bug#36171: 25.1; Emacs displays Hebrew text incorrectly

[Eli Zaretskii]

> Cc: 36171@debbugs.gnu.org, YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
> From: Raoul Comninos <revrari@mweb.co.za>
> Date: Thu, 13 Jun 2019 20:39:10 +0200
> 
> I have tried out several different fonts but there is no change to the 
> problem.
> 
> I still see the circles.

That's because your Emacs uses the XFT/FLT shaping, not the HarfBuzz
shaping.

Try starting Emacs like this:

  emacs -Q -xrm Emacs.fontBackend:xfthb

and then see if the problem goes away.  You should see "xfthb" in the
"C-u C-x =" display, here you currently see "xft":

>    xft:-unknown-DejaVu Sans-normal-normal-normal-*-26-*-*-*-*-0-iso10646-1
     ^^^

> I added (add-to-list 'default-frame-alist '(font-backend xfthb)) to my 
> .emacs file, but this made no difference.

My crystal ball says that you added that too late in the init file.
You must do this at the very beginning.

In any case, for whatever reason, your Emacs still uses the XFT font
backend, not the HarfBuzz-powered xfthb.  I believe that's why you see
the circles: FLT doesn't support composition of the characters from
the Alphabetic Presentations Forms block.