Re: display-supports-face-attributes-p question

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Sun, 29 Aug 2021 19:22:44 +0800
> 
> It appears that gui_face_attributes_p can't find properties differing
> between the :slant italic font and the default font; the EQ comparison
> at xfaces.c:5163 always evaluates to true.  What confuses me is how this
> is possible, as, if I understand correctly, (struct font *)->props
> should be populated by `make_font_object' from the contents of the
> entity, and if the font driver finds a font with :slant italic, the
> entity should also have it's slant set to italic.

When the call to lookup_face in gui_supports_face_attributes_p gets
into realize_gui_face, please show the results of

  (gdb) pp attrs[LFACE_FONT_INDEX]

before and after the call to font_load_for_lface in this snippet:

      if (! FONT_OBJECT_P (attrs[LFACE_FONT_INDEX]))
        attrs[LFACE_FONT_INDEX]
          = font_load_for_lface (f, attrs, Ffont_spec (0, NULL));