Issue #28449: tarfile.open() with mode "r" or "r:" now tries to open a tar

file with compression before trying to open it without compression.  Otherwise
it had 50% chance failed with ignore_zeros=True.
This commit is contained in:
Serhiy Storchaka 2016-10-30 20:58:31 +02:00
commit 3e7f593c87
3 changed files with 14 additions and 2 deletions

View File

@ -1554,7 +1554,9 @@ class TarFile(object):
if mode in ("r", "r:*"):
# Find out which *open() is appropriate for opening the file.
for comptype in cls.OPEN_METH:
def not_compressed(comptype):
return cls.OPEN_METH[comptype] == 'taropen'
for comptype in sorted(cls.OPEN_METH, key=not_compressed):
func = getattr(cls, cls.OPEN_METH[comptype])
if fileobj is not None:
saved_pos = fileobj.tell()

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@ -3,6 +3,7 @@ import os
import io
from hashlib import md5
from contextlib import contextmanager
from random import Random
import unittest
import unittest.mock
@ -349,12 +350,17 @@ class CommonReadTest(ReadTest):
def test_ignore_zeros(self):
# Test TarFile's ignore_zeros option.
# generate 512 pseudorandom bytes
data = Random(0).getrandbits(512*8).to_bytes(512, 'big')
for char in (b'\0', b'a'):
# Test if EOFHeaderError ('\0') and InvalidHeaderError ('a')
# are ignored correctly.
with self.open(tmpname, "w") as fobj:
fobj.write(char * 1024)
fobj.write(tarfile.TarInfo("foo").tobuf())
tarinfo = tarfile.TarInfo("foo")
tarinfo.size = len(data)
fobj.write(tarinfo.tobuf())
fobj.write(data)
tar = tarfile.open(tmpname, mode="r", ignore_zeros=True)
try:

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@ -99,6 +99,10 @@ Core and Builtins
Library
-------
- Issue #28449: tarfile.open() with mode "r" or "r:" now tries to open a tar
file with compression before trying to open it without compression. Otherwise
it had 50% chance failed with ignore_zeros=True.
- Issue #23262: The webbrowser module now supports Firefox 36+ and derived
browsers. Based on patch by Oleg Broytman.