diff --git a/addons/web/tests/test_login.py b/addons/web/tests/test_login.py
index e811c48d007..0fd6236c7ac 100644
--- a/addons/web/tests/test_login.py
+++ b/addons/web/tests/test_login.py
@@ -5,21 +5,25 @@ from odoo.tests.common import get_db_name, HOST, HttpCase, new_test_user, Opener
 
 
 class TestWebLoginCommon(HttpCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        new_test_user(cls.env, 'internal_user', context={'lang': 'en_US'})
+        new_test_user(cls.env, 'portal_user', groups='base.group_portal')
+
     def setUp(self):
         super().setUp()
-        new_test_user(self.env, 'portal_user', groups='base.group_portal')
-
-    def login(self, username, password):
-        """Log in with provided credentials and return response to POST request or raises for status."""
         self.session = http.root.session_store.new()
         self.session.update(http.get_default_session(), db=get_db_name())
         self.opener = Opener(self.env.cr)
         self.opener.cookies.set('session_id', self.session.sid, domain=HOST, path='/')
 
+    def login(self, username, password, csrf_token=None):
+        """Log in with provided credentials and return response to POST request or raises for status."""
         res_post = self.url_open('/web/login', data={
             'login': username,
             'password': password,
-            'csrf_token': http.Request.csrf_token(self),
+            'csrf_token':csrf_token or http.Request.csrf_token(self),
         })
         res_post.raise_for_status()
 
@@ -28,9 +32,7 @@ class TestWebLoginCommon(HttpCase):
 
 class TestWebLogin(TestWebLoginCommon):
     def test_web_login(self):
-        new_test_user(self.env, 'jackoneill', context={'lang': 'en_US'})
-
-        res_post = self.login('jackoneill', 'jackoneill')
+        res_post = self.login('internal_user', 'internal_user')
         # ensure we are logged-in
         self.url_open(
             '/web/session/check',
@@ -44,3 +46,15 @@ class TestWebLogin(TestWebLoginCommon):
         res_post = self.login('portal_user', 'portal_user')
         # ensure we end up on the right page for external users. Valid without portal installed.
         self.assertEqual(res_post.request.path_url, '/web/login_successful')
+
+    def test_web_login_bad_xhr(self):
+        # simulate the user downloaded the login form
+        csrf_token = http.Request.csrf_token(self)
+
+        # simulate that the JS sended a bad XHR to a route that is
+        # auth='none' using the same session (e.g. via a service worker)
+        bad_xhr = self.url_open('/web/login_successful', allow_redirects=False)
+        self.assertNotEqual(bad_xhr.status_code, 200)
+
+        # log in using the above form, it should still be valid
+        self.login('internal_user', 'internal_user', csrf_token)
diff --git a/odoo/http.py b/odoo/http.py
index b47629cdc07..7226ef0afc9 100644
--- a/odoo/http.py
+++ b/odoo/http.py
@@ -1841,9 +1841,10 @@ class HttpDispatcher(Dispatcher):
         """
         if isinstance(exc, SessionExpiredException):
             session = self.request.session
+            was_connected = session.uid is not None
             session.logout(keep_db=True)
             response = self.request.redirect_query('/web/login', {'redirect': self.request.httprequest.full_path})
-            if not session.is_explicit:
+            if not session.is_explicit and was_connected:
                 root.session_store.rotate(session, self.request.env)
                 response.set_cookie('session_id', session.sid, max_age=SESSION_LIFETIME, httponly=True)
             return response