From c361e3abc3cff2d63f16233547b48813c3d32c60 Mon Sep 17 00:00:00 2001
From: andrewlewis <andrewlewis@google.com>
Date: Tue, 20 Aug 2019 08:40:44 +0100
Subject: [PATCH] Fix handling of delayed AdsLoader.start

AdsMediaSource posts AdsLoader.start to the main thread during preparation, but
the app may call AdsLoader.setPlayer(null) before it actually runs (e.g., if
initializing then quickly backgrounding the player).

This is valid usage of the API so handle this case instead of asserting. Because
not calling setPlayer at all is a pitfall of the API, track whether setPlayer
has been called and still assert that in AdsLoader.start.

PiperOrigin-RevId: 264329632
---
 .../android/exoplayer2/ext/ima/ImaAdsLoader.java     | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java
index e37f192c97..3a9d83769b 100644
--- a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java
+++ b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java
@@ -327,6 +327,7 @@ public final class ImaAdsLoader
   private final AdDisplayContainer adDisplayContainer;
   private final com.google.ads.interactivemedia.v3.api.AdsLoader adsLoader;
 
+  private boolean wasSetPlayerCalled;
   @Nullable private Player nextPlayer;
   private Object pendingAdRequestContext;
   private List<String> supportedMimeTypes;
@@ -558,6 +559,7 @@ public final class ImaAdsLoader
     Assertions.checkState(
         player == null || player.getApplicationLooper() == Looper.getMainLooper());
     nextPlayer = player;
+    wasSetPlayerCalled = true;
   }
 
   @Override
@@ -585,9 +587,12 @@ public final class ImaAdsLoader
 
   @Override
   public void start(EventListener eventListener, AdViewProvider adViewProvider) {
-    Assertions.checkNotNull(
-        nextPlayer, "Set player using adsLoader.setPlayer before preparing the player.");
+    Assertions.checkState(
+        wasSetPlayerCalled, "Set player using adsLoader.setPlayer before preparing the player.");
     player = nextPlayer;
+    if (player == null) {
+      return;
+    }
     this.eventListener = eventListener;
     lastVolumePercentage = 0;
     lastAdProgress = null;
@@ -617,6 +622,9 @@ public final class ImaAdsLoader
 
   @Override
   public void stop() {
+    if (player == null) {
+      return;
+    }
     if (adsManager != null && imaPausedContent) {
       adPlaybackState =
           adPlaybackState.withAdResumePositionUs(