Extract requerying of navigational properties from DbContext

osu.Game/Beatmaps/BeatmapManager.cs

@@ -174,21 +174,7 @@ namespace osu.Game.Beatmaps
             if (beatmapSet.Beatmaps.Any(b => b.BaseDifficulty == null))
                 throw new InvalidOperationException($"Cannot import {nameof(BeatmapInfo)} with null {nameof(BeatmapInfo.BaseDifficulty)}.");
 
-            var dbContext = ContextFactory.Get();
+            beatmapSet.Requery(ContextFactory);
-
-            // Workaround System.InvalidOperationException
-            // The instance of entity type 'RulesetInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
-            foreach (var beatmap in beatmapSet.Beatmaps)
-            {
-                beatmap.Ruleset = dbContext.RulesetInfo.Find(beatmap.RulesetID);
-            }
-
-            // Workaround System.InvalidOperationException
-            // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
-            foreach (var file in beatmapSet.Files)
-            {
-                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
-            }
 
             // check if a set already exists with the same online id, delete if it does.
             if (beatmapSet.OnlineBeatmapSetID != null)

osu.Game/Database/Extensions.cs

@@ -0,0 +1,44 @@
+// 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 System.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Scoring;
+
+namespace osu.Game.Database
+{
+    public static class Extensions
+    {
+        public static void Requery(this BeatmapSetInfo beatmapSetInfo, IDatabaseContextFactory databaseContextFactory)
+        {
+            var dbContext = databaseContextFactory.Get();
+
+            foreach (var beatmap in beatmapSetInfo.Beatmaps)
+            {
+                // Workaround System.InvalidOperationException
+                // The instance of entity type 'RulesetInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
+                beatmap.Ruleset = dbContext.RulesetInfo.Find(beatmap.RulesetID);
+            }
+
+            beatmapSetInfo.Files.Requery(databaseContextFactory);
+        }
+
+        public static void Requery(this ScoreInfo scoreInfo, IDatabaseContextFactory databaseContextFactory)
+        {
+            scoreInfo.Files.Requery(databaseContextFactory);
+            scoreInfo.Beatmap.BeatmapSet.Files.Requery(databaseContextFactory);
+        }
+
+        public static void Requery<T>(this List<T> files, IDatabaseContextFactory databaseContextFactory) where T : class, INamedFileInfo
+        {
+            var dbContext = databaseContextFactory.Get();
+
+            foreach (var file in files)
+            {
+                // Workaround System.InvalidOperationException
+                // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
+                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
+            }
+        }
+    }
+}

osu.Game/Scoring/ScoreManager.cs

@@ -54,19 +54,7 @@ namespace osu.Game.Scoring
 
         protected override void PreImport(ScoreInfo model)
         {
-            var dbContext = ContextFactory.Get();
+            model.Requery(ContextFactory);
-
-            // Workaround System.InvalidOperationException
-            // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
-            foreach (var file in model.Files)
-            {
-                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
-            }
-
-            foreach (var file in model.Beatmap.BeatmapSet.Files)
-            {
-                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
-            }
         }
 
         protected override ScoreInfo CreateModel(ArchiveReader archive)

osu.Game/Skinning/SkinManager.cs

@@ -144,14 +144,7 @@ namespace osu.Game.Skinning
 
         protected override void PreImport(SkinInfo model)
         {
-            var dbContext = ContextFactory.Get();
+            model.Files.Requery(ContextFactory);
-
-            // Workaround System.InvalidOperationException
-            // The instance of entity type 'FileInfo' cannot be tracked because another instance with the same key value for {'ID'} is already being tracked.
-            foreach (var file in model.Files)
-            {
-                file.FileInfo = dbContext.FileInfo.Find(file.FileInfoID);
-            }
         }
 
         /// <summary>