Emitter: negative emitRate causes app to hang

import QtQuick 2.3
import QtQuick.Window 2.2

import QtQuick.Particles 2.0

Window {
    visible: true
    width: 400
    height: 400

    Rectangle {
        width: 100
        height: 100
        color: "blue"
        anchors.centerIn: parent

        NumberAnimation on rotation {
            from: 0
            to: 360
            duration: 3000
            loops: Animation.Infinite
            running: true
        }
    }

    ParticleSystem {
        Emitter {
//            emitRate: -1
        }
    }
}