bug#6204: vc-dir always splits the frame

[martin rudalics]

>> There are simpler options `same-window-buffer-names' and
>> `same-window-regexps' that are very easy to understand
>> (a simple list of window names).
>
> I hate those for 2 reasons:
> - they're very limited (can't be used to say "always in another window",
>   or "maybe not the same window, but at least the same frame", ...).

And this will be our major pain.  The prefix "same-" is hardcoded :-(

> - they're currently abused by elisp code.
>
>>> (or, worse, permanently adding its buffer names to it)
>> This is a legitimate way for an application to define
>> its default behavior.  Look for example at:
>> ;;;###autoload (add-hook 'same-window-regexps "\\*info\\*\\(\\|<[0-9]+>\\)")
>
> This is exactly the kind of evil I don't want: such variables should
> only ever be modified by the user.  And `add-hook' is an abuse here as
> well since same-window-regexps is not a hook.

Precisely.

martin