[cairo] Blast from the past: Problem with text rendering on Win32+ClearType

[Brent Fulgham]

I'm trying to track down the cause of a bug we are seeing in the Cairo
build of WebKit.  Most discussion on this issue is currently tracked
on https://bugs.webkit.org/show_bug.cgi?id=29618.

The issue is that font rendering with ClearType enabled fonts produces
strange output for the last characters of various lines, as shown in
(https://bug-29618-attachments.webkit.org/attachment.cgi?id=39884).

Our bug sounds suspiciously similar to a message thread from 2006
(http://lists.freedesktop.org/archives/cairo/2006-October/008081.html),
where some corrections were made to the handling of ARGB surfaces in
the Windows logic.

I'm wondering if this problem may not have been truly resolved, or if
perhaps we have a regression.

Does anyone know if this original problem is in the current 1.8.8
sources (this is the release we are using).

Otherwise, the issue may be with the font handling for non-RGB24
surfaces in http://cgit.freedesktop.org/cairo/tree/src/cairo-win32-font.c#n1427.

Thanks,

-Brent