Re: problem with mh-e and 2002-08-20 change to font-core.el

[Richard Stallman <rms@gnu.org>]

    > font-lock-face properties go in mode-specific places.

    But do the properties belong to the text or to the mode.

I am not sure that question makes real sense, but the
font-lock-face property is not specific to any one mode.
The right font-lock-face properties for one mode are wrong
for some others.

    I have the impression that most of those font-lock-face properties
    are added together with the corresponding text and that they can't
    be recovered just from the text.  I.e. erasing them might not
    be the right thing to do since it loses information.

For Occur mode, this is correct.  Info mode automatically applies
the properties to the text.

With the current code, changing from Occur mode to Fundamental mode
and back to Occur mode would lose the font-lock-face properties.
That is a bug.

With the change you propose, changing from Occur mode to Fundamental
mode and then to Info mode would leave you with font-lock-face
properties left over from Occur mode.  That would be a bug.

Is there any way to make both cases work right?

    The "erase the font-lock-face property when changing-mode" hook you
    added is only added when you turn on font-lock-mode, so the
    font-lock-face property will stay if you don't turn on font-lock-mode
    before changing major-mode.

Now I understand.  Is there a method that fixes this too?