gtk arabic colorings

[Ahmed El-Helw <ahmed at piousity dot net>]

alsalam 3ala man itaba3 al huda -
hope everyone is doing well.  i have been stuck for a while on this  
issue
and was wondering if anyone could suggest how to get this to work.  i am
trying to write a tajweed highlighting engine... in order to do so, i  
need to
be able to color certain letters in an ayah a different color.

the problem i am having is getting this to properly render in gtk.
i've tried two different approaches:

1. making two identical TextTags with nothing differing except the  
colors,
2. playing around with pango_parse_markup() and, for instance,  
GtkLabels to
    see if i could get anything to work.

with the first, i had total failure - the letters would come out  
separated [ie the shaping
would break].

with the second, it depends on what i did - if, for instance, i just  
did color span of the
first half the string to be blue and that's it, it appeared to  
perhaps work fine [i say it
"appeared to work fine" b/c at that size, its hard to really tell  
whether they are two
separate letters or are connected to each other, but they seem  
connected but am not
totally sure on that] -- but when i tried making the font larger, you  
could clearly see shaping broken.

i tried to email owen and ask him, and his response a few months ago  
was that it was
working as far as he knew and if i could write a c demo showing it to  
submit a bug to
bugzilla - i've done so recently and emailed him, but i take it he's  
really busy and so
hasn't gotten a chance to write back.  in addition, ppl on the gtk- 
app-devel list didn't
answer either.

if anyone can give me any sort of tip would be greatly appreciated.
thanks,
-ahmed