bpo-26660, bpo-35144: Fix permission errors in TemporaryDirectory cleanup. (GH-10320)

TemporaryDirectory.cleanup() failed when non-writeable or non-searchable
files or directories were created inside a temporary directory.

1 files changed, 32 insertions, 2 deletions

diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index a66d6f3750..e8b111eae2 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -778,8 +778,38 @@ class TemporaryDirectory(object):
             warn_message="Implicitly cleaning up {!r}".format(self))
 
     @classmethod
+    def _rmtree(cls, name):
+        def onerror(func, path, exc_info):
+            if issubclass(exc_info[0], PermissionError):
+                def resetperms(path):
+                    try:
+                        _os.chflags(path, 0)
+                    except AttributeError:
+                        pass
+                    _os.chmod(path, 0o700)
+
+                try:
+                    if path != name:
+                        resetperms(_os.path.dirname(path))
+                    resetperms(path)
+
+                    try:
+                        _os.unlink(path)
+                    # PermissionError is raised on FreeBSD for directories
+                    except (IsADirectoryError, PermissionError):
+                        cls._rmtree(path)
+                except FileNotFoundError:
+                    pass
+            elif issubclass(exc_info[0], FileNotFoundError):
+                pass
+            else:
+                raise
+
+        _shutil.rmtree(name, onerror=onerror)
+
+    @classmethod
     def _cleanup(cls, name, warn_message):
-        _shutil.rmtree(name)
+        cls._rmtree(name)
         _warnings.warn(warn_message, ResourceWarning)
 
     def __repr__(self):
@@ -793,4 +823,4 @@ class TemporaryDirectory(object):
 
     def cleanup(self):
         if self._finalizer.detach():
-            _shutil.rmtree(self.name)
+            self._rmtree(self.name)