chromium/third_party/blink/web_tests/external/wpt/css/css-position/sticky/position-sticky-nested-table.html

<!DOCTYPE html>
<title>Nested position:sticky table elements should render correctly</title>
<link rel="match" href="position-sticky-nested-table-ref.html" />
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="This test checks that nested position:sticky table elements render correctly" />

<script src="../resources/ref-rectangle.js"></script>

<style>
.group {
  display: inline-block;
  position: relative;
  width: 150px;
  height: 250px;
}

.scroller {
  position: relative;
  width: 100px;
  height: 200px;
  overflow-x: hidden;
  overflow-y: auto;
}

.contents {
  height: 700px;
}

.prepadding {
  height: 100px;
}

table {
  border-collapse: collapse;
}

td, th {
  height: 50px;
  width: 50px;
  padding: 0;
}

th {
  background: green;
}

.sticky {
  position: sticky;
  top: 25px;
}

.indicator {
  position: absolute;
  left: 0;
  background-color: red;
  height: 50px;
  width: 50px;
}

</style>

<script>
window.addEventListener('load', function() {
  document.getElementById('scroller1').scrollTop = 50;
  document.getElementById('scroller2').scrollTop = 125;
  document.getElementById('scroller3').scrollTop = 250;
});
</script>

<div>You should see three green rectangles below. No red or blue should be visible.</div>

<div class="group">
  <div id="scroller1" class="scroller">
    <div class="contents">
      <div class="indicator" style="top: 100px;"></div>
      <div class="prepadding"></div>
      <table>
        <thead class="sticky">
          <tr class="sticky">
            <th class="sticky"></th>
          </tr>
        </thead>
        <tbody>
          <tr><td></td></tr>
          <tr><td></td></tr>
          <tr><td></td></tr>
        </tbody>
      </table>
    </div>
  </div>
</div>

<div class="group">
  <div id="scroller2" class="scroller">
    <div class="contents">
      <div class="indicator" style="top: 150px;"></div>
      <div class="prepadding"></div>
      <table>
        <thead class="sticky">
          <tr class="sticky">
            <th class="sticky"></th>
          </tr>
        </thead>
        <tbody>
          <tr><td></td></tr>
          <tr><td></td></tr>
          <tr><td></td></tr>
        </tbody>
      </table>
    </div>
  </div>
</div>

<div class="group">
  <div id="scroller3" class="scroller">
    <div class="contents">
      <div class="indicator" style="top: 250px;"></div>
      <div class="prepadding"></div>
      <table>
        <thead class="sticky">
          <tr class="sticky">
            <th class="sticky"></th>
          </tr>
        </thead>
        <tbody>
          <tr><td></td></tr>
          <tr><td></td></tr>
          <tr><td></td></tr>
        </tbody>
      </table>
    </div>
  </div>
</div>