Fix mode-line-format handling bug in Ediff.

* lisp/vc/ediff-init.el (ediff-strip-mode-line-format): Handle non-list
mode-line formats.

Fixes: debbugs:10839

3 files changed, 13 insertions, 5 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index c4ec297cb30..5455d4320f8 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-02-19  Chong Yidong  <cyd@gnu.org>
+
+        * vc/ediff-init.el (ediff-strip-mode-line-format): Handle non-list
+        mode-line formats (Bug#10839).
+
 2012-02-18  Glenn Morris  <rgm@gnu.org>
 
         * mail/rmail.el (rmail-dont-reply-to-names): Mark as obsolete.
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 49e23a3b2f6..2d327c7a0f0 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -4700,7 +4700,7 @@ SENDERS is a string of regexps separated by commas.
 ;;;***
 
 ;;;### (autoloads (unforward-rmail-message undigestify-rmail-message)
-;;;;;;  "undigest" "undigest.el" "1be42b2d20b13004f0ad1b504630ed00")
+;;;;;;  "undigest" "undigest.el" "a31a35802a2adbc51be42959c3043dbd")
 ;;; Generated autoloads from undigest.el
 
 (autoload 'undigestify-rmail-message "undigest" "\
@@ -4711,8 +4711,9 @@ Leaves original message, deleted, before the undigestified messages.
 
 (autoload 'unforward-rmail-message "undigest" "\
 Extract a forwarded message from the containing message.
-This puts the forwarded message into a separate rmail message
-following the containing message.
+This puts the forwarded message into a separate rmail message following
+the containing message.  This command is only useful when messages are
+forwarded with `rmail-enable-mime-composing' set to nil.
 
 \(fn)" t nil)
 
diff --git a/lisp/vc/ediff-init.el b/lisp/vc/ediff-init.el
index 806be855909..2de5e4dbdaf 100644
--- a/lisp/vc/ediff-init.el
+++ b/lisp/vc/ediff-init.el
@@ -1743,8 +1743,10 @@ Unless optional argument INPLACE is non-nil, return a new string."
 
 ;; If ediff modified mode line, strip the modification
 (defsubst ediff-strip-mode-line-format ()
-  (if (member (car mode-line-format) '(" A: " " B: " " C: " " Ancestor: "))
-      (setq mode-line-format (nth 2 mode-line-format))))
+  (and (consp mode-line-format)
+       (member (car mode-line-format)
+               '(" A: " " B: " " C: " " Ancestor: "))
+       (setq mode-line-format (nth 2 mode-line-format))))
 
 ;; Verify that we have a difference selected.
 (defsubst ediff-valid-difference-p (&optional n)