Index: django/contrib/admin/sites.py
===================================================================
--- django/contrib/admin/sites.py	(revision 10514)
+++ django/contrib/admin/sites.py	(revision 10515)
@@ -113,8 +113,10 @@
             return self.logout(request)
 
         if not self.has_permission(request):
-            return self.login(request)
-
+            response = self.login(request)
+            if response:
+                return response
+            # with post data in session, continue
 
         if url == '':
             return self.index(request)
@@ -245,7 +247,7 @@
                         # overwrite request.POST with the saved post_data, and continue
                         request.POST = post_data
                         request.user = user
-                        return view_func(request, *args, **kwargs)
+                        return None
                     else:
                         request.session.delete_test_cookie()
                         return http.HttpResponseRedirect(request.path)