bug#19812: 24.4; suggest `shell-mode' not interactive

[Lars Ingebrigtsen <larsi@gnus.org>]

Kevin Ryde <user42_kevin@yahoo.com.au> writes:

> Maybe :interactive, just to write it in the positive sense.  The default
> must be t for compatibility.

That makes sense, and is easy to implement in this case.  We usually
treat the absence of a parameter the same as nil (since Emacs Lisp isn't
Common Lisp), but we don't have to do that here.

> A couple of words in the docs could note that special modes usually
> should be nil.

True, but I don't think we need to limit the interactivity here, though.
When there's little chance of confusion, having the mode be interactive
isn't that big a deal (and might be useful for somebody, sometime).

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no