From aea5de9410339737ab75f0bf61dd4ce1bb89722e Mon Sep 17 00:00:00 2001
From: Wei Jia <wjia@google.com>
Date: Mon, 21 May 2018 18:48:25 -0700
Subject: [PATCH] MediaPlayer: sanity check track before dereferencing

Test: media post submit tests passed
Bug: 78175875
Change-Id: I6a23fc859a077eba03a17a562a7c3bb01d97e85b
---
 media/java/android/media/MediaPlayer.java | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/media/java/android/media/MediaPlayer.java b/media/java/android/media/MediaPlayer.java
index 392a1eb01d302..ada91be9ca4de 100644
--- a/media/java/android/media/MediaPlayer.java
+++ b/media/java/android/media/MediaPlayer.java
@@ -2848,8 +2848,12 @@ public class MediaPlayer extends PlayerBase
                     mInbandTrackIndices.set(i);
                 }
 
+                if (tracks[i] == null) {
+                    Log.w(TAG, "unexpected NULL track at index " + i);
+                }
                 // newly appeared inband track
-                if (tracks[i].getTrackType() == TrackInfo.MEDIA_TRACK_TYPE_SUBTITLE) {
+                if (tracks[i] != null
+                        && tracks[i].getTrackType() == TrackInfo.MEDIA_TRACK_TYPE_SUBTITLE) {
                     SubtitleTrack track = mSubtitleController.addTrack(
                             tracks[i].getFormat());
                     mIndexTrackPairs.add(Pair.create(i, track));