diff -r 000000000000 -r 6474c204b198 docshell/test/unit/test_bug442584.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docshell/test/unit/test_bug442584.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,34 @@
+var prefetch = Cc["@mozilla.org/prefetch-service;1"].
+               getService(Ci.nsIPrefetchService);
+var ios = Cc["@mozilla.org/network/io-service;1"].
+          getService(Ci.nsIIOService);
+var prefs = Cc["@mozilla.org/preferences-service;1"].
+            getService(Ci.nsIPrefBranch);
+
+function run_test() {
+  // Fill up the queue
+  prefs.setBoolPref("network.prefetch-next", true);
+  for (var i = 0; i < 5; i++) {
+    var uri = ios.newURI("http://localhost/" + i, null, null);
+    prefetch.prefetchURI(uri, uri, null, true);
+  }
+
+  // Make sure the queue has items in it...
+  var queue = prefetch.enumerateQueue();
+  do_check_true(queue.hasMoreElements());
+
+  // Now disable the pref to force the queue to empty...
+  prefs.setBoolPref("network.prefetch-next", false);
+  queue = prefetch.enumerateQueue();
+  do_check_false(queue.hasMoreElements());
+
+  // Now reenable the pref, and add more items to the queue.
+  prefs.setBoolPref("network.prefetch-next", true);
+  for (var i = 0; i < 5; i++) {
+    var uri = ios.newURI("http://localhost/" + i, null, null);
+    prefetch.prefetchURI(uri, uri, null, true);
+  }
+  queue = prefetch.enumerateQueue();
+  do_check_true(queue.hasMoreElements());
+}
+