Interesting, if you reload this page in Arora with debugging enabled, it crashes.

<script>
//fuck you.
</script>
<script>
function length(x) {
    return x.length;
}

//alert(length(null));
</script>
<script>

function bar() {
    throw new Error("I like Ike!");
}

function foo() { document.body.appendChild(document.createTextNode('hi'); return bar(); }
document.onload = function() { foo() }
</script>