Work around MediaSource duration bug.

Fixes #1967

Change-Id: Ie2a41cb17427316ce65cf180507c1fb1f2c6f11a

lib/media/streaming_engine.js

@@ -1145,8 +1145,11 @@ shaka.media.StreamingEngine = class {
       // We should only do this if the duration needs to shrink.
       // Growing it by less than 1ms can actually cause buffering on
       // replay, as in https://github.com/google/shaka-player/issues/979
+      // On some platforms, this can spuriously be 0, so ignore this case.
+      // https://github.com/google/shaka-player/issues/1967,
       const duration = this.playerInterface_.mediaSourceEngine.getDuration();
-      if (duration < this.manifest_.presentationTimeline.getDuration()) {
+      if (duration != 0 &&
+          duration < this.manifest_.presentationTimeline.getDuration()) {
         this.manifest_.presentationTimeline.setDuration(duration);
       }
     }

test/media/streaming_engine_unit.js

@@ -995,6 +995,27 @@ describe('StreamingEngine', () => {
     expect(timeline.setDuration).not.toHaveBeenCalled();
   });
 
+  // https://github.com/google/shaka-player/issues/1967
+  it('does not change duration when 0', () => {
+    setupVod();
+    mediaSourceEngine = new shaka.test.FakeMediaSourceEngine(segmentData);
+    createStreamingEngine();
+
+    onStartupComplete.and.callFake(() => setupFakeGetTime(0));
+    onChooseStreams.and.callFake(defaultOnChooseStreams);
+
+    // The duration can spuriously be set to 0, so we should ignore this and not
+    // update the duration.
+    mediaSourceEngine.getDuration.and.returnValue(0);
+
+    // Here we go!
+    streamingEngine.start();
+
+    runTest();
+    expect(mediaSourceEngine.endOfStream).toHaveBeenCalled();
+    expect(timeline.setDuration).not.toHaveBeenCalled();
+  });
+
   it('applies fudge factor for appendWindowStart', () => {
     setupVod();
     mediaSourceEngine = new shaka.test.FakeMediaSourceEngine(segmentData);