From: Serhiy Storchaka Date: Fri, 7 Oct 2016 20:12:53 +0000 (+0300) Subject: Issue #26293: Fixed writing ZIP files that starts not from the start of the X-Git-Tag: v2.7.13rc1~86 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=58ab4b57da2e5db7ff9b9940dd21bbbe4d804957;p=python Issue #26293: Fixed writing ZIP files that starts not from the start of the file. Offsets in ZIP file now are relative to the start of the archive in conforming to the specification. --- diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py index 4000b30be8..986808131e 100644 --- a/Lib/test/test_zipfile.py +++ b/Lib/test/test_zipfile.py @@ -344,6 +344,49 @@ class TestsWithSourceFile(unittest.TestCase): f.seek(len(data)) with zipfile.ZipFile(f, "r") as zipfp: self.assertEqual(zipfp.namelist(), [TESTFN]) + self.assertEqual(zipfp.read(TESTFN), self.data) + with open(TESTFN2, 'rb') as f: + self.assertEqual(f.read(len(data)), data) + zipfiledata = f.read() + with io.BytesIO(zipfiledata) as bio, zipfile.ZipFile(bio) as zipfp: + self.assertEqual(zipfp.namelist(), [TESTFN]) + self.assertEqual(zipfp.read(TESTFN), self.data) + + def test_read_concatenated_zip_file(self): + with io.BytesIO() as bio: + with zipfile.ZipFile(bio, 'w', zipfile.ZIP_STORED) as zipfp: + zipfp.write(TESTFN, TESTFN) + zipfiledata = bio.getvalue() + data = b'I am not a ZipFile!'*10 + with open(TESTFN2, 'wb') as f: + f.write(data) + f.write(zipfiledata) + + with zipfile.ZipFile(TESTFN2) as zipfp: + self.assertEqual(zipfp.namelist(), [TESTFN]) + self.assertEqual(zipfp.read(TESTFN), self.data) + + def test_append_to_concatenated_zip_file(self): + with io.BytesIO() as bio: + with zipfile.ZipFile(bio, 'w', zipfile.ZIP_STORED) as zipfp: + zipfp.write(TESTFN, TESTFN) + zipfiledata = bio.getvalue() + data = b'I am not a ZipFile!'*1000000 + with open(TESTFN2, 'wb') as f: + f.write(data) + f.write(zipfiledata) + + with zipfile.ZipFile(TESTFN2, 'a') as zipfp: + self.assertEqual(zipfp.namelist(), [TESTFN]) + zipfp.writestr('strfile', self.data) + + with open(TESTFN2, 'rb') as f: + self.assertEqual(f.read(len(data)), data) + zipfiledata = f.read() + with io.BytesIO(zipfiledata) as bio, zipfile.ZipFile(bio) as zipfp: + self.assertEqual(zipfp.namelist(), [TESTFN, 'strfile']) + self.assertEqual(zipfp.read(TESTFN), self.data) + self.assertEqual(zipfp.read('strfile'), self.data) def test_ignores_newline_at_end(self): with zipfile.ZipFile(TESTFN2, "w", zipfile.ZIP_STORED) as zipfp: diff --git a/Lib/zipfile.py b/Lib/zipfile.py index 3ab66cea69..1d1065083b 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -772,6 +772,7 @@ class ZipFile(object): # set the modified flag so central directory gets written # even if no files are added to the archive self._didModify = True + self._start_disk = self.fp.tell() elif key == 'a': try: # See if file is a zip file @@ -785,6 +786,7 @@ class ZipFile(object): # set the modified flag so central directory gets written # even if no files are added to the archive self._didModify = True + self._start_disk = self.fp.tell() else: raise RuntimeError('Mode must be "r", "w" or "a"') except: @@ -815,17 +817,18 @@ class ZipFile(object): offset_cd = endrec[_ECD_OFFSET] # offset of central directory self._comment = endrec[_ECD_COMMENT] # archive comment - # "concat" is zero, unless zip was concatenated to another file - concat = endrec[_ECD_LOCATION] - size_cd - offset_cd + # self._start_disk: Position of the start of ZIP archive + # It is zero, unless ZIP was concatenated to another file + self._start_disk = endrec[_ECD_LOCATION] - size_cd - offset_cd if endrec[_ECD_SIGNATURE] == stringEndArchive64: # If Zip64 extension structures are present, account for them - concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator) + self._start_disk -= (sizeEndCentDir64 + sizeEndCentDir64Locator) if self.debug > 2: - inferred = concat + offset_cd - print "given, inferred, offset", offset_cd, inferred, concat + inferred = self._start_disk + offset_cd + print "given, inferred, offset", offset_cd, inferred, self._start_disk # self.start_dir: Position of start of central directory - self.start_dir = offset_cd + concat + self.start_dir = offset_cd + self._start_disk fp.seek(self.start_dir, 0) data = fp.read(size_cd) fp = cStringIO.StringIO(data) @@ -855,7 +858,7 @@ class ZipFile(object): t>>11, (t>>5)&0x3F, (t&0x1F) * 2 ) x._decodeExtra() - x.header_offset = x.header_offset + concat + x.header_offset = x.header_offset + self._start_disk x.filename = x._decodeFilename() self.filelist.append(x) self.NameToInfo[x.filename] = x @@ -1198,7 +1201,7 @@ class ZipFile(object): raise RuntimeError('Compressed size larger than uncompressed size') # Seek backwards and write file header (which will now include # correct CRC and file sizes) - position = self.fp.tell() # Preserve current position in file + position = self.fp.tell() # Preserve current position in file self.fp.seek(zinfo.header_offset, 0) self.fp.write(zinfo.FileHeader(zip64)) self.fp.seek(position, 0) @@ -1284,11 +1287,10 @@ class ZipFile(object): file_size = zinfo.file_size compress_size = zinfo.compress_size - if zinfo.header_offset > ZIP64_LIMIT: - extra.append(zinfo.header_offset) + header_offset = zinfo.header_offset - self._start_disk + if header_offset > ZIP64_LIMIT: + extra.append(header_offset) header_offset = 0xffffffffL - else: - header_offset = zinfo.header_offset extra_data = zinfo.extra if extra: @@ -1332,7 +1334,7 @@ class ZipFile(object): # Write end-of-zip-archive record centDirCount = len(self.filelist) centDirSize = pos2 - pos1 - centDirOffset = pos1 + centDirOffset = pos1 - self._start_disk requires_zip64 = None if centDirCount > ZIP_FILECOUNT_LIMIT: requires_zip64 = "Files count" diff --git a/Misc/NEWS b/Misc/NEWS index 6be73784fc..1a737b84f8 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -49,6 +49,10 @@ Core and Builtins Library ------- +- Issue #26293: Fixed writing ZIP files that starts not from the start of the + file. Offsets in ZIP file now are relative to the start of the archive in + conforming to the specification. + - Fix possible integer overflows and crashes in the mmap module with unusual usage patterns.