*** emacs/lisp/calendar/todo-mode.el.~1.72.~	2009-01-09 11:48:58.000000000 +0100
--- emacs/lisp/calendar/todo-mode.el	2009-01-21 00:39:08.000000000 +0100
***************
*** 527,554 ****
      (narrow-to-region (todo-item-start) (todo-item-end))))
  
  ;;;###autoload
! (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 posn
!           (progn
!             (goto-char posn)
!             (kill-line))
!         (insert "-*- mode: todo; \n")
!         (forward-char -1)))
!     (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
  (defun todo-add-item-non-interactively (new-item category)
--- 527,571 ----
      (narrow-to-region (todo-item-start) (todo-item-end))))
  
  ;;;###autoload
! (defun todo-add-category (&optional cat)
    "Add new category CAT to the TODO list."
!   (interactive)
!   (let ((buf (find-file-noselect todo-file-do t))
! 	(prompt "Category: "))
!     (unless (zerop (buffer-size buf))
!       (and (null todo-categories)
! 	   (null todo-cats)
! 	   (error "Error in %s: File is non-empty but contains no category" 
! 		  todo-file-do)))
!     (unless cat (setq cat (read-from-minibuffer prompt)))
!     (with-current-buffer buf
!       ;; reject names that could induce bugs and confusion
!       (while (and (cond ((string= "" cat)
! 			 (setq prompt "Enter a non-empty category name: "))
! 			((string-match "\\`\\s-+\\'" cat)
! 			 (setq prompt "Enter a category name that is not only white space: "))
! 			((member cat todo-categories)
! 			 (setq prompt "Enter a non-existing category name: ")))
! 		  (setq cat (read-from-minibuffer prompt))))
!       ;; initialize a newly created Todo buffer for Todo mode
!       (unless (file-exists-p todo-file-do) (todo-mode))
!       (setq todo-categories (cons cat todo-categories))
!       (widen)
!       (goto-char (point-min))
!       (if (search-forward "-*- mode: todo; " 17 t)
! 	  (kill-line)
! 	(insert "-*- mode: todo; \n")
! 	(forward-char -1))
!       (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))
!       (if (interactive-p)
! 	  ;; properly display the newly added category
! 	  (progn (setq todo-category-number 0) (todo-show))
! 	0))))
  
  ;;;###autoload
  (defun todo-add-item-non-interactively (new-item category)
***************
*** 929,935 ****
  (defun todo-show ()
    "Show TODO list."
    (interactive)
!   (if (file-exists-p todo-file-do)
        (find-file todo-file-do)
      (todo-initial-setup))
    (if (null todo-categories)
--- 946,957 ----
  (defun todo-show ()
    "Show TODO list."
    (interactive)
!   ;; Call todo-initial-setup only if there is neither a Todo file nor
!   ;; a corresponding unsaved buffer.
!   (if (or (file-exists-p todo-file-do)
! 	  (let* ((buf (get-buffer (file-name-nondirectory todo-file-do)))
! 		 (bufname (buffer-file-name buf)))
! 	    (equal (expand-file-name todo-file-do) bufname)))
        (find-file todo-file-do)
      (todo-initial-setup))
    (if (null todo-categories)