diff --git a/layout/base/crashtests/143862-1a-inner.html b/layout/base/crashtests/143862-1a-inner.html
new file mode 100644
index 00000000000..0313843b192
--- /dev/null
+++ b/layout/base/crashtests/143862-1a-inner.html
@@ -0,0 +1,19 @@
+<title>Testcase, bug 143862</title>
+<style type="text/css">
+html { overflow: hidden; }
+</style>
+<script>
+dump("143862-1-inner.html: A\n");
+window.addEventListener("load", o, false);
+function o()
+{
+  dump("143862-1-inner.html: B*\n");
+  document.documentElement.offsetHeight;
+  dump("143862-1-inner.html: B\n");
+  document.open();
+  dump("143862-1-inner.html: C\n");
+  parent.document.documentElement.removeAttribute("class");
+  dump("143862-1-inner.html: D\n");
+  document.close();
+}
+</script>
diff --git a/layout/base/crashtests/143862-1.html b/layout/base/crashtests/143862-1a.html
similarity index 59%
rename from layout/base/crashtests/143862-1.html
rename to layout/base/crashtests/143862-1a.html
index cae462fbddd..099e1661c06 100644
--- a/layout/base/crashtests/143862-1.html
+++ b/layout/base/crashtests/143862-1a.html
@@ -2,6 +2,6 @@
 <head>
 </head>
 <body>
-<iframe src="143862-1-inner.html"></iframe>
+<iframe src="143862-1a-inner.html"></iframe>
 </body>
 </html>
diff --git a/layout/base/crashtests/143862-1b-inner.html b/layout/base/crashtests/143862-1b-inner.html
new file mode 100644
index 00000000000..c81c02f4154
--- /dev/null
+++ b/layout/base/crashtests/143862-1b-inner.html
@@ -0,0 +1,17 @@
+<title>Testcase, bug 143862</title>
+<style type="text/css">
+html { overflow: hidden; }
+</style>
+<script>
+dump("143862-1-inner.html: A\n");
+window.addEventListener("DOMContentLoaded", o, false);
+function o()
+{
+  dump("143862-1-inner.html: B\n");
+  document.open();
+  dump("143862-1-inner.html: C\n");
+  parent.document.documentElement.removeAttribute("class");
+  dump("143862-1-inner.html: D\n");
+  document.close();
+}
+</script>
diff --git a/layout/base/crashtests/143862-1b.html b/layout/base/crashtests/143862-1b.html
new file mode 100644
index 00000000000..ec40fb0ade1
--- /dev/null
+++ b/layout/base/crashtests/143862-1b.html
@@ -0,0 +1,7 @@
+<html class="reftest-wait">
+<head>
+</head>
+<body>
+<iframe src="143862-1b-inner.html"></iframe>
+</body>
+</html>
diff --git a/layout/base/crashtests/143862-1-inner.html b/layout/base/crashtests/143862-1c-inner.html
similarity index 90%
rename from layout/base/crashtests/143862-1-inner.html
rename to layout/base/crashtests/143862-1c-inner.html
index 628229a9a78..ed59d42e688 100644
--- a/layout/base/crashtests/143862-1-inner.html
+++ b/layout/base/crashtests/143862-1c-inner.html
@@ -4,7 +4,7 @@ html { overflow: hidden; }
 </style>
 <script>
 dump("143862-1-inner.html: A\n");
-setTimeout(o, 100);
+o();
 function o()
 {
   dump("143862-1-inner.html: B\n");
diff --git a/layout/base/crashtests/143862-1c.html b/layout/base/crashtests/143862-1c.html
new file mode 100644
index 00000000000..8893c0c6d54
--- /dev/null
+++ b/layout/base/crashtests/143862-1c.html
@@ -0,0 +1,7 @@
+<html class="reftest-wait">
+<head>
+</head>
+<body>
+<iframe src="143862-1c-inner.html"></iframe>
+</body>
+</html>
diff --git a/layout/base/crashtests/crashtests.list b/layout/base/crashtests/crashtests.list
index 5d03152dbda..8c038376cbb 100644
--- a/layout/base/crashtests/crashtests.list
+++ b/layout/base/crashtests/crashtests.list
@@ -14,7 +14,9 @@ load 123049-1.html
 load 123946-1.html
 load 128855-1.html
 load 133410-1.html
-load 143862-1.html
+load 143862-1a.html
+load 143862-1b.html
+load 143862-1c.html
 load 143862-2.html
 load 147320-1.html
 load 148245-1.html
