Fixed #33607 -- Made PostgresIndex.create_sql() respect the "using" argument.

django/contrib/postgres/indexes.py

@@ -25,7 +25,7 @@ class PostgresIndex(Index):
     def create_sql(self, model, schema_editor, using="", **kwargs):
         self.check_supported(schema_editor)
         statement = super().create_sql(
-            model, schema_editor, using=" USING %s" % self.suffix, **kwargs
+            model, schema_editor, using=" USING %s" % (using or self.suffix), **kwargs
         )
         with_params = self.get_with_params()
         if with_params:

tests/postgres_tests/test_indexes.py

@@ -8,6 +8,7 @@ from django.contrib.postgres.indexes import (
     GistIndex,
     HashIndex,
     OpClass,
+    PostgresIndex,
     SpGistIndex,
 )
 from django.db import NotSupportedError, connection
@@ -646,6 +647,21 @@ class SchemaTests(PostgreSQLTestCase):
                     editor.add_index(Scene, index)
         self.assertNotIn(index_name, self.get_constraints(Scene._meta.db_table))
 
+    def test_custom_suffix(self):
+        class CustomSuffixIndex(PostgresIndex):
+            suffix = "sfx"
+
+            def create_sql(self, model, schema_editor, using="gin", **kwargs):
+                return super().create_sql(model, schema_editor, using=using, **kwargs)
+
+        index = CustomSuffixIndex(fields=["field"], name="custom_suffix_idx")
+        self.assertEqual(index.suffix, "sfx")
+        with connection.schema_editor() as editor:
+            self.assertIn(
+                " USING gin ",
+                str(index.create_sql(CharFieldModel, editor)),
+            )
+
     def test_op_class(self):
         index_name = "test_op_class"
         index = Index(