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

[Stephen Berman]

On Wed, 23 Sep 2020 22:05:55 -0400 Stefan Monnier <monnier@iro.umontreal.ca> 
wrote:

>> 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
contents are not displayed in archive-mode is about 95 MB, but I have
some much larger ZIP file whose contents are displayed in archive-mode
with no problem.  But maybe there are more recent format changes for
other reasons.  I'm using a patched version of unzip 6.0, which is the
most recent from 2009, but the patch is from 2019 (though I don't see
anything in it about format changes).  I did search the web briefly but
found nothing about valid byte sequences at the end of the file.  But
I'll go ahead and file a bug report, maybe someone who knows more about
the ZIP format will see how to fix or extend arc-mode.el.

Steve Berman