css/css-flexbox/flexbox-definite-sizes-004.html

<!doctype html>
<meta charset="utf-8">
<title>CSS Test: nested flex containers with definite max-height</title>
<link rel="match" href="flexbox-definite-sizes-001-ref.html">
<link rel="author" href="mailto:dholbert@mozilla.com" title="Daniel Holbert">
<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
<link rel="help" href="https://drafts.csswg.org/css-flexbox/#definite-sizes">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1449326">
<style>
body { overflow: hidden }

.outerFlex {
  display: flex;
  width: 100px;
  /* Implicit "align-items:stretch" */
}

.innerFlex {
  display: flex;
  width: 100px;
  background: red;

  /* This reveals if we miscalculate the height of our flex item: */
  align-items: flex-end;
}

.block {
  width: 100px;
  max-height: 100%;
  background-color: green;
}
</style>
<p>Test passes if you see a green 100px x 100px square, and no red</p>
<div class="outerFlex">
  <div class="innerFlex" style="max-height: 100px">
    <div class="block"><div style="height:9999px"></div></div>
  </div>
</div>