fix indexing songs with null artists/album artists (#2592)

CHANGELOG.md

@@ -23,6 +23,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix building sequential schedules across a UTC offset change
 - Fix block start time calculation across a UTC offset change
 - Fix XMLTV generation for channels using on-demand playout mode
+- Fix some removed songs from appearing in the trash
 
 ### Changed
 - Use smaller batch size for search index updates (100, down from 1000)

ErsatzTV.Application/MediaCards/Mapper.cs

@@ -140,7 +140,7 @@ internal static class Mapper
         return new SongCardViewModel(
             songMetadata.SongId,
             songMetadata.Title,
-            string.Join(", ", songMetadata.Artists) + album,
+            string.Join(", ", songMetadata.Artists ?? []) + album,
             songMetadata.SortTitle,
             GetThumbnail(songMetadata, None, None),
             songMetadata.Song.State);

ErsatzTV.Infrastructure/Search/ElasticSearchIndex.cs

@@ -730,6 +730,9 @@ public class ElasticSearchIndex : ISearchIndex
         {
             try
             {
+                metadata.AlbumArtists ??= [];
+                metadata.Artists ??= [];
+
                 var doc = new ElasticSearchItem
                 {
                     Id = song.Id,

ErsatzTV.Infrastructure/Search/LuceneSearchIndex.cs

@@ -1287,12 +1287,13 @@ public sealed class LuceneSearchIndex : ISearchIndex
     private async Task UpdateSong(ISearchRepository searchRepository, Song song)
     {
         Option<SongMetadata> maybeMetadata = song.SongMetadata.HeadOrNone();
-        if (maybeMetadata.IsSome)
+        foreach (var metadata in maybeMetadata)
         {
-            SongMetadata metadata = maybeMetadata.ValueUnsafe();
-
             try
             {
+                metadata.AlbumArtists ??= [];
+                metadata.Artists ??= [];
+
                 var doc = new Document
                 {
                     new StringField(IdField, song.Id.ToString(CultureInfo.InvariantCulture), Field.Store.YES),