[Python-checkins] cpython (merge 3.6 -> default): Issue #26293: Fixed writing ZIP files that starts not from the start of the

Fri Oct 7 15:25:22 EDT 2016

https://hg.python.org/cpython/rev/64a19fe3a16a
changeset: 104352:64a19fe3a16a
parent: 104349:def217aaad2f
parent: 104351:b06e75ae1981
user: Serhiy Storchaka <storchaka at gmail.com>
date: Fri Oct 07 22:25:05 2016 +0300
summary:
 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.
files:
 Lib/test/test_zipfile.py | 43 ++++++++++++++++++++++++++++
 Lib/zipfile.py | 30 +++++++++---------
 Misc/NEWS | 4 ++
 3 files changed, 62 insertions(+), 15 deletions(-)

diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -420,6 +420,49 @@
 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
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -1103,10 +1103,10 @@
 # even if no files are added to the archive
 self._didModify = True
 try:
- self.start_dir = self.fp.tell()
+ self.start_dir = self._start_disk = self.fp.tell()
 except (AttributeError, OSError):
 self.fp = _Tellable(self.fp)
- self.start_dir = 0
+ self.start_dir = self._start_disk = 0
 self._seekable = False
 else:
 # Some file-like objects can provide tell() but not seek()
@@ -1127,7 +1127,7 @@
 # set the modified flag so central directory gets written
 # even if no files are added to the archive
 self._didModify = True
- self.start_dir = self.fp.tell()
+ self.start_dir = self._start_disk = self.fp.tell()
 else:
 raise ValueError("Mode must be 'r', 'w', 'x', or 'a'")
 except:
@@ -1171,17 +1171,18 @@
 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 = io.BytesIO(data)
@@ -1221,7 +1222,7 @@
 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
 self.filelist.append(x)
 self.NameToInfo[x.filename] = x
 
@@ -1685,11 +1686,10 @@
 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 = 0xffffffff
- else:
- header_offset = zinfo.header_offset
 
 extra_data = zinfo.extra
 min_version = 0
@@ -1736,7 +1736,7 @@
 # Write end-of-zip-archive record
 centDirCount = len(self.filelist)
 centDirSize = pos2 - self.start_dir
- centDirOffset = self.start_dir
+ centDirOffset = self.start_dir - self._start_disk
 requires_zip64 = None
 if centDirCount > ZIP_FILECOUNT_LIMIT:
 requires_zip64 = "Files count"
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -64,6 +64,10 @@
 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.
+
 - Issue #28380: unittest.mock Mock autospec functions now properly support
 assert_called, assert_not_called, and assert_called_once.
 
-- 
Repository URL: https://hg.python.org/cpython
