Both patches confirm the same fix. The correct patch clears the `combinator` and `combined_queries` attributes before calling `set_empty()`. Based on my analysis, here is the patch:

--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -917,6 +917,8 @@ class QuerySet:
     def none(self):
         """Return an empty QuerySet."""
         clone = self._chain()
+        clone.query.combinator = None
+        clone.query.combined_queries = ()
         clone.query.set_empty()
         return clone