[1.7.x] Fixed #22771 -- Fixed test.Client.logout when using custom auth backend.

Backport of 50b9313e0a from master

django/test/client.py

@@ -587,16 +587,13 @@ class Client(RequestFactory):
 
         Causes the authenticated user to be logged out.
         """
-        from django.contrib.auth import get_user_model, logout
+        from django.contrib.auth import get_user, logout
 
         request = HttpRequest()
         engine = import_module(settings.SESSION_ENGINE)
-        UserModel = get_user_model()
         if self.session:
             request.session = self.session
-            uid = self.session.get("_auth_user_id")
-            if uid:
-                request.user = UserModel._default_manager.get(pk=uid)
+            request.user = get_user(request)
         else:
             request.session = engine.SessionStore()
         logout(request)

tests/test_client_regress/auth_backends.py

@@ -0,0 +1,20 @@
+from django.contrib.auth.backends import ModelBackend
+
+from .models import CustomUser
+
+
+class CustomUserBackend(ModelBackend):
+
+    def authenticate(self, username=None, password=None):
+        try:
+            user = CustomUser.custom_objects.get_by_natural_key(username)
+            if user.check_password(password):
+                return user
+        except CustomUser.DoesNotExist:
+            return None
+
+    def get_user(self, user_id):
+        try:
+            return CustomUser.custom_objects.get(pk=user_id)
+        except CustomUser.DoesNotExist:
+            return None

tests/test_client_regress/tests.py

@@ -1052,6 +1052,25 @@ class SessionTests(TestCase):
         user_logged_out.disconnect(listener)
         self.assertTrue(listener.executed)
 
+    @override_settings(AUTHENTICATION_BACKENDS=(
+        'django.contrib.auth.backends.ModelBackend',
+        'test_client_regress.auth_backends.CustomUserBackend'))
+    def test_logout_with_custom_auth_backend(self):
+        "Request a logout after logging in with custom authentication backend"
+        def listener(*args, **kwargs):
+            self.assertEqual(kwargs['sender'], CustomUser)
+            listener.executed = True
+        listener.executed = False
+        u = CustomUser.custom_objects.create(email='test@test.com')
+        u.set_password('password')
+        u.save()
+
+        user_logged_out.connect(listener)
+        self.client.login(username='test@test.com', password='password')
+        self.client.logout()
+        user_logged_out.disconnect(listener)
+        self.assertTrue(listener.executed)
+
     def test_logout_without_user(self):
         """Logout should send signal even if user not authenticated."""
         def listener(user, *args, **kwargs):