todo-mode.el: Remove dependence on auto-mode-alist.

* calendar/todo-mode.el: Remove dependence on auto-mode-alist,
to avoid errors when trying to create or visit a file foo.todo
located outside to todo-directory, and to allow having such files
without them being tied to Todo mode.
(todo-show, todo-move-category, todo-merge-category, todo-find-archive)
(todo-archive-done-item, todo-find-filtered-items-file)
(todo-filter-items, todo-find-item, todo-diary-goto-entry)
(todo-category-completions, todo-read-category): When visiting a
Todo file, make sure we're in the right mode and the buffer local
variables are set.
(todo-make-categories-list, todo-reset-nondiary-marker)
(todo-reset-done-string, todo-reset-comment-string): After
processing all Todo files, kill the buffers of those files that
weren't being visited before the processing.
(todo-display-as-todo-file, todo-add-to-buffer-list)
(todo-visit-files-commands): Comment out.
(todo-modes-set-3, todo-mode): Comment out additions to find-file-hook.
(auto-mode-alist): Remove add-to-list calls making Todo file
extensions unrestrictedly tied to Todo modes.

* doc/misc/todo-mode.texi: Update in light of changes due to bug#17482.
Replace numerous mistaken uses of literal quotes with proper
Texinfo markup.
(Todo Mode Entry Points): Comment out reference to using find-file
or Dired to visit Todo files, since this has been disabled (bug#17482).

2 files changed, 153 insertions, 89 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 57cf0490fea..1d450e3d5d5 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,25 @@
+2014-05-23  Stephen Berman  <stephen.berman@gmx.net>
+
+        * calendar/todo-mode.el: Remove dependence on auto-mode-alist,
+        to avoid errors when trying to create or visit a file foo.todo
+        located outside to todo-directory, and to allow having such files
+        without them being tied to Todo mode (bug#17482).
+        (todo-show, todo-move-category, todo-merge-category, todo-find-archive)
+        (todo-archive-done-item, todo-find-filtered-items-file)
+        (todo-filter-items, todo-find-item, todo-diary-goto-entry)
+        (todo-category-completions, todo-read-category): When visiting a
+        Todo file, make sure we're in the right mode and the buffer local
+        variables are set.
+        (todo-make-categories-list, todo-reset-nondiary-marker)
+        (todo-reset-done-string, todo-reset-comment-string): After
+        processing all Todo files, kill the buffers of those files that
+        weren't being visited before the processing.
+        (todo-display-as-todo-file, todo-add-to-buffer-list)
+        (todo-visit-files-commands): Comment out.
+        (todo-modes-set-3, todo-mode): Comment out additions to find-file-hook.
+        (auto-mode-alist): Remove add-to-list calls making Todo file
+        extensions unrestrictedly tied to Todo modes.
+
 2014-05-23  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * emacs-lisp/nadvice.el (advice--member-p): Change second arg.
diff --git a/lisp/calendar/todo-mode.el b/lisp/calendar/todo-mode.el
index 1b15317ffc6..ab2ab3e4cb8 100644
--- a/lisp/calendar/todo-mode.el
+++ b/lisp/calendar/todo-mode.el
@@ -566,13 +566,13 @@ less than or equal the category's top priority setting."
 ;;; Entering and exiting
 ;; -----------------------------------------------------------------------------
 
-(defcustom todo-visit-files-commands (list 'find-file 'dired-find-file)
-  "List of file finding commands for `todo-display-as-todo-file'.
-Invoking these commands to visit a todo file or todo archive file
-calls `todo-show' or `todo-find-archive', so that the file is
-displayed correctly."
-  :type '(repeat function)
-  :group 'todo)
+;; (defcustom todo-visit-files-commands (list 'find-file 'dired-find-file)
+;;   "List of file finding commands for `todo-display-as-todo-file'.
+;; Invoking these commands to visit a todo file or todo archive file
+;; calls `todo-show' or `todo-find-archive', so that the file is
+;; displayed correctly."
+;;   :type '(repeat function)
+;;   :group 'todo)
 
