* lisp/help-mode.el (help-bookmark-make-record, help-bookmark-jump): New funs.

(help-mode): Use them.

1 files changed, 35 insertions, 1 deletions

diff --git a/lisp/help-mode.el b/lisp/help-mode.el
index eb0834e243a..d3fe21abd95 100644
--- a/lisp/help-mode.el
+++ b/lisp/help-mode.el
@@ -267,6 +267,8 @@ The format is (FUNCTION ARGS...).")
   'help-function 'customize-create-theme
   'help-echo (purecopy "mouse-2, RET: edit this theme file"))
 
+(defvar bookmark-make-record-function)
+
 ;;;###autoload
 (define-derived-mode help-mode special-mode "Help"
   "Major mode for viewing help text and navigating references in it.
@@ -274,7 +276,9 @@ Entry to this mode runs the normal hook `help-mode-hook'.
 Commands:
 \\{help-mode-map}"
   (set (make-local-variable 'revert-buffer-function)
-       'help-mode-revert-buffer))
+       'help-mode-revert-buffer)
+  (set (make-local-variable 'bookmark-make-record-function)
+       'help-bookmark-make-record))
 
 ;;;###autoload
 (defun help-mode-setup ()
@@ -791,6 +795,36 @@ help buffer by other means."
   (with-output-to-temp-buffer (help-buffer)
     (insert string)))
 
+
+;; Bookmark support
+
+(declare-function bookmark-prop-get "bookmark" (bookmark prop))
+
+(defun help-bookmark-make-record ()
+  "Create and return a help-mode bookmark record.
+Implements `bookmark-make-record-function' for help-mode buffers."
+  (unless (car help-xref-stack-item)
+    (error "Cannot create bookmark - help command not known"))
+  `(,@(bookmark-make-record-default 'NO-FILE 'NO-CONTEXT)
+      (buffer-name . "*Help*")
+      (help-fn     . ,(car help-xref-stack-item))
+      (help-arg    . ,(cadr help-xref-stack-item))
+      (position    . ,(point))
+      (handler     . help-bookmark-jump)))
+
+;;;###autoload
+(defun help-bookmark-jump (bookmark)
+  "Jump to help-mode bookmark BOOKMARK.
+Handler function for record returned by `help-bookmark-make-record'.
+BOOKMARK is a bookmark name or a bookmark record."
+  (let ((help-fn   (bookmark-prop-get bookmark 'help-fn))
+        (help-arg  (bookmark-prop-get bookmark 'help-arg))
+        (position  (bookmark-prop-get bookmark 'position)))
+    (funcall help-fn help-arg)
+    (pop-to-buffer "*Help*")
+    (goto-char position)))
+
+
 (provide 'help-mode)
 
 ;;; help-mode.el ends here