Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path: <ian.g.kelly@gmail.com>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.024
X-Spam-Evidence: '*H*': 0.95; '*S*': 0.00; 'jesse': 0.05; '32-bit': 0.09; 'indicates': 0.09; 'bug': 0.12; 'jan': 0.12; 'archive': 0.14; 'integers.': 0.16; 'reason?': 0.16; 'unsigned': 0.16; 'wrote:': 0.18; 'wed,': 0.18; 'thu,': 0.19; 'integer': 0.24; 'file.': 0.24; 'signed': 0.27; 'header:In-Reply-To:1': 0.27; 'chris': 0.29; 'url:bugs': 0.29; 'am,': 0.29; 'message- id:@mail.gmail.com': 0.30; 'boundary': 0.31; 'file': 0.32; 'url:python': 0.33; 'limitation': 0.33; 'but': 0.35; 'received:google.com': 0.35; 'thanks': 0.36; 'subject:?': 0.36; 'url:org': 0.36; 'should': 0.36; 'problems': 0.38; 'to:addr :python-list': 0.38; 'pm,': 0.38; 'does': 0.39; 'to:addr:python.org': 0.39; 'ensure': 0.60; 'even': 0.60; 'simply': 0.61; 'zip': 0.64; 'details': 0.65; 'limit': 0.70; '2015': 0.84
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=hiJOvSZFyQZ95K8lak/wuUx2pGF43KxjWMBGjIQS6Ys=; b=NgmYkjL321bZLjaNqKGsdRTdrC6PZw4HYMdVGo7AHKgyG209qIot84inpxxIaiv/nZ fbnu+6niAAvG3na4Ju0in6Syj7h576CehtSBlE3tmbdCG05NQiThDzvF/Ij/yLA69izL M/hjPBDIBH8JQt62wSLva/MZ3HONUrG74wI9FFQo31jvVKQnSzcpECcatCC5vzJmlbDb CwF6t5sEHSEq7nYS5DOEKBPTO41JvRhOW/feZ4reXjWjpxR6HAWTSn3ViBKP/6yGKV2O FUB6M2uyjlDihtSrRTdmFSQuVyRfqYcrMy0PqmPDUkbgRJBR3MWwlMjEKKY6SvuWWHVh o0pw==
X-Received: by 10.70.88.161 with SMTP id bh1mr3669709pdb.36.1422563214562; Thu, 29 Jan 2015 12:26:54 -0800 (PST)
MIME-Version: 1.0
In-Reply-To: <CAE6kEriXAyuLjeHqt4LJLBeEpUVinYWyaHZ9D1XPgv1kEzADEw@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com> <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com> <CALwzidkEUem2pEu-OP_RBV6yPZKCdQcTQZ9P86b6cPn0SVhf_Q@mail.gmail.com> <CAE6kEriXAyuLjeHqt4LJLBeEpUVinYWyaHZ9D1XPgv1kEzADEw@mail.gmail.com>
From: Ian Kelly <ian.g.kelly@gmail.com>
Date: Thu, 29 Jan 2015 13:26:14 -0700
Subject: Re: why zip64_limit defined as 1<<31 -1?
To: Python <python-list@python.org>
Content-Type: text/plain; charset=UTF-8
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.18280.1422563217.18130.python-list@python.org>
Lines: 29
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1422563217 news.xs4all.nl 2868 [2001:888:2000:d::a6]:34555
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:84840

On Thu, Jan 29, 2015 at 12:12 PM, jesse <chat2jesse@gmail.com> wrote:
>
> On Jan 29, 2015 9:27 AM, "Ian Kelly" <ian.g.kelly@gmail.com> wrote:
>>
>> On Wed, Jan 28, 2015 at 2:36 PM, Chris Angelico <rosuav@gmail.com> wrote:
>> > On Thu, Jan 29, 2015 at 5:53 AM, jesse <chat2jesse@gmail.com> wrote:
>> >> should not it be 1<<32 -1(4g)?
>> >>
>> >> normal zip archive format should be able to support 4g file.
>> >>
>> >> thanks
>> >
>> > 1<<31-1 is the limit for a signed 32-bit integer. You'd have to look
>> > into the details of the zip file format to see whether that's the
>> > official limit or not; it might simply be that some (un)archivers have
>> > problems with >2GB files, even if the official stance is that it's
>> > unsigned.
>>
>> The bug in which zip64 support was added indicates that the value was
>> indeed chosen as the limit of a signed 32-bit integer:
>>
>> http://bugs.python.org/issue1446489
>
> ok,  then why signed 32-bit integer instead of unsigned 32 integer? any
> technical limitation reason? the chosen 2G boundary does not conform to zip
> standard specification.

I don't know specifically, but as Chris said it may be to ensure
compatibility with unzip programs that use signed 32-bit integers.