Fixed #21513 -- Added method_decorator support for argumented decorator

Copied attributes into the decorated method and special case __name__
copy as this will not be present on a Class object. Added regression
test to decorator suite.

django/utils/decorators.py

@@ -39,9 +39,13 @@ def method_decorator(decorator):
         update_wrapper(_wrapper, func)
 
         return _wrapper
-    update_wrapper(_dec, decorator)
+
+    update_wrapper(_dec, decorator, assigned=available_attrs(decorator))
     # Change the name to aid debugging.
+    if hasattr(decorator, '__name__'):
         _dec.__name__ = 'method_decorator(%s)' % decorator.__name__
+    else:
+        _dec.__name__ = 'method_decorator(%s)' % decorator.__class__.__name__
     return _dec
 
 

tests/decorators/tests.py

@@ -1,4 +1,4 @@
-from functools import wraps
+from functools import wraps, update_wrapper
 from unittest import TestCase
 import warnings
 
@@ -174,6 +174,16 @@ def myattr2_dec(func):
 
 myattr2_dec_m = method_decorator(myattr2_dec)
 
+class ClsDec(object):
+    def __init__(self, myattr):
+        self.myattr = myattr
+
+    def __call__(self, f):
+
+        def wrapped():
+            return f() and self.myattr
+        return update_wrapper(wrapped, f)
+
 
 class MethodDecoratorTests(TestCase):
     """
@@ -214,6 +224,16 @@ class MethodDecoratorTests(TestCase):
         self.assertEqual(Test.method.__doc__, 'A method')
         self.assertEqual(Test.method.__name__, 'method')
 
+    # Test for argumented decorator
+    def test_argumented(self):
+        class Test(object):
+            @method_decorator(ClsDec(False))
+            def method(self):
+                return True
+
+        # t = Test()
+        self.assertEqual(Test().method(), False)
+        
 
 class XFrameOptionsDecoratorsTests(TestCase):
     """