* calendar/todos.el (todos-check-format): Add check of well-formedness of

categories sexp.  If it is well-formed but differs from
todos-categories, do not signal an error but display a message.

2 files changed, 41 insertions, 21 deletions

diff --git a/lisp/calendar/ChangeLog b/lisp/calendar/ChangeLog
index 5168fe33671..e3d3b45f5a9 100644
--- a/lisp/calendar/ChangeLog
+++ b/lisp/calendar/ChangeLog
@@ -1,3 +1,9 @@
+2013-04-24  Stephen Berman  <stephen.berman@gmx.net>
+
+        * todos.el (todos-check-format): Add check of well-formedness of
+        categories sexp.  If it is well-formed but differs from
+        todos-categories, do not signal an error but display a message.
+
 2013-04-21  Stephen Berman  <stephen.berman@gmx.net>
 
         * todos.el: Fixes and improvements related to item relocation.
diff --git a/lisp/calendar/todos.el b/lisp/calendar/todos.el
index 30c64efb0f0..9e1e4904d9c 100644
--- a/lisp/calendar/todos.el
+++ b/lisp/calendar/todos.el
@@ -1066,31 +1066,45 @@ short Todos Archive or Top Priorities file name, respectively."
 
 (defun todos-check-format ()
   "Signal an error if the current Todos file is ill-formatted.
-Otherwise return t.  The error message gives the line number
-where the invalid formatting was found."
+Otherwise return t.  Display a message if the file is well-formed
+but the categories sexp differs from the current value of
+`todos-categories'."
   (save-excursion
     (save-restriction
       (widen)
       (goto-char (point-min))
-      (let ((cats (prin1-to-string todos-categories))
-            (sexp (buffer-substring-no-properties (line-beginning-position)
-                                                  (line-end-position))))
-        ;; Check for `todos-categories' sexp as the first line
-        (unless (string= sexp cats)
-          (error "Invalid or missing todos-categories sexp")))
-      (forward-line)
-      (let ((legit (concat "\\(^" (regexp-quote todos-category-beg) "\\)"
-                           "\\|\\(" todos-date-string-start todos-date-pattern "\\)"
-                           "\\|\\(^[ \t]+[^ \t]*\\)"
-                           "\\|^$"
-                           "\\|\\(^" (regexp-quote todos-category-done) "\\)"
-                           "\\|\\(" todos-done-string-start "\\)")))
-        (while (not (eobp))
-          (unless (looking-at legit)
-            (error "Illegitimate Todos file format at line %d"
-                   (line-number-at-pos (point))))
-          (forward-line)))))
-  ;; (message "This Todos file is well-formatted.")
+      (let* ((cats (prin1-to-string todos-categories))
+             (ssexp (buffer-substring-no-properties (line-beginning-position)
+                                                    (line-end-position)))
+             (sexp (read ssexp)))
+        ;; Check the first line for `todos-categories' sexp.
+        (dolist (c sexp)
+          (let ((v (cdr c)))
+            (unless (and (stringp (car c))
+                         (vectorp v)
+                         (= 4 (length v)))
+              (error "Invalid or missing todos-categories sexp"))))
+        (forward-line)
+        ;; Check well-formedness of categories.
+        (let ((legit (concat "\\(^" (regexp-quote todos-category-beg) "\\)"
+                             "\\|\\(" todos-date-string-start todos-date-pattern "\\)"
+                             "\\|\\(^[ \t]+[^ \t]*\\)"
+                             "\\|^$"
+                             "\\|\\(^" (regexp-quote todos-category-done) "\\)"
+                             "\\|\\(" todos-done-string-start "\\)")))
+          (while (not (eobp))
+            (unless (looking-at legit)
+              (error "Illegitimate Todos file format at line %d"
+                     (line-number-at-pos (point))))
+            (forward-line)))
+        ;; Warn user if categories sexp has changed.
+        (unless (string= ssexp cats)
+          (message (concat "The sexp at the beginning of the file differs "
+                           "from the value of `todos-categories.\n"
+                           "If the sexp is wrong, you can fix it with "
+                           "M-x todos-repair-categories-sexp,\n"
+                           "but note this reverts any changes you have "
+                           "made in the order of the categories."))))))
   t)
 
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