bug#24103: 25.1.50; Add white space separator when appending string

[Eli Zaretskii <eliz@gnu.org>]

> From: Tino Calancha <tino.calancha@gmail.com>
> Date: Fri, 29 Jul 2016 18:57:41 +0900 (JST)
> 
> 
> I)
> emacs -Q ~
> M-: (goto-char (dired-subdir-min)) RET
> M-: (dired-goto-next-file) RET
> w
> ;; copied first file name into kill-ring
> M-: (dired-next-line 1) RET
> C-M-w w
> ;; This append second file name to the kill-ring.
> ;; Note that there is no separator between the first/second file name.
> 
> II)
> emacs -Q ~
> M-: (goto-char (dired-subdir-min)) RET
> w
> ;; dir name copied into kill-ring
> M-: (goto-char (dired-subdir-max)) RET
> w
> ;; copied '' into kill-ring
> 
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> >From 80e9eb3fc790148a70dbf1da5d12e22681180bee Mon Sep 17 00:00:00 2001
> From: Tino Calancha <tino.calancha@gmail.com>
> Date: Fri, 29 Jul 2016 18:53:38 +0900
> Subject: [PATCH] Add white space separator when appending string
> 
> * lisp/dired.el (dired-copy-filename-as-kill):
> Add white space before string when command is appending.
> Copy just non-empty strings (Bug#24103).

Isn't this second-guessing what the user means?  What if the kill ring
has "/foo/bar/" and the user wants to append a file name to that, thus
creating a valid absolute file name?

Thanks.