rmail-summary-mark-deleted optional argument fix

* lisp/mail/rmailsum.el (rmail-summary-mark-deleted): Argument N
is optional, so don't assume that it's a number (bug#39076).

diff --git a/lisp/mail/rmailsum.el b/lisp/mail/rmailsum.el
index d29115a95701d4ea0c9e0f5f26f650ab9f45f8da..7f99ecdcf2c60220c5f20730fd6efe432e9c29ef 100644 (file)
--- a/lisp/mail/rmailsum.el
+++ b/lisp/mail/rmailsum.el
@@ -974,8 +974,9 @@ a negative argument means to delete and move forward."
          (delete-char 1)
          (insert "D"))
        ;; Discard cached new summary line.
-       (with-current-buffer rmail-buffer
-         (aset rmail-summary-vector (1- n) nil))))
+        (when n
+         (with-current-buffer rmail-buffer
+           (aset rmail-summary-vector (1- n) nil)))))
   (beginning-of-line))
 
 (defun rmail-summary-update-line (n)