bug#15273: 24.3.50; Combining character sequences are displayed weirdly

[Jan Djärv]

Hello.

7 sep 2013 kl. 11:59 skrev Eli Zaretskii <eliz@gnu.org>:

>> From: Jan Djärv <jan.h.d@swipnet.se>
>> Date: Sat, 7 Sep 2013 10:54:58 +0200
>> Cc: xfq.free@gmail.com,
>> 15273@debbugs.gnu.org
>> 
>> Except the larger bug that Emacs does not handle combining characters 
>> correctly in the general case, i.e. not combining the ! and the triangle on 
>> X11 and W32 (and Mac port).
> 
> Is there any application out there that does combine these 2
> characters, with any font?  If not, perhaps it's not an Emacs issue
> after all.

Yes, the builtin TextEdit application does it.

> 
> E.g., Code2000, which is really good, produces a composed character
> for a followed by u+20d0, but not for a followed by u+20e4.  You can
> experiment with other combining diacriticals from that Unicode block,
> and you will see that some of them combine, while others do not.
> 
> If the fonts do not tell us to combine characters, the only way to do
> that is to provide an Emacs composition rule for those characters.
> 
>> And if it is a bug in the NS font driver, that is also an Emacs issue.  
>> There must be one, either metrics should be corrected or the NS font driver 
>> should be modified to behave in the same (incorrect) way as the other 
>> platforms.
> 
> If you mean the incorrect display of the lone u+20e4, then I just
> installed the STIX fonts (from
> http://sourceforge.net/projects/stixfonts/files/?source=navbar) on my
> Windows box, and didn't see any problems as originally reported here.
> Can you install the latest STIX fonts and try with that on NS?  If the
> problem persists, then I agree that nsfont.m is probably the culprit.

The behaviour iis the same with that STIX version as it is with the OSX 
supplied STIX version.

        Jan D.