Initially empty BorderImage that has a shader effect applied never becomes visible

import QtQuick 2.0

Item {
    width: 640
    height: 480

    BorderImage {
        id: image
        anchors.centerIn: parent

        property bool empty: false // <--- change to 'true' and it never becomes visible!
        source: empty ? "" : "test.png"

        property bool initial
        Component.onCompleted: initial = empty
    }

    ShaderEffect {
        id: effect
        anchors.fill: image
        property variant source: ShaderEffectSource {
            sourceItem: image
            hideSource: true
        }
    }

    MouseArea {
        anchors.fill: parent
        onClicked: image.empty = !image.empty

        Text {
            text: "Initially empty: " + image.initial
            anchors { margins: 10; left: parent.left; top: parent.top }
        }
        Text {
            text: "Image source: " + image.source
            anchors { margins: 10; left: parent.left; bottom: parent.bottom }
        }
        Text {
            text: "(click the background to toggle)"
            anchors { margins: 10; right: parent.right; bottom: parent.bottom }
        }
    }
}