1 files changed, 28 insertions, 7 deletions

diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 6e46df254b2..8d7e046126c 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -2835,16 +2835,27 @@ the result will be a local, non-Tramp, file name."
                         (list (replace-match " \\\\\n" nil nil (cadr args))))
                        (setq i (+ i 250))))
                    (cdr args)))
+           ;; Use a human-friendly prompt, for example for `shell'.
+           (prompt (format "PS1=%s"
+                           (format "%s %s"
+                                   (file-remote-p default-directory)
+                                   tramp-initial-end-of-output)))
+           ;; We use as environment the difference to toplevel
+           ;; `process-environment'.
+           env
+           (env
+            (dolist
+                (elt
+                 (cons prompt (nreverse (copy-sequence process-environment)))
+                 env)
+              (or (member elt (default-toplevel-value 'process-environment))
+                  (setq env (cons elt env)))))
            (command
             (when (stringp program)
-              (format "cd %s && exec %s env PS1=%s %s"
+              (format "cd %s && exec %s env %s %s"
                       (tramp-shell-quote-argument localname)
                       (if heredoc (format "<<'%s'" tramp-end-of-heredoc) "")
-                      ;; Use a human-friendly prompt, for example for `shell'.
-                      (tramp-shell-quote-argument
-                       (format "%s %s"
-                               (file-remote-p default-directory)
-                               tramp-initial-end-of-output))
+                      (mapconcat 'tramp-shell-quote-argument env " ")
                       (if heredoc
                           (format "%s\n(\n%s\n) </dev/tty\n%s"
                                   program (car args) tramp-end-of-heredoc)
@@ -2931,10 +2942,20 @@ the result will be a local, non-Tramp, file name."
     (error "Implementation does not handle immediate return"))
 
   (with-parsed-tramp-file-name default-directory nil
-    (let (command input tmpinput stderr tmpstderr outbuf ret)
+    (let (command env input tmpinput stderr tmpstderr outbuf ret)
       ;; Compute command.
       (setq command (mapconcat 'tramp-shell-quote-argument
                                (cons program args) " "))
+      ;; We use as environment the difference to toplevel `process-environment'.
+      (setq env
+            (dolist (elt (nreverse (copy-sequence process-environment)) env)
+              (or (member elt (default-toplevel-value 'process-environment))
+                  (setq env (cons elt env)))))
+      (when env
+        (setq command
+              (format
+               "env %s %s"
+               (mapconcat 'tramp-shell-quote-argument env " ") command)))
       ;; Determine input.
       (if (null infile)
           (setq input "/dev/null")