Index: lisp/calendar/todo-mode.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/calendar/todo-mode.el,v
retrieving revision 1.57
diff -c -r1.57 todo-mode.el
*** lisp/calendar/todo-mode.el	8 Feb 2006 07:54:11 -0000	1.57
--- lisp/calendar/todo-mode.el	4 Jan 2007 12:06:10 -0000
***************
*** 1,6 ****
  ;;; todo-mode.el --- major mode for editing TODO list files
  
! ;; Copyright (C) 1997, 1999, 2001, 2002, 2003, 2004, 2005, 2006
  ;;   Free Software Foundation, Inc.
  
  ;; Author: Oliver Seidel <os10000@seidel-space.de>
--- 1,6 ----
  ;;; todo-mode.el --- major mode for editing TODO list files
  
! ;; Copyright (C) 1997, 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007
  ;;   Free Software Foundation, Inc.
  
  ;; Author: Oliver Seidel <os10000@seidel-space.de>
***************
*** 532,555 ****
  (defun todo-add-category (cat)
    "Add new category CAT to the TODO list."
    (interactive "sCategory: ")
!   (save-window-excursion
!     (setq todo-categories (cons cat todo-categories))
!     (find-file todo-file-do)
!     (widen)
!     (goto-char (point-min))
!     (let ((posn (search-forward "-*- mode: todo; " 17 t)))
!       (if (not (null posn)) (goto-char posn))
!       (if (equal posn nil)
!           (progn
!             (insert "-*- mode: todo; \n")
!             (forward-char -1))
!         (kill-line)))
!     (insert (format "todo-categories: %S; -*-" todo-categories))
!     (forward-char 1)
!     (insert (format "%s%s%s\n%s\n%s %s\n"
!                     todo-prefix todo-category-beg cat
!                     todo-category-end
!                     todo-prefix todo-category-sep)))
    0)
  
  ;;;###autoload
--- 532,557 ----
  (defun todo-add-category (cat)
    "Add new category CAT to the TODO list."
    (interactive "sCategory: ")
!   (if (member cat todo-categories)
!       (error "This category already exists")
!     (save-window-excursion
!       (setq todo-categories (cons cat todo-categories))
!       (find-file todo-file-do)
!       (widen)
!       (goto-char (point-min))
!       (let ((posn (search-forward "-*- mode: todo; " 17 t)))
! 	(if (not (null posn)) (goto-char posn))
! 	(if (equal posn nil)
! 	    (progn
! 	      (insert "-*- mode: todo; \n")
! 	      (forward-char -1))
! 	  (kill-line)))
!       (insert (format "todo-categories: %S; -*-" todo-categories))
!       (forward-char 1)
!       (insert (format "%s%s%s\n%s\n%s %s\n"
! 		      todo-prefix todo-category-beg cat
! 		      todo-category-end
! 		      todo-prefix todo-category-sep))))
    0)
  
  ;;;###autoload
***************
*** 952,957 ****
--- 954,961 ----
    (find-file todo-file-do)
    (erase-buffer)
    (todo-mode)
+   (setq todo-categories nil
+ 	todo-cats nil)
    (todo-add-category "Todo"))
  
  (provide 'todo-mode)
Index: lisp/ChangeLog
===================================================================
RCS file: /sources/emacs/emacs/lisp/ChangeLog,v
retrieving revision 1.10526
diff -C0 -r1.10526 ChangeLog
*** lisp/ChangeLog	3 Jan 2007 20:17:09 -0000	1.10526
--- lisp/ChangeLog	4 Jan 2007 12:06:30 -0000
***************
*** 0 ****
--- 1,7 ----
+ 2007-01-04  Michaël Cadilhac  <michael.cadilhac@lrde.org>
+ 
+ 	* calendar/todo-mode.el (todo-add-category): Prevent adding a category
+ 	that already exists.
+ 	(todo-initial-setup): Make sure the setup is empty by setting the
+ 	category lists to nil.
+