Re: bug#55745: [PATCH] Add support for the Hanifi Rohingya script

[Eli Zaretskii <eliz@gnu.org>]

> From: समीर सिंह Sameer Singh <lumarzeli30@gmail.com>
> Date: Wed, 1 Jun 2022 18:55:17 +0530
> Cc: emacs-devel@gnu.org
> 
>  Does the font you use support those characters?  Does it support Tamil
>  in general?
> 
> Yes the font supports the supplement characters, but does not support Tamil in general.

Then I think this is the problem.  Tamil requires special support from
the font, as evidenced by this snippet from fontset.el:

     (tamil ,(font-spec :registry "iso10646-1" :otf '(tml2 nil (akhn)))
            ,(font-spec :registry "iso10646-1" :otf '(taml nil (akhn))))

As you see, we request special OTF features, and thus by default will
not accept a font that doesn't have them.  You can override that by
customizing the fontset via set-fontset-font.

Are you aware of any good Tamil fonts that support the Tamil
Supplemental block?  I don't seem to be able to find any such fonts.

>  > I even added a separate tamil-supplement script to (script-representative-chars) but nothing worked.
> 
>  There's no tamil-supplement script, though.
> 
> Unicode defines one, but AFAIK Emacs removes the "supplement" word from these characters. I think it is
> defined in admin/unidata/blocks.awk 

Yes, that's what produces charscript.el.