QWidgetAction with a focusable widget causes wrong QMenuBar activation with QMainWindow & global QMenuBar

When an application has a global QMenuBar plus QMainWindow with its own menu bar, Qt will incorrectly swap to the global menu when a focusable widget is placed in a menu of the QMainWindow menu bar and focused.

Reproduction:

1. Run attached test case
2. Open “MainWindow menu” menu
3. Focus the QLineEdit

Expected: QLineEdit is focused, no other change
Actual: The active QMenuBar is changed to the global one, which breaks the menu bar