Segfault in XRenderCompositeDoublePoly

[Andreas Volz]

Hello,

While hacking in an application I got a segfault from
XRenderCompositeDoublePoly in libXrender-0.9.2.

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1215826256 (LWP 28888)]
0xb7a1bf60 in XRenderCompositeDoublePoly ()
from /usr/lib/libXrender.so.1 (gdb) bt
#0  0xb7a1bf60 in XRenderCompositeDoublePoly ()
from /usr/lib/libXrender.so.1 #1  0xb7c19ee6 in _xre_poly_draw ()
   from /usr/lib/evas/modules/engines/xrender_x11/linux-gnu-i686/module.so

The problem was a specific set of points added to the polygon as test:

(11, -50), (-10, 30), (-10, -50), (15, 120)

I think the function should never segfault, even if I add a maybe
illegal polygon.

BTW: Is there a graphic primitive to draw an (filled) arc or circle
with Xrender? Or do I have to implement my own circle algorithm?

Is there an documentation, beside source, about the xorg and in special
Xrender functions?

regards
Andreas