Avoid media item transitions for auto discontinuities when ads involved

#minor-release

PiperOrigin-RevId: 372433555

RELEASENOTES.md

@@ -51,6 +51,8 @@
     *   Added a combined and structured metadata object (`MediaMetadata`) to
         Player, accessible through `getMediaMetadata` or by listening to
         `EventListener.onMediaMetadataChanged`.
+    *   Fix bug when transitions from content to ad periods called
+        `onMediaItemTransition` by mistake.
 *   UI:
     *   Add builder for `PlayerNotificationManager`.
     *   Add group setting to `PlayerNotificationManager`.

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java

@@ -1462,7 +1462,6 @@ import java.util.concurrent.CopyOnWriteArraySet;
     int newWindowIndex =
         newTimeline.getPeriodByUid(playbackInfo.periodId.periodUid, period).windowIndex;
     Object newWindowUid = newTimeline.getWindow(newWindowIndex, window).uid;
-    int firstPeriodIndexInNewWindow = window.firstPeriodIndex;
     if (!oldWindowUid.equals(newWindowUid)) {
       @Player.MediaItemTransitionReason int transitionReason;
       if (positionDiscontinuity
@@ -1480,8 +1479,8 @@ import java.util.concurrent.CopyOnWriteArraySet;
       return new Pair<>(/* isTransitioning */ true, transitionReason);
     } else if (positionDiscontinuity
         && positionDiscontinuityReason == DISCONTINUITY_REASON_AUTO_TRANSITION
-        && newTimeline.getIndexOfPeriod(playbackInfo.periodId.periodUid)
-            == firstPeriodIndexInNewWindow) {
+        && oldPlaybackInfo.periodId.windowSequenceNumber
+            < playbackInfo.periodId.windowSequenceNumber) {
       return new Pair<>(/* isTransitioning */ true, MEDIA_ITEM_TRANSITION_REASON_REPEAT);
     }
     return new Pair<>(/* isTransitioning */ false, /* mediaItemTransitionReason */ C.INDEX_UNSET);