From 5d3b322dce452dd75e8602ced9f0d02f9d6a5837 Mon Sep 17 00:00:00 2001
From: Daniel F Moisset <dmoisset@machinalis.com>
Date: Fri, 7 Apr 2017 15:13:57 +0200
Subject: [PATCH] Made MultiValueDict.__deepcopy__()'s memo kwarg an arg.

It's always provided.
---
 django/utils/datastructures.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/django/utils/datastructures.py b/django/utils/datastructures.py
index dd405e1337..aba5bcf1c2 100644
--- a/django/utils/datastructures.py
+++ b/django/utils/datastructures.py
@@ -91,9 +91,7 @@ class MultiValueDict(dict):
             for k, v in self.lists()
         ])
 
-    def __deepcopy__(self, memo=None):
-        if memo is None:
-            memo = {}
+    def __deepcopy__(self, memo):
         result = self.__class__()
         memo[id(self)] = result
         for key, value in dict.items(self):