<html>
    <body style="margin: 0;">
        <div style="-webkit-writing-mode: vertical-rl; overflow: -webkit-paged-y; -webkit-column-gap: 20px; width: 600px; height: 100px;">
            <div style="width: 50%;"></div>
            <div style="width: 50%;"></div>
            <div style="width: 50%;"></div>
            <div id="target" style="width: 50%;"></div>
            <div id="result"></div>
        </div>
        <script>
            if (window.testRunner)
                testRunner.dumpAsText();
            // FIXME: This is incorrect. The startContainer should be the 3rd div, not the 4th.
            document.getElementById("result").innerText = document.caretRangeFromPoint(550, 115).startContainer === document.getElementById("target") ? "PASS" : "FAIL";
        </script>
    </body>
</html>