Re: Crash with --enable-checking and some glyphs

[Eli Zaretskii]

Ping!  Can you please show the information I asked for?  I'd like to
find a solution to this problem.

> Date: Fri, 26 Nov 2021 18:27:59 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: rpluim@gmail.com, emacs-devel@gnu.org
> 
> > From: Lars Ingebrigtsen <larsi@gnus.org>
> > Cc: rpluim@gmail.com,  emacs-devel@gnu.org
> > Date: Fri, 26 Nov 2021 16:04:57 +0100
> > 
> > Eli Zaretskii <eliz@gnu.org> writes:
> > 
> > >     if (pcm)
> > >       {
> > >         it->phys_ascent = pcm->ascent + boff;
> > >         it->phys_descent = pcm->descent - boff;
> > >         it->pixel_width = pcm->width;
> > >
> > > please tell what are the values of pcm->ascent and pcm->descent.
> > >
> > > I want to know whether the font is the culprit or some code of ours
> > > overrides the value from the font.  Then we can devise the solution.
> > 
> > gdb) next
> > 30909                     it->phys_ascent = pcm->ascent + boff;
> > (gdb) p pcm->ascent 
> > $1 = 18
> > (gdb) p pcm->descent 
> > $2 = -3
> 
> So the glyph metrics also report a negative descent.
> 
> But what about the font?  We don't use the above for it->descent, at
> least not directly.  So where in the code did it->descent get
> negative?