fix(angular.equals): do not match keys defined in the prototype chain

Merely testing for object[key] will give incorrect results on keys
defined in Object.prototype.
Note: IE8 is generally broken in this regard since `for...in` never returns
certain property keys even if they are defined directly on the object.

See #2141 - partially merges this PR

1 files changed, 8 insertions, 0 deletions

diff --git a/test/AngularSpec.js b/test/AngularSpec.js
index 8fda7a65..bf952249 100644
--- a/test/AngularSpec.js
+++ b/test/AngularSpec.js
@@ -270,6 +270,14 @@ describe('angular', function() {
       expect(equals(new Date(0), 0)).toBe(false);
       expect(equals(0, new Date(0))).toBe(false);
     });
+
+    it('should correctly test for keys that are present on Object.prototype', function() {
+      // MS IE8 just doesn't work for this kind of thing, since "for ... in" doesn't return
+      // things like hasOwnProperty even if it is explicitly defined on the actual object!
+      if (msie<=8) return;
+      expect(equals({}, {hasOwnProperty: 1})).toBe(false);
+      expect(equals({}, {toString: null})).toBe(false);
+    });
   });
 
   describe('size', function() {