> Looks right to restrict it to the selected frame.
 > (I don't know if this should be installed since
 > it only gives an unexpected result in one minor test.)

Hmmm...  When the frame is deleted or not the selected one, we should
try to select the one that contains the window that was selected before
calling 'display-buffer'.  When the frame is not deleted and is the
already selected one, I think we should keep it alone.  Patch attached.

martin