LayoutTests/fast/dom/gc-12.html

<p>
This test verifies that DOM nodes are not garbage collected as long as a node in the 
tree is referenced from JavaScript.
</p>

<pre id="console"></pre>

<script>
function log(s)
{
    document.getElementById("console").appendChild(document.createTextNode(s + "\n"));
}

function shouldBeNode(a, aDescription)
{
    if (!(a instanceof Node)) {
        log("FAIL: " + aDescription + " should be a Node but instead is " + a + ".");
        return;
    }

    log("PASS: " + aDescription + " should be a Node and is.");
}

function gc()
{
    if (window.GCController)
        return GCController.collect();

    for (var i = 0; i < 10000; i++)
        var s = new String("");
}

(function () {
    if (window.testRunner) {
        testRunner.dumpAsText();
    }

    (function() {
        // Try to create an orphan tree by removal.
        var p = document.createElement("p");
        document.body.appendChild(p);
        p.innerHTML ='<div><span id="span"><br></span></div>';
        var span = document.getElementById("span");
        p.innerHTML = "";

        gc();

        shouldBeNode(span, "span");
        shouldBeNode(span.parentNode, "span.parentNode");
        shouldBeNode(span.firstChild, "span.firstChild");
    })();

    (function() {
        // Try to create an orphan tree by insertion.
        var p = document.createElement("p");
        var span = document.createElement("span");
        p.appendChild(span);
        p = null;

        gc();

        shouldBeNode(span, "span");
        shouldBeNode(span.parentNode, "span.parentNode");
    })();
})();
</script>