QMenu highlighting behaves differently when menu item activated with shortcut versus Key_Return.

After a menu item is activated by navigating to it with arrow keys and then pressing the Return key, no menu item will be highlighted and activeAction() will return null. However, if the same menu item is activated by a keyboard shortcut, the menu item becomes highlighted and will be returned by activeAction().

For users, this inconsistent behaviour isn't very noticeable (because most menus close when a menu item is activated), but this difference does foul up the qmenu autotest (tests/auto/widgets/widgets/qmenu/tst_qmenu.cpp), as shown by a QEXPECT_FAIL in the keyboardNavigation() test function.