gh-74696: Do not change the current working directory in shutil.make_archive() if possible

Doc/library/shutil.rst

@@ -574,12 +574,18 @@ provided. They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
 
  .. note::
 
- This function is not thread-safe.
+ This function is not thread-safe when custom archivers registered
+ with :func:`register_archive_format` are used. In this case it
+ temporarily changes the current working directory of the process
+ to perform archiving.
 
  .. versionchanged:: 3.8
  The modern pax (POSIX.1-2001) format is now used instead of
  the legacy GNU format for archives created with ``format="tar"``.
 
+ .. versionchanged:: 3.10.6
+ This function is now made thread-safe during creation of standard
+ ``.zip`` and tar archives.
 
 .. function:: get_archive_formats()
 

Lib/shutil.py

@@ -897,7 +897,7 @@ def _get_uid(name):
  return None
 
 def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
- owner=None, group=None, logger=None):
+ owner=None, group=None, logger=None, root_dir=None):
  """Create a (possibly compressed) tar file from all the files under
  'base_dir'.
 
@@ -954,14 +954,20 @@ def _set_uid_gid(tarinfo):
 
  if not dry_run:
  tar = tarfile.open(archive_name, 'w|%s' % tar_compression)
+ arcname = base_dir
+ if root_dir is not None:
+ base_dir = os.path.join(root_dir, base_dir)
  try:
- tar.add(base_dir, filter=_set_uid_gid)
+ tar.add(base_dir, arcname, filter=_set_uid_gid)
  finally:
  tar.close()
 
+ if root_dir is not None:
+ archive_name = os.path.abspath(archive_name)
  return archive_name
 
-def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
+def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0,
+ logger=None, owner=None, group=None, root_dir=None):
  """Create a zip file from all the files under 'base_dir'.
 
  The output zip file will be named 'base_name' + ".zip". Returns the
@@ -985,42 +991,60 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
  if not dry_run:
  with zipfile.ZipFile(zip_filename, "w",
  compression=zipfile.ZIP_DEFLATED) as zf:
- path = os.path.normpath(base_dir)
- if path != os.curdir:
- zf.write(path, path)
+ arcname = os.path.normpath(base_dir)
+ if root_dir is not None:
+ base_dir = os.path.join(root_dir, base_dir)
+ base_dir = os.path.normpath(base_dir)
+ if arcname != os.curdir:
+ zf.write(base_dir, arcname)
  if logger is not None:
- logger.info("adding '%s'", path)
+ logger.info("adding '%s'", base_dir)
  for dirpath, dirnames, filenames in os.walk(base_dir):
+ arcdirpath = dirpath
+ if root_dir is not None:
+ arcdirpath = os.path.relpath(arcdirpath, root_dir)
+ arcdirpath = os.path.normpath(arcdirpath)
  for name in sorted(dirnames):
- path = os.path.normpath(os.path.join(dirpath, name))
- zf.write(path, path)
+ path = os.path.join(dirpath, name)
+ arcname = os.path.join(arcdirpath, name)
+ zf.write(path, arcname)
  if logger is not None:
  logger.info("adding '%s'", path)
  for name in filenames:
- path = os.path.normpath(os.path.join(dirpath, name))
+ path = os.path.join(dirpath, name)
+ path = os.path.normpath(path)
  if os.path.isfile(path):
- zf.write(path, path)
+ arcname = os.path.join(arcdirpath, name)
+ zf.write(path, arcname)
  if logger is not None:
  logger.info("adding '%s'", path)
 
+ if root_dir is not None:
+ zip_filename = os.path.abspath(zip_filename)
  return zip_filename
 
+# Maps the name of the archive format to a tuple containing:
+# * the archiving function
+# * extra keyword arguments
+# * description
+# * does it support the root_dir argument?
 _ARCHIVE_FORMATS ={
- 'tar': (_make_tarball, [('compress', None)], "uncompressed tar file"),
+ 'tar': (_make_tarball, [('compress', None)],
+ "uncompressed tar file", True),
 }
 
 if _ZLIB_SUPPORTED:
  _ARCHIVE_FORMATS['gztar'] = (_make_tarball, [('compress', 'gzip')],
- "gzip'ed tar-file")
- _ARCHIVE_FORMATS['zip'] = (_make_zipfile, [], "ZIP file")
+ "gzip'ed tar-file", True)
+ _ARCHIVE_FORMATS['zip'] = (_make_zipfile, [], "ZIP file", True)
 
 if _BZ2_SUPPORTED:
  _ARCHIVE_FORMATS['bztar'] = (_make_tarball, [('compress', 'bzip2')],
- "bzip2'ed tar-file")
+ "bzip2'ed tar-file", True)
 
 if _LZMA_SUPPORTED:
  _ARCHIVE_FORMATS['xztar'] = (_make_tarball, [('compress', 'xz')],
- "xz'ed tar-file")
+ "xz'ed tar-file", True)
 
 def get_archive_formats():
  """Returns a list of supported formats for archiving and unarchiving.
@@ -1051,7 +1075,7 @@ def register_archive_format(name, function, extra_args=None, description=''):
  if not isinstance(element, (tuple, list)) or len(element) !=2:
  raise TypeError('extra_args elements are : (arg_name, value)')
 
