QmlDesigner: crashfix

Check if object is not 0 and we are not called back from the
destructor.

src/plugins/qmldesigner/designercore/instances/objectnodeinstance.cpp

@@ -782,7 +782,9 @@ QObject* ObjectNodeInstance::createObject(const NodeMetaInfo &metaInfo, QDeclara
 
 QObject *ObjectNodeInstance::object() const
 {
-    return m_object.data();
+        if (!m_object.isNull() && !QObjectPrivate::get(m_object.data())->wasDeleted)
+            return m_object.data();
+        return 0;
 }
 
 bool ObjectNodeInstance::hasContent() const

src/plugins/qmldesigner/designercore/instances/qmlgraphicsitemnodeinstance.cpp

@@ -178,7 +178,10 @@ QRectF QmlGraphicsItemNodeInstance::boundingRect() const
         }
     }
 
-    return qmlGraphicsItem()->boundingRect();
+    if (qmlGraphicsItem())
+        return qmlGraphicsItem()->boundingRect();
+
+    return QRectF();
 }
 
 //QVariant anchorLineFor(QDeclarativeItem *item, const AnchorLine &anchorLine)