This test ensure that global-to-global re-entry works correctly and does not clobber anything.  This passes if it does not crash.
<script>
if (this.testRunner)
    testRunner.dumpAsText();
try {
    // The important part of the test is the global reentry from the document.write passed implicitly to eval
    // the rest is just to ensure the test crahes reliably (errr... or something) if something goes wrong with
    // the reentry.
    __defineSetter__("implicitCall", eval);
    var a;
    a.b = (implicitCall = 'document.write("<script>var b, c, d, e, f, g, h, i, j, k, l, m, n, o, p;</"+"script>");');
    a = a.b;
    throw "";
} catch(e) {
}
</script>