1 files changed, 61 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/css-anchor-position/position-try-002.html b/testing/web-platform/tests/css/css-anchor-position/position-try-002.html
new file mode 100644
index 0000000000..c3d550adb1
--- /dev/null
+++ b/testing/web-platform/tests/css/css-anchor-position/position-try-002.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<title>Tests that overflowing the inset-modified containing block triggers position fallback</title>
+<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#fallback">
+<link rel="author" href="mailto:xiaochengh@chromium.org">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/check-layout-th.js"></script>
+<script src="support/test-common.js"></script>
+<style>
+.cb {
+  width: 400px;
+  height: 400px;
+  transform: scale(1);
+  background: yellow;
+}
+.anchor1 {
+  anchor-name: --a;
+  margin-left: 100px;
+  width: 100px;
+  height: 100px;
+  background: blue;
+}
+.target {
+  position: absolute;
+  position-try-options: --f1, --f2;
+  width: min-content;
+  height: 100px;
+  background: orange;
+  /* 1: Position to the left of the anchor. */
+  left: 0;
+  right: anchor(--a left);
+  top: anchor(--a top);
+}
+.inline-spacer {
+  display: inline-block;
+  width: 200px;
+  height: 100px;
+}
+@position-try --f1 {
+  /* 2: Position to the right of the anchor. */
+  left: anchor(--a right);
+  right: 0;
+  top: anchor(--a top);
+}
+@position-try --f2 {
+  /* 3: Placeholder fallback that shouldn't be selected when the previous
+        ones do not overflow the available space. */
+  inset: 0;
+}
+</style>
+<body onload="checkLayoutForAnchorPos('.target')">
+  <!-- The first base style overflows the inset-modifed containing block -->
+  <div class="cb">
+    <div class="anchor1"></div>
+    <div class="target"
+         data-offset-x=200 data-offset-y=0
+         data-expected-width=200 data-expected-height=100>
+      <span class="inline-spacer"></span>
+    </div>
+  </div>
+</body>