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

From: Eli Zaretskii <[email-masked]>
Date: Mon, 01 Sep 2014 22:08:03 +0300

> From: Wolfgang Jenkner <[email-masked]>
> Date: Mon, 01 Sep 2014 20:45:58 +0200
> Cc: [email-masked]
> 
> On Sun, Aug 31 2014, Drew Adams wrote:
> 
> > (elisp) `Other Font Lock Variables' says this about it:
> >
> >  Variable: font-lock-extra-managed-props
> >  This variable specifies additional properties (other than
> >  `font-lock-face') that are being managed by Font Lock mode.  It is
> >  used by `font-lock-default-unfontify-region', which normally only
> >  manages the `font-lock-face' property.  If you want Font Lock to
> >  manage other properties as well, you must specify them in a
> >  FACESPEC in `font-lock-keywords' as well as add them to this list.
> >  *Note Search-based Fontification::.
> 
> I think `font-lock-face' is a typo here (it should read `face').
> 
> It is clear from looking a the code (or doing some experiments) that
> font-lock-default-unfontify-region doesn't remove the `font-lock-face'
> property.

The "it" in that text alludes to font-lock-extra-managed-props, not to
font-lock-face.  After all, the former is what is being documented in
the text you cited; the latter is just mentioned because
font-lock-face is another kind of specification of "additional"
properties of interest to Font Lock.