Re: master 2399541: Remove font-lock toggle from font-lock-update

[Gregory Heytings]

> FWIW, I'm not sure if `font-lock-update` (ether it's Paul's or the 
> other) is really better than the old `font-lock-fontify-block`.  I think 
> they all suffer from being fundamentally "defined by their 
> implementation" making it hard to evolve when some change is made to the 
> font-lock machinery.

Hmmm...  You said: "`font-lock-fontify-region` is an important function 
internally (it's the one and only function which performs font-locking, 
fundamentally)".  Is it wrong to use it nonetheless?

> I'd much prefer a longer `font-lock-fontify-diwm` which tries to 
> reproduce more or less the same behavior as your favorite, but by 
> explicitly testing the different circumstances you care about.

Could you perhaps give an example of such a circumstance and its 
corresponding action?