bug#54173: 28.0.91; Training wheels for query-replace

[Eli Zaretskii <eliz@gnu.org>]

> From: Augusto Stoffel <arstoffel@gmail.com>
> Cc: 54173@debbugs.gnu.org
> Date: Sun, 27 Feb 2022 08:55:51 +0100
> 
> On Sun, 27 Feb 2022 at 08:54, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > I don't think it's a good idea to leave documentation and help to
> > users.  I'd rather we made the help text better, or maybe introduce a
> > key to display a more detailed help text.  Emacs should not have
> > sub-optimal help text.
> 
> I agree, and I suggested a defcustom here so the user can choose between
> two predefined options, the default prompt:
> 
> ```
> Query replacing a with b: (‘?’ for help)
> ```
> 
> and a two-line prompt including a little summary:
> 
> ```
> Query replacing a with b: (‘?’ for help)
> Replace ‘y’ once, ‘.’ and exit, ‘!’ all; skip to ‘n’ next, ‘^’ previous; ‘U’ undo all.

But since '?' produces a more detailed help, and that help text stays
on display thereafter, do we really need one more variant?  Maybe the
default message could be expanded instead (but not to such a long
text, which would resize the mini-window in many cases)?

> > Can you tell why you have trouble remembering some of the keys, and
> > how changing the help message could countermand that?
> 
> My issue is mainly with '.' and '^'.  I rarely need those operations, so
> by the time I do I already forgot the keys.  With a summary help line
> below the prompt, it's very hard to not be reminded.

Then how about adding '.' and '^' to the default help text?

> PS: Should we define 'p' as a synonym for '^' in 'query-replace-map'?

Probably.