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

[Tino Calancha <tino.calancha@gmail.com>]

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

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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).
---
  lisp/dired.el | 9 +++++----
  1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/lisp/dired.el b/lisp/dired.el
index 5d14291..095ab14 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -2467,10 +2467,11 @@ dired-copy-filename-as-kill
  				    'no-dir (prefix-numeric-value arg))))
                            (dired-get-marked-files 'no-dir))
                          " "))))
-    (if (eq last-command 'kill-region)
-	(kill-append string nil)
-      (kill-new string))
-    (message "%s" string)))
+    (unless (string= string "")
+      (if (eq last-command 'kill-region)
+          (kill-append (concat " " string) nil)
+        (kill-new string))
+      (message "%s" string))))


  ;; Keeping Dired buffers in sync with the filesystem and with each other
-- 
2.8.1


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GNU Emacs 25.1.50 (x86_64-pc-linux-gnu, GTK+ Version 3.20.6)
  of 2016-07-28
Repository revision: 4a5b6e621c68172bb69d60fe8a76932f7c779f81