Re: delphi-other-face mismatch

[martin rudalics]

Thanks for the patient explanations.

>       If FACE is empty the display engine interprets the semantics of
>     FACE
>
> I am not sure what situation you're talking about.  Where in the data
> structure was nil encountered?

I needlessly complicated things here.  All I wanted to say is that the
display engine handles

(defface face nil
  "Nil face.")

(put-text-property (line-beginning-position) (line-end-position) 'face 'face)

and

(put-text-property (line-beginning-position) (line-end-position) 'face nil)

much the same way.

>     The first three don't address the problem that nil is not a valid value
>     for a variable storing FACE.  The fourth does but I can't imagine how to
>     implement it.
>
> How about this?
>
> (defface nil nil
>   "Face which specifies no attributes."
>   :group 'basic-faces)

The problem is that routines dealing with faces seem to interpret nil in
a special way.  On my Emacs having a face nil may break `customize-face'
with point before a default face character.  In this case customize-face
proposes as default "nil" instead of "all faces".  Customizing nil gives
me a strange empty "*Customize Faces*" buffer.

Moreover `describe-face' sometimes describes the face nil when there are
other face properties for the character after point.  Probably these
behaviors could be resolved easily within `read-face-name' - if someone
can reproduce them.