Issue #26494: Fixed crash on iterating exhausting iterators.
Affected classes are generic sequence iterators, iterators of bytearray,
list, tuple, set, frozenset, dict, OrderedDict and corresponding views.
diff --git a/Lib/test/seq_tests.py b/Lib/test/seq_tests.py
index f4673d4..f019e8d 100644
--- a/Lib/test/seq_tests.py
+++ b/Lib/test/seq_tests.py
@@ -4,6 +4,7 @@
 
 import unittest
 import sys
+from test import test_support as support
 
 # Various iterables
 # This is used for checking the constructor (here and in test_deque.py)
@@ -402,3 +403,7 @@
         self.assertEqual(a.index(0, -4*sys.maxint, 4*sys.maxint), 2)
         self.assertRaises(ValueError, a.index, 0, 4*sys.maxint,-4*sys.maxint)
         self.assertRaises(ValueError, a.index, 2, 0, -10)
+
+    def test_free_after_iterating(self):
+        support.check_free_after_iterating(self, iter, self.type2test)
+        support.check_free_after_iterating(self, reversed, self.type2test)