* mail/rmail.el (rmail-expunge-confirmed): Return nil if nothing to do.

Don't call rmail-modify-format here.
(rmail-expunge): Call it here after expunge is confirmed.
(rmail-confirm-expunge): Doc fix.  Mark as risky.
(rmail-convert-babyl-to-mbox): Call rmail-modify-format.
(rmail-set-attribute): Call rmail-dont-modify-format only for `unseen'.
For other attributes, call `rmail-modify-format',
and propagate the modified flag to rmail-buffer.

2 files changed, 35 insertions, 13 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index fcb89a96436..b1241123942 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,14 @@
+2009-05-18  Richard M Stallman  <rms@gnu.org>
+
+        * mail/rmail.el (rmail-expunge-confirmed): Return nil if nothing to do.
+        Don't call rmail-modify-format here.
+        (rmail-expunge): Call it here after expunge is confirmed.
+        (rmail-confirm-expunge): Doc fix.  Mark as risky.
+        (rmail-convert-babyl-to-mbox): Call rmail-modify-format.
+        (rmail-set-attribute): Call rmail-dont-modify-format only for `unseen'.
+        For other attributes, call `rmail-modify-format',
+        and propagate the modified flag to rmail-buffer.
+
 2009-05-17  Richard M Stallman  <rms@gnu.org>
 
         * mail/rmailedit.el (rmail-edit-current-message):
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 0eb500e52e0..b348495f178 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -440,12 +440,15 @@ the frame where you have the RMAIL buffer displayed."
   :group 'rmail-files)
 
 (defcustom rmail-confirm-expunge 'y-or-n-p
-  "Whether and how to ask for confirmation before expunging deleted messages."
+  "Whether and how to ask for confirmation before expunging deleted messages.
+The value, if non-nil is a function to call with a question (string)
+as argument, to ask the user that question."
   :type '(choice (const :tag "No confirmation" nil)
                  (const :tag "Confirm with y-or-n-p" y-or-n-p)
                  (const :tag "Confirm with yes-or-no-p" yes-or-no-p))
   :version "21.1"
   :group 'rmail-files)
+(put 'rmail-confirm-expunge 'risky-local-variable t)
 
 ;;;###autoload
 (defvar rmail-mode-hook nil
@@ -967,6 +970,7 @@ This function also reinitializes local variables used by Rmail."
             (rmail-perm-variables)
             (rmail-variables)
             (setq rmail-was-converted t)
+            (rmail-dont-modify-format)
             (goto-char (point-max))
             (rmail-set-message-counters))
           (message "Replacing BABYL format with mbox format...done"))
@@ -2257,6 +2261,10 @@ change; nil means current message."
       (setq n (1+ n))))
   (if (stringp attr)
       (error "Unknown attribute `%s'" attr))
+  ;; Ask for confirmation before setting any attribute except `unseen'
+  ;; if it would force a format change.
+  (unless (= attr rmail-unseen-attr-index)
+    (rmail-modify-format))
   (with-current-buffer rmail-buffer
     (or msgnum (setq msgnum rmail-current-message))
     (when (> msgnum 0)
@@ -2269,8 +2277,12 @@ change; nil means current message."
             (if (= msgnum rmail-current-message)
                 (rmail-display-labels)))
           ;; Don't save in mbox format over a Babyl file
-          ;; merely because of this.
-          (rmail-dont-modify-format)))))
+          ;; merely because of a change in `unseen' attribute.
+          (if (= attr rmail-unseen-attr-index)
+              (rmail-dont-modify-format)
+            ;; Otherwise, if we modified the file text via the view buffer,
+            ;; mark the main buffer modified too.
+            (set-buffer-modified-p t))))))
 
 (defun rmail-message-attr-p (msg attrs)
   "Return non-nil if message number MSG has attributes matching regexp ATTRS."
@@ -3252,17 +3264,15 @@ Deleted messages stay in the file until the \\[rmail-expunge] command is given."
       newnum)))
 
 (defun rmail-expunge-confirmed ()
-  "Return t if deleted message should be expunged. If necessary, ask the user.
-See also user-option `rmail-confirm-expunge'."
+  "Return t if expunge is needed and desirable.
+If `rmail-confirm-expunge' is non-nil, ask user to confirm."
   (set-buffer rmail-buffer)
-  ;; FIXME shouldn't this return nil if there is nothing to expunge?
-  ;; Eg to save rmail-expunge wasting its time?
-  (or (not (stringp rmail-deleted-vector))
-      (not (string-match "D" rmail-deleted-vector))
-      (if rmail-confirm-expunge
-          (funcall rmail-confirm-expunge
-                   "Erase deleted messages from Rmail file? ")
-        (progn (rmail-modify-format) t))))
+  (and (stringp rmail-deleted-vector)
+       (string-match "D" rmail-deleted-vector)
+       (if rmail-confirm-expunge
+           (funcall rmail-confirm-expunge
+                    "Erase deleted messages from Rmail file? ")
+         t)))
 
 (defun rmail-only-expunge (&optional dont-show)
   "Actually erase all deleted messages in the file."
@@ -3357,6 +3367,7 @@ consistent with the Rmail buffer).  If DONT-SHOW is non-nil, it
 does not pop any summary buffer."
   (interactive)
   (when (rmail-expunge-confirmed)
+    (rmail-modify-format)
     (let ((was-deleted (rmail-message-deleted-p rmail-current-message))
           (was-swapped (rmail-buffers-swapped-p)))
       (rmail-only-expunge t)