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Diffstat (limited to 'Lib/test/test_builtin.py')
-rw-r--r-- | Lib/test/test_builtin.py | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py index bc5afdc..8e3a925 100644 --- a/Lib/test/test_builtin.py +++ b/Lib/test/test_builtin.py @@ -608,6 +608,23 @@ class BuiltinTest(unittest.TestCase): s2 = s.swapcase().swapcase() self.assert_(intern(s2) is s) + # Subclasses of string can't be interned, because they + # provide too much opportunity for insane things to happen. + # We don't want them in the interned dict and if they aren't + # actually interned, we don't want to create the appearance + # that they are by allowing intern() to succeeed. + class S(str): + def __hash__(self): + return 123 + + self.assertRaises(TypeError, intern, S("abc")) + + # It's still safe to pass these strings to routines that + # call intern internally, e.g. PyObject_SetAttr(). + s = S("abc") + setattr(s, s, s) + self.assertEqual(getattr(s, s), s) + def test_iter(self): self.assertRaises(TypeError, iter) self.assertRaises(TypeError, iter, 42, 42) |