Issue #16402: In range slicing, fix shadowing of exceptions from __index__ method.
diff --git a/Lib/test/test_range.py b/Lib/test/test_range.py
index ede0791..4dab448 100644
--- a/Lib/test/test_range.py
+++ b/Lib/test/test_range.py
@@ -312,6 +312,15 @@
self.assertRaises(TypeError, range, IN())
+ # Test use of user-defined classes in slice indices.
+ self.assertEqual(list(range(10)[:I(5)]), list(range(5)))
+
+ with self.assertRaises(RuntimeError):
+ range(0, 10)[:IX()]
+
+ with self.assertRaises(TypeError):
+ range(0, 10)[:IN()]
+
def test_count(self):
self.assertEqual(range(3).count(-1), 0)
self.assertEqual(range(3).count(0), 1)