Subject: Re: bug#41005: problem with rendering Persian text in Emacs 27

From: Amin Bandali <[email-masked]>
Date: Tue, 21 Jul 2020 22:12:19 -0400

Eli Zaretskii <[email-masked]> writes:

>> From: Amin Bandali <[email-masked]>
>> Cc: Eli Zaretskii <[email-masked]>,  [email-masked],
>>   [email-masked],  Pip Cet <[email-masked]>
>> Date: Tue, 21 Jul 2020 13:53:25 -0400
>> 
>> Lastly, it might be worth mentioning that if I recall correctly, when
>> using xfthb with emacs-27, I observe the same issue.  Which may suggest
>> that perhaps the issue is related to Emacs's HarfBuzz support.
>
> But that's exactly the configuration that was fixed...
>

It is strange.  I did some more testing.  Whether with xfthb (emacs-27)
or ftcrhb (master), it seems like typing in Persian in *scratch* works
okay.  However, if I paste (yank) Persian text, e.g. from Wikipedia,
into *scratch*, the issue surfaces and yanked text is garbled.  Further,
Persian text in Gnus's article-mode and in message-mode is always
garbled to begin with.  It does seem like a HarfBuzz issue to me.
Please feel free to grab the Vazir font and test for yourself.

Hossein, do you also get this behaviour with Emacs's HarfBuzz?

Any other users using Emacs for Persian or Arabic?  I wonder if this
issue happens for other right-to-left languages, e.g. Hebrew.