gh-81325: tarfile should accept a path-like object when writing a compressed gzip

Author: aeurielesn

Lib/tarfile.py

@@ -353,7 +353,7 @@ def __init__(self, name, mode, comptype, fileobj, bufsize,
             fileobj = _StreamProxy(fileobj)
             comptype = fileobj.getcomptype()
 
-        self.name     = name or ""
+        self.name     = os.fspath(name) if name is not None else ""
         self.mode     = mode
         self.comptype = comptype
         self.fileobj  = fileobj

Lib/test/test_tarfile.py

@@ -1737,6 +1737,16 @@ def test_file_mode(self):
         finally:
             os.umask(original_umask)
 
+    def test_pathlike_name(self):
+        expected_name = os.path.abspath(tmpname)
+        tarpath = os_helper.FakePath(tmpname)
+
+        for func in (tarfile.open, tarfile.TarFile.open):
+            with self.subTest():
+                with func(tarpath, self.mode) as tar:
+                    self.assertEqual(tar.name, expected_name)
+                    os_helper.unlink(tmpname)
+
 
 class GzipStreamWriteTest(GzipTest, StreamWriteTest):
     def test_source_directory_not_leaked(self):