fix(ng): in angular.copy do not call hasOwnProperty on objects with not prototype

angular.copy can be called with an object that has no prototype. Call
Object.prototype.hasOwnProperty instead of object.hasOwnProperty to
safely check if object has a property

Author: mohsen1

src/Angular.js

@@ -262,7 +262,7 @@ function forEach(obj, iterator, context) {
         obj.forEach(iterator, context, obj);
     } else {
       for (key in obj) {
-        if (obj.hasOwnProperty(key)) {
+        if (hasOwnProperty.call(obj, key)) {
           iterator.call(context, obj[key], key, obj);
         }
       }
@@ -754,7 +754,7 @@ function copy(source, destination, stackSource, stackDest) {
         });
       }
       for (var key in source) {
-        if (source.hasOwnProperty(key)) {
+        if (hasOwnProperty.call(source, key)) {
           result = copy(source[key], null, stackSource, stackDest);
           if (isObject(source[key])) {
             stackSource.push(source[key]);
@@ -854,7 +854,7 @@ function equals(o1, o2) {
           keySet[key] = true;
         }
         for (key in o2) {
-          if (!keySet.hasOwnProperty(key) &&
+          if (!hasOwnProperty.call(keySet, key) &&
               key.charAt(0) !== '$' &&
               o2[key] !== undefined &&
               !isFunction(o2[key])) return false;

test/AngularSpec.js

@@ -24,6 +24,12 @@ describe('angular', function() {
       expect(copy([], arr)).toBe(arr);
     });
 
+    it("should copy objects with no prototype", function() {
+      var obj = Object.create(null);
+      obj.value = 0;
+      expect(copy({}, obj)).toBe(obj);
+    });
+
     it("should preserve prototype chaining", function() {
       var GrandParentProto = {};
       var ParentProto = Object.create(GrandParentProto);