From 3ef848ac25e8956f5c13973a964ac5f2f8db0ae5 Mon Sep 17 00:00:00 2001
From: Oliver Sartun <osartun@gmail.com>
Date: Thu, 24 Oct 2013 11:47:45 +0200
Subject: [PATCH] The merge method now makes use of the unregisterAll method

---
 Backbone.Undo.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Backbone.Undo.js b/Backbone.Undo.js
index 0a6e857..86d9b06 100644
--- a/Backbone.Undo.js
+++ b/Backbone.Undo.js
@@ -706,13 +706,12 @@
 			if (undoManager instanceof UndoManager &&
 				undoManager.stack instanceof UndoStack) {
 				// unregister already registered objects
-				var registeredObjects = this.objectRegistry.get(),
-				hasObjects = !!registeredObjects.length;
-				if (hasObjects) apply(this.unregister, this, registeredObjects);
+				var registeredObjects = this.objectRegistry.get();
+				this.unregisterAll();
 				// replace the stack reference
 				this.stack = undoManager.stack;
 				// register the just unregistered objects, now on the new stack
-				if (hasObjects) apply(this.register, this, registeredObjects);
+				apply(this.register, this, registeredObjects);
 			}
 		},
 		/**