1 files changed, 25 insertions, 0 deletions
diff --git a/docshell/test/mochitest/file_bug1742865_outer.sjs b/docshell/test/mochitest/file_bug1742865_outer.sjs
new file mode 100644
index 0000000000..bad8b23f00
--- /dev/null
+++ b/docshell/test/mochitest/file_bug1742865_outer.sjs
@@ -0,0 +1,25 @@
+Cu.importGlobalProperties(["URLSearchParams"]);
+
+function handleRequest(request, response) {
+  response.write(
+    `<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <script>
+    window.addEventListener("message", ({ data }) => {
+      if (data == "loadNext") {
+        location.href += "&loadnext=1";
+        return;
+      }
+      // Forward other messages to the frame.
+      document.getElementById("frame").contentWindow.postMessage(data, "*");
+    });
+  </script>
+</head>
+<body>
+  <iframe src="file_bug1742865.sjs?${request.queryString}" id="frame"></iframe>
+</body>
+</html>`
+  );
+}