- _ARCHIVE_FORMATS[name] = (function, extra_args, description)
+ _ARCHIVE_FORMATS[name] = (function, extra_args, description, False)
 
 def unregister_archive_format(name):
  del _ARCHIVE_FORMATS[name]
@@ -1075,36 +1099,38 @@ def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
  uses the current owner and group.
  """
  sys.audit("shutil.make_archive", base_name, format, root_dir, base_dir)
- save_cwd = os.getcwd()
- if root_dir is not None:
- if logger is not None:
- logger.debug("changing into '%s'", root_dir)
- base_name = os.path.abspath(base_name)
- if not dry_run:
- os.chdir(root_dir)
-
- if base_dir is None:
- base_dir = os.curdir
-
- kwargs ={'dry_run': dry_run, 'logger': logger}
-
  try:
  format_info = _ARCHIVE_FORMATS[format]
  except KeyError:
  raise ValueError("unknown archive format '%s'" % format) from None
 
+ kwargs ={'dry_run': dry_run, 'logger': logger,
+ 'owner': owner, 'group': group}
+
  func = format_info[0]
  for arg, val in format_info[1]:
  kwargs[arg] = val
 
- if format != 'zip':
- kwargs['owner'] = owner
- kwargs['group'] = group
+ if base_dir is None:
+ base_dir = os.curdir
+
+ support_root_dir = format_info[3]
+ save_cwd = None
+ if root_dir is not None:
+ if support_root_dir:
+ kwargs['root_dir'] = root_dir
+ else:
+ save_cwd = os.getcwd()
+ if logger is not None:
+ logger.debug("changing into '%s'", root_dir)
+ base_name = os.path.abspath(base_name)
+ if not dry_run:
+ os.chdir(root_dir)
 
  try:
  filename = func(base_name, base_dir, **kwargs)
  finally:
- if root_dir is not None:
+ if save_cwd is not None:
  if logger is not None:
  logger.debug("changing back to '%s'", save_cwd)
  os.chdir(save_cwd)
@@ -1217,6 +1243,11 @@ def _unpack_tarfile(filename, extract_dir):
  finally:
  tarobj.close()
 
+# Maps the name of the unpack format to a tuple containing:
+# * extensions
+# * the unpacking function
+# * extra keyword arguments
+# * description
 _UNPACK_FORMATS ={
  'tar': (['.tar'], _unpack_tarfile, [], "uncompressed tar file"),
  'zip': (['.zip'], _unpack_zipfile, [], "ZIP file"),

Lib/test/test_shutil.py

@@ -51,6 +51,9 @@
 except ImportError:
  _winapi = None
 
+no_chdir = unittest.mock.patch('os.chdir',
+ side_effect=AssertionError("shouldn't call os.chdir()"))
+
 def _fake_rename(*args, **kwargs):
  # Pretend the destination path is on a different filesystem.
  raise OSError(getattr(errno, 'EXDEV', 18), "Invalid cross-device link")
@@ -1342,7 +1345,7 @@ def test_make_tarball(self):
  work_dir = os.path.dirname(tmpdir2)
  rel_base_name = os.path.join(os.path.basename(tmpdir2), 'archive')
 
- with os_helper.change_cwd(work_dir):
+ with os_helper.change_cwd(work_dir), no_chdir:
  base_name = os.path.abspath(rel_base_name)
  tarball = make_archive(rel_base_name, 'gztar', root_dir, '.')
 
@@ -1356,7 +1359,7 @@ def test_make_tarball(self):
  './file1', './file2', './sub/file3'])
 
  # trying an uncompressed one
- with os_helper.change_cwd(work_dir):
+ with os_helper.change_cwd(work_dir), no_chdir:
  tarball = make_archive(rel_base_name, 'tar', root_dir, '.')
  self.assertEqual(tarball, base_name + '.tar')
  self.assertTrue(os.path.isfile(tarball))
@@ -1392,7 +1395,8 @@ def _create_files(self, base_dir='dist'):
  def test_tarfile_vs_tar(self):
  root_dir, base_dir = self._create_files()
  base_name = os.path.join(self.mkdtemp(), 'archive')
- tarball = make_archive(base_name, 'gztar', root_dir, base_dir)
+ with no_chdir:
+ tarball = make_archive(base_name, 'gztar', root_dir, base_dir)
 
  # check if the compressed tarball was created
  self.assertEqual(tarball, base_name + '.tar.gz')
@@ -1409,13 +1413,15 @@ def test_tarfile_vs_tar(self):
  self.assertEqual(self._tarinfo(tarball), self._tarinfo(tarball2))
 
