Project: mule
Issue MULE-8469: Message transformation must no update payloads data type when payload was not transformed
DefaulMuleMessage#transformMessage(MuleEvent, Transformer) always updates the message data type to the transformer output data type. That is wrong because some transformers update parts of the message other than the payload. (like message properties) Probably those transformers should be plain message processors, but a way to fix this problem is to check that payload has changed after the transformation.
Story points: 3