<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<style> .selected { color: blue; } </style>
</head>
<body>
<p>This tests horizontal caret movement in vertical writing mode.</p>
<div id="test" style="font-family: monospace; font-size: 20px; height: 15ex; -webkit-writing-mode: vertical-rl; outline: none;" contenteditable>
<p dir="rtl">אני חתול.<br>אין לי שם.</p>
</div>
<pre id="log"></pre>
<script>

var test = document.getElementById('test');
window.getSelection().setPosition(test.getElementsByTagName('p')[0].lastChild, 5);
window.getSelection().modify('Extend', 'Backward', 'Line');

</script>
</body>
</html>