Fix custom lookup serializer for class error [API-1669]

hazelcast/serialization/service.py

@@ -444,7 +444,8 @@ def lookup_custom_serializer(self, obj_type):
         serializer = self._type_dict.get(obj_type, None)
         if serializer is not None:
             return serializer
-        for super_type in obj_type.__subclasses__():
+
+        for super_type in obj_type.__mro__:
             serializer = self.register_from_super_type(obj_type, super_type)
             if serializer is not None:
                 return serializer

tests/unit/serialization/custom_global_serialization_test.py

@@ -42,6 +42,14 @@ def __eq__(self, other):
         return False
 
 
+class TheOtherCustomClass(CustomClass):
+    def __init__(self, uid, name, text, source=None):
+        super(TheOtherCustomClass, self).__init__(uid, name, text, source)
+
+    def __eq__(self, other):
+        return super(TheOtherCustomClass, self).__eq__(other)
+
+
 class CustomSerializer(StreamSerializer):
     def write(self, out, obj):
         if isinstance(obj, CustomClass):
@@ -128,3 +136,30 @@ def test_double_register_custom_serializer(self):
 
         with self.assertRaises(ValueError):
             service._registry.safe_register_serializer(TheOtherCustomSerializer, CustomClass)
+
+    def test_serializing_class_instances(self):
+        config = Config()
+        config.custom_serializers = {CustomClass: CustomSerializer}
+        service = SerializationServiceV1(config)
+
+        data1 = service.to_data(CustomClass)
+        deserialized1 = service.to_object(data1)
+
+        self.assertEqual(CustomClass, deserialized1)
+
+        data2 = service.to_data(TheOtherCustomClass)
+        deserialized2 = service.to_object(data2)
+
+        self.assertEqual(TheOtherCustomClass, deserialized2)
+
+    def test_serializing_child_class_instances_with_super_class_serializer(self):
+        config = Config()
+        config.custom_serializers = {TheOtherCustomClass: TheOtherCustomSerializer}
+        service = SerializationServiceV1(config)
+
+        obj = TheOtherCustomClass("uid", "some name", "description text", "CUSTOM")
+        data = service.to_data(obj)
+        deserialized = service.to_object(data)
+
+        self.assertTrue(isinstance(deserialized, CustomClass))
+        self.assertEqual(obj, deserialized)