bug#52384: [External] : bug#52384: 26.3; dired buffer navigation tweak

[Drew Adams <drew.adams@oracle.com>]

> >> > (The Dired+ versions of these commands wrap
> >> > around, if option `diredp-wrap-around-flag'
> >> > has its default value of `t'.)
> >>
> >> Yet another feature I had already implemented
> >> since Emacs 21.1 and sent to you for review in 2007.
> >
> > Interesting.  Or is that tongue in cheek?
> >
> > I just searched all messages I've received from
> > you, including those in 2007, from mailing lists
> > and direct mails, and I don't find any such
> > suggestion or review request.  Could you point
> > to it - I'm curious.  I expect that if that were
> > the case I would most likely have added it to
> > Dired+ long before I did (which was not until
> > July 12, 2013).
> 
> I don't remember exactly, but the closest is in the
> thread "TAB for non-editing modes" on emacs-devel
> with the discussion about using TAB in dired
> to move between directories.  When TAB/S-TAB will go
> to the next/previous directory, then `<' and `>'
> will be free to use for going to the first/last file.

This is that thread:

https://lists.gnu.org/archive/html/emacs-devel/2007-09/msg01976.html

I see nothing there that resembles anything like an 
implementation of wraparound navigation for Dired,
let alone a request by you to review that.  I don't
even find any suggestion that such wraparound be
added to Dired.  I see nothing even vaguely related
to a suggestion about wraparound navigation.

Checking your and my posts (and others) in that
thread, I find nothing about any of this.  Could
you point to the message(s) you're referring to?
A URL would be good.
___

More importantly, `<' and `>' going to the first
and last file, respectively, has nothing to do with
wraparound.  So if that's what you suggested or
implemented, it's something else entirely.

> >> But I don't use it too much because it's not
> >> so useful with --group-directories-first
> >> that really should be the default.
> >
> > I have that as default for my own use.  But I
> > often change sort orders, especially for date.
> 
> When you change sort orders, directories still
> remain at the top?  So first are directories
> sorted by date, then below files sorted by date?

For my own use, I use non-nil `ls-lisp-dirs-first',
so directories remain listed first.  (But I use
`emacs -Q` for some testing and some bug filing.)

When `ls-lisp-dirs-first' is non-nil, dirs are
listed first.  And yes, their order changes when
sorting is by date vs name, or some other order.
But as a group, yes, they remain listed first,
before ordinary files, within any given dir
listing.

The point is that it can be useful to sometimes
see some or all dir lines interspersed with
ordinary-file lines.

Again, a classic example is when subdir listings
are inserted: Directory lines in those listings
are separated from those of the main listing and
from those of other subdir listings.  `>' and
`<' let you move among consecutive dir lines
throughout the buffer.

`<' and `>' have their own raisons d'etre.  They
are not the same as `p' and `n'.  (And yes, it
makes sense for both >/< and n/p to optionally
wrap around.)