1 files changed, 39 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/browsers/sandboxing/sandbox-new-execution-context.html b/testing/web-platform/tests/html/browsers/sandboxing/sandbox-new-execution-context.html
new file mode 100644
index 0000000000..dc1953aee6
--- /dev/null
+++ b/testing/web-platform/tests/html/browsers/sandboxing/sandbox-new-execution-context.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<html>
+  <head>
+    <title>Reuse of iframe about:blank document execution context</title>
+    <link rel="author" title="Dan Clark" href="mailto:daniec@microsoft.com">
+    <link rel="help" href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#sandboxing">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+
+  <body>
+    <h1>Reuse of iframe about:blank document execution context in sandbox="allow-scripts" iframe</h1>
+    <script type="text/javascript">
+      async_test(t => {
+        let iframe = document.createElement("iframe");
+        document.body.appendChild(iframe);
+
+        let iframeAboutBlankDocument = iframe.contentDocument;
+        assert_equals(iframeAboutBlankDocument.URL, "about:blank");
+
+        iframe.sandbox = "allow-scripts";
+        iframe.src = './sandbox-new-execution-context-iframe.html';
+
+        iframe.onload = t.step_func_done(() => {
+          assert_equals(iframe.contentDocument, null,
+            "New document in sandboxed iframe should have opaque origin");
+
+          assert_equals(Object.getPrototypeOf(iframeAboutBlankDocument).changeFromSandboxedIframe, undefined,
+            "Sandboxed iframe contents should not have been able to mess with type system of about:blank document");
+
+          let iframeAboutBlankContents = iframeAboutBlankDocument.querySelectorAll('body');
+          assert_equals(iframeAboutBlankContents[0].tagName, "BODY",
+            "about:blank document's contents should still be accessible");
+        });
+      },"iframe with sandbox should load with new execution context");
+    </script>
+    <div id="log"></div>
+  </body>
+</html>