Thai rendering regression after harfbuzz-ng

[Theppitak Karoonboonyanan <thep linux thai net>]

Hi,

As described in Bug #595539, there is a serious regression in
rendering Thai with OT font using Pango master. The bug is
very obvious to users, as it changes meanings of words.
And it should not be exposed to users at all in stable release.

I need some help in tracking down the problem.

The GSUB rule input holds input[1..count-1] in the array,
with input[0] skipped. And match_input() matches only
count-1 items. So, where is input[0] matched?

Is there any other hint?

Regards,
-- 
Theppitak Karoonboonyanan
http://linux.thai.net/~thep/