1 files changed, 40 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/css-scroll-anchoring/abspos-contributes-to-static-parent-bounds.html b/testing/web-platform/tests/css/css-scroll-anchoring/abspos-contributes-to-static-parent-bounds.html
new file mode 100644
index 0000000000..5d8ff9a911
--- /dev/null
+++ b/testing/web-platform/tests/css/css-scroll-anchoring/abspos-contributes-to-static-parent-bounds.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+
+body, html, #static { height: 0; }
+#abs {
+  position: absolute;
+  left: 50px;
+  top: 50px;
+  height: 1200px;
+  padding: 50px;
+  border: 5px solid gray;
+}
+#anchor {
+  background-color: #afa;
+  width: 100px;
+  height: 100px;
+}
+
+</style>
+<div id="static">
+  <div id="abs">
+    <div id="changer"></div>
+    <div id="anchor"></div>
+  </div>
+</div>
+<script>
+
+// Tests that the "bounds" of an element, for the purpose of visibility in the
+// anchor node selection algorithm, include any space occupied by the element's
+// positioned descendants.
+
+test(() => {
+  document.scrollingElement.scrollTop = 120;
+  document.querySelector("#changer").style.height = "100px";
+  assert_equals(document.scrollingElement.scrollTop, 220);
+}, "Abs-pos with zero-height static parent.");
+
+</script>