Make Help mode inherit from special-mode.

* help-mode.el (help-mode-map): Add special-mode-map to parent.
(help-mode): Derive help-mode from special-mode. Don't invoke
view-mode from help-mode.
(help-xref-override-view-map): Remove.
(help-make-xrefs): Remove minor-mode-overriding-map-alist since
view-mode is not used anymore.

2 files changed, 13 insertions, 39 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 4af6010b556..5d4470a7f87 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,12 @@
+2011-08-28  Christoph Scholtes  <cschol2112@googlemail.com>
+
+        * help-mode.el (help-mode-map): Add special-mode-map to parent.
+        (help-mode): Derive help-mode from special-mode. Don't invoke
+        view-mode from help-mode.
+        (help-xref-override-view-map): Remove.
+        (help-make-xrefs): Remove minor-mode-overriding-map-alist since
+        view-mode is not used anymore.
+
 2011-08-28  Chong Yidong  <cyd@stupidchicken.com>
 
         * server.el (server-port): Doc fix.
diff --git a/lisp/help-mode.el b/lisp/help-mode.el
index 1a96f29c4cc..64c114c993d 100644
--- a/lisp/help-mode.el
+++ b/lisp/help-mode.el
@@ -35,13 +35,12 @@
 
 (defvar help-mode-map
   (let ((map (make-sparse-keymap)))
-    (set-keymap-parent map button-buffer-map)
-
+    (set-keymap-parent map (make-composed-keymap button-buffer-map
+                                                 special-mode-map))
     (define-key map [mouse-2] 'help-follow-mouse)
     (define-key map "\C-c\C-b" 'help-go-back)
     (define-key map "\C-c\C-f" 'help-go-forward)
     (define-key map "\C-c\C-c" 'help-follow-symbol)
-    ;; Documentation only, since we use minor-mode-overriding-map-alist.
     (define-key map "\r" 'help-follow)
     map)
   "Keymap for help mode.")
@@ -266,37 +265,13 @@ The format is (FUNCTION ARGS...).")
   'help-function 'customize-create-theme
   'help-echo (purecopy "mouse-2, RET: edit this theme file"))
 
-;;;###autoload
-(defun help-mode ()
+(define-derived-mode help-mode special-mode "Help"
   "Major mode for viewing help text and navigating references in it.
 Entry to this mode runs the normal hook `help-mode-hook'.
 Commands:
 \\{help-mode-map}"
-  (interactive)
-  (kill-all-local-variables)
-  (use-local-map help-mode-map)
-  (setq mode-name "Help")
-  (setq major-mode 'help-mode)
-
-  (view-mode)
-  (set (make-local-variable 'view-no-disable-on-exit) t)
-  ;; With Emacs 22 `view-exit-action' could delete the selected window
-  ;; disregarding whether the help buffer was shown in that window at
-  ;; all.  Since `view-exit-action' is called with the help buffer as
-  ;; argument it seems more appropriate to have it work on the buffer
-  ;; only and leave it to `view-mode-exit' to delete any associated
-  ;; window(s).
-  (setq view-exit-action
-        (lambda (buffer)
-          ;; Use `with-current-buffer' to make sure that `bury-buffer'
-          ;; also removes BUFFER from the selected window.
-          (with-current-buffer buffer
-            (bury-buffer))))
-
   (set (make-local-variable 'revert-buffer-function)
-       'help-mode-revert-buffer)
-
-  (run-mode-hooks 'help-mode-hook))
+       'help-mode-revert-buffer))
 
 ;;;###autoload
 (defun help-mode-setup ()
@@ -403,13 +378,6 @@ it does not already exist."
        (error "Current buffer is not in Help mode"))
      (current-buffer))))
 
-(defvar help-xref-override-view-map
-  (let ((map (make-sparse-keymap)))
-    (set-keymap-parent map view-mode-map)
-    (define-key map "\r" nil)
-    map)
-  "Replacement keymap for `view-mode' in help buffers.")
-
 ;;;###autoload
 (defun help-make-xrefs (&optional buffer)
   "Parse and hyperlink documentation cross-references in the given BUFFER.
@@ -594,9 +562,6 @@ that."
                                      (current-buffer)))
           (when (or help-xref-stack help-xref-forward-stack)
             (insert "\n")))
-        ;; View mode steals RET from us.
-        (set (make-local-variable 'minor-mode-overriding-map-alist)
-             (list (cons 'view-mode help-xref-override-view-map)))
         (set-buffer-modified-p old-modified)))))
 
 ;;;###autoload