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

[Glenn Morris <rgm@gnu.org>]

Eli Zaretskii wrote:

> That leaves system administrators no means of forcing a specific
> version of Info manual to be found by default.

That is true, it does not, but only for manuals that come with Emacs. I
cannot think of a case where a *sysadmin* would want to force Emacs to
prefer some other version of a manual to the one that comes with Emacs.
Can you give an example?
(And they could always do it with some site-specific elisp if they
really wanted to. But I expect it to be very much a fringe case.)

> Also, Emacs comes with a few manuals that can have other versions from
> elsewhere (like info.info or gnus.info).

(IIRC, Karl has stated that he considers Emacs the canonical home for
info.info.)

By default, Emacs uses the Gnus that comes with Emacs.
To get it to use a different Gnus, you have to customize load-path.
I do not think it unreasonable that you should have to similarly
customize Info-directory-list to get the right manual.

> Is this the only situation where the current arrangement doesn't DTRT,
> or are there more?  If this is the only one, then you cannot solve it
> successfully: the Info system simply doesn't support well the use case
> where several different manuals have identical names.

I don't understand why it cannot be solved successfully by doing what I
said. I don't care about seeing multiple versions of the manuals with
the same name, I want to see only one version, and I want that version
to be the version that comes with Emacs.

> What if the user installs newer versions of, say, Gnus or Org from
> their respective repositories?

See my comment above.
(Frankly, I suspect what happens at present in most such cases is that
people install the lisp files in their load-path, but do not do anything
with INFOPATH, so end up seeing the wrong Info pages anyway.)

And note that the Mac platform has already behaved as I request for some
years. I don't recall seeing any complaints.