From e03623f7012cd25075fd90d01dad4504fac684cf Mon Sep 17 00:00:00 2001
From: tonihei <tonihei@google.com>
Date: Fri, 20 Jul 2018 03:25:11 -0700
Subject: [PATCH] Fix issue with keeping window sequence number after repeated
 seeks.

The number is shelved in calls to queue.clear() to keep it for the next
media period. However, the queue may also become empty by repeated calls to
advancePlayingPeriod which may happen when seeking to an unprepared period.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=205376036
---
 .../android/exoplayer2/MediaPeriodQueue.java  |  4 +-
 .../android/exoplayer2/ExoPlayerTest.java     | 38 +++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java b/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java
index 717f873622..17a8ddd8d4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java
@@ -228,11 +228,13 @@ import com.google.android.exoplayer2.util.Assertions;
         reading = playing.next;
       }
       playing.release();
-      playing = playing.next;
       length--;
       if (length == 0) {
         loading = null;
+        oldFrontPeriodUid = playing.uid;
+        oldFrontPeriodWindowSequenceNumber = playing.info.id.windowSequenceNumber;
       }
+      playing = playing.next;
     } else {
       playing = loading;
       reading = loading;
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java b/library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java
index c05f8914f5..559a915b2b 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java
@@ -1980,6 +1980,44 @@ public final class ExoPlayerTest {
         .inOrder();
   }
 
+  @Test
+  public void testRepeatedSeeksToUnpreparedPeriodInSameWindowKeepsWindowSequenceNumber()
+      throws Exception {
+    Timeline timeline =
+        new FakeTimeline(
+            new TimelineWindowDefinition(
+                /* periodCount= */ 2,
+                /* id= */ 0,
+                /* isSeekable= */ true,
+                /* isDynamic= */ false,
+                /* durationUs= */ 10 * C.MICROS_PER_SECOND));
+    FakeMediaSource mediaSource = new FakeMediaSource(timeline, /* manifest= */ null);
+    ActionSchedule actionSchedule =
+        new ActionSchedule.Builder("testSeekToUnpreparedPeriod")
+            .pause()
+            .waitForPlaybackState(Player.STATE_READY)
+            .seek(/* windowIndex= */ 0, /* positionMs= */ 9999)
+            .seek(/* windowIndex= */ 0, /* positionMs= */ 1)
+            .seek(/* windowIndex= */ 0, /* positionMs= */ 9999)
+            .play()
+            .build();
+    ExoPlayerTestRunner testRunner =
+        new ExoPlayerTestRunner.Builder()
+            .setMediaSource(mediaSource)
+            .setActionSchedule(actionSchedule)
+            .build()
+            .start()
+            .blockUntilEnded(TIMEOUT_MS);
+
+    testRunner.assertPlayedPeriodIndices(0, 1, 0, 1);
+    assertThat(mediaSource.getCreatedMediaPeriods())
+        .containsAllOf(
+            new MediaPeriodId(/* periodIndex= */ 0, /* windowSequenceNumber= */ 0),
+            new MediaPeriodId(/* periodIndex= */ 1, /* windowSequenceNumber= */ 0));
+    assertThat(mediaSource.getCreatedMediaPeriods())
+        .doesNotContain(new MediaPeriodId(/* periodIndex= */ 1, /* windowSequenceNumber= */ 1));
+  }
+
   @Test
   public void testRecursivePlayerChangesReportConsistentValuesForAllListeners() throws Exception {
     // We add two listeners to the player. The first stops the player as soon as it's ready and both