TransferSubscriptions is described to transfer a subscription from one session to another.
What is the expected behavior if the subscription is already owned by the calling session?
(I know it is a pretty stupid client behavior when the client tries this.)

In case of the regular behavior, the status notification with GoodSubscriptionTransferred notifies the old session that the session does no longer own the subscription.
Thus the client session does not know if the subscription was transferred by itself (and thus still owns the subscription) or if the subscription was transferred to a different session.

Is this a wrong client behavior, is it a valid operation or is it intentionally undefined behavior and recommended to not try this?
Shall the transfer operation fail and if so with which status?
Shall the server omit the GoodSubscriptionTransferred notification when the source and target session are the same?

Please clarify and update the specification.