[2.2.x] Fixed #30312 -- Relaxed admin check from django.contrib.sessions to SessionMiddleware subclasses.

Backport of efeceba589974b95b35b2e25df86498c96315518 from master

1 files changed, 6 insertions, 1 deletions

diff --git a/django/contrib/admin/checks.py b/django/contrib/admin/checks.py
index aaf6ed2cf0..aa549943cb 100644
--- a/django/contrib/admin/checks.py
+++ b/django/contrib/admin/checks.py
@@ -68,7 +68,6 @@ def check_dependencies(**kwargs):
         ('django.contrib.contenttypes', 401),
         ('django.contrib.auth', 405),
         ('django.contrib.messages', 406),
-        ('django.contrib.sessions', 407),
     )
     for app_name, error_code in app_dependencies:
         if not apps.is_installed(app_name):
@@ -121,6 +120,12 @@ def check_dependencies(**kwargs):
             "be in MIDDLEWARE in order to use the admin application.",
             id='admin.E409',
         ))
+    if not _contains_subclass('django.contrib.sessions.middleware.SessionMiddleware', settings.MIDDLEWARE):
+        errors.append(checks.Error(
+            "'django.contrib.sessions.middleware.SessionMiddleware' must "
+            "be in MIDDLEWARE in order to use the admin application.",
+            id='admin.E410',
+        ))
     return errors