bug#21846: 25.0.50; emacs hebrew script bidi nikud rendering bug

[Benjamin Riefenstahl <b.riefenstahl@turtle-trading.net>]

Mark David writes:
> The nikud placement is good to excellent in the fonts tried so far.

Thank you for confirming that.

> However, I tried a few more, and found one that's terrible: Aharoni
>
> This font seems to systematically misplace not all but most base char
> + nikud combinations in my sample file.  (Screen shot attached.)  Any
> way to fix this?

When I install this from the package manager, I get a PostScript font,
not a TrueType font (you can verify that yourself with "fc-list 'Aharoni
CLM' file").  I don't know how PostScript fonts are handled by Emacs.
But, not surprisingly, it does not go through the FLT file that we have
been hacking on so far.

Note that AFAIK, PostScript fonts do not have the kind of metadata that
is needed for positioning individual glyphs as OpenType has, so all the
functionality comes from code.  Still, Harfbuzz can do it, so in
principle, Emacs can, too.  ;-)