bug#25864: 25.1; Incorrect rendering for Bengali compound character

[Mandar Mitra]

handa wrote (Mon, Feb 27, 2017 at 11:01:37PM +0900):
> Hi,
> 
> Which Bengali font are you using with Emacs?

Hi, I'm using Lohit Bengali. I have the following in my .emacs:

(set-fontset-font t (cons (decode-char 'ucs #x0980)
                          (decode-char 'ucs #x09ff))
                    (font-spec :name "Lohit Bengali" :size 16.0))

I also tried SutonnyBanglaOMJ and SoleimanLipi, both of which have the same 
problem. Please let me know if there's another font that I should try.

BTW, I tried this on Linux Mint 18.1 via a virtual machine, and observed the 
same problem. I can try this again and report the versions of libotf and 
m17n_flt if that helps.

Many thanks for your time!
-mandar.


> If you are not sure about it, please type C-u C-x = while putting point
> (cursor) on that incorrectly rendered Bengali character.  The *Help*
> buffer shows which font is used.
> 
> ---
> K. Handa
> handa@gnu.org
> 
> In article <83o9xqqofm.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:
> 
> > > Date: Sat, 25 Feb 2017 20:35:30 +0530
> > > From: Mandar Mitra <mandar.mitra@gmail.com>
> > > Cc: 25864@debbugs.gnu.org
> > > 
> > > Eli Zaretskii wrote (Fri, Feb 24, 2017 at 08:14:27PM +0200):
> > > > > Date: Fri, 24 Feb 2017 03:45:46 +0530
> > > > > From: Mandar Mitra <mandar.mitra@gmail.com>
> > > > > 
> > > > > The following Bengali compound character is not rendered correctly. 
> > > > > To reproduce, start emacs -Q, and type / paste from a character map 
> > > > > the following text:
> > > > > 
> > > > > ত্র (0x09A4, 0x09CD, Ox09B0) should be rendered as something that 
> > > > > looks similar to এ. 
> > > > > 
> > > > > This sequence is rendered correctly in LibreOffice, gedit, and 
> > > > > similar.
> > > > 
> > > > Can you show snapshots of the incorrect and correct rendering on your
> > > > system?
> > > 
> > > 
> > > Attached the compound character (pronounced tra) as rendered by emacs and 
> > > libreoffice.
> 
> > Thanks.
> 
> > On MS-Windows, I see the character rendered by Emacs as in your
> > LibreOffice snapshot.  So I think the problem is specific to libotf
> > and m17n_flt, or maybe you need to upgrade them to their latest
> > versions.
> 
> > I will CC Handa-san, who maintains m17n_flt, in the hope that he could
> > comment on the problem.
>