bug#56695: A new and old font problem with Arabic

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 25 Jul 2022 17:29:23 +0200 (CEST)
> From: "fr_ml@t-online.de" <fr_ml@t-online.de>
> Cc: "56695@debbugs.gnu.org" <56695@debbugs.gnu.org>
> 
> > This is expected: Emacs caches the results of previous text-shaping.
> > You should invoke
> > 
> >   M-: (clear-composition-cache) RET
> > 
> > to force Emacs to forget the old text-shaping results.
> If I have the positioning problem, this command doesn't solve it.

It doesn't always work, indeed.

> > > It works, Emacs uses the font correctly.
> > > And it seems that the positioning is then much better. The old problem is still there but not so often.
> > 
> > Does this mean we can close this bug?
> It's better but it's strange. And unfortunately  some years ago this
> problem wasn't there at all.

I'm guessing "some years ago" you used different versions of the same
fonts.  A font that was OK in the past could regress later.

For correct complex shaping, it is very important to find good fonts.
I suggest to look for a good Arabic font that is fixed-pitch, and use
it instead of DejaVu Sans.

> But it's ok.  We can close it.  Many thanks.

Done.