xfiles crashing when launched while a window is in fullscreen mode

[alpheratz0]

Hi! Here is the error code:

X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  53 (X_CreatePixmap)
  Value in failed request:  0x0
  Serial number of failed request:  385
  Current serial number in output stream:  396

I did some debugging and it is caused by a call to calcsize with w or h set to 0
from the ConfigureNotify event handler.