fix for angular.Object.equals to handle equals({},null)

src/Angular.js

@@ -631,6 +631,7 @@ function copy(source, destination){
  */
 function equals(o1, o2) {
   if (o1 == o2) return true;
+  if (o1 === null || o2 === null) return false;
   var t1 = typeof o1, t2 = typeof o2, length, key, keySet;
   if (t1 == t2 && t1 == 'object') {
     if (o1 instanceof Array) {

test/AngularSpec.js

@@ -89,6 +89,28 @@ describe('equals', function(){
   it('should ignore functions', function(){
     expect(equals({func: function() {}}, {bar: function() {}})).toEqual(true);
   });
+
+  it('should work well with nulls', function() {
+    expect(equals(null, '123')).toBe(false);
+    expect(equals('123', null)).toBe(false);
+
+    var obj = {foo:'bar'};
+    expect(equals(null, obj)).toBe(false);
+    expect(equals(obj, null)).toBe(false);
+
+    expect(equals(null, null)).toBe(true);
+  });
+
+  it('should work well with undefined', function() {
+    expect(equals(undefined, '123')).toBe(false);
+    expect(equals('123', undefined)).toBe(false);
+
+    var obj = {foo:'bar'};
+    expect(equals(undefined, obj)).toBe(false);
+    expect(equals(obj, undefined)).toBe(false);
+
+    expect(equals(undefined, undefined)).toBe(true);
+  });
 });
 
 describe('parseKeyValue', function() {