bug#5475: Archives with filenames with square brackets

[Eli Zaretskii <eliz@gnu.org>]

> From: Chong Yidong <cyd@stupidchicken.com>
> Date: Tue, 26 Jan 2010 16:05:20 -0500
> Cc: 5475@debbugs.gnu.org
> 
> > When a zip archive contains a file with square brackets in its name
> > (e.g. "file[name].txt") then visiting this file displays an error:
> >
> >   caution: filename not matched:  file[name].txt
> 
> I assume this is a specific quirk of unzip that it handles square
> brackets specially (characters like * seem to be handled literally).

I think it treats all wildcard characters the same.  A `*' may not
cause a warning because a file whose name is literally foo*, matches
the wildcard foo*.

> How about this patch?
> 
> *** lisp/arc-mode.el	2010-01-13 08:35:10 +0000
> --- lisp/arc-mode.el	2010-01-26 21:03:54 +0000
> ***************
> *** 1782,1787 ****
> --- 1782,1791 ----
>       (apply 'vector (nreverse files))))
>   
>   (defun archive-zip-extract (archive name)
> +   (when (string-match "[][]" name)
> +     (require 'comint)
> +     (let ((comint-file-name-quote-list '(?\] ?\[)))
> +       (setq name (comint-quote-filename name))))
>     (if (equal (car archive-zip-extract) "pkzip")
>         (archive-*-extract archive name archive-zip-extract)
>       (archive-extract-by-stdout archive name archive-zip-extract)))

First, why not use shell-quote-argument, instead of requiring comint?

Second, could someone please see if pkzip also expands wildcards
internally?  If it does not, the quoting will need to be done only in
the non-pkzip branch.  We also need to test this on MS-Windows.

But most importantly, this patch is not clean, IMO: it hardcodes into
archive-zip-extract (the function) some knowledge of what can be the
possible values of archive-zip-extract the defcustom.  What if
tomorrow there will be a 3rd possibility, in addition to pkzip and
unzip?

That is why I thought about some less trivial patch: add to the data
structures that are values of these defcustom's a flag to indicate
whether the file name needs to be quoted or not.