Inconsistent return value for PUT on action between Swagger and implementation

According to the Swagger file, when PUT is called on an action it returns an ItemId.

see: https://github.com/openwhisk/openwhisk/blob/master/core/controller/src/resources/whiskswagger.json#L285

In practice if the action already exist it seems to fail (i.e. not update possible) and if the action does not already exist it creates it (expected) but does not return an itemId but the full action.