Re: [Emacs-diffs] master 05a5a94: Correct calculation of CC Mode's font-lock region.

[Stefan Monnier]

>> >     (c-extend-after-change-region): Explicitly apply 'fontified properties
>> >     to the extended bits of the font lock region.

>> Sounds like this is working around a problem elsewhere, so better add
>> a comment explaining what's going on.

> jit-lock-force-redisplay (that function which is set to run on the
> expiry of a 0 second timer, when jit-lock-fontify-now suspects that some
> area which has already been rendered requires to be re-rendered) doesn't
> seem to work.  At least, I couldn't get it to work.

That doesn't explain why you need to set the `fontified' property
manually, which is normally done by the code that runs
c-extend-after-change-region (via
font-lock-extend-after-change-region-function).

> f-l-extend-j-l-r-after-change has a recently fixed bug, where the
> extended region is only returned to the caller in certain circumstances.
> Those circumstances no longer hold in CC Mode.  To allow CC Mode to
> continue to work in already released Emacs versions, it is necessary to
> set the 'fontified text-property to nil from
> c-extend-after-change-region.

Ah, so that's what's going on.  This is the part that needs to be
documented in a comment (and I really mean a comment, not in a ChangeLog).


        Stefan