Merge pull request #4292 from Noodlex/fix_model_event_changeId

Trigger the "changeId" event only if prevId is different from this.id.

backbone.js

@@ -523,7 +523,9 @@
  if (this.idAttribute in attrs) {
  var prevId = this.id;
  this.id = this.get(this.idAttribute);
- this.trigger('changeId', this, prevId, options);
+ if (this.id !== prevId) {
+ this.trigger('changeId', this, prevId, options);
+ }
  }
 
  // Trigger all relevant attribute changes.

test/model.js

@@ -1476,4 +1476,15 @@
  assert.equal(model.id, 3);
  });
 
+ QUnit.test('#4289 - Trigger "changeId" need to be generate only if the content id change', function(assert) {
+ assert.expect(1);
+ var model = new Backbone.Model({id: 1});
+ model.idAttribute = 'id';
+ model.on('changeId', function(m) {
+ assert.equal(m.get('id'), 2);
+ });
+ model.set({id: 1});
+ model.set({id: 2});
+ });
+
 })(QUnit);