<!DOCTYPE html>
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1290093">
<div style="columns:2;">
<span style="position:relative;">
<div style="position:absolute;"></div>
<div id="spanner" style="column-span:all;"></div>
</span>
</div>
<script>
document.body.offsetTop;
// This doesn't actually affect layout, but changing display type requires re-attach.
spanner.style.display = "flow-root";
</script>