This tests for a regression against
<i><a href="https://bugs.webkit.org/show_bug.cgi?id=6942">https://bugs.webkit.org/show_bug.cgi?id=6942</a>
Assertion failure in HTMLSelectElementImpl::selectedIndex (m_multiple)</i>
<hr>
No assertion failure (on a debug build) means test PASS.
<select id="t">
</select>
<script type="text/javascript">
    if (window.testRunner)
        testRunner.dumpAsText();
    document.getElementById('t').selectedIndex;
</script>