Merge pull request #165 from sarugaku/permission-error-handling

Windows Permission error handling

Author: matteius

src/pythonfinder/finders/system_finder.py

@@ -57,7 +57,12 @@ def __init__(
         venv = os.environ.get("VIRTUAL_ENV")
         if venv:
             bin_dir = "Scripts" if os.name == "nt" else "bin"
-            venv_path = Path(venv).resolve() / bin_dir
+            try:
+                venv_path = Path(venv).resolve() / bin_dir
+            except (PermissionError, OSError):
+                # resolve() can raise PermissionError on Windows for restricted
+                # system directories; fall back to a non-resolving join.
+                venv_path = Path(venv) / bin_dir
 
             # For Windows tests with Unix-style paths
             if os.name == "nt" and str(venv).startswith("/"):

src/pythonfinder/utils/path_utils.py

@@ -238,11 +238,14 @@ def exists_and_is_accessible(path: Path) -> bool:
     """
     try:
         return path.exists()
-    except PermissionError as pe:
-        if pe.errno == errno.EACCES:  # Permission denied
+    except PermissionError as error:
+        if error.errno == errno.EACCES or getattr(error, "winerror", None) == 5:
             return False
-        else:
-            raise
+        raise
+    except OSError as error:
+        if error.errno == errno.EACCES or getattr(error, "winerror", None) == 5:
+            return False
+        raise
 
 
 def is_in_path(path: str | Path, parent_path: str | Path) -> bool:

tests/test_path_utils.py

@@ -241,6 +241,19 @@ def test_exists_and_is_accessible():
         ):
             exists_and_is_accessible(Path("/usr/bin/python"))
 
+    class WindowsAccessDenied(OSError):
+        def __init__(self):
+            super().__init__("Access is denied")
+            self.winerror = 5
+            self.errno = None
+
+    with mock.patch("pathlib.Path.exists", side_effect=WindowsAccessDenied()):
+        assert not exists_and_is_accessible(Path("/usr/bin/python"))
+
+    with pytest.raises(OSError):
+        with mock.patch("pathlib.Path.exists", side_effect=OSError(1, "Other error")):
+            exists_and_is_accessible(Path("/usr/bin/python"))
+
 
 def test_is_in_path():
     """Test that is_in_path correctly checks if a path is inside another path."""