diff -r 000000000000 -r 6474c204b198 parser/htmlparser/tests/mochitest/file_bug543062.sjs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parser/htmlparser/tests/mochitest/file_bug543062.sjs	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+var timer;
+
+function armTimer(response) {
+  timer = Components.classes["@mozilla.org/timer;1"]
+    .createInstance(Components.interfaces.nsITimer);
+  timer.initWithCallback(function() {
+      if (getState("docwritepreloadssecond") == "second" && getState("docwritepreloadsthird") == "third") {
+        response.write("ok(true, 'Second and third scripts should have started loading while the first one is loading');");
+        response.finish();
+      } else {
+        armTimer(response);
+      }
+    }, 20, Components.interfaces.nsITimer.TYPE_ONE_SHOT);
+}
+
+function handleRequest(request, response)
+{
+  response.setHeader("Cache-Control", "no-cache", false);
+  response.setHeader("Content-Type", "text/javascript", false);
+  if (request.queryString.indexOf("first") != -1) {
+    response.write("// first\n");
+    response.processAsync();
+    armTimer(response);
+  } else if (request.queryString.indexOf("second") != -1) {
+    response.write("// second\n");
+    setState("docwritepreloadssecond", "second");
+  } else {
+    response.write("// third\n");
+    setState("docwritepreloadsthird", "third");
+  }
+}
+