bug#53729: 29.0.50; Tamil text not shaped in modeline

[Visuwesh]

[சனி, பிப்ரவரி 19 2022] Eli Zaretskii wrote:

>> Date: Sat, 19 Feb 2022 10:23:32 +0200
>> From: Eli Zaretskii <eliz@gnu.org>
>> Cc: visuweshm@gmail.com, 53729@debbugs.gnu.org
>> 
>> Please try this much simpler reproducer:
>> 
>>   emacs -Q
>>   C-x b கட்டற்ற மென்பொருள் RET
>> 
>> At this point you should see a buffer whose name is "கட்டற்ற மென்பொருள்"
>> and whose mode line displays the buffer name correctly.
>> 
>>   M-: (set-buffer-multibyte nil) RET
>> 
>> Now the buffer's name should display incorrectly on the mode line.
>> 
>> IOW, the problem happens when the buffer is unibyte, probably because
>> we disable text shaping (a.k.a. "character compositions") in that
>> case.
>
> I hope I've now fixed this on the master branch, please test.

Can confirm that it is fixed.  Thanks a lot, Eli!