null/undefined are replaced with the global object in all browsers except IE9

When I do this:

Object.prototype.toString.call( null )

or t开发者_StackOverflow中文版his:

Object.prototype.toString.call( )

the browsers return the following string value (in both cases):

Chrome 9: [object global]

Safari 5: [object DOMWindow]

Firefox 3.6: [object Window]

Opera 11: [object Window]

However in IE9 RC the return values are [object Null] and [object Undefined] respectively.

The ES5 specification states:

NOTE The thisArg value is passed without modification as the this value. This is a change from Edition 3, where a undefined or null thisArg is replaced with the global object and ToObject is applied to all other values and that result is passed as the this value.

See here: http://es5.github.com/#x15.3.4.4

Does this mean that IE9 is the only browser that follows this newly introduced rule?

I'm going to go out on a limb and say yes. ;)

FYI, I just tested FF4, and it gives [object Null] and [object Undefined]