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Test Info: Warnings
- This test has a WPT meta file that expects 1 subtest issues.
 - This WPT test may be referenced by the following Test IDs:
            
- /css/css-scroll-anchoring/negative-layout-overflow.html - WPT Dashboard Interop Dashboard
 
 
<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
body {
  height: 1200px;
}
#header {
  position: relative;
  height: 100px;
}
#evil {
  position: relative;
  top: -900px;
  height: 1000px;
  width: 100px;
}
#changer {
  height: 100px;
}
#anchor {
  height: 100px;
  background-color: green;
}
</style>
<div id="header">
  <div id="evil"></div>
</div>
<div id="changer"></div>
<div id="anchor"></div>
<script>
// Tests that the anchor selection algorithm correctly accounts for negative
// positioning when computing bounds for visibility.
test(() => {
  document.scrollingElement.scrollTop = 250;
  document.querySelector("#changer").style.height = "200px";
  assert_equals(document.scrollingElement.scrollTop, 350);
}, "Anchor selection accounts for negative positioning.");
</script>