diff options
| -rw-r--r-- | Lib/test/test_zipfile.py | 14 | ||||
| -rw-r--r-- | Lib/zipfile.py | 22 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2018-08-06-11-01-18.bpo-34341.E0b9p2.rst | 2 |
3 files changed, 38 insertions, 0 deletions
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py index 4c6f57c..7b8922f 100644 --- a/Lib/test/test_zipfile.py +++ b/Lib/test/test_zipfile.py @@ -770,6 +770,20 @@ class StoredTestZip64InSmallFiles(AbstractTestZip64InSmallFiles, with zipfile.ZipFile(TESTFN2, "r", zipfile.ZIP_STORED) as zipfp: self.assertEqual(zipfp.namelist(), ["absolute"]) + def test_append(self): + # Test that appending to the Zip64 archive doesn't change + # extra fields of existing entries. + with zipfile.ZipFile(TESTFN2, "w", allowZip64=True) as zipfp: + zipfp.writestr("strfile", self.data) + with zipfile.ZipFile(TESTFN2, "r", allowZip64=True) as zipfp: + zinfo = zipfp.getinfo("strfile") + extra = zinfo.extra + with zipfile.ZipFile(TESTFN2, "a", allowZip64=True) as zipfp: + zipfp.writestr("strfile2", self.data) + with zipfile.ZipFile(TESTFN2, "r", allowZip64=True) as zipfp: + zinfo = zipfp.getinfo("strfile") + self.assertEqual(zinfo.extra, extra) + @requires_zlib class DeflateTestZip64InSmallFiles(AbstractTestZip64InSmallFiles, unittest.TestCase): diff --git a/Lib/zipfile.py b/Lib/zipfile.py index 7f23778..89df90b 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -159,6 +159,27 @@ _CD64_NUMBER_ENTRIES_TOTAL = 7 _CD64_DIRECTORY_SIZE = 8 _CD64_OFFSET_START_CENTDIR = 9 +_EXTRA_FIELD_STRUCT = struct.Struct('<HH') + +def _strip_extra(extra, xids): + # Remove Extra Fields with specified IDs. + unpack = _EXTRA_FIELD_STRUCT.unpack + modified = False + buffer = [] + start = i = 0 + while i + 4 <= len(extra): + xid, xlen = unpack(extra[i : i + 4]) + j = i + 4 + xlen + if xid in xids: + if i != start: + buffer.append(extra[start : i]) + start = j + modified = True + i = j + if not modified: + return extra + return b''.join(buffer) + def _check_zipfile(fp): try: if _EndRecData(fp): @@ -1819,6 +1840,7 @@ class ZipFile: min_version = 0 if extra: # Append a ZIP64 field to the extra's + extra_data = _strip_extra(extra_data, (1,)) extra_data = struct.pack( '<HH' + 'Q'*len(extra), 1, 8*len(extra), *extra) + extra_data diff --git a/Misc/NEWS.d/next/Library/2018-08-06-11-01-18.bpo-34341.E0b9p2.rst b/Misc/NEWS.d/next/Library/2018-08-06-11-01-18.bpo-34341.E0b9p2.rst new file mode 100644 index 0000000..46a9cde --- /dev/null +++ b/Misc/NEWS.d/next/Library/2018-08-06-11-01-18.bpo-34341.E0b9p2.rst @@ -0,0 +1,2 @@ +Appending to the ZIP archive with the ZIP64 extension no longer grows the +size of extra fields of existing entries. |