Fix serialization / deserialization.

- Serialization was not taking the registered name and package from the registry.
- Deserialization was selecting symbols by postfix as a fallback.

PiperOrigin-RevId: 689181378

tf_keras/saving/object_registration_test.py

@@ -112,21 +112,23 @@ def from_config(cls, config):
         self.assertEqual(5, new_inst._val)
 
     def test_serialize_custom_function(self):
-        @object_registration.register_keras_serializable()
+        @object_registration.register_keras_serializable(
+            package="Test", name="func"
+        )
         def my_fn():
             return 42
 
-        serialized_name = "Custom>my_fn"
+        serialized_name = "Test>func"
         class_name = object_registration._GLOBAL_CUSTOM_NAMES[my_fn]
         self.assertEqual(serialized_name, class_name)
         fn_class_name = object_registration.get_registered_name(my_fn)
         self.assertEqual(fn_class_name, class_name)
 
         config = serialization_lib.serialize_keras_object(my_fn)
         if tf.__internal__.tf2.enabled():
-            self.assertEqual("my_fn", config["config"])
+            self.assertEqual(serialized_name, config["config"])
         else:
-            self.assertEqual(class_name, config)
+            self.assertEqual(serialized_name, config)
         fn = serialization_lib.deserialize_keras_object(config)
         self.assertEqual(42, fn())
 

tf_keras/saving/serialization_lib.py

@@ -378,7 +378,7 @@ def _get_class_or_fn_config(obj):
     """Return the object's config depending on its type."""
     # Functions / lambdas:
     if isinstance(obj, types.FunctionType):
-        return obj.__name__
+        return object_registration.get_registered_name(obj)
     # All classes:
     if hasattr(obj, "get_config"):
         config = obj.get_config()
@@ -789,15 +789,6 @@ def _retrieve_class_or_fn(
                 if obj is not None:
                     return obj
 
-            # Retrieval of registered custom function in a package
-            filtered_dict = {
-                k: v
-                for k, v in custom_objects.items()
-                if k.endswith(full_config["config"])
-            }
-            if filtered_dict:
-                return next(iter(filtered_dict.values()))
-
         # Otherwise, attempt to retrieve the class object given the `module`
         # and `class_name`. Import the module, find the class.
         try: