diff options
| -rw-r--r-- | Lib/test/test_zipfile/test_core.py | 10 | ||||
| -rw-r--r-- | Lib/zipfile/__init__.py | 2 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2024-07-29-15-20-30.gh-issue-122356.wKCmFx.rst | 3 |
3 files changed, 13 insertions, 2 deletions
diff --git a/Lib/test/test_zipfile/test_core.py b/Lib/test/test_zipfile/test_core.py index 36f7f54..c36228c 100644 --- a/Lib/test/test_zipfile/test_core.py +++ b/Lib/test/test_zipfile/test_core.py @@ -1969,10 +1969,16 @@ class OtherTests(unittest.TestCase): zip_contents = fp.read() # - passing a file-like object fp = io.BytesIO() - fp.write(zip_contents) + end = fp.write(zip_contents) + self.assertEqual(fp.tell(), end) + mid = end // 2 + fp.seek(mid, 0) self.assertTrue(zipfile.is_zipfile(fp)) - fp.seek(0, 0) + # check that the position is left unchanged after the call + # see: https://github.com/python/cpython/issues/122356 + self.assertEqual(fp.tell(), mid) self.assertTrue(zipfile.is_zipfile(fp)) + self.assertEqual(fp.tell(), mid) def test_non_existent_file_raises_OSError(self): # make sure we don't raise an AttributeError when a partially-constructed diff --git a/Lib/zipfile/__init__.py b/Lib/zipfile/__init__.py index 08c83cf..6907ae6 100644 --- a/Lib/zipfile/__init__.py +++ b/Lib/zipfile/__init__.py @@ -241,7 +241,9 @@ def is_zipfile(filename): result = False try: if hasattr(filename, "read"): + pos = filename.tell() result = _check_zipfile(fp=filename) + filename.seek(pos) else: with open(filename, "rb") as fp: result = _check_zipfile(fp) diff --git a/Misc/NEWS.d/next/Library/2024-07-29-15-20-30.gh-issue-122356.wKCmFx.rst b/Misc/NEWS.d/next/Library/2024-07-29-15-20-30.gh-issue-122356.wKCmFx.rst new file mode 100644 index 0000000..0a4632c --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-07-29-15-20-30.gh-issue-122356.wKCmFx.rst @@ -0,0 +1,3 @@ +Guarantee that the position of a file-like object passed to +:func:`zipfile.is_zipfile` is left untouched after the call. +Patch by Bénédikt Tran. |