Re: M-= in Dired

[Juri Linkov]

> If there are no objections, I will simply unbind dired-backup-diff, and
> improve the behavior of = (dired-diff) so that it uses any existing
> backup file as the minibuffer input default, like M-x diff does.

I think it's possible to do this in dired-diff without throwing away
useful functionality of using as default a marked file or a file in
adjacent windows (dwim-target).  The top default value could be
a backup file but remaining defaults could remain the same as before.

PS: Since `diff-backup' uses `diff-latest-backup-file',
would it be more correct to use it in `diff' and `dired-diff'
instead of `file-newest-backup'?