ZipFile does not supports Unicode Path Extra Field (0x7075) zip header field

[ivansorokintech]

BPO	41928
Nosy	@agiudiceandrea
PRs	bpo-41928: Add support for Unicode Path Extra Field in ZipFile #23736
Files	23.zip

^{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 = None
created_at = <Date 2020-10-04.11:21:41.399>
labels = ['type-feature', 'library', '3.10']
title = 'ZipFile does not supports Unicode Path Extra Field (0x7075) zip header field'
updated_at = <Date 2021-01-22.01:30:26.942>
user = 'https://bugs.python.org/ivansorokintech'

bugs.python.org fields:

activity = <Date 2021-01-22.01:30:26.942>
actor = 'andreaerdna'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-10-04.11:21:41.399>
creator = 'ivan.sorokin.tech'
dependencies = []
files = ['49491']
hgrepos = []
issue_num = 41928
keywords = ['patch']
message_count = 3.0
messages = ['377931', '377945', '385467']
nosy_count = 2.0
nosy_names = ['ivan.sorokin.tech', 'andreaerdna']
pr_nums = ['23736']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue41928'
versions = ['Python 3.10']

Linked PRs

• gh-86094 Add support for Unicode Path Extra Field in ZipFile #102566

[ivansorokintech]

See attached sample. Well-known unzip command line tool lists its contents correctly:

$ unzip -l 23.zip
Archive:  23.zip
  Length      Date    Time    Name
---------  ---------- -----   

---

81408  2012-10-23 19:03   Β' ΦΑΣΗ ΠΕ06 ΣΧΟΛΕΙΑ ΕΑΕΠ (ΙΝΤ).xls

--------- -------
81408 1 file

But ZipFile lists the same file inside this archive as
ü' öÇæå Åä06 æòÄèäêÇ äÇäÅ (êîÆ).xls

It's because ZipFile completely ignores Unicode Path Extra Field (0x7075) zip header field.

See .ZIP specification for details on this field meaning and usage:
https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT

[ivansorokintech]

Grand unified algorithm to read filenames from zip files correctly:

1. Do zip entry have «Unicode Path Extra Field» (0x7075)? Use it for file name.
2. Is Unicode flag (0x800) set in «Flags» Field of zip entry? Assume «Filename» Field is in UTF-8.
3. Do «HostOS» Field of zip entry have values of 0 (FAT) or 11 (NTFS)? Assume «Filename» Field is in OEM charset corresponding to system locale.
4. Assume «Filename» Field is in UTF-8.

p7zip with oemcp patch (https://github.com/unxed/oemcp/) uses exactly this method, and is able to process all zip files in my test set correctly (my test set contains several zips generated by different packers on windows, macos, linux, and by online services). The same algorithm should be used in any zip unpacker wishing to process non-latin filenames as gently as possible.

[agiudiceandrea]

I submitted more than a month ago a PR that adds support for Unicode Path Extra Field in ZipFile.
The PR #23736 is awaiting a review in order to be merged.