2 files changed, 10 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 0b8c538a336..91a6e41860f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2014-08-09  Martin Rudalics  <rudalics@gmx.at>
+
+        * window.el (display-buffer-below-selected): Restore original
+        behavior if buffer is already displayed in the window below the
+        selected one (Bug#18181).
+
 2014-08-08  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * mouse.el (mouse--down-1-maybe-follows-link): Don't convert the down
diff --git a/lisp/window.el b/lisp/window.el
index c771f01707e..09fe52dee88 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -6373,7 +6373,10 @@ again with `display-buffer-pop-up-window'."
 This either splits the selected window or reuses the window below
 the selected one."
   (let (window)
-    (or (and (not (frame-parameter nil 'unsplittable))
+    (or (and (setq window (window-in-direction 'below))
+             (eq buffer (window-buffer window))
+             (window--display-buffer buffer window 'reuse alist))
+        (and (not (frame-parameter nil 'unsplittable))
              (let ((split-height-threshold 0)
                    split-width-threshold)
                (setq window (window--try-to-split-window (selected-window) alist)))