Re: arc-mode.el bug or malformed ZIP file?

[Stefan Monnier]

>>> undamaged).  So at least unzip can deal with this file.  So is this a
>>> bug in arc-mode.el?
>> Probably.  Could be a new file format, for instance (e.g. maybe the old
>> format understood by arc-mode.el is limited to 2GB sizes or something
>> like that?).
> The size can't be the reason for the failure: the ZIP file whose

I'm not saying it's because of the size, but because of a change of
format (and this new format was introduced because of size limits in
the old format).

Eli just installed a patch a few days ago which seems to confirm my
suspicion:

    commit f31c6792ab98c8be343838f59d96e35c05353521 (emacs-27)
    Author: Eli Zaretskii <eliz@gnu.org>
    Date:   Fri Sep 25 17:11:11 2020 +0300
    
        Fix support for Zip64 zip files
        
        * lisp/arc-mode.el (archive-zip-summarize): Fix detection of Zip64
        central directory.  Support 64-bit file size field used by Zip64.
        (Bug#43597)


-- Stefan