--- emacs-24.2/lisp/simple.el	2012-08-22 22:33:42.000000000 -0700
+++ emacs-24.2/lisp/simple.el.new2	2012-12-12 22:52:46.258462306 -0800
@@ -3233,6 +3233,7 @@
 	    (kill-new string nil yank-handler)))
 	(when (or string (eq last-command 'kill-region))
 	  (setq this-command 'kill-region))
+	(setq deactivate-mark t)
 	nil)
     ((buffer-read-only text-read-only)
      ;; The code above failed because the buffer, or some of the characters