Steps to reproduce:
1. run pioneers (http://pio.sourceforge.net/)
2. Join in a game
3. When moving slider between game board window and chat window to the top,
the program crashes and dissapears (segfault) 



Stack trace:
Core was generated by `/usr/local/bin/pioneers'.
Program terminated with signal 11, Segmentation fault.

+ Trace 81961

Other information:
This crash happens when all of the points are zeroes (x and y)
that is following code causes the crash:

GdkPoint points[6];
for (int i = 0; i < 6; ++i) {
points[i].x = 0; points[i].y = 0;
}
gdk_region_polygon(points, 6, GDK_EVEN_ODD_RULE);