I found this when testing my game on Windows 7. On Windows 7 (don’t know about other versions) the user can resize the window to zero height. This causes issues.
Because frequently, you want to divide by the window width and height in order to scale for example the mouse cursor.
I think it would be preferable if Panda disallowed a height of zero because it makes no sense. On MacOS, the minimal window size a user can resize a window to is 73x1 and that is already a stretch.