gh-112795: Allow / folder in a zipfile

Lib/test/test_zipfile/_path/test_path.py

@@ -577,3 +577,15 @@ def test_getinfo_missing(self, alpharep):
  zipfile.Path(alpharep)
  with self.assertRaises(KeyError):
  alpharep.getinfo('does-not-exist')
+
+ def test_root_folder_in_zipfile(self):
+ """
+ gh-112795: Some tools or self constructed codes will add '/' folder to
+ the zip file, this is a strange behavior, but we should support it.
+ """
+ in_memory_file = io.BytesIO()
+ zf = zipfile.ZipFile(in_memory_file, "w")
+ zf.mkdir('/')
+ zf.writestr('./a.txt', 'aaa')
+ tmpdir = pathlib.Path(self.fixtures.enter_context(temp_dir()))
+ zf.extractall(tmpdir)

Lib/zipfile/__init__.py

@@ -1772,7 +1772,7 @@ def _extract_member(self, member, targetpath, pwd):
  # filter illegal characters on Windows
  arcname = self._sanitize_windows_name(arcname, os.path.sep)
 
- if not arcname:
+ if not arcname and not member.is_dir():
  raise ValueError("Empty filename.")
 
  targetpath = os.path.join(targetpath, arcname)

Misc/NEWS.d/next/Library/2024-01-07-00-56-41.gh-issue-112932.OfhUu7.rst

@@ -0,0 +1,3 @@
+Restore the ability for :mod:`zipfile` to ``extractall`` from zip files with
+a "/" directory entry in them as is commonly added to zips by some wiki or
+bug tracker data exporters.