* net/tramp.el (tramp-methods): Add docstring for `tramp-login-env'

  and `tramp-copy-env'.

* net/tramp-sh.el (tramp-methods) <sudo>: Add `tramp-login-env'.
  (tramp-maybe-open-connection): Handle `tramp-login-env'.

lisp/ChangeLog

+2014-03-21  Michael Albinus  <michael.albinus@gmx.de>
+
+	* net/tramp.el (tramp-methods): Add docstring for `tramp-login-env'
+	and `tramp-copy-env'.
+
+	* net/tramp-sh.el (tramp-methods) <sudo>: Add `tramp-login-env'.
+	(tramp-maybe-open-connection): Handle `tramp-login-env'.
+
 2014-03-21  Glenn Morris  <rgm@gnu.org>
 	* electric.el (electric-indent-post-self-insert-function): Add doc.

lisp/net/tramp-sh.el

@@ -227,6 +227,8 @@ detected as prompt when being sent on echoing hosts, therefore.")
   '("sudo"
     (tramp-login-program        "sudo")
     (tramp-login-args           (("-u" "%u") ("-s") ("-H") ("-p" "Password:")))
+    ;; Local $SHELL could be a nasty one, like zsh or fish.  Let's override it.
+    (tramp-login-env            (("SHELL") ("/bin/sh")))
     (tramp-remote-shell         "/bin/sh")
     (tramp-remote-shell-args    ("-c"))
     (tramp-connection-timeout   10)))
@@ -4492,6 +4494,9 @@ connection if a previous connection has died for some reason."
 			 (login-args
 			  (tramp-get-method-parameter
 			   l-method 'tramp-login-args))
+			 (login-env
+			  (tramp-get-method-parameter
+			   l-method 'tramp-login-env))
 			 (async-args
 			  (tramp-get-method-parameter
 			   l-method 'tramp-async-args))
@@ -4549,6 +4554,24 @@ connection if a previous connection has died for some reason."
 			  tramp-current-user   (or g-user   l-user)
 			  tramp-current-host   (or g-host   l-host))
 
+		    ;; Add login environment.
+		    (when login-env
+		      (setq
+		       login-env
+		       (mapcar
+			(lambda (x)
+			  (setq x (mapcar (lambda (y) (format-spec y spec)) x))
+			  (unless (member "" x) (mapconcat 'identity x " ")))
+			login-env))
+		      (while login-env
+			(setq command
+			      (format
+			       "%s=%s %s"
+			       (pop login-env)
+			       (tramp-shell-quote-argument (pop login-env))
+			       command)))
+		      (setq command (concat "env " command)))
+
 		    ;; Replace `login-args' place holders.
 		    (setq
 		     l-host (or l-host "")

lisp/net/tramp.el

@@ -230,6 +230,9 @@ pair of the form (KEY VALUE).  The following KEYs are defined:
     `tramp-make-tramp-temp-file'.  \"%k\" indicates the keep-date
     parameter of a program, if exists.  \"%c\" adds additional
     `tramp-ssh-controlmaster-options' options for the first hop.
+  * `tramp-login-env'
+     A list of environment variables and their values, which will
+     be set when calling `tramp-login-program'.
   * `tramp-async-args'
     When an asynchronous process is started, we know already that
     the connection works.  Therefore, we can pass additional
@@ -242,6 +245,9 @@ pair of the form (KEY VALUE).  The following KEYs are defined:
   * `tramp-copy-args'
     This specifies the list of parameters to pass to the above mentioned
     program, the hints for `tramp-login-args' also apply here.
+  * `tramp-copy-env'
+     A list of environment variables and their values, which will
+     be set when calling `tramp-copy-program'.
   * `tramp-copy-keep-date'
     This specifies whether the copying program when the preserves the
     timestamp of the original file.