From 0846e5d4603434c2bbf8a528677cf1ff3fe29b95 Mon Sep 17 00:00:00 2001 From: Bar Harel Date: Mon, 23 Dec 2019 20:31:00 +0200 Subject: [3.8] bpo-38878: Fix os.PathLike __subclasshook__ (GH-17336) (GH-17684) https://bugs.python.org/issue38878 --- Lib/os.py | 6 +++++- Lib/test/test_os.py | 8 ++++++++ Misc/NEWS.d/next/Library/2019-11-22-12-08-52.bpo-38878.EJ0cFf.rst | 2 ++ 3 files changed, 15 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2019-11-22-12-08-52.bpo-38878.EJ0cFf.rst diff --git a/Lib/os.py b/Lib/os.py index 52d3f1d741..253cad1a59 100644 --- a/Lib/os.py +++ b/Lib/os.py @@ -26,6 +26,8 @@ import abc import sys import stat as st +from _collections_abc import _check_methods + _names = sys.builtin_module_names # Note: more names are added to __all__ later. @@ -1070,7 +1072,9 @@ class PathLike(abc.ABC): @classmethod def __subclasshook__(cls, subclass): - return hasattr(subclass, '__fspath__') + if cls is PathLike: + return _check_methods(subclass, '__fspath__') + return NotImplemented if name == 'nt': diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index 4a076e3bbf..11454b2e88 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -4017,6 +4017,14 @@ class TestPEP519(unittest.TestCase): self.assertRaises(ZeroDivisionError, self.fspath, FakePath(ZeroDivisionError())) + def test_pathlike_subclasshook(self): + # bpo-38878: subclasshook causes subclass checks + # true on abstract implementation. + class A(os.PathLike): + pass + self.assertFalse(issubclass(FakePath, A)) + self.assertTrue(issubclass(FakePath, os.PathLike)) + class TimesTests(unittest.TestCase): def test_times(self): diff --git a/Misc/NEWS.d/next/Library/2019-11-22-12-08-52.bpo-38878.EJ0cFf.rst b/Misc/NEWS.d/next/Library/2019-11-22-12-08-52.bpo-38878.EJ0cFf.rst new file mode 100644 index 0000000000..9cbdf08dd5 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-11-22-12-08-52.bpo-38878.EJ0cFf.rst @@ -0,0 +1,2 @@ +Fixed __subclasshook__ of :class:`os.PathLike` to return a correct result +upon inheritence. Patch by Bar Harel. -- cgit v1.2.1