 (defun todo-short-file-name (file)
   "Return the short form of todo file FILE's name.
@@ -740,9 +740,12 @@ corresponding todo file, displaying the corresponding category."
                                              "Choose a regexp items file: "
                                              rxf) 'regexp))))))
                      (if (file-exists-p fi-file)
-                         (set-window-buffer
-                          (selected-window)
-                          (set-buffer (find-file-noselect fi-file 'nowarn)))
+                         (progn
+                           (set-window-buffer
+                            (selected-window)
+                            (set-buffer (find-file-noselect fi-file 'nowarn)))
+                           (unless (derived-mode-p 'todo-filtered-items-mode)
+                             (todo-filtered-items-mode)))
                        (message "There is no %s file for %s"
                                 (cond ((eq todo-show-first 'top)
                                        "top priorities")
@@ -757,6 +760,9 @@ corresponding todo file, displaying the corresponding category."
           (unless (todo-check-file file) (throw 'end nil))
           (set-window-buffer (selected-window)
                              (set-buffer (find-file-noselect file 'nowarn)))
+          (if (equal (file-name-extension (buffer-file-name)) "toda")
+              (unless (derived-mode-p 'todo-archive-mode) (todo-archive-mode))
+            (unless (derived-mode-p 'todo-mode) (todo-mode)))
           ;; When quitting an archive file, show the corresponding
           ;; category in the corresponding todo file, if it exists.
           (when (assoc cat todo-categories)
@@ -1449,6 +1455,10 @@ the archive of the file moved to, creating it if it does not exist."
                  (if (member buf (funcall todo-files-function t))
                      (concat (file-name-sans-extension nfile) ".toda")
                    nfile))
+              (if (equal (file-name-extension (buffer-file-name)) "toda")
+                  (unless (derived-mode-p 'todo-archive-mode)
+                    (todo-archive-mode))
+                (unless (derived-mode-p 'todo-mode) (todo-mode)))
               (let* ((nfile-short (todo-short-file-name nfile))
                      (prompt (concat
                               (format "Todo file \"%s\" already has "
@@ -1564,6 +1574,7 @@ archive file and the source category is deleted."
              (done-count (todo-get-count 'done cat)))
         ;; Merge into goal todo category.
         (with-current-buffer (get-buffer (find-file-noselect gfile))
+          (unless (derived-mode-p 'todo-mode) (todo-mode))
           (widen)
           (goto-char (point-min))
           (let ((buffer-read-only nil))
@@ -2995,6 +3006,7 @@ displayed."
       (when place
         (set-window-buffer (selected-window)
                            (set-buffer (find-file-noselect archive)))
+        (unless (derived-mode-p 'todo-archive-mode) (todo-archive-mode))
         (if (member place '(other-archive other-cat))
             (setq todo-category-number 1)
           (todo-category-number cat))
@@ -3070,6 +3082,7 @@ this category does not exist in the archive, it is created."
           (if (not (or marked all item))
               (throw 'end (message "Only done items can be archived"))
             (with-current-buffer archive
+              (unless (derived-mode-p 'todo-archive-mode) (todo-archive-mode))
               (let (buffer-read-only)
                 (widen)
                 (goto-char (point-min))
@@ -3091,12 +3104,12 @@ this category does not exist in the archive, it is created."
                 (todo-update-categories-sexp)
                 ;; If archive is new, save to file now (with
                 ;; write-region to avoid prompt for file to save to)
-                ;; to update todo-archives, and to let auto-mode-alist
-                ;; take effect below on visiting the archive.
+                ;; to update todo-archives, and set the mode for
+                ;; visiting the archive below.
                 (unless (nth 7 (file-attributes afile))
                   (write-region nil nil afile t t)
                   (setq todo-archives (funcall todo-files-function t))
-                  (kill-buffer))))
+                  (todo-archive-mode))))
             (with-current-buffer tbuf
               (cond
                (all
@@ -3957,7 +3970,9 @@ regexp items."
     (setq file (completing-read "Choose a filtered items file: "
                                 falist nil t nil nil (car falist)))
     (setq file (cdr (assoc-string file falist)))
-    (find-file file)))
+    (find-file file)
+    (unless (derived-mode-p 'todo-filtered-items-mode)
+      (todo-filtered-items-mode))))
 
