IssueTracker

Background

We are seeing the following runtime crash:

java.lang.NullPointerException
	at com.snap.media.playback.core.renderer.ScImageRenderer.getName(ScImageRenderer.kt:1)
	at com.google.android.exoplayer2.trackselection.MappingTrackSelector.selectTracks(MappingTrackSelector.java:385)
	at com.snap.media.playback.core.trackselection.ScTrackSelector.selectTracks(ScTrackSelector.java:59)
	at com.google.android.exoplayer2.MediaPeriodHolder.selectTracks(MediaPeriodHolder.java:238)
	at com.google.android.exoplayer2.MediaPeriodHolder.handlePrepared(MediaPeriodHolder.java:186)
	at com.google.android.exoplayer2.ExoPlayerImplInternal.handlePeriodPrepared(ExoPlayerImplInternal.java:2209)
	at com.google.android.exoplayer2.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:505)
	at android.os.Handler.dispatchMessage(Handler.java:103)
	at android.os.Looper.loopOnce(Looper.java:232)
	at android.os.Looper.loop(Looper.java:317)
	at android.os.HandlerThread.run(HandlerThread.java:85)

Analaysis

Where the original code looks like the following:

const TAG = "ScImageRenderer"
class ScImageRenderer {
  // ...
  fun getName() = TAG
}

class MappingTrackSelector {
    public final TrackSelectorResult selectTracks(RendererCapabilities[] rendererCapabilities, TrackGroupArray trackGroups, MediaSource.MediaPeriodId periodId, Timeline timeline) throws ExoPlaybackException {
     // ...
             for(unmappedTrackGroupCount = 0; unmappedTrackGroupCount < rendererCapabilities.length; ++unmappedTrackGroupCount) {
            int rendererTrackGroupCount = rendererTrackGroupCounts[unmappedTrackGroupCount];
            rendererTrackGroupArrays[unmappedTrackGroupCount] = new TrackGroupArray((TrackGroup[])Util.nullSafeArrayCopy(rendererTrackGroups[unmappedTrackGroupCount], rendererTrackGroupCount));
            rendererFormatSupports[unmappedTrackGroupCount] = (int[][])Util.nullSafeArrayCopy(rendererFormatSupports[unmappedTrackGroupCount], rendererTrackGroupCount);
            // OFFENDING LINE:
            rendererNames[unmappedTrackGroupCount] = rendererCapabilities[unmappedTrackGroupCount].getName();
            rendererTrackTypes[unmappedTrackGroupCount] = rendererCapabilities[unmappedTrackGroupCount].getTrackType();
        }
     // ...
   }
}

In the final binary, the class ScImageRenderer is compiled into JDe and the getName method is replaced with throws null.

public class JDe implements B8e, C8e, mN5, rJa {

    // ... 
    @Override // B8e, C8e
    public String getName() {
        throw null;
    }
}

I'll share a compiler dump over email