Subject: Re: bug#50660: 28.0.50; Text artifacting when the cursor moves over text under mouse face that originally displayed a box

From: Eli Zaretskii <[email-masked]>
Date: Sat, 16 Oct 2021 09:09:34 +0300

> From: Po Lu <[email-masked]>
> Cc: [email-masked],  [email-masked]
> Date: Sat, 16 Oct 2021 08:18:25 +0800
> 
> Eli Zaretskii <[email-masked]> writes:
> 
> > This part doesn't look right to me: FACE_FOR_CHAR could potentially
> > yield a face with a different font, but the glyph codes in the glyph
> > string will reference the previous font, because
> > get_glyph_face_and_encoding was called before the face was changed.
> 
> But now that I think of it, what if the original font has different
> metrics than the mouse face?  In that case, shouldn't s->font be the
> original font and not the font of the mouse face?  Thanks.

I don't think I follow: what is "the original font" in this context?
And when you say "shouldn't s->font be", do you mean what it should be
before or after the processing in fill_glyph_string?