Bug in anchor placement with ligatures in Indic (Devanagari).

[Manjunath Sripadarao <manju paqrat com>]

Hello,
   I am trying to design an opentype Indic font devanagari. I am using 
pango + gedit for testing. There is a bug when placing
a certain anchor mark with ligatures. In my font, I am placing an anchor 
onto a ligature like this
http://www.ece.uic.edu/~msripada/delme/3-1.png
and this should actually appear like this (this is wrong but it is to 
illustrate the problem)
http://www.ece.uic.edu/~msripada/delme/3-2.png.
It actually appears like this in gedit + pango
http://www.ece.uic.edu/~msripada/delme/3-3.png

Note as I move the anchor upwards it seems to be rendered in pango 
progressively lower.
http://www.ece.uic.edu/~msripada/delme/4-1.png
http://www.ece.uic.edu/~msripada/delme/4-2.png
http://www.ece.uic.edu/~msripada/delme/4-3.png

This seems to happen only with ra_vattu, the other marks are rendered 
correctly, so I think this has something
to do with the way pango handles the 'vatu' opentype feature. But I am 
just guessing.
For further information, I have uploaded the font and it's source at
http://www.ece.uic.edu/~msripada/delme/dvng10a.sfd.bz2
http://www.ece.uic.edu/~msripada/delme/Devanagari.ttf.bz2

Also note this won't even work without Owen's cff patch to pango. And I 
don't think he has committed it to pango CVS yet.
So here is the patch also...
http://www.ece.uic.edu/~msripada/delme/pango-1.2.5-cff.patch

Thanks,
Manju