diff -r 000000000000 -r 6474c204b198 netwerk/test/unit/test_bug376660.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/test/unit/test_bug376660.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,68 @@
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+
+var listener = {
+  expect_failure: false,
+  QueryInterface: function listener_qi(iid) {
+    if (iid.equals(Ci.nsISupports) ||
+        iid.equals(Ci.nsIUnicharStreamLoaderObserver)) {
+      return this;
+    }
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+  onDetermineCharset : function onDetermineCharset(loader, context, data)
+  {
+    return "us-ascii";
+  },
+  onStreamComplete : function onStreamComplete (loader, context, status, data)
+  {
+    try {
+      if (this.expect_failure)
+        do_check_false(Components.isSuccessCode(status));
+      else
+        do_check_eq(status, Components.results.NS_OK);
+      do_check_eq(data, "");
+      do_check_neq(loader.channel, null);
+      tests[current_test++]();
+    } finally {
+      do_test_finished();
+    }
+  }
+};
+
+var current_test = 0;
+var tests = [test1, test2, done];
+
+function run_test() {
+  tests[current_test++]();
+}
+
+function test1() {
+  var f =
+      Cc["@mozilla.org/network/unichar-stream-loader;1"].
+      createInstance(Ci.nsIUnicharStreamLoader);
+  f.init(listener);
+
+  var ios = Components.classes["@mozilla.org/network/io-service;1"]
+                      .getService(Components.interfaces.nsIIOService);
+  var chan = ios.newChannel("data:text/plain,", null, null);
+  chan.asyncOpen(f, null);
+  do_test_pending();
+}
+
+function test2() {
+  var f =
+      Cc["@mozilla.org/network/unichar-stream-loader;1"].
+      createInstance(Ci.nsIUnicharStreamLoader);
+  f.init(listener);
+
+  var ios = Components.classes["@mozilla.org/network/io-service;1"]
+                      .getService(Components.interfaces.nsIIOService);
+  var chan = ios.newChannel("http://localhost:0/", null, null);
+  listener.expect_failure = true;
+  chan.asyncOpen(f, null);
+  do_test_pending();
+}
+
+function done() {
+}