bug#64270: 30.0.50; Font update for no toolkit menu

[Eli Zaretskii <eliz@gnu.org>]

> From: Manuel Giraud <manuel@ledu-giraud.fr>
> Cc: 64270@debbugs.gnu.org
> Date: Tue, 27 Jun 2023 18:07:33 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Manuel Giraud <manuel@ledu-giraud.fr>
> >> Cc: 64270@debbugs.gnu.org
> >> Date: Tue, 27 Jun 2023 16:13:15 +0200
> >> 
> >> Eli Zaretskii <eliz@gnu.org> writes:
> >> 
> >> > If this is not what you meant, then how would Emacs know which font to
> >> > select for menus when the default face's font is changed?
> >> 
> >> For my usage, I imagine that yes the menu font would change when I
> >> change the frame's default face.  But this because my menu face is
> >> already derived from the default face.
> >> 
> >> For the general usage, my idea (and what I start doing in my patch, see
> >> my first message) is to query the MENU_FACE_ID.  So the font into the
> >> menus would change if the user modify its menu face.
> >
> > This is a misunderstanding: I didn't ask what would be the trigger to
> > change the font.  I asked how would Emacs know _which_ font to choose
> > for the menus?
> 
> I also am not sure I understand.  I don't think that Emacs has to choose
> a font here.  It would use the font used for the menu face.  What am I
> missing?

How is this different from what happens today?