bug#24977: 25.1; search and query-replace in Dired

[Drew Adams]

> > I have no argument with the new commands.  My argument is to keep
> > the old commands as well, with their bindings and menu items, and
> > to give the new commands new bindings and new menu items.
> 
> Because that wouldn't be confusing. Either the menu items will look
> almost the same (but perform slightly differently), or they will
> have to be very long, to describe the difference.

They _should_ be similar because the functionality is similar
(regexp search & query-replace).  Their difference should reflect
their main difference.  The main difference I see is that one
searches using (any) Emacs regexps and the other searches using
`find' (with all of its advantages and disadvantages).

"... Using `find'" or "... With `find'" in the new menu items is
not long, and it says quite a _lot_ about what the command does.

> > When you kinda sorta sometimes
> > get behavior that is similar to what you might expect (e.g. from
> > the regexp alone), the actual behavior can be all the more
> > confusing if this difference is not described clearly.
> 
> Indeed. But careful handling of uncertain cases and showing user-
> error for tricky regexps should make the behavior make sense.

Making some more sense is no doubt possible.  Handling some
more cases is no doubt possible.  But as you said, some things
are not possible ("We obviously can't support those"), and any
simulation of ordinary Emacs searching would be ad hoc.

Again, I have no problem with adding these useful commands.
The problem is subtracting the older, also useful commands
(and their key bindings).  There is no reason to do that.