From 867d287b3acfdb6b7de0f193b86b93ec52d034e5 Mon Sep 17 00:00:00 2001
From: Tim Graham <timograham@gmail.com>
Date: Tue, 18 Aug 2015 17:57:01 -0400
Subject: [PATCH] Added a test to ensure empty sessions are saved.

---
 tests/sessions_tests/tests.py | 39 +++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tests/sessions_tests/tests.py b/tests/sessions_tests/tests.py
index 713ff9e553..76e625aa76 100644
--- a/tests/sessions_tests/tests.py
+++ b/tests/sessions_tests/tests.py
@@ -695,6 +695,45 @@ class SessionMiddlewareTests(TestCase):
         # The session is accessed so "Vary: Cookie" should be set.
         self.assertEqual(response['Vary'], 'Cookie')
 
+    def test_empty_session_saved(self):
+        """"
+        If a session is emptied of data but still has a key, it should still
+        be updated.
+        """
+        request = RequestFactory().get('/')
+        response = HttpResponse('Session test')
+        middleware = SessionMiddleware()
+
+        # Set a session key and some data.
+        middleware.process_request(request)
+        request.session['foo'] = 'bar'
+        # Handle the response through the middleware.
+        response = middleware.process_response(request, response)
+        self.assertEqual(tuple(request.session.items()), (('foo', 'bar'),))
+        # A cookie should be set, along with Vary: Cookie.
+        self.assertIn(
+            'Set-Cookie: sessionid=%s' % request.session.session_key,
+            str(response.cookies)
+        )
+        self.assertEqual(response['Vary'], 'Cookie')
+
+        # Empty the session data.
+        del request.session['foo']
+        # Handle the response through the middleware.
+        response = HttpResponse('Session test')
+        response = middleware.process_response(request, response)
+        self.assertEqual(dict(request.session.values()), {})
+        session = Session.objects.get(session_key=request.session.session_key)
+        self.assertEqual(session.get_decoded(), {})
+        # While the session is empty, it hasn't been flushed so a cookie should
+        # still be set, along with Vary: Cookie.
+        self.assertGreater(len(request.session.session_key), 8)
+        self.assertIn(
+            'Set-Cookie: sessionid=%s' % request.session.session_key,
+            str(response.cookies)
+        )
+        self.assertEqual(response['Vary'], 'Cookie')
+
 
 # Don't need DB flushing for these tests, so can use unittest.TestCase as base class
 class CookieSessionTests(SessionTestsMixin, unittest.TestCase):