* net/tramp-sh.el (tramp-open-connection-setup-interactive-shell):

Reduce the amount of set environment variable commands.

lisp/ChangeLog

+2014-10-14  Jérémy Compostella  <jeremy.compostella@intel.com>
+	    Michael Albinus  <michael.albinus@gmx.de>
+
+	* net/tramp-sh.el (tramp-open-connection-setup-interactive-shell):
+	Reduce the amount of set environment variable commands.
+
 2014-10-12  Fabián Ezequiel Gallina  <fgallina@gnu.org>
 	Fix import completion.  (Bug#18582)

lisp/net/tramp-sh.el

@@ -3955,10 +3955,8 @@ process to set up.  VEC specifies the connection."
 
   (tramp-message vec 5 "Setting shell prompt")
   (tramp-send-command
-   vec (format "PS1=%s" (tramp-shell-quote-argument tramp-end-of-output)) t)
-  (tramp-send-command vec "PS2=''" t)
-  (tramp-send-command vec "PS3=''" t)
-  (tramp-send-command vec "PROMPT_COMMAND=''" t)
+   vec (format "PS1=%s PS2='' PS3='' PROMPT_COMMAND=''"
+	       (tramp-shell-quote-argument tramp-end-of-output)) t)
 
   ;; Try to set up the coding system correctly.
   ;; CCC this can't be the right way to do it.  Hm.
@@ -4078,15 +4076,22 @@ process to set up.  VEC specifies the connection."
   (let ((env (append (when (tramp-get-remote-locale vec) ; Discard `(nil)'.
 		       `(,(tramp-get-remote-locale vec)))
 		     (copy-sequence tramp-remote-process-environment)))
-	unset item)
+	unset vars item)
     (while env
       (setq item (tramp-compat-split-string (car env) "="))
       (setcdr item (mapconcat 'identity (cdr item) "="))
       (if (and (stringp (cdr item)) (not (string-equal (cdr item) "")))
-	  (tramp-send-command
-	   vec (format "%s=%s; export %s" (car item) (cdr item) (car item)) t)
+	  (push (format "%s %s" (car item) (cdr item)) vars)
 	(push (car item) unset))
       (setq env (cdr env)))
+    (when vars
+      (tramp-send-command
+       vec
+       (format "while read var val; do export $var=$val; done <<'%s'\n%s\n%s"
+	       tramp-end-of-heredoc
+	       (mapconcat 'identity vars "\n")
+	       tramp-end-of-heredoc)
+       t))
     (when unset
       (tramp-send-command
        vec (format "unset %s" (mapconcat 'identity unset " ")) t))))