[1.7.x] Fixed #22477 -- Removed contrib middleware from the global settings defaults.

Also added a compatibility check for changed middleware defaults.

2 files changed, 37 insertions, 0 deletions

diff --git a/django/core/checks/__init__.py b/django/core/checks/__init__.py
index 0d2780abd3..d215b82513 100644
--- a/django/core/checks/__init__.py
+++ b/django/core/checks/__init__.py
@@ -8,6 +8,7 @@ from .registry import register, run_checks, tag_exists, Tags
 
 # Import these to force registration of checks
 import django.core.checks.compatibility.django_1_6_0  # NOQA
+import django.core.checks.compatibility.django_1_7_0  # NOQA
 import django.core.checks.model_checks  # NOQA
 
 __all__ = [
diff --git a/django/core/checks/compatibility/django_1_7_0.py b/django/core/checks/compatibility/django_1_7_0.py
new file mode 100644
index 0000000000..7340be6915
--- /dev/null
+++ b/django/core/checks/compatibility/django_1_7_0.py
@@ -0,0 +1,36 @@
+from __future__ import unicode_literals
+
+from .. import Warning, register, Tags
+
+
+@register(Tags.compatibility)
+def check_1_7_compatibility(**kwargs):
+    errors = []
+    errors.extend(_check_middleware_classes(**kwargs))
+    return errors
+
+
+def _check_middleware_classes(app_configs=None, **kwargs):
+    """
+    Checks if the user has *not* overridden the ``MIDDLEWARE_CLASSES`` setting &
+    warns them about the global default changes.
+    """
+    from django.conf import settings
+
+    # MIDDLEWARE_CLASSES is overridden by default by startproject. If users
+    # have removed this override then we'll warn them about the default changes.
+    if not settings.is_overridden('MIDDLEWARE_CLASSES'):
+        return [
+            Warning(
+                "MIDDLEWARE_CLASSES is not set.",
+                hint=("Django 1.7 changed the global defaults for the MIDDLEWARE_CLASSES."
+                      "django.contrib.sessions.middleware.SessionMiddleware, "
+                      "django.contrib.auth.middleware.AuthenticationMiddleware, and "
+                      "django.contrib.messages.middleware.MessageMiddleware were removed from the defaults."
+                      "If your project needs these middleware then you should configure this setting."),
+                obj=None,
+                id='1_7.W001',
+            )
+        ]
+    else:
+        return []