bpo-38355: Fix ntpath.realpath failing on sys.executable (GH-16551)

1 files changed, 9 insertions, 11 deletions

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 01f1f42..d4ecff9 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -560,13 +560,6 @@ else:
         return path
 
     def _getfinalpathname_nonstrict(path):
-        # Fast path to get the final path name. If this succeeds, there
-        # is no need to go any further.
-        try:
-            return _getfinalpathname(path)
-        except OSError:
-            pass
-
         # These error codes indicate that we should stop resolving the path
         # and return the value we currently have.
         # 1: ERROR_INVALID_FUNCTION
@@ -579,8 +572,9 @@ else:
         # 67: ERROR_BAD_NET_NAME (implies remote server unavailable)
         # 87: ERROR_INVALID_PARAMETER
         # 123: ERROR_INVALID_NAME
+        # 1920: ERROR_CANT_ACCESS_FILE
         # 1921: ERROR_CANT_RESOLVE_FILENAME (implies unfollowable symlink)
-        allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 67, 87, 123, 1921
+        allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 67, 87, 123, 1920, 1921
 
         # Non-strict algorithm is to find as much of the target directory
         # as we can and join the rest.
@@ -615,9 +609,13 @@ else:
             unc_prefix = '\\\\?\\UNC\\'
             new_unc_prefix = '\\\\'
             cwd = os.getcwd()
-        did_not_exist = not exists(path)
         had_prefix = path.startswith(prefix)
-        path = _getfinalpathname_nonstrict(path)
+        try:
+            path = _getfinalpathname(path)
+            initial_winerror = 0
+        except OSError as ex:
+            initial_winerror = ex.winerror
+            path = _getfinalpathname_nonstrict(path)
         # The path returned by _getfinalpathname will always start with \\?\ -
         # strip off that prefix unless it was already provided on the original
         # path.
@@ -635,7 +633,7 @@ else:
             except OSError as ex:
                 # If the path does not exist and originally did not exist, then
                 # strip the prefix anyway.
-                if ex.winerror in {2, 3} and did_not_exist:
+                if ex.winerror == initial_winerror:
                     path = spath
         return path