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Title: 2.3c1: confused by garbage at the very end of zip
Type: Stage:
Components: Library (Lib) Versions: Python 2.3
Status: closed Resolution: rejected
Dependencies: Superseder:
Assigned To: akuchling Nosy List: akuchling, alanmcintyre, nms
Priority: normal Keywords: patch

Created on 2003-07-19 15:00 by nms, last changed 2022-04-10 16:10 by admin. This issue is now closed.

File name Uploaded Description Edit nms, 2003-07-19 15:00 Lib/ patch for "garbage at the end of zip file" error
Messages (4)
msg44307 - (view) Author: Nikolai Saoukh (nms) Date: 2003-07-19 15:00
Some zip files can contain garbage past the End of Central Directory. _EndRecData() treat it as comment, thus failing
sanity check for comment length.
msg44308 - (view) Author: A.M. Kuchling (akuchling) * (Python committer) Date: 2006-12-22 18:25
Under what circumstances do zip files have garbage appended to them?  Are there buggy zipfile-generating programs out there, or does the garbage come from, say, an extra newline added when a zipfile is attached to an e-mail?

The patch looks OK, but I'm nervous about adding code to silently ignore an incorrect zipfile.
msg59409 - (view) Author: Alan McIntyre (alanmcintyre) * (Python committer) Date: 2008-01-06 22:28
Since there's no reply about where ZIP files with appended 'garbage'
might come from, should this be closed?  I agree with amk; it doesn't
seem wise to ignore incorrectly formatted files without a good reason.

On a related note, it seems that correctly formatted ZIP files with
comments longer than 4k will not be recognized as a ZIP file by the
zipfile module.  There's some comment about not looking at more than the
last 4k of the file for "efficiency" reasons, but failing to interpret a
correct file seems to override the efficiency concern of
reading/searching another 60k of data.  I'll open a separate tracker
item for this, since it's not strictly related to the original issue.
msg60161 - (view) Author: A.M. Kuchling (akuchling) * (Python committer) Date: 2008-01-19 14:00
I searched for references to 'zip file concatenate|append' and
found no reference to extra data being ignored, so I'll agree with Alan
and close this patch.  Thanks for your contribution, anyway!
Date User Action Args
2022-04-10 16:10:02adminsetgithub: 38877
2008-01-19 14:00:04akuchlingsetstatus: open -> closed
resolution: rejected
messages: + msg60161
2008-01-06 22:28:43alanmcintyresetnosy: + alanmcintyre
messages: + msg59409
2003-07-19 15:00:48nmscreate