rmail.el: If view buffer gets lost with the real text, don't save

the Rmail file as just one message.

2 files changed, 13 insertions, 4 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index e1ece83b6a6..0648c9dc5cd 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,10 @@
 2012-03-10  Richard Stallman  <rms@gnu.org>
 
+        * mail/rmail.el (rmail-buffers-swapped-p): Don't assume dead
+        view buffer means not swapped.
+        (rmail-view-buffer-kill-buffer-hook): Give buf name in error msg.
+        (rmail-write-region-annotate): Error if real text has disappeared.
+
         * epa-mail.el (epa-mail-encrypt): Bind inhibit-read-only.
 
 2012-03-10  Chong Yidong  <cyd@gnu.org>
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 2d327c7a0f0..3a9ba8122ab 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -1363,8 +1363,7 @@ sets the current buffer's `buffer-file-coding-system' to that of
 (defun rmail-buffers-swapped-p ()
   "Return non-nil if the message collection is in `rmail-view-buffer'."
   ;; This is analogous to tar-data-swapped-p in tar-mode.el.
-  (and (buffer-live-p rmail-view-buffer)
-       rmail-buffer-swapped))
+  rmail-buffer-swapped)
 
 (defun rmail-change-major-mode-hook ()
   ;; Bring the actual Rmail messages back into the main buffer.
@@ -1406,7 +1405,8 @@ If so restore the actual mbox message collection."
         (kill-buffer rmail-view-buffer))))
 
 (defun rmail-view-buffer-kill-buffer-hook ()
-  (error "Can't kill message view buffer by itself"))
+  (error "Can't kill Rmail view buffer `%s' by itself"
+         (buffer-name (current-buffer))))
 
 ;; Set up the permanent locals associated with an Rmail file.
 (defun rmail-perm-variables ()
@@ -4472,7 +4472,11 @@ encoded string (and the same mask) will decode the string."
 
 ;; Used in `write-region-annotate-functions' to write rmail files.
 (defun rmail-write-region-annotate (start end)
-  (when (and (null start) (rmail-buffers-swapped-p))
+  (when (and (null start) rmail-buffer-swapped)
+    (unless (buffer-live-p rmail-view-buffer)
+      (error "Buffer `%s' with real text of `%s' has disappeared"
+             (buffer-name rmail-view-buffer)
+             (buffer-name (current-buffer))))
     (setq rmail-message-encoding buffer-file-coding-system)
     (set-buffer rmail-view-buffer)
     (widen)