signal.connect does not work with arguments in QML JS

If you have a signal with an object argument, like MouseArea.clicked, and connect that signal to a function in a JS file using the connect function, like mouseArea.clicked.connect(Script.func), then the signal argument is wrapped in an extra QVariant and not usable in the JS function. Note that it works perfectly fine if you call function with the signal argument from the handler, like onClicked: Script.func(mouse).

This does not appear in QML 2.