<!DOCTYPE html>
<title>Reference of testcases for bug 1279403</title>
<style>
span {
  height: 100px;
  width: 100px;
  background: green;
  position: fixed;
  top: 50px;
}
div {
  height: 100px;
  width: 100px;
  background: blue;
}
#first {
}
#second {
  position: fixed;
}
</style>
<span></span>
<div id="first"></div>
<div id="second"></div>