[cairo] xlib bug, with testcase

[Soeren Sandmann]

Behdad Esfahbod <behdad at behdad.org> writes:

> > That's a temporary fix, I have no idea what the problem inside this loop
> > might be, maybe Fred can shed some light.
> 
> That function is not ignoring source alpha as it should be.  Attaching
> fix.  Going to do a quick review of other places that may have the same
> bug.

Good catch - I think we have the same problem in the SSE2 version of
this operation.


Thanks,
Soren