Does Internet Explorer 9 choke on extra commas at the end of array and object literals?

Question

Modern browsers and environments like Node.js allow you to say {a:1, b:2,} or [1,2,3,]. This has historically been problematic with Internet Explorer. Is this fixed in Inter

Answer 1

This document claims it is/will be corrected: http://blogs.msdn.com/b/ie/archive/2010/06/25/enhanced-scripting-in-ie9-ecmascript-5-support-and-more.aspx

Corrected Issues

Trailing commas in array literals added to the array’s length

Example

var len = [1,2,3,].length;

alert(len); //should be 3, IE8 says 4

It makes no specific mention of Objects. Just Arrays.

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EDIT: More info. From this PDF document:

http://download.microsoft.com/download/8/4/2/8427CF1B-08B3-4557-952D-102E7A8FA64C/[MS-ES3].pdf

...dowloaded from this page: http://msdn.microsoft.com/en-us/library/ff520996(VS.85).aspx

JScript 5.8 supports the occurrence of a single trailing comma as the last item within an ObjectLiteral. JScript 5.7 does not support this extension.