bug#7563: 23.2; `split-string-and-unquote' mis-documented / purpose unclear

[Eli Zaretskii]

> Cc: "7563-done@debbugs.gnu.org" <7563-done@debbugs.gnu.org>,
>  "1212-done@debbugs.gnu.org" <1212-done@debbugs.gnu.org>
> From: Dave Abrahams <dave@boostpro.com>
> Date: Sat, 11 Dec 2010 12:57:30 -0500
> 
> Sorry, let me precise: your fix is correct inasmuch as it fulfills your 
> intention, but the text you were working on is still wrong because it says 
> quite clearly that backslash escaping is supported, but as I have shown, it 
> is not. 

Quoting with backslashes _is_ supported, in the Lisp string style.
Try this, for example:

  (split-string-and-unquote "\"foo\\\"bar\" bar") => ("foo\"bar" "bar")

> Specifically it specifically states they handle backslashes, and strongly 
> implies that they have generally-useful semantics for interacting with 
> arbitrary shells, when in fact they are essentially implementation details of 
> call-/start-process whose semantics are only appropriate to an undocumented 
> set of conditions set up in those two functions. 

I tried to make it more clear that these functions are mainly for
working with command-line arguments of call-/start-process.

> >>  * The functions' design still has nothing to do with shell quoting;
> >>    they are hard-coded to work with double-quotes and only
> >>    double-quotes, which is not guaranteed to work for an arbitrary
> >>    definition of "shell."
> > 
> > I believe the manual says precisely that.  If the problem is with
> > mentioning "shell", would removing that solve this difficulty?
> 
> It would certainly help

Done.