Allow duplicated MediaItems in a legacy session

MediaItems are not meant to be unique in a playlist. If a legacy
session publishes multiple items that get converted to equal MediaItems,
the current code fails because we look up queue ids in a Map (that
doesn't allow duplicate entries).

Fix this by storing a simple list of items with additional data.

Issue: androidx/media#290
PiperOrigin-RevId: 521993802
(cherry picked from commit 219967c5)

libraries/session/src/main/java/androidx/media3/session/MediaControllerImplLegacy.java

@@ -1795,7 +1795,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     currentTimeline =
         isQueueChanged
             ? QueueTimeline.create(newLegacyPlayerInfo.queue)
-            : new QueueTimeline((QueueTimeline) oldControllerInfo.playerInfo.timeline);
+            : ((QueueTimeline) oldControllerInfo.playerInfo.timeline).copy();
 
     boolean isMetadataCompatChanged =
         oldLegacyPlayerInfo.mediaMetadataCompat != newLegacyPlayerInfo.mediaMetadataCompat
@@ -1987,8 +1987,6 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     Integer mediaItemTransitionReason;
     boolean isOldTimelineEmpty = oldControllerInfo.playerInfo.timeline.isEmpty();
     boolean isNewTimelineEmpty = newControllerInfo.playerInfo.timeline.isEmpty();
-    int newCurrentMediaItemIndex =
-        newControllerInfo.playerInfo.sessionPositionInfo.positionInfo.mediaItemIndex;
     if (isOldTimelineEmpty && isNewTimelineEmpty) {
       // Still empty Timelines.
       discontinuityReason = null;
@@ -2000,13 +1998,13 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     } else {
       MediaItem oldCurrentMediaItem =
           checkStateNotNull(oldControllerInfo.playerInfo.getCurrentMediaItem());
-      int oldCurrentMediaItemIndexInNewTimeline =
-          ((QueueTimeline) newControllerInfo.playerInfo.timeline).indexOf(oldCurrentMediaItem);
-      if (oldCurrentMediaItemIndexInNewTimeline == C.INDEX_UNSET) {
+      boolean oldCurrentMediaItemExistsInNewTimeline =
+          ((QueueTimeline) newControllerInfo.playerInfo.timeline).contains(oldCurrentMediaItem);
+      if (!oldCurrentMediaItemExistsInNewTimeline) {
         // Old current item is removed.
         discontinuityReason = Player.DISCONTINUITY_REASON_REMOVE;
         mediaItemTransitionReason = Player.MEDIA_ITEM_TRANSITION_REASON_PLAYLIST_CHANGED;
-      } else if (oldCurrentMediaItemIndexInNewTimeline == newCurrentMediaItemIndex) {
+      } else if (oldCurrentMediaItem.equals(newControllerInfo.playerInfo.getCurrentMediaItem())) {
         // Current item is the same.
         long oldCurrentPosition =
             MediaUtils.convertToCurrentPositionMs(

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaControllerWithMediaSessionCompatTest.java

@@ -78,6 +78,7 @@ import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.ext.truth.os.BundleSubject;
 import androidx.test.filters.MediumTest;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
 import com.google.common.collect.Range;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
@@ -415,6 +416,41 @@ public class MediaControllerWithMediaSessionCompatTest {
   }
 
   @Test
+  public void setQueue_withDuplicatedMediaItems_updatesAndNotifiesTimeline() throws Exception {
+    MediaController controller = controllerTestRule.createController(session.getSessionToken());
+    CountDownLatch latch = new CountDownLatch(1);
+    AtomicReference<Timeline> timelineFromParamRef = new AtomicReference<>();
+    AtomicReference<Timeline> timelineFromGetterRef = new AtomicReference<>();
+    AtomicInteger reasonRef = new AtomicInteger();
+    Player.Listener listener =
+        new Player.Listener() {
+          @Override
+          public void onTimelineChanged(
+              Timeline timeline, @Player.TimelineChangeReason int reason) {
+            timelineFromParamRef.set(timeline);
+            timelineFromGetterRef.set(controller.getCurrentTimeline());
+            reasonRef.set(reason);
+            latch.countDown();
+          }
+        };
+    threadTestRule.getHandler().postAndSync(() -> controller.addListener(listener));
+
+    List<MediaItem> mediaItems = MediaTestUtils.createMediaItems(/* size= */ 2);
+    Timeline testTimeline =
+        MediaTestUtils.createTimeline(
+            ImmutableList.copyOf(Iterables.concat(mediaItems, mediaItems)));
+    List<QueueItem> testQueue =
+        MediaTestUtils.convertToQueueItemsWithoutBitmap(
+            MediaUtils.convertToMediaItemList(testTimeline));
+    session.setQueue(testQueue);
+
+    assertThat(latch.await(TIMEOUT_MS, MILLISECONDS)).isTrue();
+    MediaTestUtils.assertMediaIdEquals(testTimeline, timelineFromParamRef.get());
+    MediaTestUtils.assertMediaIdEquals(testTimeline, timelineFromGetterRef.get());
+    assertThat(reasonRef.get()).isEqualTo(Player.TIMELINE_CHANGE_REASON_PLAYLIST_CHANGED);
+  }
+
+  @Test
   public void setQueue_withDescription_notifiesTimelineWithMetadata() throws Exception {
     CountDownLatch latch = new CountDownLatch(1);
     AtomicReference<Timeline> timelineRef = new AtomicReference<>();