message: Do not add tag to non-saved objects
diff: @@ -77,6 +77,9 @@ class TagView(BaseSupersetView):
  @expose('/tags/<object_type:object_type>/<int:object_id>/', methods=['GET'])
  def get(self, object_type, object_id):
  """List all tags a given object has."""
  + if object_id == 0:
  + return json_success(json.dumps([]))
  +
  query = db.session.query(TaggedObject).filter(and_(
  TaggedObject.object_type == object_type,
  TaggedObject.object_id == object_id))
  @@ -87,6 +90,9 @@ class TagView(BaseSupersetView):
  @expose('/tags/<object_type:object_type>/<int:object_id>/', methods=['POST'])
  def post(self, object_type, object_id):
  """Add new tags to an object."""
  + if object_id == 0:
  + return Response(status=404)
  +
  tagged_objects = []
  for name in request.get_json(force=True):
  if ':' in name:
  