Re: @@symbol hooks and cross domain frames

On 7/16/15 7:37 PM, Adam Klein wrote:
> Can you sketch this in just slightly more detail? Yes, everything is on
> instances. Additionally, any attempt to [[Get]] a data property
> cross-origin fails.

Looking at https://etherpad.mozilla.org/html5-cross-origin-objects in 
the section describing [[GetOwnProperty]] there's this bit:

   If the property is a value-prop and whitelisted for reading, return
   a property descriptor with |configurable| set to true, |enumerable|
   set to false, |writable| set to false, and |value|to a
   Caller-Appropriate Representation of the Original value.

This is needed to support things like location.replace() cross-origin; 
the [[Get]] of the "replace" property needs to succeed.

I'm just suggesting we use this exact mechanism for @@isConcatSpreadable 
(as in, make that property name "whitelisted for reading"), with the 
"Caller-Appropriate Representation" being the ES value undefined.

-Boris

Received on Friday, 17 July 2015 00:14:31 UTC