bug#22866: 24.5; 'C-h S' leads to inaccurate result

[Drew Adams]

> > > For the function `delete-char'.  'C-h S' takes me to:
> > > (emacs)Top > Killing > Deletion and Killing > Deletion
> > > However, it should go to: (elisp)Top > Text > Deletion
> >
> > Why do you think so?  This is a user command, not just an
> > Elisp function.  An Emacs user looking for information about
> > it interactively will expect to go to its description in the
> > Emacs manual.  If we have to choose one or the other, we
> > should, I think, favor user help, especially for a command.
> >
> > That said... (1) Maybe we could cross-reference the one from
> > the other manual?  (2) It might be good if `C-h S' popped
> > up a buffer of links to references in both manuals.  (3) It
> > would be good if *Help* output from `C-h f' and `C-h k'
> > provided links to the manuals (both).
> 
> I think the way to solve this is to have a new Help command that
> would specifically look up a function name in the ELisp manual.

That too would work.

If someone wanted references to both manuals, it would still be
helpful if that new command, as well as `C-h S', interpreted
certain prefix-arg values as requesting that, and showed links
to them (e.g., as I described).

For example:

* A non-negative prefix arg could do as now: query for the mode.
* A non-positive prefix arg could show links to both manuals.

(So a zero arg would do both.)