Use _pytest.pathlib.safe_exists in get_dirs_from_args (#11407)

Related to #11394

Author: nicoddemus

src/_pytest/config/__init__.py

@@ -59,6 +59,7 @@
 from _pytest.pathlib import import_path
 from _pytest.pathlib import ImportMode
 from _pytest.pathlib import resolve_package_path
+from _pytest.pathlib import safe_exists
 from _pytest.stash import Stash
 from _pytest.warning_types import PytestConfigWarning
 from _pytest.warning_types import warn_explicit_for
@@ -562,12 +563,8 @@ def _set_initial_conftests(
             anchor = absolutepath(current / path)
 
             # Ensure we do not break if what appears to be an anchor
-            # is in fact a very long option (#10169).
-            try:
-                anchor_exists = anchor.exists()
-            except OSError:  # pragma: no cover
-                anchor_exists = False
-            if anchor_exists:
+            # is in fact a very long option (#10169, #11394).
+            if safe_exists(anchor):
                 self._try_load_conftest(anchor, importmode, rootpath)
                 foundanchor = True
         if not foundanchor:

src/_pytest/config/findpaths.py

@@ -15,6 +15,7 @@
 from _pytest.outcomes import fail
 from _pytest.pathlib import absolutepath
 from _pytest.pathlib import commonpath
+from _pytest.pathlib import safe_exists
 
 
 def _parse_ini_config(path: Path) -> iniconfig.IniConfig:
@@ -147,14 +148,6 @@ def get_dir_from_path(path: Path) -> Path:
             return path
         return path.parent
 
-    def safe_exists(path: Path) -> bool:
-        # This can throw on paths that contain characters unrepresentable at the OS level,
-        # or with invalid syntax on Windows (https://bugs.python.org/issue35306)
-        try:
-            return path.exists()
-        except OSError:
-            return False
-
     # These look like paths but may not exist
     possible_paths = (
         absolutepath(get_file_part_from_node_id(arg))

src/_pytest/pathlib.py

@@ -1,6 +1,5 @@
 import atexit
 import contextlib
-import errno
 import fnmatch
 import importlib.util
 import itertools
@@ -780,7 +779,7 @@ def safe_exists(p: Path) -> bool:
     """Like Path.exists(), but account for input arguments that might be too long (#11394)."""
     try:
         return p.exists()
-    except OSError as e:
-        if e.errno == errno.ENAMETOOLONG:
-            return False
-        raise
+    except (ValueError, OSError):
+        # ValueError: stat: path too long for Windows
+        # OSError: [WinError 123] The filename, directory name, or volume label syntax is incorrect
+        return False

testing/test_pathlib.py

@@ -688,7 +688,6 @@ def test_safe_exists(tmp_path: Path) -> None:
         Path,
         "exists",
         autospec=True,
-        side_effect=OSError(errno.EIO, "another kind of error"),
+        side_effect=ValueError("name too long"),
     ):
-        with pytest.raises(OSError):
-            _ = safe_exists(p)
+        assert safe_exists(p) is False