Validate that __length_hint__ returns a usable result.
diff --git a/Lib/test/test_iterlen.py b/Lib/test/test_iterlen.py
index 2123501..cd92801 100644
--- a/Lib/test/test_iterlen.py
+++ b/Lib/test/test_iterlen.py
@@ -208,6 +208,11 @@
def __length_hint__(self):
raise RuntimeError('hello')
+class NoneLengthHint(object):
+ def __iter__(self): return iter(range(10))
+ def __length_hint__(self):
+ return None
+
class TestLengthHintExceptions(unittest.TestCase):
def test_issue1242657(self):
@@ -219,6 +224,11 @@
self.assertRaises(RuntimeError, b.extend, BadLen())
self.assertRaises(RuntimeError, b.extend, BadLengthHint())
+ def test_invalid_hint(self):
+ # Make sure an invalid result doesn't muck-up the works
+ self.assertEqual(list(NoneLengthHint()), list(range(10)))
+
+
def test_main():
unittests = [
TestRepeat,