bug#51155: 29.0.50; Incorrect weight used in Cantarell VF

[Eli Zaretskii]

> From: Utkarsh Singh <utkarsh190601@gmail.com>
> Cc: 51155@debbugs.gnu.org
> Date: Thu, 14 Oct 2021 08:13:33 +0530
> 
> On 2021-10-13, 22:29 +0200, Lars Ingebrigtsen <larsi@gnus.org> wrote:
> 
> > Eli Zaretskii <eliz@gnu.org> writes:
> >
> >>> Weight table:
> >>> 
> >>> | Face       | Weight |
> >>> |------------+--------|
> >>> | Extra bold |    205 |
> >>> | Bold       |    200 |
> >>> | Regular    |     80 |
> >>> | Light      |     50 |
> >>
> >> I think that's the problem: Emacs thinks that Regular should have the
> >> weight of 100, see font.c.
> >
> > So this is basically bug#32210 again, I think?
> >
> > When we last discussed this (a couple years ago), I said I'd try to look
> > into this complex issue, so perhaps now's the time.  I'll start poking
> > at this morass tomorrow, I think.
> 
> For testing, I changed Regular to weight of 80 but Emacs is still
> loading the Light variant.

That's not necessarily enough, as there's more code involved here.

I think only stepping with a debugger through the relevant code will
tell us what happens and why.