gh-113659: Skip hidden .pth files (GH-113660)

Skip .pth files with names starting with a dot or hidden file attribute.

Lib/site.py

@@ -74,6 +74,7 @@ import os
 import builtins
 import _sitebuiltins
 import io
+import stat
 
 # Prefixes for site-packages; add additional prefixes like /usr/local here
 PREFIXES = [sys.prefix, sys.exec_prefix]
@@ -168,6 +169,14 @@ def addpackage(sitedir, name, known_paths):
     else:
         reset = False
     fullname = os.path.join(sitedir, name)
+    try:
+        st = os.lstat(fullname)
+    except OSError:
+        return
+    if ((getattr(st, 'st_flags', 0) & stat.UF_HIDDEN) or
+        (getattr(st, 'st_file_attributes', 0) & stat.FILE_ATTRIBUTE_HIDDEN)):
+        _trace(f"Skipping hidden .pth file: {fullname!r}")
+        return
     _trace(f"Processing .pth file: {fullname!r}")
     try:
         # locale encoding is not ideal especially on Windows. But we have used
@@ -221,7 +230,8 @@ def addsitedir(sitedir, known_paths=None):
         names = os.listdir(sitedir)
     except OSError:
         return
-    names = [name for name in names if name.endswith(".pth")]
+    names = [name for name in names
+             if name.endswith(".pth") and not name.startswith(".")]
     for name in sorted(names):
         addpackage(sitedir, name, known_paths)
     if reset:

Lib/test/test_site.py

@@ -19,6 +19,7 @@ import io
 import os
 import re
 import shutil
+import stat
 import subprocess
 import sys
 import sysconfig
@@ -195,6 +196,45 @@ class HelperFunctionsTests(unittest.TestCase):
         finally:
             pth_file.cleanup()
 
+    def test_addsitedir_dotfile(self):
+        pth_file = PthFile('.dotfile')
+        pth_file.cleanup(prep=True)
+        try:
+            pth_file.create()
+            site.addsitedir(pth_file.base_dir, set())
+            self.assertNotIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
+            self.assertIn(pth_file.base_dir, sys.path)
+        finally:
+            pth_file.cleanup()
+
+    @unittest.skipUnless(hasattr(os, 'chflags'), 'test needs os.chflags()')
+    def test_addsitedir_hidden_flags(self):
+        pth_file = PthFile()
+        pth_file.cleanup(prep=True)
+        try:
+            pth_file.create()
+            st = os.stat(pth_file.file_path)
+            os.chflags(pth_file.file_path, st.st_flags | stat.UF_HIDDEN)
+            site.addsitedir(pth_file.base_dir, set())
+            self.assertNotIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
+            self.assertIn(pth_file.base_dir, sys.path)
+        finally:
+            pth_file.cleanup()
+
+    @unittest.skipUnless(sys.platform == 'win32', 'test needs Windows')
+    @support.requires_subprocess()
+    def test_addsitedir_hidden_file_attribute(self):
+        pth_file = PthFile()
+        pth_file.cleanup(prep=True)
+        try:
+            pth_file.create()
+            subprocess.check_call(['attrib', '+H', pth_file.file_path])
+            site.addsitedir(pth_file.base_dir, set())
+            self.assertNotIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
+            self.assertIn(pth_file.base_dir, sys.path)
+        finally:
+            pth_file.cleanup()
+
     # This tests _getuserbase, hence the double underline
     # to distinguish from a test for getuserbase
     def test__getuserbase(self):

Misc/NEWS.d/next/Security/2024-01-02-19-52-23.gh-issue-113659.DkmnQc.rst

@@ -0,0 +1 @@
+Skip ``.pth`` files with names starting with a dot or hidden file attribute.