(rmail-output-body-to-file): Avoid error if message has no subject.

Use and set rmail-default-body-file.

1 files changed, 12 insertions, 6 deletions

diff --git a/lisp/mail/rmailout.el b/lisp/mail/rmailout.el
index 1834ff5ae26..7a8bfcf393e 100644
--- a/lisp/mail/rmailout.el
+++ b/lisp/mail/rmailout.el
@@ -333,12 +333,18 @@ The optional fourth argument FROM-GNUS is set when called from GNUS."
 FILE-NAME defaults, interactively, from the Subject field of the message."
   (interactive
    (let ((default-file
-           (mail-fetch-field "Subject")))
-     (list (read-file-name
-            "Output message body to file: "
-            (file-name-directory default-file)
-            default-file
-            nil default-file))))
+           (or (mail-fetch-field "Subject")
+               rmail-default-body-file)))
+     (list (setq rmail-default-body-file
+                 (read-file-name
+                  "Output message body to file: "
+                  (and default-file (file-name-directory default-file))
+                  default-file
+                  nil default-file)))))
+  (setq file-name
+        (expand-file-name file-name
+                          (and rmail-default-body-file
+                               (file-name-directory rmail-default-body-file))))
   (save-excursion
     (goto-char (point-min))
     (search-forward "\n\n")