bug#73752: 29.4; Ligatures are randomly rendered with extra spaces

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 27 Oct 2024 13:46:55 -0400
> Cc: visuweshm@gmail.com, luangruo@yahoo.com, 73752@debbugs.gnu.org
> From: Yixuan Chen <xuan@xlk.me>
> 
> > Sorry, I still don't understand.  Your code does
> > 
> >    (highlight-lines-matching-regexp (cdr face) (car face))
> > 
> > This potentially shows each line in a different face, and thus can
> > affect the metrics of the SPC character glyph which is what the
> > indentation is made of.  So why is this a problem, let alone a bug?
> 
> The problem is executing that line at 10PM today may render the font one 
> way, while executing that line at 6AM tomorrow (with exactly the same 
> "face" variable) may render the font a different way, even if all the 
> other variables remains the same.

But you modify the faces in a random fashion, so why is this a
surprise that it is not deterministic?