<!DOCTYPE html>
<html>
<head>
<script src="../../resources/js-test.js"></script>
<script>
"use strict";

description('Check that we properly handle nested document loads during unload events. Passes if we do not debug assert.');

window.jsTestIsAsync = true;

function runTest() {
    let topFrame = document.documentElement.appendChild(document.createElement("iframe"));
    topFrame.id = 'topFrame';

    let aFrame = topFrame.contentDocument.documentElement.appendChild(document.createElement("iframe"));
    aFrame.id = 'aFrame';

    aFrame.contentWindow.onunload = () => {
        topFrame.src = "javascript:''";

        let bFrame;

        try {
            bFrame = topFrame.contentDocument.appendChild(document.createElement("iframe"));
        } catch (e) {
            testPassed("Threw exception: " + e);
            finishJSTest();
            return;
        }
        bFrame.id = 'bFrame';

        bFrame.contentWindow.onunload = () => {
            topFrame.src = "javascript:''";

            let doc = topFrame.contentDocument;

            topFrame.onload = () => {
                topFrame.onload = () => {
                    topFrame.onload = null;
                    let s = doc.createElement("form");
                    s.action = "javascript:alert(location)";
                    s.submit();
                };

                topFrame.src = "resources/subframe-success.html";
            };

        };
    };

    topFrame.src = "javascript:''";
}
</script>
</head>
<body onload="runTest()">
</body>
</html>