Changed how pytest reacts to long filenames and changed its test

src/_pytest/config/__init__.py

@@ -529,14 +529,12 @@ class PytestPluginManager(PluginManager):
                 path = path[:i]
             anchor = absolutepath(current / path)
             try:
-                if anchor.exists():  # we found some file object
-                    self._try_load_conftest(anchor, namespace.importmode, rootpath)
-                    foundanchor = True
-                print(str(anchor))
+                anchor_exists = anchor.exists()
             except OSError:
-                import pytest
-
-                raise pytest.UsageError(f"filename is too long: {anchor}")
+                anchor_exists = False
+            if anchor_exists:
+                self._try_load_conftest(anchor, namespace.importmode, rootpath)
+                foundanchor = True
         if not foundanchor:
             self._try_load_conftest(current, namespace.importmode, rootpath)
 

testing/test_config.py

@@ -1780,24 +1780,25 @@ def test_help_and_version_after_argument_error(pytester: Pytester) -> None:
     assert result.ret == ExitCode.USAGE_ERROR
 
 
-def test_filename_too_long(pytester: Pytester) -> None:
+def test_filename_too_long(pytester: Pytester, monkeypatch: MonkeyPatch) -> None:
+    """And OSError may be raised if filename is too long. This test ensures
+    the issue of that error not being caught does not regress."""
+
     path_str = (
-        "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-        + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-        + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-        + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-        + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+        "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" * 50
     )
+
+    def FilePathTooLong(p):
+        if len(str(p)) >= 200:
+            raise OSError()
+
+    monkeypatch.setattr(Path, "exists", FilePathTooLong, raising=True)
+
     config = pytester.parseconfig()
     config.known_args_namespace.file_or_dir.append(path_str)
-    pytest.raises(
-        UsageError,
-        config.pluginmanager._set_initial_conftests,
-        config.known_args_namespace,
-        rootpath=config.rootpath,
+    config.pluginmanager._set_initial_conftests(
+        config.known_args_namespace, rootpath=config.rootpath
     )
-    result = pytester.runpytest(path_str)
-    assert result.ret == ExitCode.USAGE_ERROR
 
 
 def test_help_formatter_uses_py_get_terminal_width(monkeypatch: MonkeyPatch) -> None: