Fixed small leak introduced by #901

backbone.js

@@ -470,7 +470,7 @@
     // Add a model, or list of models to the set. Pass **silent** to avoid
     // firing the `add` event for every new model.
     add: function(models, options) {
-      var i, index, length, model, cids = {}, ids = {};
+      var i, index, length, model, cid, cids = {}, ids = {};
       options || (options = {});
       models = _.isArray(models) ? models.slice() : [models];