[4.0.x] Fixed #33043 -- Made method_decorator() preserve wrapper assignments.

Regression in f434f5b84f.

Backport of 8806e8809e from main

django/utils/decorators.py

@@ -37,7 +37,7 @@ def _multi_decorate(decorators, method):
         # 'self' argument, but it's a closure over self so it can call
         # 'func'. Also, wrap method.__get__() in a function because new
         # attributes can't be set on bound method objects, only on functions.
-        bound_method = partial(method.__get__(self, type(self)))
+        bound_method = wraps(method)(partial(method.__get__(self, type(self))))
         for dec in decorators:
             bound_method = dec(bound_method)
         return bound_method(*args, **kwargs)

tests/decorators/tests.py

@@ -425,6 +425,29 @@ class MethodDecoratorTests(SimpleTestCase):
                 def __module__(cls):
                     return "tests"
 
+    def test_wrapper_assignments(self):
+        """@method_decorator preserves wrapper assignments."""
+        func_name = None
+        func_module = None
+
+        def decorator(func):
+            @wraps(func)
+            def inner(*args, **kwargs):
+                nonlocal func_name, func_module
+                func_name = getattr(func, '__name__', None)
+                func_module = getattr(func, '__module__', None)
+                return func(*args, **kwargs)
+            return inner
+
+        class Test:
+            @method_decorator(decorator)
+            def method(self):
+                return 'tests'
+
+        Test().method()
+        self.assertEqual(func_name, 'method')
+        self.assertIsNotNone(func_module)
+
 
 class XFrameOptionsDecoratorsTests(TestCase):
     """