fix the `compute-window-rectangle` function, so that it is not lager than the display size
fix the `compute-window-rectangle` function, so that it is not lager than the display size

snmsts/lem,cxxxr/lem,cxxxr/lem,cxxxr/lem,snmsts/lem,snmsts/lem,snmsts/lem,cxxxr/lem