Re: Thai rendering regression after harfbuzz-ng

[Behdad Esfahbod <behdad behdad org>]

On 09/19/2009 10:31 AM, Theppitak Karoonboonyanan wrote:
> 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.

Interesting.  In general the new code is much more robust, so I'm surprised.

> 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?

input[0] is matched by callers of match_input.

> Is there any other hint?

I'm off to a cycling trip to Niagara Falls in a couple hours.  Will debug this 
tomorrow or Monday before the release.  Just give me the font.

In the mean time, you can compile pango with CPPFLAGS=-DHB_DEBUG=100 and check 
the log to see what's going on.

behdad

> Regards,