Issue #24731: Fixed crash on converting objects with special methods

__str__, __trunc__, and __float__ returning instances of subclasses of
str, long, and float to subclasses of str, long, and float correspondingly.

1 files changed, 15 insertions, 0 deletions

diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py
index 2ca6cf2..0dd8efc 100644
--- a/Lib/test/test_int.py
+++ b/Lib/test/test_int.py
@@ -45,6 +45,9 @@ if have_unicode:
         (unichr(0x200), ValueError),
 ]
 
+class IntSubclass(int):
+    pass
+
 class IntLongCommonTests(object):
 
     """Mixin of test cases to share between both test_int and test_long."""
@@ -477,6 +480,18 @@ class IntTestCases(IntLongCommonTests, unittest.TestCase):
                     self.fail("Failed to raise TypeError with %s" %
                               ((base, trunc_result_base),))
 
+                class TruncReturnsIntSubclass(base):
+                    def __trunc__(self):
+                        return True
+                good_int = TruncReturnsIntSubclass()
+                n = int(good_int)
+                self.assertEqual(n, 1)
+                self.assertIs(type(n), bool)
+                n = IntSubclass(good_int)
+                self.assertEqual(n, 1)
+                self.assertIs(type(n), IntSubclass)
+
+
 def test_main():
     run_unittest(IntTestCases)