 (defun todo-go-to-source-item ()
   "Display the file and category of the filtered item at point."
@@ -4088,6 +4103,8 @@ multifile commands for further details."
                             (completing-read "Choose a regexp items file: "
                                              rxf) 'regexp))))
            (find-file fname)
+           (unless (derived-mode-p 'todo-filtered-items-mode)
+             (todo-filtered-items-mode))
            (todo-prefix-overlays)
            (todo-check-filtered-items-file))
           (t
@@ -4341,6 +4358,9 @@ its priority has changed, and `same' otherwise."
                    todo-global-current-todo-file)))
     (find-file-noselect file)
     (with-current-buffer (find-buffer-visiting file)
+      (if archive
+          (unless (derived-mode-p 'todo-archive-mode) (todo-archive-mode))
+        (unless (derived-mode-p 'todo-mode) (todo-mode)))
       (save-restriction
         (widen)
         (goto-char (point-min))
@@ -4917,23 +4937,28 @@ the file."
                  ;; Make sure to include newly created archives, e.g. due to
                  ;; todo-move-category.
                  (when (member archive (funcall todo-files-function t))
-                   (let ((archive-count 0))
-                     (with-current-buffer (find-file-noselect archive)
-                       (widen)
-                       (goto-char (point-min))
-                       (when (re-search-forward
-                              (concat "^" (regexp-quote todo-category-beg)
-                                      cat "$")
-                              (point-max) t)
-                         (forward-line)
-                         (while (not (or (looking-at
-                                          (concat
-                                           (regexp-quote todo-category-beg)
-                                           "\\(.*\\)\n"))
-                                         (eobp)))
-                           (when (looking-at todo-done-string-start)
-                             (setq archive-count (1+ archive-count)))
-                           (forward-line))))
+                   (let ((archive-count 0)
+                         (visiting (find-buffer-visiting archive)))
+                     (with-current-buffer (or visiting
+                                              (find-file-noselect archive))
+                       (save-excursion
+                         (save-restriction
+                           (widen)
+                           (goto-char (point-min))
+                           (when (re-search-forward
+                                  (concat "^" (regexp-quote todo-category-beg)
+                                          cat "$")
+                                  (point-max) t)
+                             (forward-line)
+                             (while (not (or (looking-at
+                                              (concat
+                                               (regexp-quote todo-category-beg)
+                                               "\\(.*\\)\n"))
+                                             (eobp)))
+                               (when (looking-at todo-done-string-start)
+                                 (setq archive-count (1+ archive-count)))
+                               (forward-line)))))
+                       (unless visiting (kill-buffer)))
                      (todo-update-count 'archived archive-count cat))))
                 ((looking-at todo-done-string-start)
                  (todo-update-count 'done 1 cat))
@@ -5157,6 +5182,11 @@ Overrides `diary-goto-entry'."
     (if (not (and (file-exists-p file)
                   (find-file-other-window file)))
         (message "Unable to locate this diary entry")
+      ;; If it's a Todo file, make sure it's in Todo mode.
+      (when (and (equal (file-name-directory (file-truename file))
+                        (file-truename todo-directory))
+                 (not (derived-mode-p 'todo-mode)))
+        (todo-mode))
       (when (eq major-mode 'todo-mode) (widen))
       (goto-char (point-min))
       (when (re-search-forward (format "%s.*\\(%s\\)" date content) nil t)
@@ -5596,6 +5626,9 @@ have been removed."
         (add-to-list 'files curfile))
       (dolist (f files listall)
         (with-current-buffer (find-file-noselect f 'nowarn)
+          (if archive
+              (unless (derived-mode-p 'todo-archive-mode) (todo-archive-mode))
+            (unless (derived-mode-p 'todo-mode) (todo-mode)))
           ;; Ensure category is properly displayed in case user
           ;; switches to file via a non-Todo mode command.  And if
           ;; done items in category are visible, keep them visible.
@@ -5681,6 +5714,7 @@ categories from `todo-category-completions-files'."
            (categories (cond (file0
                               (with-current-buffer
                                   (find-file-noselect file0 'nowarn)
+                                (unless (derived-mode-p 'todo-mode) (todo-mode))
                                 (let ((todo-current-todo-file file0))
                                   todo-categories)))
                              ((and add (not file))
@@ -5960,23 +5994,28 @@ the empty string (i.e., no time string)."
                   (regexp-quote diary-nonmarking-symbol) "\\)?"))
     (when (not (equal value oldvalue))
       (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (let (buffer-read-only)
-            (widen)
-            (goto-char (point-min))
-            (while (not (eobp))
-              (if (re-search-forward
-                   (concat "^\\(" todo-done-string-start "[^][]+] \\)?"
-                           "\\(?1:" (regexp-quote (car oldvalue))
-                           "\\)" todo-date-pattern "\\( "
-                           diary-time-regexp "\\)?\\(?2:"
-                           (regexp-quote (cadr oldvalue)) "\\)")
-                   nil t)
-                  (progn
-                    (replace-match (nth 0 value) t t nil 1)
-                    (replace-match (nth 1 value) t t nil 2))
-                (forward-line)))
-            (todo-category-select)))))))
+        (let ((buf (find-buffer-visiting f)))
+          (with-current-buffer (find-file-noselect f)
+            (let (buffer-read-only)
+              (widen)
+              (goto-char (point-min))
+              (while (not (eobp))
+                (if (re-search-forward
+                     (concat "^\\(" todo-done-string-start "[^][]+] \\)?"
+                             "\\(?1:" (regexp-quote (car oldvalue))
+                             "\\)" todo-date-pattern "\\( "
+                             diary-time-regexp "\\)?\\(?2:"
+                             (regexp-quote (cadr oldvalue)) "\\)")
+                     nil t)
+                    (progn
+                      (replace-match (nth 0 value) t t nil 1)
+                      (replace-match (nth 1 value) t t nil 2))
+                  (forward-line)))
+              (if buf
+                  (when (derived-mode-p 'todo-mode 'todo-archive-mode)
+                    (todo-category-select))
+                (save-buffer)
+                (kill-buffer)))))))))
 
