Popup's CloseOnEscape policy prevents escape key from being used without closing the popup

import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Controls 2.1

Window {
    id: window
    visible: true
    width: 400
    height: 400

    Popup {
        id: popup
        width: 400
        height: 400

        contentItem: Rectangle {
            id: keySequenceEditor
            focus: true
            color: "salmon"

            Keys.onEscapePressed: {
                focus = false
                // Popup shouldn't close
                event.accepted = true
            }
        }
    }

    Button {
        objectName: "Button"
        text: "open"
        onClicked: popup.open()
    }
}