* lisp/help-fns.el (describe-variable): Add original value, if applicable.

2 files changed, 18 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 7310e8d3dc8..a43c267c932 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2010-09-20  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * help-fns.el (describe-variable): Add original value, if applicable.
+
 2010-09-20  Juanma Barranquero  <lekktu@gmail.com>
 
         * subr.el (y-or-n-p): Remove leftover code from 2010-09-17T13:30:30Z!monnier@iro.umontreal.ca.
diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 4456a494099..9739762637a 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -645,7 +645,20 @@ it is displayed along with the global value."
                   ;; inappropriate e.g C-h v <RET> features <RET>
                   ;; (help-xref-on-pp from (point))
                   (if (< (point) (+ from 20))
-                      (delete-region (1- from) from)))))
+                      (delete-region (1- from) from))
+                  (let* ((sv (get variable 'standard-value))
+                         (origval (and (consp sv)
+                                       (condition-case nil
+                                           (eval (car sv))
+                                         (error :help-eval-error)))))
+                    (when (and (consp sv)
+                               (not (equal origval val))
+                               (not (equal origval :help-eval-error)))
+                      (princ "\nOriginal value was \n")
+                      (setq from (point))
+                      (pp origval)
+                      (if (< (point) (+ from 20))
+                          (delete-region (1- from) from)))))))
             (terpri)
 
             (when locus