diff -r 000000000000 -r 6474c204b198 netwerk/test/unit/test_resumable_truncate.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/test/unit/test_resumable_truncate.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,89 @@
+Cu.import("resource://testing-common/httpd.js");
+
+var httpserver = null;
+
+function make_channel(url, callback, ctx) {
+  var ios = Cc["@mozilla.org/network/io-service;1"].
+            getService(Ci.nsIIOService);
+  return ios.newChannel(url, "", null);
+}
+
+const responseBody = "response body";
+
+function cachedHandler(metadata, response) {
+  var body = responseBody;
+  if (metadata.hasHeader("Range")) {
+    var matches = metadata.getHeader("Range").match(/^\s*bytes=(\d+)?-(\d+)?\s*$/);
+    var from = (matches[1] === undefined) ? 0 : matches[1];
+    var to = (matches[2] === undefined) ? responseBody.length - 1 : matches[2];
+    if (from >= responseBody.length) {
+      response.setStatusLine(metadata.httpVersion, 416, "Start pos too high");
+      response.setHeader("Content-Range", "*/" + responseBody.length, false);
+      return;
+    }
+    body = responseBody.slice(from, to + 1);
+    // always respond to successful range requests with 206
+    response.setStatusLine(metadata.httpVersion, 206, "Partial Content");
+    response.setHeader("Content-Range", from + "-" + to + "/" + responseBody.length, false);
+  }
+
+  response.setHeader("Content-Type", "text/plain", false);
+  response.setHeader("ETag", "Just testing");
+  response.setHeader("Accept-Ranges", "bytes");
+
+  response.bodyOutputStream.write(body, body.length);
+}
+
+function Canceler(continueFn) {
+  this.continueFn = continueFn;
+}
+
+Canceler.prototype = {
+  QueryInterface: function(iid) {
+    if (iid.equals(Ci.nsIStreamListener) ||
+        iid.equals(Ci.nsIRequestObserver) ||
+        iid.equals(Ci.nsISupports))
+      return this;
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+
+  onStartRequest: function(request, context) {
+  },
+
+  onDataAvailable: function(request, context, stream, offset, count) {
+    request.QueryInterface(Ci.nsIChannel)
+           .cancel(Components.results.NS_BINDING_ABORTED);
+  },
+
+  onStopRequest: function(request, context, status) {
+    do_check_eq(status, Components.results.NS_BINDING_ABORTED);
+    this.continueFn();
+  }
+};
+
+function finish_test() {
+  httpserver.stop(do_test_finished);
+}
+
+function start_cache_read() {
+  var chan = make_channel("http://localhost:" +
+                          httpserver.identity.primaryPort + "/cached/test.gz");
+  chan.asyncOpen(new ChannelListener(finish_test, null), null);
+}
+
+function start_canceler() {
+  var chan = make_channel("http://localhost:" +
+                          httpserver.identity.primaryPort + "/cached/test.gz");
+  chan.asyncOpen(new Canceler(start_cache_read), null);
+}
+
+function run_test() {
+  httpserver = new HttpServer();
+  httpserver.registerPathHandler("/cached/test.gz", cachedHandler);
+  httpserver.start(-1);
+
+  var chan = make_channel("http://localhost:" +
+                          httpserver.identity.primaryPort + "/cached/test.gz");
+  chan.asyncOpen(new ChannelListener(start_canceler, null), null);
+  do_test_pending();
+}