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

__bytes__, __trunc__, and __float__ returning instances of subclasses of
bytes, int, and float to subclasses of bytes, int, and float correspondingly.

1 files changed, 7 insertions, 4 deletions

diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index 56a60df007..ce8df40d16 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -43,6 +43,9 @@ def duplicate_string(text):
     """
     return text.encode().decode()
 
+class StrSubclass(str):
+    pass
+
 class UnicodeTest(string_tests.CommonTest,
         string_tests.MixinStrUnicodeUserStringTest,
         string_tests.MixinStrUnicodeTest,
@@ -1441,11 +1444,8 @@ class UnicodeTest(string_tests.CommonTest,
             'unicode remains unicode'
         )
 
-        class UnicodeSubclass(str):
-            pass
-
         for text in ('ascii', '\xe9', '\u20ac', '\U0010FFFF'):
-            subclass = UnicodeSubclass(text)
+            subclass = StrSubclass(text)
             self.assertEqual(str(subclass), text)
             self.assertEqual(len(subclass), len(text))
             if text == 'ascii':
@@ -2199,6 +2199,9 @@ class UnicodeTest(string_tests.CommonTest,
         s = str(StrSubclassToStrSubclass("foo"))
         self.assertEqual(s, "foofoo")
         self.assertIs(type(s), StrSubclassToStrSubclass)
+        s = StrSubclass(StrSubclassToStrSubclass("foo"))
+        self.assertEqual(s, "foofoo")
+        self.assertIs(type(s), StrSubclass)
 
     def test_unicode_repr(self):
         class s1: