remove call to update_content_type, assert retvl is None

Author: iscai-msft

msrest/serialization.py

@@ -1495,10 +1495,10 @@ def failsafe_deserialize(self, target_obj, response_data, content_type=None):
 
         :param str target_obj: The target object type to deserialize to.
         :param str/dict data: The response data to deseralize.
+        :param str content_type: Swagger "produces" if available.
         """
         try:
-            data = self._unpack_content(response_data, content_type)
-            return self(target_obj, data)
+            return self(target_obj, data, content_type=content_type)
         except:
             _LOGGER.warning(
                 "Ran into a deserialization error. Ignoring since this is failsafe deserialization"

tests/test_serialization.py

@@ -2543,7 +2543,8 @@ def __init__(self, **kwargs):
         with pytest.raises(DeserializationError):
             self.d(Error, json.dumps(''), 'text/html')
 
-        self.d.failsafe_deserialize(Error, json.dumps(''), 'text/html')
+        deserialized = self.d.failsafe_deserialize(Error, json.dumps(''), 'text/html')
+        assert deserialized is None
 
 class TestModelInstanceEquality(unittest.TestCase):