[HarfBuzz] Patch for harfbuzz

[Khaled Hosny]

On Wed, Oct 26, 2011 at 09:13:36AM +0100, John Tapsell wrote:
> Hi guys,
> 
>   I have a font with GPOS kerning with position and advancement
> adjustments for arabic.  This seems to be fairly rare as I cannot find
> another font with GPOS kerning for a RTL language.

Not that rare actually (unless you are counting free fonts only).

>   Using Qt, I got the following result:
> http://picpaste.com/pics/malcom_text_with_unmodified_qt-zkLg01BQ.1319616036.png
> 
>   The below patch fixes the adjustment problems, making it look like:
> http://picpaste.com/pics/malcom_text_with_modified_qt-kItcU2Cx.1319616047.png

I reported that issue years ago in Qt's bug tracker[1] and it was closed
without a fix, reported again here earlier tis year (this time with a
patch)[2], no idea why it is so hard to fix such an obvious and quite
visible rendering bug!

In the mean time I just gave up an removed kerning completely from later
versions of the font.

[1] https://bugreports.qt.nokia.com//browse/QTBUG-4475
[2] http://lists.freedesktop.org/archives/harfbuzz/2011-January/001062.html

Regards,
 Khaled