Ensure assignValue assigns values if they aren't the same own value. [closes #2022]

lodash.js

@@ -2160,8 +2160,7 @@
      */
     function assignValue(object, key, value) {
       var objValue = object[key];
-      if ((!eq(objValue, value) ||
-            (eq(objValue, objectProto[key]) && !hasOwnProperty.call(object, key))) ||
+      if (!(hasOwnProperty.call(object, key) && eq(objValue, value)) ||
           (value === undefined && !(key in object))) {
         object[key] = value;
       }

test/test.js

@@ -3497,6 +3497,16 @@
       assert.deepEqual(_.create({}, new Foo), { 'a': 1, 'c': 3 });
     });
 
+    QUnit.test('should assign properties that shadow those of `prototype`', function(assert) {
+      assert.expect(1);
+
+      function Foo() {
+        this.a = 1;
+      }
+      var object = _.create(new Foo, { 'a': 1 });
+      assert.deepEqual(lodashStable.keys(object), ['a']);
+    });
+
     QUnit.test('should accept a falsey `prototype` argument', function(assert) {
       assert.expect(1);