1 files changed, 63 insertions, 0 deletions
diff --git a/layout/reftests/bugs/256180-4.html b/layout/reftests/bugs/256180-4.html
new file mode 100644
index 0000000000..eabe43ada6
--- /dev/null
+++ b/layout/reftests/bugs/256180-4.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>585-element-deep display: block</title>
+<script>
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/publicdomain/zero/1.0/
+
+function count() {
+    var depth = 0;
+    var deepest = 0;
+    var current = document;
+    var next = null;
+    outer: for (;;) {
+        if ((next = current.firstChild)) {
+            depth++;
+            if (depth > deepest) {
+                deepest = depth;
+            }
+            current = next;
+            continue;
+        }
+        for (;;) {
+            if ((next = current.nextSibling)) {
+                current = next;
+                break;
+            }
+            current = current.parentNode;
+            depth--;
+            if (current == document) {
+                break outer;
+            }
+        }
+    }
+
+    var h1 = document.getElementsByTagName("h1")[0];
+    var p = document.createElement("p");
+    var t = document.createTextNode("Actual depth (including text leaves): " + deepest);
+    p.appendChild(t);
+    h1.parentNode.insertBefore(p, h1.nextSibling);
+}
+
+function deep() {
+    var t = document.createTextNode("PASS");
+    var div = document.createElement("div");
+    div.appendChild(t);
+    for (var i = 0; i < 582; i++) {
+        var another = document.createElement("div");
+        another.appendChild(div);
+        div = another;
+    }
+    document.body.appendChild(div);
+    count();
+}
+
+window.addEventListener('DOMContentLoaded', deep, false);
+</script>
+</head>
+<body>
+<h1>585-element-deep display: block</h1>
+</body>
+</html>