  # trying an uncompressed one
- tarball = make_archive(base_name, 'tar', root_dir, base_dir)
+ with no_chdir:
+ tarball = make_archive(base_name, 'tar', root_dir, base_dir)
  self.assertEqual(tarball, base_name + '.tar')
  self.assertTrue(os.path.isfile(tarball))
 
  # now for a dry_run
- tarball = make_archive(base_name, 'tar', root_dir, base_dir,
- dry_run=True)
+ with no_chdir:
+ tarball = make_archive(base_name, 'tar', root_dir, base_dir,
+ dry_run=True)
  self.assertEqual(tarball, base_name + '.tar')
  self.assertTrue(os.path.isfile(tarball))
 
@@ -1431,7 +1437,7 @@ def test_make_zipfile(self):
  work_dir = os.path.dirname(tmpdir2)
  rel_base_name = os.path.join(os.path.basename(tmpdir2), 'archive')
 
- with os_helper.change_cwd(work_dir):
+ with os_helper.change_cwd(work_dir), no_chdir:
  base_name = os.path.abspath(rel_base_name)
  res = make_archive(rel_base_name, 'zip', root_dir)
 
@@ -1444,7 +1450,7 @@ def test_make_zipfile(self):
  'dist/file1', 'dist/file2', 'dist/sub/file3',
  'outer'])
 
- with os_helper.change_cwd(work_dir):
+ with os_helper.change_cwd(work_dir), no_chdir:
  base_name = os.path.abspath(rel_base_name)
  res = make_archive(rel_base_name, 'zip', root_dir, base_dir)
 
@@ -1462,7 +1468,8 @@ def test_make_zipfile(self):
  def test_zipfile_vs_zip(self):
  root_dir, base_dir = self._create_files()
  base_name = os.path.join(self.mkdtemp(), 'archive')
- archive = make_archive(base_name, 'zip', root_dir, base_dir)
+ with no_chdir:
+ archive = make_archive(base_name, 'zip', root_dir, base_dir)
 
  # check if ZIP file was created
  self.assertEqual(archive, base_name + '.zip')
@@ -1488,7 +1495,8 @@ def test_zipfile_vs_zip(self):
  def test_unzip_zipfile(self):
  root_dir, base_dir = self._create_files()
  base_name = os.path.join(self.mkdtemp(), 'archive')
- archive = make_archive(base_name, 'zip', root_dir, base_dir)
+ with no_chdir:
+ archive = make_archive(base_name, 'zip', root_dir, base_dir)
 
  # check if ZIP file was created
  self.assertEqual(archive, base_name + '.zip')
@@ -1546,7 +1554,7 @@ def test_tarfile_root_owner(self):
  base_name = os.path.join(self.mkdtemp(), 'archive')
  group = grp.getgrgid(0)[0]
  owner = pwd.getpwuid(0)[0]
- with os_helper.change_cwd(root_dir):
+ with os_helper.change_cwd(root_dir), no_chdir:
  archive_name = make_archive(base_name, 'gztar', root_dir, 'dist',
  owner=owner, group=group)
 
@@ -1564,31 +1572,38 @@ def test_tarfile_root_owner(self):
 
  def test_make_archive_cwd(self):
  current_dir = os.getcwd()
+ root_dir = self.mkdtemp()
  def _breaks(*args, **kw):
  raise RuntimeError()
+ dirs = []
+ def _chdir(path):
+ dirs.append(path)
+ orig_chdir(path)
 
  register_archive_format('xxx', _breaks, [], 'xxx file')
  try:
- try:
- make_archive('xxx', 'xxx', root_dir=self.mkdtemp())
- except Exception:
- pass
+ with support.swap_attr(os, 'chdir', _chdir) as orig_chdir:
+ try:
+ make_archive('xxx', 'xxx', root_dir=root_dir)
+ except Exception:
+ pass
  self.assertEqual(os.getcwd(), current_dir)
+ self.assertEqual(dirs, [root_dir, current_dir])
  finally:
  unregister_archive_format('xxx')
 
  def test_make_tarfile_in_curdir(self):
  # Issue #21280
  root_dir = self.mkdtemp()
- with os_helper.change_cwd(root_dir):
+ with os_helper.change_cwd(root_dir), no_chdir:
  self.assertEqual(make_archive('test', 'tar'), 'test.tar')
  self.assertTrue(os.path.isfile('test.tar'))
 
  @support.requires_zlib()
  def test_make_zipfile_in_curdir(self):
  # Issue #21280
  root_dir = self.mkdtemp()
- with os_helper.change_cwd(root_dir):
+ with os_helper.change_cwd(root_dir), no_chdir:
  self.assertEqual(make_archive('test', 'zip'), 'test.zip')
  self.assertTrue(os.path.isfile('test.zip'))
 

Misc/NEWS.d/next/Library/2022-05-24-11-19-04.gh-issue-74696.-cnf-A.rst

@@ -0,0 +1,2 @@
+:func:`shutil.make_archive` no longer temporarily changes the current
+working directory during creation of standard ``.zip`` or tar archives.