Re: Fwd: overlay face property not used for after-string property

[Richard Stallman <rms@gnu.org>]

    > The fix we are discussing will get rid of this problem, right?

    No, the problem with the before-string/display/after-string properties
    being affected by a face from the buffer appears to be a completely
    unrelated issue which will need to be debugged separately.

I see.  We have one problem with overlay properties, and
another with text properties.

I think I just fixed the most of the problem for overlay properties.
Now overlay before-strings and after-strings should be unaffected by
the face properties of all overlays.  They are, however, affected
by `face' text properties and by region highlighting.

It is not 100% clear that that is correct; you might want a longer
overlay's `face' property, or a higher priority overlay's `face'
property, to affect the before-strings and after-strings of smaller
overlays.  That seems like somewhat of a can of worms.  The rule I
implemented is simple and clear.

Do you agree?  And do you get good results from the fix?
(It is in Emacs 22.)

Do you think the same rule is right for display property strings that
come from overlays?  That is, obey `face' text properties, but not
`face' overlay properties?

Once we are sure what is right for overlay properties, I will start
dealing with the text property effects.