When finishing full screen on Mac OS X, sometimes crashes

1. Create new application (Qt Widgets Application)
2. Put one QLineEdit or QTreeView object on form. I think widgets that have focus mark can reproduce it. QPushButton or QLabel can't.
3. Press fullscreen button (top right corner) and finish full screen button few times (2-3), the application is crushed when finishing full screen mode.

When crush, the following message is dumped on console.

2014-10-15 13:52:16.091 test[82614:507] unlockFocus called too many times. Called on 
<_NSThemeFullScreenButton: 0x101377370>.