[ python-Bugs-1336623 ] tarfile can't extract some tar archives..

[SourceForge.net]

Bugs item #1336623, was opened at 2005-10-24 10:47
Message generated for change (Comment added) made by nnorwitz
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1336623&group_id=5470

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Python Library
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Submitted By: A. Murat EREN (meren)
Assigned to: Nobody/Anonymous (nobody)
Summary: tarfile can't extract some tar archives..

Initial Comment:
Here is a small demo to reproduce the same problem:


-----------------8<-----------------8<-----------------8<-----------------8<---
meren at pardus /home/meren $ wget
ftp://ftp.sleepycat.com/releases/db.1.85.tar.gz
(...)
100%[============>] 270,953       17.13K/s    ETA 00:00

20:21:09 (15.25 KB/s) - `db.1.85.tar.gz' saved [270,953]

meren at pardus /home/meren $ file db.1.85.tar.gz
db.1.85.tar.gz: gzip compressed data, from Unix
meren at pardus /home/meren $ python
>>> tar = tarfile.open("db.1.85.tar.gz", "r:gz")
>>> for tarinfo in tar:
...     print tarinfo.name
...
db.1.85
db.1.85/btree
db.1.85/btree/Makefile.inc
db.1.85/btree/bt_close.c
db.1.85/btree/bt_conv.c
db.1.85/btree/bt_debug.c
db.1.85/btree/bt_delete.c
db.1.85/btree/btree.h
db.1.85/btree/bt_get.c
db.1.85/btree/bt_open.c
(...) 
>>> for tarinfo in tar:
...     tar.extract(tarinfo)
...
>>>  Ctrl + D
meren at pardus /home/meren $ ls db*
db.1.85
db.1.85.tar.gz
meren at pardus /home/meren $ file db.1.85
db.1.85: empty
meren at pardus /home/meren $ cat db.1.85
meren at pardus /home/meren $ 
----------------->8----------------->8----------------->8----------------->8---

Also this file is extracting with the same result too:
ftp://ftp.linux.org.tr/pub/mirrors/gentoo/distfiles/ncompress-4.2.4.tar.gz

This thing is very rarely happening, but it is
happening. Also, I could extract these archives
properly via the native 'tar' binary..


Thanks in advance,
Ciao.

----------------------------------------------------------------------

>Comment By: Neal Norwitz (nnorwitz)
Date: 2005-10-27 23:01

Message:
Logged In: YES 
user_id=33168

Committed revision 41340.
Committed revision 41341.


----------------------------------------------------------------------

Comment By: A. Murat EREN (meren)
Date: 2005-10-26 05:35

Message:
Logged In: YES 
user_id=718263

thanks for the patch, it is just working.

----------------------------------------------------------------------

Comment By: Lars Gustäbel (gustaebel)
Date: 2005-10-26 03:31

Message:
Logged In: YES 
user_id=642936

I submitted patch #1338314 which fixes this problem.
tarfile.py is aware of these "buggy" archives, but the
workaround did not work anymore.
Thank you for your report, especially for the vast number of
test archives.

----------------------------------------------------------------------

Comment By: A. Murat EREN (meren)
Date: 2005-10-25 11:58

Message:
Logged In: YES 
user_id=718263

no files attached.. sorry, here it is..

----------------------------------------------------------------------

Comment By: A. Murat EREN (meren)
Date: 2005-10-25 11:36

Message:
Logged In: YES 
user_id=718263

I figured out that this is a very pesky problem.

The problem is coming from the tar archives themselves.
Simply, the "tarinfo.isdir()" check in the library returns
false for the directories and they are extracting like a
regular file.. How did they create these fool archives I
don't know, and I couldn't reproduce similar buggy archives
by myself. It would be nice to know.

Because of the problem is not in the python library, it is
very difficult to implement an efficent workaround to
properly extract this kind of buggy tar archives. I'm going
to attach a dirty workaround to show the idea (is anyone
reading these reports?)..


Ciao..

----------------------------------------------------------------------

Comment By: A. Murat EREN (meren)
Date: 2005-10-24 11:19

Message:
Logged In: YES 
user_id=718263

more examples: 
 
ftp://ftp.porcupine.org/pub/security/portmap_5beta.tar.gz 
ftp://ftp.porcupine.org/pub/security/tcp_wrappers_7.6.tar.gz 
 
additionally, the same problem appearing when trying to extract 
these archives with the "ark" (yet another kde tool, just a simple 
front-end for the tar command. interesting, isn't it). 
 
 
Ciao. 

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1336623&group_id=5470