Workaround to clip fixed positioned element to parent

HTML

<div class="child pink">Fixed positioned element</div>

<div class="parent-container">
    <div class="parent">
        <div class="child red">Fixed positioned element</div>
    </div>
</div>

<h1>Workaround to clip fixed positioned element to parent</h1>

<p>For more details see <a href="http://stackoverflow.com/a/23859719/328272">our answer</a> at StackOverflow's question "<a href="http://stackoverflow.com/a/23859719">parent &amp; child with position fixed, parent overflow:hidden bug</a>".</p>

<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
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<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>
<p>Dummy text to cause scrollbars</p>

CSS

body {
  font: 14px arial;
}

.parent-container {
  position: relative;
  width: 300px;
  height: 200px;
}

.parent {
  position: absolute;
  width: 300px;
  height: 200px;
  background-color: yellow;
  clip: rect(0, auto, auto, 0);
}

.child {
  position: fixed;
  top: 50px;
  left: 50px;
  padding: 1em;
  background-color: red;
}

.child.pink {
  background-color: blue;
}