bug#18367: 24.4.50; [PATCH] Text property `font-lock-ignore', to protect from font-lock

[Drew Adams]

> > > Bug or missing feature: Prevent font-lock from changing text
> > > properties on text that has property `font-lock-ignore'.  See
> > > http://lists.gnu.org/archive/html/emacs-devel/2014-
> > > 08/msg00540.html
> >
> > Could you add a short explanation for why font-lock-face is
> > not sufficient?
> 
> I'm not sure about that question.  But I see a problem in cases
> where packages use the 'face property without using font-lock...
> and other packages come and invoke font-lock in such a buffer....
> In such a case, all the fontification with 'face is erased.
> 
> I guess it is an error to use 'face in any buffer that could become
> subject to font-locking caused by some mode or package.  If that's
> the case - if it is recommended to use font-lock-face in all these
> situations, we should say in the manual that 'face is dangerous to
> use in such situations: (info "(elisp) Special Properties")

It should not be "an error" to use `face' in a font-locked buffer.

That's precisely the problem, IMO: Font-lock has taken over property
`face'.  That's not right.  It does not (should not) own `face'.
There should at least be a simple way to say "Hands off this
occurrence of `face'!"