prop with function() for value

I was making a demo for when attr is passed a function and noticed in
jQuery.prop() it has this line of code:
value = value.call(elem, [index]);
Was it intended this would pass back an array of length one? Or
should it instead doing an apply or be:
value = value.call(elem, index);
I can make a ticket and patch if you like but I wanted to make sure it
was not intended first.
David