New submission from Peter Ebden: In Python 2.7.13, using zipfile.ZipFile to write into a file with some initial preamble produces a zip file that cannot be read again by some zip implementations. Our use case is using pex (https://github.com/pantsbuild/pex) which writes a zip that begins with a shebang, and later attempting to manipulate that using Go's standard archive/zip package. In 2.7.12 that works OK, but in 2.7.13 the .pex file is rejected on reading. Linux's command-line unzip tool will read the archive, but issues a warning ("4 extra bytes at beginning or within zipfile") which wasn't present previously. zipfile.ZipFile does read the files OK.
I assume this is related to https://bugs.python.org/issue26293 since that's the most obvious zipfile change in 2.7.13. It's pretty easy to reproduce using the example in that issue: from zipfile import ZipFile with open('a.zip', 'wb') as base: base.write(b'old\n') with ZipFile(base, 'a') as myzip: myzip.write('eggs.txt') unzip -t a.zip Archive: a.zip warning [a.zip]: 4 extra bytes at beginning or within zipfile (attempting to process anyway) ... ---------- components: Library (Lib) messages: 284172 nosy: Peter Ebden priority: normal severity: normal status: open title: Regression in zipfile writing in 2.7.13 versions: Python 2.7 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue29094> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
