bug#16407: Info-directory-list should always put this Emacs's info direc first

[Eli Zaretskii <eliz@gnu.org>]

> From: Glenn Morris <rgm@gnu.org>
> Cc: 16407@debbugs.gnu.org
> Date: Fri, 10 Jan 2014 15:11:45 -0500
> 
> Eli Zaretskii wrote:
> 
> > On a multi-user system, INFOPATH can be customized differently for
> > each user, but /usr/share/info is a single directory.  Suppose some
> > users want to stay with an older Emacs, while others want the bleeding
> > edge.
> 
> I don't really get your point. I contend that "Emacs N should show the
> manuals for version N", without the user needing to do anything special.

As I said, this is generally impossible.

> (I'm assuming throughout that each Emacs version is installed in a
> separate location, otherwise the info pages stomp all over each other
> anyway, as you said.)

But what happens in reality is either the stomping or the manual is
renamed into emacs-xx, to allow several versions of manuals coexist.

> Sorry, I think it's overly complicated for this day-and-age, and could
> stand to be simplified.

I suggest to look at a typical Debian system with several Emacs
versions installed, and see what kind of arrangement they use.  At the
time, this was one of the reasons for the complexity.  Maybe it no
longer exists, I don't know.

In any case, the problem with being able to control where Emacs looks
for the misc manuals still exists, for those Emacs packages that are
developed and distributed separately.