Popups don't work without ApplicationWindow

If I place ComboBox into Dialog from QtQuick Controls, it cannot show items list on click and I see the following error in the console:

It happens even if main window is implemented as ApplicationWindow from Qt.labs.controls.
This is due to the QQuickPopup::show() requires, that popup is placed into QQuickApplicationWindow.

Program to reproduce:

import QtQuick 2.5
import Qt.labs.controls 1.0
import QtQuick.Dialogs 1.2

ApplicationWindow {
    visible: true
    width: 640
    height: 480

    Dialog {
        visible: true

        ComboBox {
            model: [
                "1",
                "2"
            ]
        }
    }
}