Benjamin Otte (Cairo dev) and I debugged this.
We found that setting the the "buggy_gradients" field to true on the (cairo private) cairo_xlib_display_t worked around the problem. So it seems likely it's a bug in how the nvidia drivers handle gradients.
Benjamin Otte (Cairo dev) and I debugged this.
We found that setting the the "buggy_gradients" field to true on the (cairo private) cairo_xlib_ display_ t worked around the problem. So it seems likely it's a bug in how the nvidia drivers handle gradients.