Fixed #35614 -- Prevented SQLCompiler.as_subquery_condition() from mutating a query.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/foreign_object/tests.py b/tests/foreign_object/tests.py
index c9e8da5792..2d3aa800f7 100644
--- a/tests/foreign_object/tests.py
+++ b/tests/foreign_object/tests.py
@@ -223,6 +223,13 @@ class MultiColumnFKTests(TestCase):
             [m2],
         )
 
+    def test_query_does_not_mutate(self):
+        """
+        Recompiling the same subquery doesn't mutate it.
+        """
+        queryset = Friendship.objects.filter(to_friend__in=Person.objects.all())
+        self.assertEqual(str(queryset.query), str(queryset.query))
+
     def test_select_related_foreignkey_forward_works(self):
         Membership.objects.create(
             membership_country=self.usa, person=self.bob, group=self.cia