 (defun todo-reset-done-separator-string (symbol value)
   "The :set function for `todo-done-separator-string'."
@@ -6004,18 +6043,23 @@ the empty string (i.e., no time string)."
           (concat "^\\[" (regexp-quote todo-done-string)))
     (when (not (equal value oldvalue))
       (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (let (buffer-read-only)
-            (widen)
-            (goto-char (point-min))
-            (while (not (eobp))
-              (if (re-search-forward
-                   (concat "^" (regexp-quote todo-nondiary-start)
-                           "\\(" (regexp-quote oldvalue) "\\)")
-                   nil t)
-                  (replace-match value t t nil 1)
-                (forward-line)))
-            (todo-category-select)))))))
+        (let ((buf (find-buffer-visiting f)))
+          (with-current-buffer (find-file-noselect f)
+            (let (buffer-read-only)
+              (widen)
+              (goto-char (point-min))
+              (while (not (eobp))
+                (if (re-search-forward
+                     (concat "^" (regexp-quote todo-nondiary-start)
+                             "\\(" (regexp-quote oldvalue) "\\)")
+                     nil t)
+                    (replace-match value t t nil 1)
+                  (forward-line)))
+              (if buf
+                  (when (derived-mode-p 'todo-mode 'todo-archive-mode)
+                    (todo-category-select))
+                (save-buffer)
+                (kill-buffer)))))))))
 
 (defun todo-reset-comment-string (symbol value)
   "The :set function for user option `todo-comment-string'."
@@ -6025,19 +6069,23 @@ the empty string (i.e., no time string)."
     (custom-set-default symbol value)
     (when (not (equal value oldvalue))
       (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (let (buffer-read-only)
-            (save-excursion
+        (let ((buf (find-buffer-visiting f)))
+          (with-current-buffer (find-file-noselect f)
+            (let (buffer-read-only)
               (widen)
               (goto-char (point-min))
               (while (not (eobp))
                 (if (re-search-forward
-                     (concat
-                             "\\[\\(" (regexp-quote oldvalue) "\\): [^]]*\\]")
+                     (concat "\\[\\(" (regexp-quote oldvalue)
+                             "\\): [^]]*\\]")
                      nil t)
                     (replace-match value t t nil 1)
                   (forward-line)))
-              (todo-category-select))))))))
+              (if buf
+                  (when (derived-mode-p 'todo-mode 'todo-archive-mode)
+                    (todo-category-select))
+                (save-buffer)
+                (kill-buffer)))))))))
 
