Add zip64 support to shutil

[williammallard]

BPO	17189
Nosy	@pitrou, @tarekziade, @hynek, @serhiy-storchaka
Superseder	bpo-17201: Use allowZip64=True by default
Files	shutil_zip64.patch shutil_zip64_by_default.patch shutil_zip64_by_default.patch: Added documentation.

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2015-02-05.21:20:26.316>
created_at = <Date 2013-02-12.05:29:24.623>
labels = ['type-feature', 'library']
title = 'Add zip64 support to shutil'
updated_at = <Date 2015-02-05.21:20:26.316>
user = 'https://bugs.python.org/williammallard'

bugs.python.org fields:

activity = <Date 2015-02-05.21:20:26.316>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = True
closed_date = <Date 2015-02-05.21:20:26.316>
closer = 'serhiy.storchaka'
components = ['Library (Lib)']
creation = <Date 2013-02-12.05:29:24.623>
creator = 'william.mallard'
dependencies = []
files = ['29045', '29060', '29063']
hgrepos = []
issue_num = 17189
keywords = ['patch']
message_count = 8.0
messages = ['181941', '182009', '182018', '182027', '182032', '182043', '182052', '182059']
nosy_count = 5.0
nosy_names = ['pitrou', 'tarek', 'william.mallard', 'hynek', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = 'out of date'
stage = 'resolved'
status = 'closed'
superseder = '17201'
type = 'enhancement'
url = 'https://bugs.python.org/issue17189'
versions = ['Python 3.4']

[williammallard]

This patch enables creation of 64-bit zip files via make_archive().

make_archive uses ZipFile to create zip files. ZipFile already supports creation of 64-bit archives via a kwarg, but make_archive hard-codes it to 32-bit. This patch exposes the option in a backwards compatible way.

[pitrou]

Would there be a way to automatically switch the flag as necessary?
(i.e. when writing more than 2GB, I guess)

[serhiy-storchaka]

Would there be a way to automatically switch the flag as necessary?
(i.e. when writing more than 2GB, I guess)

Yes, there is a special flag for this in zipfile. It is named allowZip64.

The only reason to use allowZip64=False is when you expect to unzip a zipfile with a tool which doesn't support zip64 (PKUNZIP.EXE for DOS?) and you want to keep yourself from unintentional zipping a file larger than 2 GiB.

Perhaps sometime we should to change the default value for allowZip64 from False to True.

[pitrou]

Yes, there is a special flag for this in zipfile. It is named
allowZip64.

Then I think shutil should set allowZip64 to True by default.
People who want fine-grained control over the zipfile's characteristics can still use the zipfile module directly.

[serhiy-storchaka]

Agree.

[williammallard]

Ok, here's a patch that makes zip64 the default in make_archive() when format='zip'.

I also agree that ZipFile should set allowZip64=True by default. (PKZIP has supported zip64 since 2001!)

[serhiy-storchaka]

This should be reflected in the documentation.

[williammallard]

Documentation added. See attached.