[1.11.x] Fixed #28229 -- Fixed the value of LoginView's "next" template variable.

Backport of e7dc39fb65 from master

tests/auth_tests/test_views.py

@@ -832,6 +832,7 @@ class LoginRedirectAuthenticatedUser(AuthViewsTestCase):
         self.login()
         response = self.client.get(self.dont_redirect_url)
         self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.context['next'], '')
 
     def test_guest(self):
         """If not logged in, stay on the same page."""