Avoid redisplay error in ediff-regions-wordwise

* lisp/vc/ediff-util.el
(ediff-clone-buffer-for-region-comparison): Make sure the mark is
set before activating it.  (Bug#21567)

diff --git a/lisp/vc/ediff-util.el b/lisp/vc/ediff-util.el
index e664f9fdac38d0f24711915dced7b60643a6a1bd..7ef425449c18f68ef25e082540ec707364e6c58b 100644 (file)
--- a/lisp/vc/ediff-util.el
+++ b/lisp/vc/ediff-util.el
@@ -3348,6 +3348,7 @@ Without an argument, it saves customized diff argument, if available
     (setq wind (ediff-get-visible-buffer-window cloned-buff))
     (select-window wind)
     (delete-other-windows)
+    (or (mark) (push-mark))
     (ediff-activate-mark)
     (split-window-vertically)
     (ediff-select-lowest-window)