diff -r 000000000000 -r 6474c204b198 content/media/test/seek10.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/test/seek10.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+function test_seek10(v, seekTime, is, ok, finish) {
+
+// Test bug 523335 - ensure that if we close a stream while seeking, we
+// don't hang during shutdown. This test won't "fail" per se if it's regressed,
+// it will instead start to cause random hangs in the mochitest harness on
+// shutdown.
+
+function startTest() {
+  // Must be duration*0.9 rather than seekTime, else we don't hit that problem.
+  // This is probably due to the seek bisection finishing too quickly, before
+  // we can close the stream.
+  v.currentTime = v.duration * 0.9;
+}
+
+function done(evt) {
+  ok(true, "We don't acutally test anything...");
+  finish();
+}
+
+function seeking() {
+  ok(v.currentTime >= seekTime - 0.1, "Video currentTime should be around " + seekTime + ": " + v.currentTime);
+  v.onerror = done;
+  v.src = "not a valid video file.";
+  v.load(); // Cause the existing stream to close.
+}
+
+v.addEventListener("loadeddata", startTest, false);
+v.addEventListener("seeking", seeking, false);
+
+}