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

[Jan Djärv]

Hello.

7 sep 2013 kl. 10:40 skrev Eli Zaretskii <eliz@gnu.org>:

>> From: Jan Djärv <jan.h.d@swipnet.se>
>> Date: Sat, 7 Sep 2013 10:27:45 +0200
>> Cc: xfq.free@gmail.com,
>> 15273@debbugs.gnu.org
>> 
>> But from what I see on X11 and what you reported from W32, no other platform 
>> does produce the correct result (i.e. the ! and the triangle in the same 
>> place), so comparing to those backends doesn't help.
> 
> In that case, yes, I think we can conclude that there's no Emacs
> issue.  

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). 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.

So it is too early to dismiss this as not an Emacs issue.

> But Xue now seems to say that there are other similar
> situations with other combining characters, so we need to know if any
> compositions are involved in those.

The exact key sequences that produced them would help also.

        Jan D.