Allow null to be assigned to object properties

5 files changed, 61 insertions, 1 deletions

diff --git a/src/declarative/qml/qdeclarativebinding.cpp b/src/declarative/qml/qdeclarativebinding.cpp
index d759427..95520da 100644
--- a/src/declarative/qml/qdeclarativebinding.cpp
+++ b/src/declarative/qml/qdeclarativebinding.cpp
@@ -156,6 +156,9 @@ void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)
             QScriptValue scriptValue = d->scriptValue(0, &isUndefined);
             if (data->property.propertyTypeCategory() == QDeclarativeProperty::List) {
                 value = ep->scriptValueToVariant(scriptValue, qMetaTypeId<QList<QObject *> >());
+            } else if (scriptValue.isNull() && 
+                       data->property.propertyTypeCategory() == QDeclarativeProperty::Object) {
+                value = QVariant::fromValue((QObject *)0);
             } else {
                 value = ep->scriptValueToVariant(scriptValue, data->property.propertyType());
                 if (value.userType() == QMetaType::QObjectStar && !qvariant_cast<QObject*>(value)) {
@@ -168,6 +171,7 @@ void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)
                 }
             }
 
+
             if (data->error.isValid()) {
 
             } else if (isUndefined && data->property.isResettable()) {
diff --git a/src/declarative/qml/qdeclarativeobjectscriptclass.cpp b/src/declarative/qml/qdeclarativeobjectscriptclass.cpp
index a194354..bb5c8b7 100644
--- a/src/declarative/qml/qdeclarativeobjectscriptclass.cpp
+++ b/src/declarative/qml/qdeclarativeobjectscriptclass.cpp
@@ -353,7 +353,13 @@ void QDeclarativeObjectScriptClass::setProperty(QObject *obj,
     if (delBinding)
         delBinding->destroy();
 
-    if (value.isUndefined() && lastData->flags & QDeclarativePropertyCache::Data::IsResettable) {
+    if (value.isNull() && lastData->flags & QDeclarativePropertyCache::Data::IsQObjectDerived) {
+        QObject *o = 0;
+        int status = -1;
+        int flags = 0;
+        void *argv[] = { &o, 0, &status, &flags };
+        QMetaObject::metacall(obj, QMetaObject::WriteProperty, lastData->coreIndex, argv);
+    } else if (value.isUndefined() && lastData->flags & QDeclarativePropertyCache::Data::IsResettable) {
         void *a[] = { 0 };
         QMetaObject::metacall(obj, QMetaObject::ResetProperty, lastData->coreIndex, a);
     } else if (value.isUndefined() && lastData->propType == qMetaTypeId<QVariant>()) {
diff --git a/tests/auto/declarative/qdeclarativeecmascript/data/canAssignNullToQObject.1.qml b/tests/auto/declarative/qdeclarativeecmascript/data/canAssignNullToQObject.1.qml
new file mode 100644
index 0000000..3fd9131
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativeecmascript/data/canAssignNullToQObject.1.qml
@@ -0,0 +1,9 @@
+import Qt.test 1.0
+
+MyQmlObject {
+    property bool runTest: false
+
+    property variant a: MyQmlObject {}
+
+    objectProperty: (runTest == false)?a:null
+}
diff --git a/tests/auto/declarative/qdeclarativeecmascript/data/canAssignNullToQObject.2.qml b/tests/auto/declarative/qdeclarativeecmascript/data/canAssignNullToQObject.2.qml
new file mode 100644
index 0000000..19b0c42
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativeecmascript/data/canAssignNullToQObject.2.qml
@@ -0,0 +1,11 @@
+import Qt.test 1.0
+import Qt 4.6
+
+MyQmlObject {
+    objectProperty: MyQmlObject {}
+
+    Component.onCompleted: {
+        objectProperty = null;
+    }
+}
+
diff --git a/tests/auto/declarative/qdeclarativeecmascript/tst_qdeclarativeecmascript.cpp b/tests/auto/declarative/qdeclarativeecmascript/tst_qdeclarativeecmascript.cpp
index a2ecf74..6939290 100644
--- a/tests/auto/declarative/qdeclarativeecmascript/tst_qdeclarativeecmascript.cpp
+++ b/tests/auto/declarative/qdeclarativeecmascript/tst_qdeclarativeecmascript.cpp
@@ -141,6 +141,7 @@ private slots:
     void variantsAssignedUndefined();
     void qtbug_9792();
     void noSpuriousWarningsAtShutdown();
+    void canAssignNullToQObject();
 
     void callQtInvokables();
 private:
@@ -2190,6 +2191,35 @@ void tst_qdeclarativeecmascript::noSpuriousWarningsAtShutdown()
     }
 }
 
+void tst_qdeclarativeecmascript::canAssignNullToQObject()
+{
+    {
+    QDeclarativeComponent component(&engine, TEST_FILE("canAssignNullToQObject.1.qml"));
+
+    MyQmlObject *o = qobject_cast<MyQmlObject *>(component.create());
+    QVERIFY(o != 0);
+
+    QVERIFY(o->objectProperty() != 0);
+
+    o->setProperty("runTest", true);
+
+    QVERIFY(o->objectProperty() == 0);
+
+    delete o;
+    }
+
+    {
+    QDeclarativeComponent component(&engine, TEST_FILE("canAssignNullToQObject.2.qml"));
+
+    MyQmlObject *o = qobject_cast<MyQmlObject *>(component.create());
+    QVERIFY(o != 0);
+
+    QVERIFY(o->objectProperty() == 0);
+
+    delete o;
+    }
+}
+
 QTEST_MAIN(tst_qdeclarativeecmascript)
 
 #include "tst_qdeclarativeecmascript.moc"