<!doctype HTML>
<style>
article::after {
content: url(data:text/plain,test);}
</style>
This test passes if it does not crash.
<img usemap="#map2">
<map id=map name="map2">
<command id=command>
<article id=article></article>
</command>
</map>
<script>
command.appendChild(article);
requestAnimationFrame(() => requestAnimationFrame(() => {
map.style.content = "none";
}));
</script>