* lisp/info.el (Info-history-skip-intermediate-nodes): New defcustom.

(Info-forward-node, Info-backward-node, Info-next-preorder)
(Info-last-preorder): Use it.

Fixes: debbugs:9528

2 files changed, 36 insertions, 10 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 7e0da8727e1..0c16a44722a 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,11 @@
 2011-09-20  Juri Linkov  <juri@jurta.org>
 
+        * info.el (Info-history-skip-intermediate-nodes): New defcustom.
+        (Info-forward-node, Info-backward-node, Info-next-preorder)
+        (Info-last-preorder): Use it.  (Bug#9528)
+
+2011-09-20  Juri Linkov  <juri@jurta.org>
+
         * info.el (Info-last-preorder): Visit last menu item only when
         `Info-scroll-prefer-subnodes' is non-nil (third test-case of bug#9528).
 
diff --git a/lisp/info.el b/lisp/info.el
index 3fa35bb4d03..ea23cf35568 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -52,6 +52,15 @@ Each element of the stack is a list (FILENAME NODENAME BUFFERPOS).")
   "List of all Info nodes user has visited.
 Each element of the list is a list (FILENAME NODENAME).")
 
+(defcustom Info-history-skip-intermediate-nodes t
+  "Non-nil means don't record intermediate Info nodes to the history.
+Intermediate Info nodes are nodes visited by Info internally in the process of
+searching the node to display.  Intermediate nodes are not presented
+to the user."
+  :type 'boolean
+  :group 'info
+  :version "24.1")
+
 (defcustom Info-enable-edit nil
   "Non-nil means the \\<Info-mode-map>\\[Info-edit] command in Info can edit the current node.
 This is convenient if you want to write Info files by hand.
@@ -2668,10 +2677,13 @@ N is the digit argument used to invoke this command."
                                    "top")))
            (let ((old-node Info-current-node))
              (Info-up)
-             (let (Info-history success)
+             (let ((old-history Info-history)
+                   success)
                (unwind-protect
                    (setq success (Info-forward-node t nil no-error))
-                 (or success (Info-goto-node old-node))))))
+                 (or success (Info-goto-node old-node)))
+               (if Info-history-skip-intermediate-nodes
+                   (setq Info-history old-history)))))
           (no-error nil)
           (t (error "No pointer forward from this node")))))
 
@@ -2693,10 +2705,12 @@ N is the digit argument used to invoke this command."
            ;; If we move back at the same level,
            ;; go down to find the last subnode*.
            (Info-prev)
-           (let (Info-history)
+           (let ((old-history Info-history))
              (while (and (not (Info-index-node))
                          (save-excursion (search-forward "\n* Menu:" nil t)))
-               (Info-goto-node (Info-extract-menu-counting nil)))))
+               (Info-goto-node (Info-extract-menu-counting nil)))
+             (if Info-history-skip-intermediate-nodes
+                 (setq Info-history old-history))))
           (t
            (error "No pointer backward from this node")))))
 
@@ -2752,8 +2766,10 @@ N is the digit argument used to invoke this command."
          ;; Since logically we are done with the node with that menu,
          ;; move on from it.  But don't add intermediate nodes
          ;; to the history on recursive calls.
-         (let (Info-history)
-           (Info-next-preorder)))
+         (let ((old-history Info-history))
+           (Info-next-preorder)
+           (if Info-history-skip-intermediate-nodes
+               (setq Info-history old-history))))
         (t
          (error "No more nodes"))))
 
@@ -2767,24 +2783,28 @@ N is the digit argument used to invoke this command."
                ;; so we can scroll back through it.
                (goto-char (point-max))))
          ;; Keep going down, as long as there are nested menu nodes.
-         (let (Info-history) ; Don't add intermediate nodes to the history.
+         (let ((old-history Info-history))
            (while (Info-no-error
                    (Info-last-menu-item)
                    ;; If we go down a menu item, go to the end of the node
                    ;; so we can scroll back through it.
-                   (goto-char (point-max)))))
+                   (goto-char (point-max))))
+           (if Info-history-skip-intermediate-nodes
+               (setq Info-history old-history)))
          (recenter -1))
         ((and (Info-no-error (Info-extract-pointer "prev"))
               (not (equal (Info-extract-pointer "up")
                           (Info-extract-pointer "prev"))))
          (Info-no-error (Info-prev))
          (goto-char (point-max))
-         (let (Info-history) ; Don't add intermediate nodes to the history.
+         (let ((old-history Info-history))
            (while (Info-no-error
                    (Info-last-menu-item)
                    ;; If we go down a menu item, go to the end of the node
                    ;; so we can scroll back through it.
-                   (goto-char (point-max)))))
+                   (goto-char (point-max))))
+           (if Info-history-skip-intermediate-nodes
+               (setq Info-history old-history)))
          (recenter -1))
         ((Info-no-error (Info-up t))
          (goto-char (point-min))