<!DOCTYPE html>
<script>
    onload = function() {
        document.body.offsetTop; // trigger layout
        var elm = document.getElementById('elm');
        elm.style.display = 'none';
        document.body.offsetTop; // trigger layout
        var elm2 = document.getElementById('elm2');
        elm2.style.display = 'block';
    }
</script>
<style>
    .spanner { -webkit-column-span:all; }
</style>
<p>Test removal of of a block right before a spanner, then insertion of another block at the same position.</p>
<p>You should see two lines with the word "PASS" on a lime background below. Letter spacing is expected to vary.</p>
<div style="-webkit-columns:4; -webkit-column-gap:0; overflow:hidden; width:4em; background:lime;"><div id="elm" style="background:red;">F<br>A<br>I<br>L</div><div id="elm2" style="display:none;">P<br>A<br>S<br>S</div><div class="spanner">PASS</div>
</div>