Fix EACCES-on-Windows sharing-violation check comparing args tuple to an int

fs/error_tools.py

@@ -84,7 +84,7 @@ def __exit__(
             _errno = exc_value.errno
             fserror = os_errors.get(_errno, errors.OperationFailed)
             if _errno == errno.EACCES and sys.platform == "win32":
-                if getattr(exc_value, "args", None) == 32:  # pragma: no cover
+                if getattr(exc_value, "winerror", None) == 32:  # pragma: no cover
                     fserror = errors.ResourceLocked
             reraise(fserror, fserror(self._path, exc=exc_value), traceback)
 

tests/test_error_tools.py

@@ -2,8 +2,10 @@
 
 import errno
 import unittest
+from unittest import mock
 
 import fs.errors
+from fs import error_tools
 from fs.error_tools import convert_os_errors
 
 
@@ -23,3 +25,16 @@ def test_convert_enametoolong(self):
                 raise exception
         self.assertEqual(ctx.exception.exc, exception)
         self.assertEqual(ctx.exception.path, "/tmp/test")
+
+    def test_convert_eacces_sharing_violation_on_windows(self):
+        # On Windows, EACCES with winerror 32 (ERROR_SHARING_VIOLATION)
+        # means the file is locked by another process, not a plain
+        # permissions problem.
+        exception = OSError(errno.EACCES, "file in use")
+        exception.winerror = 32
+        with mock.patch.object(error_tools.sys, "platform", "win32"):
+            with self.assertRaises(fs.errors.ResourceLocked) as ctx:
+                with convert_os_errors("open", "/tmp/test"):
+                    raise exception
+        self.assertEqual(ctx.exception.exc, exception)
+        self.assertEqual(ctx.exception.path, "/tmp/test")