Dialog Focus problem with QCompleter on Qt/Cocoa

Please compile an run the attached example.

With Qt/Cocoa, the dialog will loose focus when the "Add Lineedit" button is being clicked.
With Qt/Carbon it works fine.

Please note the QCompleter::popup() call. Without this, the problem does not show.

I suspect the commits 6e022c5c21a44a25b1579f03498ecaeba6da9024 and 7bf4512659113f8cc78e72f1c84158ce4f70a526 have something to do with it.