5 files changed, 25 insertions, 15 deletions
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index 7586b99e7..cb38b6111 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -22,7 +22,6 @@ using MediaBrowser.Controller.Channels;
 using MediaBrowser.Controller.Chapters;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Dto;
-using MediaBrowser.Controller.Entities.Audio;
 using MediaBrowser.Controller.Entities.TV;
 using MediaBrowser.Controller.IO;
 using MediaBrowser.Controller.Library;
@@ -2129,17 +2128,6 @@ namespace MediaBrowser.Controller.Entities
                 };
             }
 
-            // Music albums usually don't have dedicated backdrops, so return one from the artist instead
-            if (GetType() == typeof(MusicAlbum) && imageType == ImageType.Backdrop)
-            {
-                var artist = FindParent<MusicArtist>();
-
-                if (artist is not null)
-                {
-                    return artist.GetImages(imageType).ElementAtOrDefault(imageIndex);
-                }
-            }
-
             return GetImages(imageType)
                 .ElementAtOrDefault(imageIndex);
         }
diff --git a/MediaBrowser.Controller/Entities/Folder.cs b/MediaBrowser.Controller/Entities/Folder.cs
index d2a3290c4..2ecb6cbdf 100644
--- a/MediaBrowser.Controller/Entities/Folder.cs
+++ b/MediaBrowser.Controller/Entities/Folder.cs
@@ -452,6 +452,7 @@ namespace MediaBrowser.Controller.Entities
                 // That's all the new and changed ones - now see if any have been removed and need cleanup
                 var itemsRemoved = currentChildren.Values.Except(validChildren).ToList();
                 var shouldRemove = !IsRoot || allowRemoveRoot;
+                var actuallyRemoved = new List<BaseItem>();
                 // If it's an AggregateFolder, don't remove
                 if (shouldRemove && itemsRemoved.Count > 0)
                 {
@@ -467,6 +468,7 @@ namespace MediaBrowser.Controller.Entities
                         {
                             Logger.LogDebug("Removed item: {Path}", item.Path);
 
+                            actuallyRemoved.Add(item);
                             item.SetParent(null);
                             LibraryManager.DeleteItem(item, new DeleteOptions { DeleteFileLocation = false }, this, false);
                         }
@@ -477,6 +479,20 @@ namespace MediaBrowser.Controller.Entities
                 {
                     LibraryManager.CreateItems(newItems, this, cancellationToken);
                 }
+
+                // After removing items, reattach any detached user data to remaining children
+                // that share the same user data keys (eg. same episode replaced with a new file).
+                if (actuallyRemoved.Count > 0)
+                {
+                    var removedKeys = actuallyRemoved.SelectMany(i => i.GetUserDataKeys()).ToHashSet();
+                    foreach (var child in validChildren)
+                    {
+                        if (child.GetUserDataKeys().Any(removedKeys.Contains))
+                        {
+                            await child.ReattachUserDataAsync(cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+                }
             }
             else
             {
diff --git a/MediaBrowser.Controller/Entities/TV/Season.cs b/MediaBrowser.Controller/Entities/TV/Season.cs
index b972ebaa6..4360253b0 100644
--- a/MediaBrowser.Controller/Entities/TV/Season.cs
+++ b/MediaBrowser.Controller/Entities/TV/Season.cs
@@ -201,12 +201,17 @@ namespace MediaBrowser.Controller.Entities.TV
 
         public List<BaseItem> GetEpisodes(Series series, User user, IEnumerable<Episode> allSeriesEpisodes, DtoOptions options, bool shouldIncludeMissingEpisodes)
         {
+            if (series is null)
+            {
+                return [];
+            }
+
             return series.GetSeasonEpisodes(this, user, allSeriesEpisodes, options, shouldIncludeMissingEpisodes);
         }
 
         public List<BaseItem> GetEpisodes()
         {
-            return Series.GetSeasonEpisodes(this, null, null, new DtoOptions(true), true);
+            return GetEpisodes(Series, null, null, new DtoOptions(true), true);
         }
 
         public override List<BaseItem> GetChildren(User user, bool includeLinkedChildren, InternalItemsQuery query)
diff --git a/MediaBrowser.Controller/Entities/TV/Series.cs b/MediaBrowser.Controller/Entities/TV/Series.cs
index 6396631f9..6a26ecaeb 100644
--- a/MediaBrowser.Controller/Entities/TV/Series.cs
+++ b/MediaBrowser.Controller/Entities/TV/Series.cs
@@ -451,7 +451,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
                 if (!currentSeasonNumber.HasValue && !seasonNumber.HasValue && parentSeason.LocationType == LocationType.Virtual)
                 {
-                    return true;
+                    return episodeItem.Season is null or { LocationType: LocationType.Virtual };
                 }
 
                 var season = episodeItem.Season;
diff --git a/MediaBrowser.Controller/Playlists/IPlaylistManager.cs b/MediaBrowser.Controller/Playlists/IPlaylistManager.cs
index 497c4a511..92aa92396 100644
--- a/MediaBrowser.Controller/Playlists/IPlaylistManager.cs
+++ b/MediaBrowser.Controller/Playlists/IPlaylistManager.cs
@@ -61,9 +61,10 @@ namespace MediaBrowser.Controller.Playlists
         /// </summary>
         /// <param name="playlistId">The playlist identifier.</param>
         /// <param name="itemIds">The item ids.</param>
+        /// <param name="position">Optional. 0-based index where to place the items or at the end if null.</param>
         /// <param name="userId">The user identifier.</param>
         /// <returns>Task.</returns>
-        Task AddItemToPlaylistAsync(Guid playlistId, IReadOnlyCollection<Guid> itemIds, Guid userId);
+        Task AddItemToPlaylistAsync(Guid playlistId, IReadOnlyCollection<Guid> itemIds, int? position, Guid userId);
 
         /// <summary>
         /// Removes from playlist.