Fix old version of beatmap potentially not being deleted during update flow

This can happen if the online IDs are not present in the `.osu` files.
Previously this was only working due to the early logic in the import
process (that relies on matching all online IDs perfectly).

osu.Game/Beatmaps/BeatmapModelDownloader.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using osu.Framework.Logging;
 using osu.Game.Database;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests;
@@ -19,5 +20,24 @@ namespace osu.Game.Beatmaps
             : base(beatmapImporter, api)
         {
         }
+
+        public bool Update(BeatmapSetInfo model)
+        {
+            return Download(model, false, onSuccess);
+
+            void onSuccess(Live<BeatmapSetInfo> imported)
+            {
+                imported.PerformWrite(updated =>
+                {
+                    Logger.Log($"Beatmap \"{updated}\"update completed successfully", LoggingTarget.Database);
+
+                    var original = updated.Realm.Find<BeatmapSetInfo>(model.ID);
+
+                    // Generally the import process will do this for us if the OnlineIDs match,
+                    // but that isn't a guarantee (ie. if the .osu file doesn't have OnlineIDs populated).
+                    original.DeletePending = true;
+                });
+            }
+        }
     }
 }

osu.Game/Database/ModelDownloader.cs

@@ -42,7 +42,9 @@ namespace osu.Game.Database
         /// <returns>The request object.</returns>
         protected abstract ArchiveDownloadRequest<T> CreateDownloadRequest(T model, bool minimiseDownloadSize);
 
-        public bool Download(T model, bool minimiseDownloadSize = false)
+        public bool Download(T model, bool minimiseDownloadSize = false) => Download(model, minimiseDownloadSize, null);
+
+        protected bool Download(T model, bool minimiseDownloadSize, Action<Live<TModel>>? onSuccess)
         {
             if (!canDownload(model)) return false;
 
@@ -67,7 +69,9 @@ namespace osu.Game.Database
                     var imported = await importer.Import(notification, new ImportTask(filename)).ConfigureAwait(false);
 
                     // for now a failed import will be marked as a failed download for simplicity.
-                    if (!imported.Any())
+                    if (imported.Any())
+                        onSuccess?.Invoke(imported.Single());
+                    else
                         DownloadFailed?.Invoke(request);
 
                     CurrentDownloads.Remove(request);

osu.Game/Screens/Select/Carousel/UpdateBeatmapSetButton.cs

@@ -90,7 +90,7 @@ namespace osu.Game.Screens.Select.Carousel
 
             Action = () =>
             {
-                beatmapDownloader.Download(beatmapSetInfo);
+                beatmapDownloader.Update(beatmapSetInfo);
                 attachExistingDownload();
             };
         }