Fix for adding models with custom set methods to collections, issue j…

…ashkenas#539

backbone.js

@@ -568,7 +568,7 @@
       if (!(model instanceof Backbone.Model)) {
         var attrs = model;
         model = new this.model(attrs, {collection: this});
-        if (model.validate && !model._performValidation(attrs, options)) model = false;
+        if (model.validate && !model._performValidation(model.attributes, options)) model = false;
       } else if (!model.collection) {
         model.collection = this;
       }

test/collection.js

@@ -44,6 +44,33 @@ $(document).ready(function() {
     equals(col.get(101), model);
   });
 
+  test("Collection: add model with attributes modified by set", function() {
+    var CustomSetModel = Backbone.Model.extend({
+      defaults: {
+        number_as_string: null //presence of defaults forces extend
+      },
+
+      validate: function (attributes) {
+        if (!_.isString(attributes.num_as_string)) {
+          return 'fail';
+        }
+      },
+
+      set: function (attributes, options) {
+        if (attributes.num_as_string) {
+          attributes.num_as_string = attributes.num_as_string.toString();
+        }
+        Backbone.Model.prototype.set.call(this, attributes, options);
+      }
+    });
+
+    var CustomSetCollection = Backbone.Collection.extend({
+      model: CustomSetModel
+    });
+    var col = new CustomSetCollection([{ num_as_string: 2 }]);
+    equals(col.length, 1);
+  });
+
   test("Collection: update index when id changes", function() {
     var col = new Backbone.Collection();
     col.add([