[cairo] Horizontal artifacts rendering to an image surface

[Floyd May]

I've been able to work around this by calling cairo_fill_preserve(...) and cairo_stroke(...) once per each outer ring. In my particular scenario, these polygons may have holes in them, so I must use CAIRO_FILL_RULE_EVEN_ODD.

Clipping is also affected in a similar way; I've accounted for this as well in my application. Could someone give me an idea as to other areas that may be affected by this?