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author | Steve Dower <steve.dower@microsoft.com> | 2017-02-04 15:05:40 -0800 |
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committer | Steve Dower <steve.dower@microsoft.com> | 2017-02-04 15:05:40 -0800 |
commit | b2fa705fd3887c326e811c418469c784353027f4 (patch) | |
tree | b3428f73de91453edbfd4df1a5d4a212d182eb44 /Lib/test/test_contains.py | |
parent | 134e58fd3aaa2e91390041e143f3f0a21a60142b (diff) | |
parent | b53654b6dbfce8318a7d4d1cdaddca7a7fec194b (diff) | |
download | cpython-b2fa705fd3887c326e811c418469c784353027f4.tar.gz |
Issue #29392: Prevent crash when passing invalid arguments into msvcrt module.
Diffstat (limited to 'Lib/test/test_contains.py')
-rw-r--r-- | Lib/test/test_contains.py | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Lib/test/test_contains.py b/Lib/test/test_contains.py index 3c6bdeffda..036a1d012d 100644 --- a/Lib/test/test_contains.py +++ b/Lib/test/test_contains.py @@ -84,6 +84,31 @@ class TestContains(unittest.TestCase): self.assertTrue(container == constructor(values)) self.assertTrue(container == container) + def test_block_fallback(self): + # blocking fallback with __contains__ = None + class ByContains(object): + def __contains__(self, other): + return False + c = ByContains() + class BlockContains(ByContains): + """Is not a container + + This class is a perfectly good iterable (as tested by + list(bc)), as well as inheriting from a perfectly good + container, but __contains__ = None prevents the usual + fallback to iteration in the container protocol. That + is, normally, 0 in bc would fall back to the equivalent + of any(x==0 for x in bc), but here it's blocked from + doing so. + """ + def __iter__(self): + while False: + yield None + __contains__ = None + bc = BlockContains() + self.assertFalse(0 in c) + self.assertFalse(0 in list(bc)) + self.assertRaises(TypeError, lambda: 0 in bc) if __name__ == '__main__': unittest.main() |