gecko-dev/layout/reftests/margin-collapsing/block-no-content-6-dyn.html

<!DOCTYPE html>
<html class="reftest-wait">
<head>
<style type="text/css">
#spacer {
 height: 40px;
}
#block1 {
 height: 20px;
 background-color: green;
}
#margin-only {
 margin-bottom: -40px;
}
#block2 {
 height: 20px;
 background-color: blue;
}
</style>
<script type="text/javascript">
function test() {
 document.getElementById('margin-only').style.marginTop = '-60px';
 document.documentElement.removeAttribute('class');
}
document.addEventListener('MozReftestInvalidate', test, false);
</script>
</head>
<body>
<div id="spacer"></div>
<div id="block1"></div>
<div id="margin-only"></div>
<div id="block2"></div>
</body>
</html>