bug#36171: 25.1; Emacs displays Hebrew text incorrectly

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: Raoul Comninos <revrari@mweb.co.za>,  36171@debbugs.gnu.org
> Date: Thu, 13 Jun 2019 18:07:06 +0200
> 
>     Eli> I don't see any such circles on my system.  I tried half a dozen
>     Eli> different fonts, and they all work correctly.  How many fonts did you
>     Eli> try?
> 
> I see circles on my GNU/Linux box, but only when using the xft font
> backend, eg the second character from the left (visually) on the
> 'Aoristic perfect' line. If I put
> 
> (add-to-list 'default-frame-alist '(font-backend xfthb))
> 
> in my .emacs, then everything displays correctly.

That's what I thought, thanks.  So these circles are a deficiency of
FLT shaping.

> I thought HarfBuzz was supposed to be preferred to xft?

It's supposed to, but, disappointedly,
https://lists.gnu.org/archive/html/emacs-devel/2019-06/msg00124.html
remains without a response, and therefore only the Windows build
currently prefers HarfBuzz.  I still hope Yamamoto-san will respond
and describe his proposal, and we could then implement the same
behavior on all platforms.