bug#34035: 26.1; Arabic shadda-kasrah renders incorrectly

[Stefan Kangas]

Stephen Berman <stephen.berman@gmx.net> writes:

> On Wed, 19 Aug 2020 09:01:06 +0100 "Basil L. Contovounesios" 
> <contovob@tcd.ie> wrote:
>
>> Stefan Kangas <stefan@marxist.se> writes:
>>
>>> So now Emacs 27.1 is released with harfbuzz support.  Could you please
>>> try this again using that and see if you can still reproduce this issue
>>> there?
>>
>> I can still reproduce all of the above on both emacs-27 and master:
>
> This seems to be a font issue independent of Emacs, e.g., I also see the
> same thing in LibreOffice Writer: with DejaVu Sans the kasrah is
> correctly displayed between the shadda and the seen, and with DejaVu
> Sans Mono, the kasrah is incorrectly displayed below the seen.

I can confirm that the font Emacs uses to correctly display this for me
in "emacs -Q" is:

ftcrhb:-PfEd-DejaVu Sans-normal-normal-normal-*-48-*-*-*-*-0-iso10646-1

I also tried LibreOffice Writer, fonts "FreeSans" and "DejaVu Sans Mono"
seem to be broken, while "DejaVu Sans" displays it correctly.

Does that mean that this is a bug/missing feature in the fonts, and not
in Emacs?

Best regards,
Stefan Kangas