<!DOCTYPE html>
<script src="../../resources/ahem.js"></script>
<p>A (deprecated) flexbox shouldn't allow its items to form a continuation chain, since a
    flexbox isn't a block flow (block container).</p>
<p>There should be a square below.</p>
<div style="font:20px/1 Ahem;">
    xxx<br>
    xxx<br>
    xxx<br>
</div>