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gh-88233: zipfile: handle extras after a zip64 extra (GH-96161) · python/cpython@62c0327 · GitHub
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gh-88233: zipfile: handle extras after a zip64 extra (GH-96161)
Previously, any data _after_ the zip64 extra would be removed. With many new tests. Fixes GH-88233 (cherry picked from commit 59e86ca) Co-authored-by: Tim Hatch <tim@timhatch.com> Automerge-Triggered-By: GH:jaraco
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‎Lib/test/test_zipfile.py‎

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@@ -3485,5 +3485,67 @@ def test_cli_with_metadata_encoding_extract(self):
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self.assertIn(name, listing)
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class StripExtraTests(unittest.TestCase):
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# Note: all of the "z" characters are technically invalid, but up
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# to 3 bytes at the end of the extra will be passed through as they
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# are too short to encode a valid extra.
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ZIP64_EXTRA = 1
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def test_no_data(self):
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s = struct.Struct("<HH")
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a = s.pack(self.ZIP64_EXTRA, 0)
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b = s.pack(2, 0)
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c = s.pack(3, 0)
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self.assertEqual(b'', zipfile._strip_extra(a, (self.ZIP64_EXTRA,)))
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self.assertEqual(b, zipfile._strip_extra(b, (self.ZIP64_EXTRA,)))
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self.assertEqual(
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b+b"z", zipfile._strip_extra(b+b"z", (self.ZIP64_EXTRA,)))
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self.assertEqual(b+c, zipfile._strip_extra(a+b+c, (self.ZIP64_EXTRA,)))
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self.assertEqual(b+c, zipfile._strip_extra(b+a+c, (self.ZIP64_EXTRA,)))
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self.assertEqual(b+c, zipfile._strip_extra(b+c+a, (self.ZIP64_EXTRA,)))
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def test_with_data(self):
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s = struct.Struct("<HH")
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a = s.pack(self.ZIP64_EXTRA, 1) + b"a"
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b = s.pack(2, 2) + b"bb"
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c = s.pack(3, 3) + b"ccc"
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self.assertEqual(b"", zipfile._strip_extra(a, (self.ZIP64_EXTRA,)))
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self.assertEqual(b, zipfile._strip_extra(b, (self.ZIP64_EXTRA,)))
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self.assertEqual(
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b+b"z", zipfile._strip_extra(b+b"z", (self.ZIP64_EXTRA,)))
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self.assertEqual(b+c, zipfile._strip_extra(a+b+c, (self.ZIP64_EXTRA,)))
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self.assertEqual(b+c, zipfile._strip_extra(b+a+c, (self.ZIP64_EXTRA,)))
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self.assertEqual(b+c, zipfile._strip_extra(b+c+a, (self.ZIP64_EXTRA,)))
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def test_multiples(self):
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s = struct.Struct("<HH")
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a = s.pack(self.ZIP64_EXTRA, 1) + b"a"
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b = s.pack(2, 2) + b"bb"
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self.assertEqual(b"", zipfile._strip_extra(a+a, (self.ZIP64_EXTRA,)))
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self.assertEqual(b"", zipfile._strip_extra(a+a+a, (self.ZIP64_EXTRA,)))
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self.assertEqual(
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b"z", zipfile._strip_extra(a+a+b"z", (self.ZIP64_EXTRA,)))
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self.assertEqual(
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b+b"z", zipfile._strip_extra(a+a+b+b"z", (self.ZIP64_EXTRA,)))
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self.assertEqual(b, zipfile._strip_extra(a+a+b, (self.ZIP64_EXTRA,)))
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self.assertEqual(b, zipfile._strip_extra(a+b+a, (self.ZIP64_EXTRA,)))
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self.assertEqual(b, zipfile._strip_extra(b+a+a, (self.ZIP64_EXTRA,)))
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def test_too_short(self):
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self.assertEqual(b"", zipfile._strip_extra(b"", (self.ZIP64_EXTRA,)))
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self.assertEqual(b"z", zipfile._strip_extra(b"z", (self.ZIP64_EXTRA,)))
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self.assertEqual(
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b"zz", zipfile._strip_extra(b"zz", (self.ZIP64_EXTRA,)))
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self.assertEqual(
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b"zzz", zipfile._strip_extra(b"zzz", (self.ZIP64_EXTRA,)))
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if __name__ == "__main__":
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unittest.main()

‎Lib/zipfile.py‎

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@@ -211,6 +211,8 @@ def _strip_extra(extra, xids):
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i = j
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if not modified:
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return extra
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if start != len(extra):
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buffer.append(extra[start:])
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return b''.join(buffer)
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def _check_zipfile(fp):

‎Misc/NEWS.d/next/Library/2022-09-05-12-17-34.gh-issue-88233.gff9qJ.rst‎

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Correctly preserve "extra" fields in ``zipfile`` regardless of their
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ordering relative to a zip64 "extra."

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