bug#71935: split-string-and-unquote mishandles dired-listing-switches with '

[Eli Zaretskii <eliz@gnu.org>]

> From: Juri Linkov <juri@linkov.net>
> Cc: 71935@debbugs.gnu.org
> Date: Thu, 04 Jul 2024 19:10:17 +0300
> 
> >> 1. (setopt dired-listing-switches "-al --block-size='1")
> >> 2. C-x d /tmp/*
> >>
> >>   /tmp:
> >>   wildcard *
> >>   /bin/bash: -c: line 0: unexpected EOF while looking for matching `''
> >>   /bin/bash: -c: line 1: syntax error: unexpected end of file
> >>
> >> 3. (setopt dired-listing-switches "-al --block-size=\\'1")
> >> 4. C-x d /tmp/
> >>
> >> Debugger entered--Lisp error: (error "Listing directory failed but ‘access-file’ worked")
> >>   error("Listing directory failed but `access-file' worked")
> >>   insert-directory("/tmp/" "--dired -N -al --block-size=\\'1" nil t)
> >
> > I think the part of insert-directory that deals with wildcard lacks
> > the call to shell-quote-argument here:
> >
> > 		      ;; NB since switches is passed to the shell, be
> > 		      ;; careful of malicious values, eg "-l;reboot".
> > 		      ;; See eg dired-safe-switches-p.
> > 		      (call-process
> > 		       shell-file-name nil t nil
> > 		       shell-command-switch
> > 		       (concat (if (memq system-type '(ms-dos windows-nt))
> > 				   ""
> > 				 "\\") ; Disregard Unix shell aliases!
> > 			       insert-directory-program
> > 			       " -d "
> > 			       (if (stringp switches)
> > 				   switches
> > 				 (mapconcat #'identity switches " "))
> >
> > Can you try running each switch through shell-quote-argument?
> 
> This part of insert-directory is used only in case of 1-2 above,
> i.e. for wildcard '/tmp/*'.  In this case the value of 'switches'
> is "--dired -N -al --block-size='1", and 'shell-quote-argument'
> returns "--dired\\ -N\\ -al\\ --block-size\\=\\'1" that fails.

I meant to call shell-quote-argument on each option, before they are
concatenated.

> For the non-wildcard case of 3-4 above, this doesn't help either.
> Using (mapcar 'shell-quote-argument (split-string-and-unquote switches))
> on ("--dired" "-N" "-al" "--block-size=\\'1") returns
> ("--dired" "-N" "-al" "--block-size\\=\\\\\\'1") that fails with
> 
>   /bin/ls: unrecognized option '--block-size\=\\\'1'

Why did you use "--block-size=\\'1"?  My idea is that the quoting
should not come from the user.