<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<link rel="author" title="Mozilla" href="https://mozilla.org">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1561450">
<link rel="help" href="https://drafts.csswg.org/css-scroll-anchoring/#suppression-triggers">
<style>
  body { margin: 0 }
  .content {
    height: 45vh;
    background: lightblue;
  }
</style>
<div class="content"></div>
<div id="hidden" style="display: none; height: 200px"></div>
<div class="content"></div>
<div class="content"></div>
<div class="content"></div>
<script>
let count = 0;
const t = async_test("Scroll adjustments don't keep happening with 0-length adjustments triggered by a single scroll operation");
onscroll = t.step_func(function() {
  ++count;
  hidden.style.display = "block";
  hidden.offsetTop;
  hidden.style.display = "none";
  let currentCount = count;
  requestAnimationFrame(t.step_func(function() {
    requestAnimationFrame(t.step_func(function() {
      if (currentCount == count) {
        t.done();
      }
    }));
  }));
});

window.onload = t.step_func(function() {
  window.scrollTo(0, document.documentElement.scrollHeight);
  window.scrollBy(0, -200);
});
</script>
