Enable PropertyChanges to correctly restore binding on alias

Change-Id: I88ffdd1d1224705e980e449b6c799c9f186143b1
Task-number: QTBUG-58271
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 54 insertions, 13 deletions

diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index 0b8eb677cb..7df8336f51 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -790,12 +790,12 @@ void QQmlPropertyPrivate::removeBinding(const QQmlProperty &that)
 QQmlAbstractBinding *
 QQmlPropertyPrivate::binding(QObject *object, QQmlPropertyIndex index)
 {
+    findAliasTarget(object, index, &object, &index);
+
     QQmlData *data = QQmlData::get(object);
     if (!data)
         return 0;
 
-    findAliasTarget(object, index, &object, &index);
-
     const int coreIndex = index.coreIndex();
     const int valueTypeIndex = index.valueTypeIndex();
 
diff --git a/tests/auto/qml/qqmlproperty/data/aliasPropertyBindings2.qml b/tests/auto/qml/qqmlproperty/data/aliasPropertyBindings2.qml
new file mode 100644
index 0000000000..60cb088209
--- /dev/null
+++ b/tests/auto/qml/qqmlproperty/data/aliasPropertyBindings2.qml
@@ -0,0 +1,23 @@
+import QtQuick 2.0
+
+Item {
+    id: root
+
+    property real test: 9
+    property real test2: 3
+
+    property alias aliasProperty: innerObject.realProperty
+
+    property QtObject innerObject: QtObject {
+        id: innerObject
+        property real realProperty: test * test + test
+    }
+
+    states: State {
+        name: "switch"
+        PropertyChanges {
+            target: root
+            aliasProperty: 32 * test2
+        }
+    }
+}
diff --git a/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp b/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
index 385ffc523a..84a1bd9cc5 100644
--- a/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
+++ b/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
@@ -135,6 +135,7 @@ private slots:
 
     // Bugs
     void crashOnValueProperty();
+    void aliasPropertyBindings_data();
     void aliasPropertyBindings();
     void noContext();
     void assignEmptyVariantMap();
@@ -1833,23 +1834,40 @@ void tst_qqmlproperty::crashOnValueProperty()
     QCOMPARE(p.read(), QVariant(20));
 }
 
-// QTBUG-13719
+void tst_qqmlproperty::aliasPropertyBindings_data()
+{
+    QTest::addColumn<QString>("file");
+    QTest::addColumn<QString>("subObject");
+
+    QTest::newRow("same object") << "aliasPropertyBindings.qml" << "";
+    QTest::newRow("different objects") << "aliasPropertyBindings2.qml" << "innerObject";
+}
+
+// QTBUG-13719, QTBUG-58271
 void tst_qqmlproperty::aliasPropertyBindings()
 {
-    QQmlComponent component(&engine, testFileUrl("aliasPropertyBindings.qml"));
+    QFETCH(QString, file);
+    QFETCH(QString, subObject);
+
+    QQmlComponent component(&engine, testFileUrl(file));
 
     QObject *object = component.create();
     QVERIFY(object != 0);
 
-    QCOMPARE(object->property("realProperty").toReal(), 90.);
+    // the object where realProperty lives
+    QObject *realPropertyObject = object;
+    if (!subObject.isEmpty())
+       realPropertyObject = object->property(subObject.toLatin1()).value<QObject*>();
+
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 90.);
     QCOMPARE(object->property("aliasProperty").toReal(), 90.);
 
     object->setProperty("test", 10);
 
-    QCOMPARE(object->property("realProperty").toReal(), 110.);
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 110.);
     QCOMPARE(object->property("aliasProperty").toReal(), 110.);
 
-    QQmlProperty realProperty(object, QLatin1String("realProperty"));
+    QQmlProperty realProperty(realPropertyObject, QLatin1String("realProperty"));
     QQmlProperty aliasProperty(object, QLatin1String("aliasProperty"));
 
     // Check there is a binding on these two properties
@@ -1868,18 +1886,18 @@ void tst_qqmlproperty::aliasPropertyBindings()
     QCOMPARE(QQmlPropertyPrivate::binding(realProperty),
              QQmlPropertyPrivate::binding(aliasProperty));
 
-    QCOMPARE(object->property("realProperty").toReal(), 96.);
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 96.);
     QCOMPARE(object->property("aliasProperty").toReal(), 96.);
 
     // Check the old binding really has not effect any more
     object->setProperty("test", 4);
 
-    QCOMPARE(object->property("realProperty").toReal(), 96.);
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 96.);
     QCOMPARE(object->property("aliasProperty").toReal(), 96.);
 
     object->setProperty("test2", 9);
 
-    QCOMPARE(object->property("realProperty").toReal(), 288.);
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 288.);
     QCOMPARE(object->property("aliasProperty").toReal(), 288.);
 
     // Revert
@@ -1890,12 +1908,12 @@ void tst_qqmlproperty::aliasPropertyBindings()
     QCOMPARE(QQmlPropertyPrivate::binding(realProperty),
              QQmlPropertyPrivate::binding(aliasProperty));
 
-    QCOMPARE(object->property("realProperty").toReal(), 20.);
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 20.);
     QCOMPARE(object->property("aliasProperty").toReal(), 20.);
 
     object->setProperty("test2", 3);
 
-    QCOMPARE(object->property("realProperty").toReal(), 20.);
+    QCOMPARE(realPropertyObject->property("realProperty").toReal(), 20.);
     QCOMPARE(object->property("aliasProperty").toReal(), 20.);
 
     delete object;
@@ -1996,7 +2014,7 @@ void tst_qqmlproperty::warnOnInvalidBinding()
     QTest::ignoreMessage(QtWarningMsg, expectedWarning.toLatin1().constData());
 
     // V8 error message for invalid binding to anchor
-    expectedWarning = testUrl.toString() + QString::fromLatin1(":14:33: Unable to assign QQuickItem_QML_6 to QQuickAnchorLine");
+    expectedWarning = testUrl.toString() + QString::fromLatin1(":14:33: Unable to assign QQuickItem_QML_8 to QQuickAnchorLine");
     QTest::ignoreMessage(QtWarningMsg, expectedWarning.toLatin1().constData());
 
     QQmlComponent component(&engine, testUrl);