 (defun todo-reset-highlight-item (symbol value)
   "The :set function for user option `todo-highlight-item'."
@@ -6435,20 +6483,20 @@ Added to `pre-command-hook' in Todo mode when user option
 `todo-show-current-file' is set to non-nil."
   (setq todo-global-current-todo-file todo-current-todo-file))
 
-(defun todo-display-as-todo-file ()
-  "Show todo files correctly when visited from outside of Todo mode.
-Added to `find-file-hook' in Todo mode and Todo Archive mode."
-  (and (member this-command todo-visit-files-commands)
-       (= (- (point-max) (point-min)) (buffer-size))
-       (member major-mode '(todo-mode todo-archive-mode))
-       (todo-category-select)))
-
-(defun todo-add-to-buffer-list ()
-  "Add name of just visited todo file to `todo-file-buffers'.
-This function is added to `find-file-hook' in Todo mode."
-  (let ((filename (file-truename (buffer-file-name))))
-    (when (member filename todo-files)
-      (add-to-list 'todo-file-buffers filename))))
+;; (defun todo-display-as-todo-file ()
+;;   "Show todo files correctly when visited from outside of Todo mode.
+;; Added to `find-file-hook' in Todo mode and Todo Archive mode."
+;;   (and (member this-command todo-visit-files-commands)
+;;        (= (- (point-max) (point-min)) (buffer-size))
+;;        (member major-mode '(todo-mode todo-archive-mode))
+;;        (todo-category-select)))
+
+;; (defun todo-add-to-buffer-list ()
+;;   "Add name of just visited todo file to `todo-file-buffers'.
+;; This function is added to `find-file-hook' in Todo mode."
+;;   (let ((filename (file-truename (buffer-file-name))))
+;;     (when (member filename todo-files)
+;;       (add-to-list 'todo-file-buffers filename))))
 
 (defun todo-update-buffer-list ()
   "Make current Todo mode buffer file car of `todo-file-buffers'.
@@ -6503,7 +6551,8 @@ Added to `window-configuration-change-hook' in Todo mode."
   "Make some settings that apply to multiple Todo modes."
   (setq-local todo-categories (todo-set-categories))
   (setq-local todo-category-number 1)
-  (add-hook 'find-file-hook 'todo-display-as-todo-file nil t))
+  ;; (add-hook 'find-file-hook 'todo-display-as-todo-file nil t)
+  )
 
 (put 'todo-mode 'mode-class 'special)
 
@@ -6522,7 +6571,7 @@ Added to `window-configuration-change-hook' in Todo mode."
     (setq-local todo-current-todo-file (file-truename (buffer-file-name))))
   (setq-local todo-show-done-only nil)
   (setq-local todo-categories-with-marks nil)
-  (add-hook 'find-file-hook 'todo-add-to-buffer-list nil t)
+  ;; (add-hook 'find-file-hook 'todo-add-to-buffer-list nil t)
   (add-hook 'post-command-hook 'todo-update-buffer-list nil t)
   (when todo-show-current-file
     (add-hook 'pre-command-hook 'todo-show-current-file nil t))
@@ -6591,13 +6640,6 @@ Added to `window-configuration-change-hook' in Todo mode."
   (todo-modes-set-1)
   (todo-modes-set-2))
 
-;;;###autoload
-(add-to-list 'auto-mode-alist '("\\.todo\\'" . todo-mode))
-;;;###autoload
-(add-to-list 'auto-mode-alist '("\\.toda\\'" . todo-archive-mode))
-;;;###autoload
-(add-to-list 'auto-mode-alist '("\\.tod[tyr]\\'" . todo-filtered-items-mode))
-
 ;; -----------------------------------------------------------------------------
 (provide 'todo-mode)