Fixed #26929 -- Deprecated extra_context parameter of contrib.auth.views.logout_then_login().

django/contrib/auth/views.py

@@ -177,11 +177,20 @@ def logout(request, *args, **kwargs):
     return LogoutView.as_view(**kwargs)(request, *args, **kwargs)
 
 
+_sentinel = object()
+
+
 @deprecate_current_app
-def logout_then_login(request, login_url=None, extra_context=None):
+def logout_then_login(request, login_url=None, extra_context=_sentinel):
     """
     Logs out the user if they are logged in. Then redirects to the log-in page.
     """
+    if extra_context is not _sentinel:
+        warnings.warn(
+            "The unused `extra_context` parameter to `logout_then_login` "
+            "is deprecated.", RemovedInDjango21Warning
+        )
+
     if not login_url:
         login_url = settings.LOGIN_URL
     login_url = resolve_url(login_url)

docs/internals/deprecation.txt

@@ -20,6 +20,9 @@ details on these changes.
   ``password_reset_confirm()``, and ``password_reset_complete()`` will be
   removed.
 
+* The ``extra_context`` parameter of ``contrib.auth.views.logout_then_login()``
+  will be removed.
+
 .. _deprecation-removed-in-2.0:
 
 2.0

docs/releases/1.11.txt

@@ -366,6 +366,9 @@ Miscellaneous
   :class:`~django.contrib.auth.views.LoginView` and
   :class:`~django.contrib.auth.views.LogoutView`.
 
+* The unused ``extra_context`` parameter of
+  ``contrib.auth.views.logout_then_login()``  is deprecated.
+
 * ``contrib.auth``’s ``password_change()``, ``password_change_done()``,
   ``password_reset()``, ``password_reset_done()``, ``password_reset_confirm()``,
   and ``password_reset_complete()`` function-based views are deprecated in favor

docs/topics/auth/default.txt

@@ -1179,6 +1179,11 @@ implementation details see :ref:`using-the-views`.
         The ``current_app`` parameter is deprecated and will be removed in
         Django 2.0. Callers should set ``request.current_app`` instead.
 
+    .. deprecated:: 1.11
+
+        The unused ``extra_context`` parameter is deprecated and will be
+        removed in Django 2.1.
+
 .. function:: password_change(request, template_name='registration/password_change_form.html', post_change_redirect=None, password_change_form=PasswordChangeForm, current_app=None, extra_context=None)
 
     .. deprecated:: 1.11

tests/auth_tests/test_views.py

@@ -27,6 +27,7 @@ from django.middleware.csrf import CsrfViewMiddleware, get_token
 from django.test import TestCase, override_settings
 from django.test.utils import patch_logger
 from django.urls import NoReverseMatch, reverse, reverse_lazy
+from django.utils.deprecation import RemovedInDjango21Warning
 from django.utils.encoding import force_text
 from django.utils.http import urlquote
 from django.utils.six.moves.urllib.parse import ParseResult, urlparse
@@ -734,6 +735,10 @@ class LogoutThenLoginTests(AuthViewsTestCase):
         self.confirm_logged_out()
         self.assertRedirects(response, '/custom/', fetch_redirect_response=False)
 
+    def test_deprecated_extra_context(self):
+        with self.assertRaisesMessage(RemovedInDjango21Warning, 'The unused `extra_context` parameter'):
+            logout_then_login(None, extra_context={})
+
 
 class LoginRedirectAuthenticatedUser(AuthViewsTestCase):
     dont_redirect_url = '/login/redirect_authenticated_user_default/'