Fixing a small bug in model inheritance: Class properties need to be inherited (along with the instance properties). See test.

backbone.js

@@ -1004,6 +1004,9 @@
       child = function(){ return parent.apply(this, arguments); };
     }
 
+    // Inherit class (static) properties from parent.
+    _.extend(child, parent);
+
     // Set the prototype chain to inherit from `parent`, without calling
     // `parent`'s constructor function.
     ctor.prototype = parent.prototype;

test/model.js

@@ -320,5 +320,29 @@ $(document).ready(function() {
     equals(lastError, "Can't change admin status.");
     equals(boundError, undefined);
   });
+  
+  test("Model: Inherit class properties", function() {
+    var Parent = Backbone.Model.extend({
+      instancePropSame: function() {},
+      instancePropDiff: function() {}
+    }, {
+      classProp: function() {}
+    });
+    var Child = Parent.extend({
+      instancePropDiff: function() {}
+    });
+    
+    var adult = new Parent;
+    var kid   = new Child;
+
+    equals(Child.classProp, Parent.classProp);
+    notEqual(Child.classProp, undefined);
+
+    equals(kid.instancePropSame, adult.instancePropSame);
+    notEqual(kid.instancePropSame, undefined);
+
+    notEqual(Child.prototype.instancePropDiff, Parent.prototype.instancePropDiff);
+    notEqual(Child.prototype.instancePropDiff, undefined);
+  });
 
 });