
> +  nil)

This callback might be the best place to inform syntax-propertize about 
the extended bounds which need to be re-parsed, so I'm not sure about 
Stefan's suggestion to return nil here.

Even calling syntax-ppss-flush-cache wouldn't be a full solution, 
because that wouldn't update the value of START in syntax-propertize.