CVS domivogt: * Don't map hide windows if they have width or height 0.

[FVWM CVS]

CVSROOT:        /home/cvs/fvwm
Module name:    fvwm
Changes by:     domivogt        06/05/11 07:04:45

Modified files:
        .              : ChangeLog 
        fvwm           : frame.c 

Log message:
* Don't map hide windows if they have width or height 0.