> From: es-discuss-bounces at mozilla.org [mailto:es-discuss-bounces at mozilla.org] On Behalf Of Erik Arvidsson  
  > Yeah, these test all look incorrect to me. IE11 implements an older draft where __proto__ was a magic property.

That’s right.  Our implementation predates the May spec updates that changed the spec for __proto__.  We will update the test contributions to tests262 to align with the updated spec.

One question from looking at implications of this change.  Is it intentional that there is no longer a way to remove (or customize) the special handling of __proto__ in object literals?  

    delete Object.prototype.__proto__
    var p = { y: 34 } 
    var o = { x: 42, __proto__: y }
    o.y === 34 // was false, now true

Luke

From: Erik Arvidsson  

> Yeah, these test all look incorrect to me. IE11 implements an older draft where `__proto__` was a magic property.

That’s right.  Our implementation predates the May spec updates that changed the spec for `__proto__`.  We will update the test contributions to tests262 to align with the updated spec.

One question from looking at implications of this change.  Is it intentional that there is no longer a way to remove (or customize) the special handling of `__proto__` in object literals?  

```js
delete Object.prototype.__proto__
var p = { y: 34 } 
var o = { x: 42, __proto__: y }
o.y === 34 // was false, now true
```