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

[Jan Djärv]

Hello.

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

>> From: Jan Djärv <jan.h.d@swipnet.se>
>> Date: Sat, 7 Sep 2013 10:02:44 +0200
>> Cc: xfq.free@gmail.com,
>> 15273@debbugs.gnu.org
>> 
>>>>> So I'm not sure what are we still discussing here, since the quality
>>>>> of fonts on any given platform is hardly on-topic in the bug tracker,
>>>>> and the NS font driver is not part of Emacs.
>>>> 
>>>> nsfont.m:
>>>> 
>>>> Copyright (C) 2006-2013 Free Software Foundation, Inc.
>>>> 
>>>> This file is part of GNU Emacs.
>>> 
>>> The OP said that he tried many fonts, and none worked correctly.
>> 
>> So what?  The NS font driver is still part of Emacs even if it has bugs.
> 
> What kind of bugs do you have in mind?  If the characters aren't
> composed, then the only bug I can think of is that nsfont.m somehow
> processes the character metrics in the font incorrectly.

Which is what I said was happening in comment #11.

>  To test this
> hypothesis Someone(TM) should show the character metrics using some
> external tool, and compare that with what nsfont.m calculates.  Or,
> alternatively, show that exactly the same font does produce a correct
> display on another platform; then we could compare the two font
> back-ends we have for these platforms.

nsfont.m has problems with composition, there is even comments about this in 
the code.
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.

> 
> As long as none of this is done, adding more pictures to this
> discussion doesn't help us make any progress.  And I cannot understand
> why requests for showing "C-u C-x =" are consistently ignored by the OP.

Adding more pictures does indeed not help much.

        Jan D.