https://github.com/python/cpython/commit/7ed6c5c6961d0849f163d4d449fb36bae312b6bc commit: 7ed6c5c6961d0849f163d4d449fb36bae312b6bc branch: main author: Dima Ryazanov <[email protected]> committer: jaraco <[email protected]> date: 2024-12-24T15:56:42Z summary:
gh-127847: Fix position in the special-cased zipfile seek (#127856) --------- Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com> Co-authored-by: Peter Bierma <[email protected]> Co-authored-by: Jason R. Coombs <[email protected]> files: A Misc/NEWS.d/next/Library/2024-12-12-07-27-51.gh-issue-127847.ksfNKM.rst M Lib/test/test_zipfile/test_core.py M Lib/zipfile/__init__.py diff --git a/Lib/test/test_zipfile/test_core.py b/Lib/test/test_zipfile/test_core.py index c36228c033a414..124e088fd15b80 100644 --- a/Lib/test/test_zipfile/test_core.py +++ b/Lib/test/test_zipfile/test_core.py @@ -2333,6 +2333,18 @@ def test_read_after_seek(self): fp.seek(1, os.SEEK_CUR) self.assertEqual(fp.read(-1), b'men!') + def test_uncompressed_interleaved_seek_read(self): + # gh-127847: Make sure the position in the archive is correct + # in the special case of seeking in a ZIP_STORED entry. + with zipfile.ZipFile(TESTFN, "w") as zipf: + zipf.writestr("a.txt", "123") + zipf.writestr("b.txt", "456") + with zipfile.ZipFile(TESTFN, "r") as zipf: + with zipf.open("a.txt", "r") as a, zipf.open("b.txt", "r") as b: + self.assertEqual(a.read(1), b"1") + self.assertEqual(b.seek(1), 1) + self.assertEqual(b.read(1), b"5") + @requires_bz2() def test_decompress_without_3rd_party_library(self): data = b'PK\x05\x06\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' diff --git a/Lib/zipfile/__init__.py b/Lib/zipfile/__init__.py index 6907ae6d5b7464..f4d396abb6e639 100644 --- a/Lib/zipfile/__init__.py +++ b/Lib/zipfile/__init__.py @@ -819,7 +819,10 @@ def seek(self, offset, whence=0): raise ValueError("Can't reposition in the ZIP file while " "there is an open writing handle on it. " "Close the writing handle before trying to read.") - self._file.seek(offset, whence) + if whence == os.SEEK_CUR: + self._file.seek(self._pos + offset) + else: + self._file.seek(offset, whence) self._pos = self._file.tell() return self._pos diff --git a/Misc/NEWS.d/next/Library/2024-12-12-07-27-51.gh-issue-127847.ksfNKM.rst b/Misc/NEWS.d/next/Library/2024-12-12-07-27-51.gh-issue-127847.ksfNKM.rst new file mode 100644 index 00000000000000..3d6e36fb538bca --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-12-12-07-27-51.gh-issue-127847.ksfNKM.rst @@ -0,0 +1 @@ +Fix the position when doing interleaved seeks and reads in uncompressed, unencrypted zip files returned by :meth:`zipfile.ZipFile.open`. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
