bug#11860: 24.1; Arabic - Harakat (diacritics, short vowels) don't appear

[Eli Zaretskii]

> From: Kenichi Handa <handa@gnu.org>
> Cc: eliz@gnu.org,jasonr@gnu.org,11860@debbugs.gnu.org,smias@yandex.ru
> Date: Wed, 29 Aug 2012 17:09:49 +0900
> 
> In article <177391346101857@web27f.yandex.ru>, Steffan <smias@yandex.ru> 
> writes:
> 
> > I've just tested it. It's different. But it doesn't work correctly.
> > In the arabic-input-method 
> 
> > h-X-SPACE-h works fine, 
> > but h-X-h doesn't work, the Sukkun disappears.
> 
> I also tested with the following windows binary
> (emacs-trunk-r109787-bin-w32-i386.zip) and confirmed the problem:
> 
> In article 
> <CAH8Pv0g81jwWvQJ1xjmnU=8DU8+h+Sb6TbMP_xfHhwiqYatO-w@mail.gmail.com>, Dani 
> Moncayo <dmoncayo@gmail.com> writes:
> > I've just uploaded a w32 binary (from today's trunk):
> >   https://www.dropbox.com/sh/7jr3vbv9tm1zod0/jPuvfrJAe8
> 
> I evaluated the attached funcion in *scratch* buffer and it
> returned this string on Windows.
> 
> "  [0 1 1575 909 18 7 10 25 8 nil]
>   [0 1 1575 760 0 7 11 25 8 [-1 1 0]]
> 
>   [0 1 1575 909 18 7 10 25 8 nil]
>   [0 1 1575 760 0 7 11 25 8 [-19 1 0]]
> 
> "
> 
> The second GLYPHs in the first and second GSTRINGs are
> different.  On GNU/Linux, they are the same, which should be
> the correct behaviour.

The problem was that the code I committed didn't expect to handle more
than a single grapheme cluster.  I now fixed that code for the case of
several grapheme clusters that are handed to the shaper all at once.
With the modified code (trunk revision 109842), both Steffan's recipe
and the check-arabic-shaper function work correctly.  Please test.

Thanks.