Fix MSDOS build broken by 2010-09-10T16:44:35Z!larsi@gnus.org, support MSDOS build...

[gnu-emacs] / lisp / button.el

diff --git a/lisp/button.el b/lisp/button.el
index 6a558af445a142f4dbea9d6eb09e862df2d03b01..c771474da3ad72a6c8b21ec6e6d8265ab658bb4a 100644 (file)
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -1,10 +1,11 @@
 ;;; button.el --- clickable buttons
 ;;
 ;; Copyright (C) 2001, 2002, 2003, 2004, 2005,
-;;   2006, 2007, 2008 Free Software Foundation, Inc.
+;;   2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 ;;
 ;; Author: Miles Bader <miles@gnu.org>
 ;; Keywords: extensions
+;; Package: emacs
 ;;
 ;; This file is part of GNU Emacs.
 ;;
@@ -84,7 +85,7 @@ Mode-specific keymaps may want to use this as their parent keymap.")
 (put 'default-button 'type 'button)
 ;; action may be either a function to call, or a marker to go to
 (put 'default-button 'action 'ignore)
-(put 'default-button 'help-echo "mouse-2, RET: Push this button")
+(put 'default-button 'help-echo (purecopy "mouse-2, RET: Push this button"))
 ;; Make overlay buttons go away if their underlying text is deleted.
 (put 'default-button 'evaporate t)
 ;; Prevent insertions adjacent to the text-property buttons from
@@ -437,15 +438,22 @@ Returns the button found."
            (goto-char (button-start button)))
       ;; Move to Nth next button
       (let ((iterator (if (> n 0) #'next-button #'previous-button))
-           (wrap-start (if (> n 0) (point-min) (point-max))))
+           (wrap-start (if (> n 0) (point-min) (point-max)))
+           opoint fail)
        (setq n (abs n))
        (setq button t)                 ; just to start the loop
-       (while (and (> n 0) button)
+       (while (and (null fail) (> n 0) button)
          (setq button (funcall iterator (point)))
          (when (and (not button) wrap)
            (setq button (funcall iterator wrap-start t)))
          (when button
            (goto-char (button-start button))
+           ;; Avoid looping forever (e.g., if all the buttons have
+           ;; the `skip' property).
+           (cond ((null opoint)
+                  (setq opoint (point)))
+                 ((= opoint (point))
+                  (setq fail t)))
            (unless (button-get button 'skip)
              (setq n (1- n)))))))
     (if (null button)