[PATCH] Recompute glyph metrics when face changes
Kirill 'Big K' Katsnelson writes:
Unfortunately, it is not quite possible to update more specific
glyphs when a face changes. Even if faces tracked glyphs which
have this face as their face, it would not be possible to notice
glyph change when this face changes through inheritance. So I
update a glyph instance in a window when both frame faces marked
as changed and glyph instance in the window is text.
An image instance might be invalidated by a face change also.
For instance XPM images can have a transparent background and
therefore inherit their background color from the glyph's face.
So this is a general problem that we have to solve.