From 2eb0150396596794ea60f4c7283c2ce251b6e704 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Fri, 15 Nov 2019 13:06:04 +0100 Subject: [PATCH 1/2] bpo-38811: Check for presence of os.link method in pathlib MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 6b5b013bcc22 ("bpo-26978: Implement pathlib.Path.link_to (Using os.link) (GH-12990)") introduced a new link_to method in pathlib. However, this makes pathlib crash when the 'os' module is missing a 'link' method. Fix this by checking for the presence of the 'link' method on pathlib module import, and if it's not present, turn it into a runtime error like those emitted when there is no lchmod() or symlink(). Signed-off-by: Toke Høiland-Jørgensen --- Lib/pathlib.py | 7 ++++++- Lib/test/test_pathlib.py | 10 ++++++++++ .../Library/2019-11-15-18-06-04.bpo-38811.AmdQ6M.rst | 1 + 3 files changed, 17 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2019-11-15-18-06-04.bpo-38811.AmdQ6M.rst diff --git a/Lib/pathlib.py b/Lib/pathlib.py index d70fde0ea3b452..e2f90bc2cfe58f 100644 --- a/Lib/pathlib.py +++ b/Lib/pathlib.py @@ -418,7 +418,12 @@ def lchmod(self, pathobj, mode): unlink = os.unlink - link_to = os.link + if hasattr(os, "link"): + link_to = os.link + else: + @staticmethod + def link_to(self, target): + raise NotImplementedError("os.link() not available on this system") rmdir = os.rmdir diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py index 058a201aebc1d8..ebfa9fafc3a52c 100644 --- a/Lib/test/test_pathlib.py +++ b/Lib/test/test_pathlib.py @@ -1759,6 +1759,7 @@ def test_rmdir(self): self.assertFileNotFound(p.stat) self.assertFileNotFound(p.unlink) + @unittest.skipUnless(hasattr(os, "link"), "os.link() is not present") def test_link_to(self): P = self.cls(BASE) p = P / 'fileA' @@ -1778,6 +1779,15 @@ def test_link_to(self): self.assertEqual(os.stat(r).st_size, size) self.assertTrue(q.stat) + @unittest.skipIf(hasattr(os, "link"), "os.link() is present") + def test_link_to_not_implemented(self): + P = self.cls(BASE) + p = P / 'fileA' + # linking to another path. + q = P / 'dirA' / 'fileAA' + with self.assertRaises(NotImplementedError): + p.link_to(q) + def test_rename(self): P = self.cls(BASE) p = P / 'fileA' diff --git a/Misc/NEWS.d/next/Library/2019-11-15-18-06-04.bpo-38811.AmdQ6M.rst b/Misc/NEWS.d/next/Library/2019-11-15-18-06-04.bpo-38811.AmdQ6M.rst new file mode 100644 index 00000000000000..0e4a7f5bdf5383 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-11-15-18-06-04.bpo-38811.AmdQ6M.rst @@ -0,0 +1 @@ +Fix an unhandled exception in :mod:`pathlib` when :meth:`os.link` is missing. Patch by Toke Høiland-Jørgensen. From 9a219c681cee2fcac0625744924dbb60f17ced94 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Sat, 16 Nov 2019 18:18:19 +0100 Subject: [PATCH 2/2] Lib: Add pathlib test for missing symlink support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This adds a test case to test_pathlib.py to test the NotImplementedError raised when symlink support is not present on the system. Also add the missing @staticmethod decorator to the function definition in pathlib.py for that error path. Signed-off-by: Toke Høiland-Jørgensen --- Lib/pathlib.py | 1 + Lib/test/test_pathlib.py | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/Lib/pathlib.py b/Lib/pathlib.py index e2f90bc2cfe58f..5142ff68d100d4 100644 --- a/Lib/pathlib.py +++ b/Lib/pathlib.py @@ -435,6 +435,7 @@ def link_to(self, target): if supports_symlinks: symlink = os.symlink else: + @staticmethod def symlink(a, b, target_is_directory): raise NotImplementedError("symlink() not available on this system") else: diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py index ebfa9fafc3a52c..d05b956be39f36 100644 --- a/Lib/test/test_pathlib.py +++ b/Lib/test/test_pathlib.py @@ -2021,6 +2021,15 @@ def test_symlink_to(self): self.assertTrue(link.is_dir()) self.assertTrue(list(link.iterdir())) + @unittest.skipIf(support.can_symlink(), "symlink support is present") + def test_symlink_to_not_implemented(self): + P = self.cls(BASE) + target = P / 'fileA' + # Symlinking a path target. + link = P / 'dirA' / 'linkAA' + with self.assertRaises(NotImplementedError): + link.symlink_to(target) + def test_is_dir(self): P = self.cls(BASE) self.assertTrue((P / 'dirA').is_dir())