LayoutTests/fast/inline/incorrect-content-height-with-empty-generated-content.html

<style>
div {
  width: 100px;
  background-color: green;
  padding: 1px;
}

span::before {
  display: block;
  content: '';
  margin-top: 100px;
  margin-bottom: 100px;
}
</style>
<!-- empty content should not prevent margin collapsing -->
<div><span></span></div>