Dispatch a change event only if the value is different

src/ol/object.js

@@ -206,7 +206,9 @@ ol.Object.prototype.set = function(key, value, opt_silent) {
   } else {
     var oldValue = this.values_[key];
     this.values_[key] = value;
-    this.notify(key, oldValue);
+    if (oldValue !== value) {
+      this.notify(key, oldValue);
+    }
   }
 };
 

test/spec/ol/object.test.js

@@ -168,6 +168,13 @@ describe('ol.Object', function() {
       expect(event.key).to.be('k');
     });
 
+    it('dispatches events only if the value is different', function() {
+      o.set('k', 1);
+      o.set('k', 1);
+      expect(listener1.calledOnce).to.be(true);
+      expect(listener2.calledOnce).to.be(true);
+    });
+
   });
 
   describe('setter', function() {