<html>
<head>
<script>
if (window.testRunner)
testRunner.dumpAsText();
window.onload = function()
{
channel = new MessageChannel;
event = document.createEvent("MessageEvent");
event.initMessageEvent(0, 0, 0, 0, 0, 0, null, [channel.port1, channel.port2]);
Array.prototype.__defineSetter__(0, function() {
event.initMessageEvent(0, 0, 0, 0, 0, 0, null, [ ]);
});
event.ports;
}
</script>
</head>
<body>
This test passes if it doesn't crash.
</body>
</html>