QKeySequence silently discards unknown key modifiers

Consider the following example:

QWidget w;
QAction a("foo", &w);

a.setShortcut(QKeySequence("Win+E"));

w.addAction(&a);
w.show();

QObject::connect(&a, SIGNAL(triggered()), &w, SLOT(close()));

Since "Win" is not a recognized key modifier, the expected result is that the shortcut does not work.

The actual result is that the action is triggered when the 'E' key is pressed.