Function.prototype iteration issue

[jdalton]

Following up from an xtend issue...
IOS 5 versions of mobile Safari will incorrectly iterate over Function.prototype.

function Foo() {}
Foo.a = function(){};

Object.keys(Foo);
// => ['a', 'prototype'] instead of ['a']

If you're interested in addressing it, libs like YUI and Lo-Dash tackle this issue.