regression Mac cocoa : with modal dialog, its parent still accepts mouse click, and the dialog cannot get focus again

the attached test case tries to raise the dialog's parent widget after showing the dialog, and then exits with 0 if the dialog has focus. or exits with 1 if the dialog loses focus.
if the mainwidget is the active window when the dialog shows, you can still click on the parent widget, then the dialog loses focus and never gets it back.
this is a refression between 462 amd 473.