QmlDesigner: crash fix

This avoids an infinite recursion. For some reason "" might be a proper
prototype in some cases.

Change-Id: Ib3af9d0ff2fbf87b2ba20a79e8b456831e7a940f
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@nokia.com>

src/plugins/qmldesigner/designercore/metainfo/nodemetainfo.cpp

@@ -182,6 +182,8 @@ QList<PropertyInfo> getQmlTypes(const CppComponentValue *ov, const ContextPtr &c
     QList<PropertyInfo> list;
     if (!ov)
         return list;
+    if (ov->className().isEmpty())
+        return list;
 
     PropertyMemberProcessor processor;
     ov->processMembers(&processor);
@@ -256,6 +258,9 @@ QList<PropertyInfo> getObjectTypes(const ObjectValue *ov, const ContextPtr &cont
     QList<PropertyInfo> list;
     if (!ov)
         return list;
+    if (ov->className().isEmpty())
+        return list;
+
     PropertyMemberProcessor processor;
     ov->processMembers(&processor);