[2.2.x] Fixed #30903 -- Fixed migrations crash on PostgreSQL when adding Index with opclasses and ordering.

Backport of fa5f3291e7f2611d53e64ab481ebe951b0161791 from master

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/indexes/tests.py b/tests/indexes/tests.py
index 8f3c032641..4f534f0693 100644
--- a/tests/indexes/tests.py
+++ b/tests/indexes/tests.py
@@ -196,6 +196,33 @@ class SchemaIndexesPostgreSQLTests(TransactionTestCase):
             cursor.execute(self.get_opclass_query % indexname)
             self.assertCountEqual(cursor.fetchall(), [('text_pattern_ops', indexname)])
 
+    def test_ops_class_descending(self):
+        indexname = 'test_ops_class_ordered'
+        index = Index(
+            name=indexname,
+            fields=['-body'],
+            opclasses=['text_pattern_ops'],
+        )
+        with connection.schema_editor() as editor:
+            editor.add_index(IndexedArticle2, index)
+        with editor.connection.cursor() as cursor:
+            cursor.execute(self.get_opclass_query % indexname)
+            self.assertCountEqual(cursor.fetchall(), [('text_pattern_ops', indexname)])
+
+    def test_ops_class_descending_partial(self):
+        indexname = 'test_ops_class_ordered_partial'
+        index = Index(
+            name=indexname,
+            fields=['-body'],
+            opclasses=['text_pattern_ops'],
+            condition=Q(headline__contains='China'),
+        )
+        with connection.schema_editor() as editor:
+            editor.add_index(IndexedArticle2, index)
+        with editor.connection.cursor() as cursor:
+            cursor.execute(self.get_opclass_query % indexname)
+            self.assertCountEqual(cursor.fetchall(), [('text_pattern_ops', indexname)])
+
 
 @skipUnless(connection.vendor == 'mysql', 'MySQL tests')
 class SchemaIndexesMySQLTests(TransactionTestCase):