(help-make-xrefs): If a symbol representing a face name is not followed by the

[bpt/emacs.git] / lisp / help-mode.el

diff --git a/lisp/help-mode.el b/lisp/help-mode.el
index 149eebb..cd8c6a1 100644 (file)
--- a/lisp/help-mode.el
+++ b/lisp/help-mode.el
@@ -68,6 +68,7 @@ The format is (FUNCTION ARGS...).")
 ;; Button types used by help
 
 (define-button-type 'help-xref
+  'follow-link t
   'action #'help-button-action)
 
 (defun help-button-action (button)
@@ -147,14 +148,13 @@ The format is (FUNCTION ARGS...).")
   :supertype 'help-xref
   'help-function (lambda (fun file)
                   (require 'find-func)
+                  (when (eq file 'C-source)
+                    (setq file
+                          (help-C-file-name (indirect-function fun) 'fun)))
                   ;; Don't use find-function-noselect because it follows
                   ;; aliases (which fails for built-in functions).
                   (let ((location
-                         (cond
-                          ((bufferp file) (cons file fun))
-                          ((string-match "\\`src/\\(.*\\.c\\)" file)
-                           (help-find-C-source fun (match-string 1 file) 'fun))
-                          (t (find-function-search-for-symbol fun nil file)))))
+                         (find-function-search-for-symbol fun nil file)))
                     (pop-to-buffer (car location))
                     (goto-char (cdr location))))
   'help-echo (purecopy "mouse-2, RET: find function's definition"))
@@ -162,15 +162,25 @@ The format is (FUNCTION ARGS...).")
 (define-button-type 'help-variable-def
   :supertype 'help-xref
   'help-function (lambda (var &optional file)
-                  (let ((location
-                         (cond
-                          ((string-match "\\`src/\\(.*\\.c\\)" file)
-                           (help-find-C-source var (match-string 1 file) 'var))
-                          (t (find-variable-noselect var file)))))
+                  (when (eq file 'C-source)
+                    (setq file (help-C-file-name var 'var)))
+                  (let ((location (find-variable-noselect var file)))
                     (pop-to-buffer (car location))
                     (goto-char (cdr location))))
   'help-echo (purecopy"mouse-2, RET: find variable's definition"))
 
+(define-button-type 'help-face-def
+  :supertype 'help-xref
+  'help-function (lambda (fun file)
+                  (require 'find-func)
+                  ;; Don't use find-function-noselect because it follows
+                  ;; aliases (which fails for built-in functions).
+                  (let ((location
+                         (find-function-search-for-symbol fun 'defface file)))
+                    (pop-to-buffer (car location))
+                    (goto-char (cdr location))))
+  'help-echo (purecopy "mouse-2, RET: find face's definition"))
+
 \f
 ;;;###autoload
 (defun help-mode ()
@@ -186,7 +196,7 @@ Commands:
   (view-mode)
   (make-local-variable 'view-no-disable-on-exit)
   (setq view-no-disable-on-exit t)
-  (run-hooks 'help-mode-hook))
+  (run-mode-hooks 'help-mode-hook))
 
 ;;;###autoload
 (defun help-mode-setup ()
@@ -195,14 +205,21 @@ Commands:
 
 ;;;###autoload
 (defun help-mode-finish ()
+  (let ((entry (assq (selected-window) view-return-to-alist)))
+       (if entry
+           ;; When entering Help mode from the Help window,
+           ;; such as by following a link, preserve the same
+           ;; meaning for the q command.
+           ;; (setcdr entry (cons (selected-window) help-return-method))
+           nil
+         (setq view-return-to-alist
+               (cons (cons (selected-window) help-return-method)
+                     view-return-to-alist))))
   (when (eq major-mode 'help-mode)
     ;; View mode's read-only status of existing *Help* buffer is lost
     ;; by with-output-to-temp-buffer.
     (toggle-read-only 1)
-    (help-make-xrefs (current-buffer)))
-  (setq view-return-to-alist
-       (list (cons (selected-window) help-return-method))))
-
+    (help-make-xrefs (current-buffer))))
 \f
 ;; Grokking cross-reference information in doc strings and
 ;; hyperlinking it.
@@ -371,9 +388,10 @@ that."
 ;;;                            (pop-to-buffer (car location))
 ;;;                            (goto-char (cdr location))))
                          (help-xref-button 8 'help-function-def sym))
-                        ((facep sym)
-                         (if (save-match-data (looking-at "[ \t\n]+face\\W"))
-                             (help-xref-button 8 'help-face sym)))
+                        ((and
+                           (facep sym)
+                           (save-match-data (looking-at "[ \t\n]+face\\W")))
+                          (help-xref-button 8 'help-face sym))
                          ((and (boundp sym) (fboundp sym))
                           ;; We can't intuit whether to use the
                           ;; variable or function doc -- supply both.
@@ -577,12 +595,11 @@ help buffer."
        (goto-char position)))))
 
 (defun help-go-back ()
-  "Invoke the [back] button (if any) in the Help mode buffer."
+  "Go back to previous topic in this help buffer."
   (interactive)
-  (let ((back-button (button-at (1- (point-max)))))
-    (if back-button
-       (button-activate back-button)
-      (error "No [back] button"))))
+  (if help-xref-stack
+      (help-xref-go-back (current-buffer))
+    (error "No previous help buffer")))
 
 (defun help-do-xref (pos function args)
   "Call the help cross-reference function FUNCTION with args ARGS.