bug#5475: Archives with filenames with square brackets

[Eli Zaretskii]

> From: Juri Linkov <juri@jurta.org>
> Cc: cyd@stupidchicken.com,  5475@debbugs.gnu.org
> Date: Mon, 01 Feb 2010 12:34:47 +0200
> 
> > Thanks.  I'm not sure we need to support 7z, I just tried it to see if
> > other unzip programs expand wildcards by default like "unzip" does.
> 
> Do you mean we don't need to support 7z in 23.2 or at all?

At all, for .zip files.

> Are there some problems with 7z that makes undesirable to support it
> (maybe, it is not free software, or has an unsuitable license?)

Its support for zip archives is sporadic at best.  On one GNU/Linux
system I tried it, it insisted that a .zip file format was
unsupported, although its Windows version that was older unzipped it
with no trouble at all.  Go figure.  And the fact that it doesn't have
a switch to make it silent, and you need to throw away its stderr
(which means you cannot display error messages) is yet another
nuisance.

> Even though it's quite rarely used format, sometimes when I try to visit
> a 7z archive in Emacs, I see only binary data.  At least, nowadays the
> need to visit a 7z archive arises more often than for obsolete formats
> like arc/lzh/zoo still supported by arc-mode.el.

I have nothing against adding support for 7z archives, although that
would be a new feature.