ZWJ/ZWNJ in Pango for Devanagari/Arabic

[Chookij Vanatham <chookij vanatham eng sun com>]

Hi Owen,

After I took a look at both Arabic and Devanagari Pango Engine,
they are not considering the case of ZWJ and ZWNJ for their shaping.

As we know that, in unicode standard, we are able to use ZWJ and
ZWNJ to control the shaping of scripts, particularly, Arabic and
Devanagari. I'm wandering that how it can be done in Pango design
because Arabic/Devanagari Pango engines themselves won't get called
for the ZWJ/ZWNJ ?

Regards,

Chookij V.