Refs #36913 -- Maintained error message determinism in MultipleChoiceField.validate().

Used Django's OrderedSet datastructure instead of set() in MultipleChoiceField.validate()
to prevent submission ordering from being discarded during validation.

Thanks to Jacob Walls, JaeHyuck Sa, Jake Howard and Simon Charette for
the reviews.

1 files changed, 2 insertions, 2 deletions

diff --git a/tests/forms_tests/field_tests/test_multiplechoicefield.py b/tests/forms_tests/field_tests/test_multiplechoicefield.py
index 90a47ceee0..0ec53e1b30 100644
--- a/tests/forms_tests/field_tests/test_multiplechoicefield.py
+++ b/tests/forms_tests/field_tests/test_multiplechoicefield.py
@@ -91,5 +91,5 @@ class MultipleChoiceFieldTest(SimpleTestCase):
 
     def test_validate_duplicated_invalid_values(self):
         f = MultipleChoiceField(choices=[("1", "one"), ("2", "Two")])
-        with self.assertRaises(ValidationError):
-            f.validate(["1", "1", "invalid", "invalid"])
+        with self.assertRaisesMessage(ValidationError, "invalid-one"):
+            f.validate(["invalid-one", "invalid-one", "invalid-two"])