bug#37514: PATCH: Add setting to allow switching to an already-visible buffer by default

[martin rudalics]

> Fortunately we already have several default key bindings for this:
>
> C-x <C-left>, C-x <left>, <XF86Back>
> C-x <C-right>, C-x <right>, <XF86Forward>

These are not auto-repeatable, alas.

> But nevertheless customizability of buffers for the C-x b prompt
> could be improved.  The current gratuitous removing visible buffers from
> C-x b prompt sometimes makes more harm than good.  One example case:
>
> 0. emacs -Q
> 1. C-h e   -- this displays *Messages* in another window
>
> Now try to show the *scratch* buffer in another window,
> the most convenient way is:
>
> 2. C-x 4 b   -- and select the current buffer *scratch*
>
> but there is no "*scratch*" in completions of C-x 4 b,
> because completions doesn't include the current buffer,
> so need to type the whole string "*scratch* RET".

To me that's two bugs in the completions mechanism itself.  It does
propose *Messages* first although that buffer is already displayed in
another window and does not propose *scratch* although that buffer
does not show in another window.  For me, a correct interpretation of
C-x 4 b is to propose *scratch* first and _maybe_ propose *Messages*
additionally for people who don't like C-x o.  C-x b in the very same
configuration does it right IMHO.

martin