<!DOCTYPE html>
<html>
<body>
<p>This tests copying the content inside a shadow tree.<br>
To manually test, copy the selected content and paste it below:</p>
<style>
#source, #destination {
    border: solid 1px #666;
    margin: 1rem 0;
}
</style>
<div id="source">
    <b>hello,
        <span id="host"><span slot="webkit">WebKit</span> <span slot="others">and other engines</slot></span>
    </b>
    <i>rocks</i>
</div>
<div id="destination" contenteditable><br></div>
<script>

document.getElementById('host').attachShadow({mode: 'closed'}).innerHTML = 'world <slot name="webkit"></slot>';
getSelection().selectAllChildren(document.getElementById('source'));

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