Fix the popitem bug in cookies

requests/cookies.py

@@ -10,6 +10,7 @@
 import calendar
 import copy
 import time
+from http.cookiejar import Cookie
 
 from ._internal_utils import to_native_string
 from .compat import Morsel, MutableMapping, cookielib, urlparse, urlunparse
@@ -324,14 +325,16 @@ def __contains__(self, name):
         except CookieConflictError:
             return True
 
-    def __getitem__(self, name):
+    def __getitem__(self, key):
         """Dict-like __getitem__() for compatibility with client code. Throws
         exception if there are more than one cookie with name. In that case,
         use the more explicit get() method instead.
 
         .. warning:: operation is O(n), not O(1).
         """
-        return self._find_no_duplicates(name)
+        if isinstance(key, Cookie):
+            key = key.name
+        return self._find_no_duplicates(key)
 
     def __setitem__(self, name, value):
         """Dict-like __setitem__ for compatibility with client code. Throws

tests/test_requests.py

@@ -1350,6 +1350,16 @@ def test_cookie_duplicate_names_raises_cookie_conflict_error(self):
         with pytest.raises(requests.cookies.CookieConflictError):
             jar.get(key)
 
+    def test_cookies_popitem(self):
+        jar = requests.cookies.RequestsCookieJar()
+        with pytest.raises(KeyError):
+            jar.popitem()
+
+        jar.set("1st_key", "1st_value")
+        jar.set("2nd_key", "2nd_value")
+        cookie = next(iter(jar))
+        assert jar.popitem() == (cookie, cookie.value)
+
     def test_cookie_policy_copy(self):
         class MyCookiePolicy(cookielib.DefaultCookiePolicy):
             pass