Fixed #35744 -- Relabelled external aliases of combined queries.

Just like normal queries, combined queries' outer references might fully
resolve before their reference is assigned its final alias.

Refs #29338.

Thanks Antony_K for the report and example, and thanks Mariusz Felisiak
for the review.

1 files changed, 10 insertions, 0 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index aef3f48f10..b7b93c235a 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1021,11 +1021,21 @@ class Query(BaseExpression):
                 if alias == old_alias:
                     table_aliases[pos] = new_alias
                     break
+
+        # 3. Rename the direct external aliases and the ones of combined
+        # queries (union, intersection, difference).
         self.external_aliases = {
             # Table is aliased or it's being changed and thus is aliased.
             change_map.get(alias, alias): (aliased or alias in change_map)
             for alias, aliased in self.external_aliases.items()
         }
+        for combined_query in self.combined_queries:
+            external_change_map = {
+                alias: aliased
+                for alias, aliased in change_map.items()
+                if alias in combined_query.external_aliases
+            }
+            combined_query.change_aliases(external_change_map)
 
     def bump_prefix(self, other_query, exclude=None):
         """