Add "Partitioned" flag to our cookies (#3830)

src/pretix/helpers/cookies.py

@@ -44,6 +44,8 @@ def set_cookie_without_samesite(request, response, key, *args, **kwargs):
         # This will only work on secure cookies as well
         # https://www.chromestatus.com/feature/5633521622188032
         response.cookies[key]['secure'] = is_secure
+        # CHIPS
+        response.cookies[key]['Partitioned'] = True
 
 
 # Based on https://www.chromium.org/updates/same-site/incompatible-clients

src/pretix/helpers/monkeypatching.py

@@ -21,6 +21,7 @@
 #
 import types
 from datetime import datetime
+from http import cookies
 
 from PIL import Image
 from requests.adapters import HTTPAdapter
@@ -88,7 +89,14 @@ def httpadapter_send(self, request, stream=False, timeout=None, verify=True, cer
     HTTPAdapter.send = httpadapter_send
 
 
+def monkeypatch_cookie_morsel():
+    # See https://code.djangoproject.com/ticket/34613
+    cookies.Morsel._flags.add("partitioned")
+    cookies.Morsel._reserved.setdefault("partitioned", "Partitioned")
+
+
 def monkeypatch_all_at_ready():
     monkeypatch_vobject_performance()
     monkeypatch_pillow_safer()
     monkeypatch_requests_timeout()
+    monkeypatch_cookie_morsel()