Comment 2 for bug 958522

StacktraceTop:
 g_assertion_message (domain=<optimized out>, file=<optimized out>, line=<optimized out>, func=0x7fda79688300 "miSetExtents", message=0x2536d80 "assertion failed: (pExtents->y1 < pExtents->y2)") at /build/buildd/glib2.0-2.30.0/./glib/gtestutils.c:1425
 g_assertion_message_expr (domain=0x7fda796832d3 "Gdk", file=0x7fda79688290 "/build/buildd/gtk+2.0-2.24.6/gdk/gdkregion-generic.c", line=337, func=0x7fda79688300 "miSetExtents", expr=<optimized out>) at /build/buildd/glib2.0-2.30.0/./glib/gtestutils.c:1436
 miSetExtents (pReg=<optimized out>) at /build/buildd/gtk+2.0-2.24.6/gdk/gdkregion-generic.c:337
 gdk_window_process_updates_internal (window=0x21b2480) at /build/buildd/gtk+2.0-2.24.6/gdk/gdkwindow.c:5487
 IA__gdk_window_process_all_updates () at /build/buildd/gtk+2.0-2.24.6/gdk/gdkwindow.c:5696