From 0315c18fe170b1b611b7d10b5dde2f196b89a7e0 Mon Sep 17 00:00:00 2001
From: Sergey Fedoseev <fedoseev.sergey@gmail.com>
Date: Tue, 22 Oct 2019 16:01:14 +0500
Subject: [PATCH] Refs #26601 -- Removed obsolete workarounds for
 MIDDLEWARE_CLASSES setting.

---
 django/contrib/admindocs/middleware.py     | 6 ++----
 django/contrib/auth/middleware.py          | 5 ++---
 django/contrib/messages/storage/session.py | 3 +--
 django/middleware/csrf.py                  | 2 +-
 4 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/django/contrib/admindocs/middleware.py b/django/contrib/admindocs/middleware.py
index 5291a846c65..77d77af715f 100644
--- a/django/contrib/admindocs/middleware.py
+++ b/django/contrib/admindocs/middleware.py
@@ -18,10 +18,8 @@ class XViewMiddleware(MiddlewareMixin):
         """
         assert hasattr(request, 'user'), (
             "The XView middleware requires authentication middleware to be "
-            "installed. Edit your MIDDLEWARE%s setting to insert "
-            "'django.contrib.auth.middleware.AuthenticationMiddleware'." % (
-                "_CLASSES" if settings.MIDDLEWARE is None else ""
-            )
+            "installed. Edit your MIDDLEWARE setting to insert "
+            "'django.contrib.auth.middleware.AuthenticationMiddleware'."
         )
         if request.method == 'HEAD' and (request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS or
                                          (request.user.is_active and request.user.is_staff)):
diff --git a/django/contrib/auth/middleware.py b/django/contrib/auth/middleware.py
index f0102c4455f..5bd176ef69f 100644
--- a/django/contrib/auth/middleware.py
+++ b/django/contrib/auth/middleware.py
@@ -1,4 +1,3 @@
-from django.conf import settings
 from django.contrib import auth
 from django.contrib.auth import load_backend
 from django.contrib.auth.backends import RemoteUserBackend
@@ -17,10 +16,10 @@ class AuthenticationMiddleware(MiddlewareMixin):
     def process_request(self, request):
         assert hasattr(request, 'session'), (
             "The Django authentication middleware requires session middleware "
-            "to be installed. Edit your MIDDLEWARE%s setting to insert "
+            "to be installed. Edit your MIDDLEWARE setting to insert "
             "'django.contrib.sessions.middleware.SessionMiddleware' before "
             "'django.contrib.auth.middleware.AuthenticationMiddleware'."
-        ) % ("_CLASSES" if settings.MIDDLEWARE is None else "")
+        )
         request.user = SimpleLazyObject(lambda: get_user(request))
 
 
diff --git a/django/contrib/messages/storage/session.py b/django/contrib/messages/storage/session.py
index 59d36d14e51..170c4940ab4 100644
--- a/django/contrib/messages/storage/session.py
+++ b/django/contrib/messages/storage/session.py
@@ -1,6 +1,5 @@
 import json
 
-from django.conf import settings
 from django.contrib.messages.storage.base import BaseStorage
 from django.contrib.messages.storage.cookie import (
     MessageDecoder, MessageEncoder,
@@ -17,7 +16,7 @@ class SessionStorage(BaseStorage):
         assert hasattr(request, 'session'), "The session-based temporary "\
             "message storage requires session middleware to be installed, "\
             "and come before the message middleware in the "\
-            "MIDDLEWARE%s list." % ("_CLASSES" if settings.MIDDLEWARE is None else "")
+            "MIDDLEWARE list."
         super().__init__(request, *args, **kwargs)
 
     def _get(self, *args, **kwargs):
diff --git a/django/middleware/csrf.py b/django/middleware/csrf.py
index abeaaff7512..77e3f042d2b 100644
--- a/django/middleware/csrf.py
+++ b/django/middleware/csrf.py
@@ -163,7 +163,7 @@ class CsrfViewMiddleware(MiddlewareMixin):
                 raise ImproperlyConfigured(
                     'CSRF_USE_SESSIONS is enabled, but request.session is not '
                     'set. SessionMiddleware must appear before CsrfViewMiddleware '
-                    'in MIDDLEWARE%s.' % ('_CLASSES' if settings.MIDDLEWARE is None else '')
+                    'in MIDDLEWARE.'
                 )
         else:
             try: