python · ronaldoussoren · Dec 21, 2023 · Dec 21, 2023 · Dec 21, 2023 · Dec 21, 2023
@@ -176,6 +176,18 @@ def addpackage(sitedir, name, known_paths):
     except OSError:
         return
     with f:
+        if name.startswith("._"):
+            # MacOS will create "._" files next to a regular file
+            # when a filesystem driver needs to store metadata that
+            # cannot be stored natively. Such files are encoded
+            # in AppleDouble format.
+            # The test looks for the magic marker at the start of such
+            # files.
+            if f.buffer.read(4) == b"\x00\x05\x16\x07" \
+               and os.path.exists(os.path.join(sitedir, name[2:])):
+                    return
+            f.seek(0)
+
         for n, line in enumerate(f):
             if line.startswith("#"):
                 continue

@@ -181,6 +181,27 @@ def test_addpackage_import_bad_pth_file(self):
             if isinstance(path, str):
                 self.assertNotIn("abc\x00def", path)
 
+    def test_addpackage_macOS_resources(self):
+        # GH-113356
+        pth_dir, pth_fn = self.make_pth("dummy\n")
+        resource_fork = os.path.join(pth_dir, "._" + pth_fn)
+        with open(resource_fork, "wb") as fp:
+            self.addCleanup(lambda: os.remove(resource_fork))
+
+            # The bytes below were generated on macOS 14 using an
+            # exFAT filesystem. Command to write an xattr:
+            # `xattr -w key value test.txt`. These bytes are not
+            # the complete AppleDouble file, but just a significant
+            # prefix.
+            fp.write(b'\x00\x05\x16\x07\x00\x02\x00\x00Mac OS X        ')
+            fp.write(b'\x00\x02\x00\x00\x00\t\x00\x00\x002\x00\x00\x0e')
+            fp.write(b'\xb0\x00\x00\x00\x02\x00\x00\x0e\xe2\x00\x00')
+            fp.write(b'\x01\x1e')
+
+        with captured_stderr() as err_out:
+            self.assertFalse(site.addpackage(pth_dir, "._" + pth_fn, set()))
+        self.assertEqual(err_out.getvalue(), "")
+
     def test_addsitedir(self):
         # Same tests for test_addpackage since addsitedir() essentially just
         # calls addpackage() for every .pth file in the directory

diff --git a/Misc/NEWS.d/next/macOS/2023-12-21-14-18-24.gh-issue-113356.Vz2osH.rst b/Misc/NEWS.d/next/macOS/2023-12-21-14-18-24.gh-issue-113356.Vz2osH.rst
@@ -0,0 +1,3 @@
+Ignore "._" prefixed pth files when those cannot be parsed. These files are
+created on macOS when the system tries store metadata that is not supported
+by the filesystem (such as extended attributes on exFAT)