bug#29465: 25.3; Confusing message for dired-do-shell-command substitution

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 28 Nov 2017 20:20:38 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 29465@debbugs.gnu.org, Tino Calancha <tino.calancha@gmail.com>
> 
> IF we feel it helps a user to prompt about something,
> and IF we feel there is a possibility that some users
> might not understand the prompt, in spite of our best
> efforts to come up with a good prompt, and IF we feel
> that understanding the prompt is important, THEN the
> doc string should make clear whatever it is that it
> is important that users understand about that prompting.
> 
> It's quite possible for a user not to understand even
> a good prompt.  S?he should be able to get the point
> by doing `C-h f', in that case.

The doc string already attempts to do that:

  `*' and `?' when not surrounded by whitespace nor `\\=`' have no special
  significance for `dired-do-shell-command', and are passed through
  normally to the shell, but you must confirm first.

We could make the intent of the confirmation even more clear, e.g.

  `*' and `?' when not surrounded by whitespace nor `\\=`' have no special
  significance for `dired-do-shell-command', and are passed through
  normally to the shell, but you must confirm first, to avoid
  inadvertently passing a wildcard to a shell command, which would cause
  that command to act on more files than you intended.

Is anything else needed to make this prompt's intent more clear?