createQmlObject crashes under various circumstances

import QtQuick 2.0

Item {
    id: root;
    function createObject() {
        return Qt.createQmlObject("
                    import QtQuick 2.0;
                    Item {
                        id: testOne;
                        x: 50;
                        y: 100;
                    }", root);
    }

    Component.onCompleted: {
        console.log(createObject().x); // expect "50", get a crash.
    }
}

import QtQuick 2.0

Item {
    id: root;
    function createObject() {
        return Qt.createQmlObject("import QtQuick 2.0; Item { id: testOne; x: 50; y: 100; }", root);
    }

    Component.onCompleted: {
        console.log(createObject().x); // expect "50", get "50"
    }
}

import QtQuick 2.0

Item {
    id: root;

    function createObject() {
        var qobjectRef;
        try {
            qobjectRef = Qt.createQmlObject("import QtQuick 2.0; Item { id: testOne; x: 50; y: 100; width: 200; height: 400; Item { id: testTwo; property int t2ip: 2; } property var t1c0ip: testOne.testTwo.t2ip; }", root);
        } catch (e) {
            console.log("error occurred: " + e.toString());
        }
        return qobjectRef;
    }

    Component.onCompleted: {
        var obj = createObject();
        console.log(obj.t1c0ip); // expect "2", get "inline:1: TypeError: Cannot read property 't2ip' of undefined" as testOne.testTwo doesn't resolve properly
    }
}

import QtQuick 2.0

Item {
    id: root;

    function createObject() {
        var qobjectRef;
        try {
            qobjectRef = Qt.createQmlObject("import QtQuick 2.0; Item { id: testOne; x: 50; y: 100; width: 200; height: 400; Item { id: testTwo; property int t2ip: 2; } property var t1c0ip: testOne.children[0].t2ip; }", root);
        } catch (e) {
            console.log("error occurred: " + e.toString());
        }
        return qobjectRef;
    }

    Component.onCompleted: {
        var obj = createObject();
        console.log(obj.t1c0ip); // expect "2", get "2"
    }
}

import QtQuick 2.0

Item {
    id: root
    Component.onCompleted: {
        var retn;
        var i = 0; var iterations = 10000;
        for (i = 0; i < iterations; ++i) {
            retn = Qt.createQmlObject("import QtQuick 2.0;Item { id: complexItem; width: 200; height: 200; x: 100; y: 100;property int first: 1;property bool second: true;property string third: '3';property int fourth: 4;property int fifth: 5;property int sixth: 6;property int seventh: 7;property int eighth: 8;signal firstSignal();signal secondSignal();function firstFunc() { first = first + 1; firstSignal(); } function secondFunc() { if (second == true) second = false; secondSignal(); } function thirdFunc() { return false; } function fourthFunc() { return 42; } Item { id: itemFoo;anchors.fill: parent;property string foo: 'foo'; } Item { id: itemBar;anchors.fill: parent;property string bar: 'bar'; Item { id: itemBaz;property string baz: 'baz'; } } property var vfoo: complexItem.children[0]; property var vbar: complexItem.children[1]; property var vbaz: complexItem.children[1].children[0]; }", root);
        }
    }
}