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Diffstat (limited to 'Lib/test/pickletester.py')
| -rw-r--r-- | Lib/test/pickletester.py | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py index 953fd5c5a2..ba893f39c2 100644 --- a/Lib/test/pickletester.py +++ b/Lib/test/pickletester.py @@ -3499,6 +3499,30 @@ class AbstractHookTests(unittest.TestCase): ValueError, 'The reducer just failed'): p.dump(h) + @support.cpython_only + def test_reducer_override_no_reference_cycle(self): + # bpo-39492: reducer_override used to induce a spurious reference cycle + # inside the Pickler object, that could prevent all serialized objects + # from being garbage-collected without explicity invoking gc.collect. + + for proto in range(0, pickle.HIGHEST_PROTOCOL + 1): + with self.subTest(proto=proto): + def f(): + pass + + wr = weakref.ref(f) + + bio = io.BytesIO() + p = self.pickler_class(bio, proto) + p.dump(f) + new_f = pickle.loads(bio.getvalue()) + assert new_f == 5 + + del p + del f + + self.assertIsNone(wr()) + class AbstractDispatchTableTests(unittest.TestCase): |