Allow to disable QMdiSubWindow hotkeys

I was trying to add a Ctrl-W hotkey to "File"->"Close File" in an Qt application with a QMdiArea. After hours of debugging and stepping through the Qt source code I discovered that QMdiSubWindow automatically creates a context menu and adds the same hotkey to its close menu item, which results in an ambiguous hotkey mapping.

This is unsatisfying, because although the hotkey and "Close File" are working correctly (the document closes), the hotkey is not displayed in the "File" menu.

I think there should be a way to disable the QMdiSubWindow context menu, or at least the hotkeys.