From 21dd98a38660747c781802afca7ca02407964383 Mon Sep 17 00:00:00 2001
From: Sergey Kolosov <m17.admin@gmail.com>
Date: Sat, 2 Apr 2016 16:11:47 +0200
Subject: [PATCH] Fixed #25699 -- Allowed using the test client if
 'django.contrib.sessions' isn't in INSTALLED_APPS.

---
 django/test/client.py      | 26 +++++++++++---------------
 docs/releases/1.10.txt     |  3 +++
 tests/test_client/tests.py | 22 ++++++++++++++++++++++
 3 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/django/test/client.py b/django/test/client.py
index 42b325bd144..8349a902fa3 100644
--- a/django/test/client.py
+++ b/django/test/client.py
@@ -9,7 +9,6 @@ from copy import copy
 from importlib import import_module
 from io import BytesIO
 
-from django.apps import apps
 from django.conf import settings
 from django.core.handlers.base import BaseHandler
 from django.core.handlers.wsgi import ISO_8859_1, UTF_8, WSGIRequest
@@ -419,17 +418,15 @@ class Client(RequestFactory):
         """
         Obtains the current session variables.
         """
-        if apps.is_installed('django.contrib.sessions'):
-            engine = import_module(settings.SESSION_ENGINE)
-            cookie = self.cookies.get(settings.SESSION_COOKIE_NAME)
-            if cookie:
-                return engine.SessionStore(cookie.value)
-            else:
-                s = engine.SessionStore()
-                s.save()
-                self.cookies[settings.SESSION_COOKIE_NAME] = s.session_key
-                return s
-        return {}
+        engine = import_module(settings.SESSION_ENGINE)
+        cookie = self.cookies.get(settings.SESSION_COOKIE_NAME)
+        if cookie:
+            return engine.SessionStore(cookie.value)
+
+        session = engine.SessionStore()
+        session.save()
+        self.cookies[settings.SESSION_COOKIE_NAME] = session.session_key
+        return session
     session = property(_session)
 
     def request(self, **request):
@@ -594,12 +591,11 @@ class Client(RequestFactory):
         Sets the Factory to appear as if it has successfully logged into a site.
 
         Returns True if login is possible; False if the provided credentials
-        are incorrect, or the user is inactive, or if the sessions framework is
-        not available.
+        are incorrect.
         """
         from django.contrib.auth import authenticate
         user = authenticate(**credentials)
-        if user and apps.is_installed('django.contrib.sessions'):
+        if user:
             self._login(user)
             return True
         else:
diff --git a/docs/releases/1.10.txt b/docs/releases/1.10.txt
index 1ad08f10c2f..fc155735dc2 100644
--- a/docs/releases/1.10.txt
+++ b/docs/releases/1.10.txt
@@ -417,6 +417,9 @@ Tests
 * Added the :setting:`DATABASES['TEST']['MIGRATE'] <TEST_MIGRATE>` option to
   allow disabling of migrations during test database creation.
 
+* You can now login and use sessions with the test client even if
+  :mod:`django.contrib.sessions` is not in :setting:`INSTALLED_APPS`.
+
 URLs
 ~~~~
 
diff --git a/tests/test_client/tests.py b/tests/test_client/tests.py
index 43f6d84a65a..5c3735601f9 100644
--- a/tests/test_client/tests.py
+++ b/tests/test_client/tests.py
@@ -348,6 +348,13 @@ class ClientTest(TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.context['user'].username, 'testclient')
 
+    @override_settings(
+        INSTALLED_APPS=['django.contrib.auth'],
+        SESSION_ENGINE='django.contrib.sessions.backends.file',
+    )
+    def test_view_with_login_when_sessions_app_is_not_installed(self):
+        self.test_view_with_login()
+
     def test_view_with_force_login(self):
         "Request a page that is protected with @login_required"
         # Get the page without logging in. Should result in 302.
@@ -590,6 +597,21 @@ class ClientTest(TestCase):
         # Check that the session was modified
         self.assertEqual(self.client.session['tobacconist'], 'hovercraft')
 
+    @override_settings(
+        INSTALLED_APPS=[],
+        SESSION_ENGINE='django.contrib.sessions.backends.file',
+    )
+    def test_sessions_app_is_not_installed(self):
+        self.test_session_modifying_view()
+
+    @override_settings(
+        INSTALLED_APPS=[],
+        SESSION_ENGINE='django.contrib.sessions.backends.nonexistent',
+    )
+    def test_session_engine_is_invalid(self):
+        with self.assertRaisesMessage(ImportError, 'nonexistent'):
+            self.test_session_modifying_view()
+
     def test_view_with_exception(self):
         "Request a page that is known to throw an error"
         with self.assertRaises(KeyError):