When application is moved out of visible area in secondary screen and fullscreen mode is actived, application goes to fullscreen on primary screen and not the secondary screen.

Steps to reproduce:
1. Launch attached application
2. Move application out of visible area in second screen
3. Press Enter to activate fullscreen mode

Actual result:
3. Application is in fullscreen on primary screen

Expected result:
3. Application should be in fullscreen on secondary screen.

Bug can't be reproduced in Qt 4.8