fix game content managers not cloning assets from IAssetLoader

src/SMAPI/Framework/ContentCoordinator.cs

@@ -5,7 +5,6 @@ using System.IO;
 using System.Linq;
 using System.Reflection;
 using Microsoft.Xna.Framework.Content;
-using Microsoft.Xna.Framework.Graphics;
 using StardewModdingAPI.Framework.Content;
 using StardewModdingAPI.Framework.ContentManagers;
 using StardewModdingAPI.Framework.Reflection;
@@ -157,27 +156,7 @@ namespace StardewModdingAPI.Framework
 
             // get cloned asset
             T data = contentManager.Load<T>(internalKey, language);
-            switch (data as object)
+            return contentManager.CloneIfPossible(data);
-            {
-                case Texture2D source:
-                    {
-                        int[] pixels = new int[source.Width * source.Height];
-                        source.GetData(pixels);
-
-                        Texture2D clone = new Texture2D(source.GraphicsDevice, source.Width, source.Height);
-                        clone.SetData(pixels);
-                        return (T)(object)clone;
-                    }
-
-                case Dictionary<string, string> source:
-                    return (T)(object)new Dictionary<string, string>(source);
-
-                case Dictionary<int, string> source:
-                    return (T)(object)new Dictionary<int, string>(source);
-
-                default:
-                    return data;
-            }
         }
 
         /// <summary>Purge assets from the cache that match one of the interceptors.</summary>

src/SMAPI/Framework/ContentManagers/BaseContentManager.cs

@@ -6,6 +6,7 @@ using System.Globalization;
 using System.IO;
 using System.Linq;
 using Microsoft.Xna.Framework.Content;
+using Microsoft.Xna.Framework.Graphics;
 using StardewModdingAPI.Framework.Content;
 using StardewModdingAPI.Framework.Exceptions;
 using StardewModdingAPI.Framework.Reflection;
@@ -109,6 +110,34 @@ namespace StardewModdingAPI.Framework.ContentManagers
 
         }
 
+        /// <summary>Get a copy of the given asset if supported.</summary>
+        /// <typeparam name="T">The asset type.</typeparam>
+        /// <param name="asset">The asset to clone.</param>
+        public T CloneIfPossible<T>(T asset)
+        {
+            switch (asset as object)
+            {
+                case Texture2D source:
+                    {
+                        int[] pixels = new int[source.Width * source.Height];
+                        source.GetData(pixels);
+
+                        Texture2D clone = new Texture2D(source.GraphicsDevice, source.Width, source.Height);
+                        clone.SetData(pixels);
+                        return (T)(object)clone;
+                    }
+
+                case Dictionary<string, string> source:
+                    return (T)(object)new Dictionary<string, string>(source);
+
+                case Dictionary<int, string> source:
+                    return (T)(object)new Dictionary<int, string>(source);
+
+                default:
+                    return asset;
+            }
+        }
+
         /// <summary>Normalise path separators in a file path. For asset keys, see <see cref="AssertAndNormaliseAssetName"/> instead.</summary>
         /// <param name="path">The file path to normalise.</param>
         [Pure]

src/SMAPI/Framework/ContentManagers/GameContentManager.cs

@@ -161,7 +161,7 @@ namespace StardewModdingAPI.Framework.ContentManagers
             T data;
             try
             {
-                data = loader.Load<T>(info);
+                data = this.CloneIfPossible(loader.Load<T>(info));
                 this.Monitor.Log($"{mod.DisplayName} loaded asset '{info.AssetName}'.", LogLevel.Trace);
             }
             catch (Exception ex)

src/SMAPI/Framework/ContentManagers/IContentManager.cs

@@ -47,6 +47,11 @@ namespace StardewModdingAPI.Framework.ContentManagers
         /// <param name="value">The asset value.</param>
         void Inject<T>(string assetName, T value);
 
+        /// <summary>Get a copy of the given asset if supported.</summary>
+        /// <typeparam name="T">The asset type.</typeparam>
+        /// <param name="asset">The asset to clone.</param>
+        T CloneIfPossible<T>(T asset);
+
         /// <summary>Normalise path separators in a file path. For asset keys, see <see cref="AssertAndNormaliseAssetName"/> instead.</summary>
         /// <param name="path">The file path to normalise.</param>
         [Pure]