[nautilus] Don't crash if there is no next_pane

[Alexander Larsson <alexl src gnome org>]

commit 39547f935a4f766eece11513eee175fffcbad2c1
Author: Andy Owen <andy-ubuntu ultra-premium com>
Date:   Mon Apr 26 10:10:18 2010 +0200

    Don't crash if there is no next_pane
    
    This happened due to menu sensitivity being wrongs (bug 616179)

 src/nautilus-navigation-window-menus.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/nautilus-navigation-window-menus.c b/src/nautilus-navigation-window-menus.c
index 5b47345..6ab44a3 100644
--- a/src/nautilus-navigation-window-menus.c
+++ b/src/nautilus-navigation-window-menus.c
@@ -163,6 +163,9 @@ action_split_view_same_location_callback (GtkAction *action,
 	window = NAUTILUS_WINDOW (user_data);
 	next_pane = nautilus_window_get_next_pane (window);
 
+	if (!next_pane) {
+		return;
+	}
 	location = nautilus_window_slot_get_location (next_pane->active_slot);
 	if (location) {
 		nautilus_window_slot_go_to (window->details->active_pane->active_slot, location, FALSE);