tarfile-write issue with file/folder permissions

Context

I've been playing with tarfile for a few days and yesterday started trying to create my own archives using tarfile-write installed via mip.

Adding a folder to it works recursively, but transferring the file to the PC via mpremote and expanding it yields all files and folders with --- --- --- permissions (0x000).

Discovery

I investigated and found the source of the issue is related to how the TarInfo object is composed in these lines

in particular on line 102 we find mode to be set to the os.stat(FILE)[0]

tarinfo.mode = stat[0]

stat[0] is either 0x8000 (file) or 0x4000 (folder).
And the subsequently applied masking yields 0x000 as permissions set while adding it to the archive.
I think that mode should be safely set to 0x1a4 > 644 > rw- r-- r--

I have tested by manually composing a TarInfo object to be handed to addfile() rather than patching add()

How to reproduce:

import tarfile
import os

os.mkdir('test_folder')
f = open('test_folder/test_file_01.txt', 'w')
f.write('file 01')
f.close()

os.mkdir('test_folder/sub_folder')

f = open('test_folder/sub_folder/test_file_02.txt', 'w')
f.write('file 02')
f.close()

archive = tarfile.TarFile('test_archive.tar', 'w')
archive.add('test_folder')
archive.close()

Copy the archive from the board to the PC via mpremote cp :test_archive.tar test_archive.tar

Expand the archive and verify the permissions for test_folder.
From Mac os I was not able to chmod 644 test_folder, but using the UI I could unrestrict access.

Looking at the folder content you can verify the same permission issue happens with sub_folder and contained file(s)

Environment:
I run a custom build for ESP32-S3, but this issue is not related to changes I have applied
(name='micropython', version=(1, 23, 0, 'preview'), _machine='LilyGo T-QT Pro with ESP32S3', _mpy=10758)

MicroPython v1.23.0-preview.48.g076516d88.dirty on 2024-01-21; LilyGo T-QT Pro with ESP32S3
Board: ESP32-S3
TarFile version: '0.4.1'

Hope someone can take a look :)
u.

Inizia in python-stdlib/tarfile-write/tarfile/write.py, nella composizione di TarInfo intorno alle righe 102-106, quindi esegui la riproduzione usando tarfile.TarFile.add() e controlla i permessi dell’archivio estratto. Confronta la modalità derivata da stat con la modalità memorizzata nell’archivio; il lavoro è completato quando i file e le cartelle estratti mantengono permessi utilizzabili invece di 0x000.