(rmail-set-attribute): Do nothing if MSGNUM is 0.

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 69e4b39e45d5812c5236045465eb2a3186f3546b..8279adaad24020f5d146695776d8b82aa45b15c7 100644 (file)
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -1109,30 +1109,31 @@ argument causes us to read a file name and use that file as the inbox."
        (omin (point-min-marker))
        (buffer-read-only nil))
     (or msgnum (setq msgnum rmail-current-message))
-    (unwind-protect
-       (save-excursion
-         (widen)
-         (goto-char (+ 3 (rmail-msgbeg msgnum)))
-         (let ((curstate
-                (not
-                 (null (search-backward (concat ", " attr ",")
-                                        (prog1 (point) (end-of-line)) t)))))
-           (or (eq curstate (not (not state)))
-               (if curstate
-                   (delete-region (point) (1- (match-end 0)))
-                 (beginning-of-line)
-                 (forward-char 2)
-                 (insert " " attr ","))))
-         (if (string= attr "deleted")
-             (rmail-set-message-deleted-p msgnum state)))
-      ;; Note: we don't use save-restriction because that does not work right
-      ;; if changes are made outside the saved restriction
-      ;; before that restriction is restored.
-      (narrow-to-region omin omax)
-      (set-marker omin nil)
-      (set-marker omax nil)
-      (if (= msgnum rmail-current-message)
-         (rmail-display-labels)))))
+    (if (> msgnum 0)
+       (unwind-protect
+           (save-excursion
+             (widen)
+             (goto-char (+ 3 (rmail-msgbeg msgnum)))
+             (let ((curstate
+                    (not
+                     (null (search-backward (concat ", " attr ",")
+                                            (prog1 (point) (end-of-line)) t)))))
+               (or (eq curstate (not (not state)))
+                   (if curstate
+                       (delete-region (point) (1- (match-end 0)))
+                     (beginning-of-line)
+                     (forward-char 2)
+                     (insert " " attr ","))))
+             (if (string= attr "deleted")
+                 (rmail-set-message-deleted-p msgnum state)))
+         ;; Note: we don't use save-restriction because that does not work right
+         ;; if changes are made outside the saved restriction
+         ;; before that restriction is restored.
+         (narrow-to-region omin omax)
+         (set-marker omin nil)
+         (set-marker omax nil)
+         (if (= msgnum rmail-current-message)
+             (rmail-display-labels))))))
 
 ;; Return t if the attributes/keywords line of msg number MSG
 ;; contains a match for the regexp LABELS.