2 files changed, 62 insertions, 2 deletions
diff --git a/src/SMAPI/Framework/ContentCoordinator.cs b/src/SMAPI/Framework/ContentCoordinator.cs
index 81265fa2..6a7385c3 100644
--- a/src/SMAPI/Framework/ContentCoordinator.cs
+++ b/src/SMAPI/Framework/ContentCoordinator.cs
@@ -117,8 +117,21 @@ namespace StardewModdingAPI.Framework
                     aggressiveMemoryOptimizations: aggressiveMemoryOptimizations
                 )
             );
+            var contentManagerForAssetPropagation = new GameContentManagerForAssetPropagation(
+                name: nameof(GameContentManagerForAssetPropagation),
+                serviceProvider: serviceProvider,
+                rootDirectory: rootDirectory,
+                currentCulture: currentCulture,
+                coordinator: this,
+                monitor: monitor,
+                reflection: reflection,
+                onDisposing: this.OnDisposing,
+                onLoadingFirstAsset: onLoadingFirstAsset,
+                aggressiveMemoryOptimizations: aggressiveMemoryOptimizations
+            );
+            this.ContentManagers.Add(contentManagerForAssetPropagation);
             this.VanillaContentManager = new LocalizedContentManager(serviceProvider, rootDirectory);
-            this.CoreAssets = new CoreAssetPropagator(this.MainContentManager.AssertAndNormalizeAssetName, reflection, aggressiveMemoryOptimizations);
+            this.CoreAssets = new CoreAssetPropagator(this.MainContentManager, contentManagerForAssetPropagation, reflection, aggressiveMemoryOptimizations);
         }
 
         /// <summary>Get a new content manager which handles reading files from the game content folder with support for interception.</summary>
@@ -298,7 +311,7 @@ namespace StardewModdingAPI.Framework
             // reload core game assets
             if (removedAssets.Any())
             {
-                IDictionary<string, bool> propagated = this.CoreAssets.Propagate(this.MainContentManager, removedAssets.ToDictionary(p => p.Key, p => p.Value)); // use an intercepted content manager
+                IDictionary<string, bool> propagated = this.CoreAssets.Propagate(removedAssets.ToDictionary(p => p.Key, p => p.Value)); // use an intercepted content manager
                 this.Monitor.Log($"Invalidated {removedAssets.Count} asset names ({string.Join(", ", removedAssets.Keys.OrderBy(p => p, StringComparer.OrdinalIgnoreCase))}); propagated {propagated.Count(p => p.Value)} core assets.", LogLevel.Trace);
             }
             else
diff --git a/src/SMAPI/Framework/ContentManagers/GameContentManagerForAssetPropagation.cs b/src/SMAPI/Framework/ContentManagers/GameContentManagerForAssetPropagation.cs
new file mode 100644
index 00000000..cbbebf02
--- /dev/null
+++ b/src/SMAPI/Framework/ContentManagers/GameContentManagerForAssetPropagation.cs
@@ -0,0 +1,47 @@
+using System;
+using System.Globalization;
+using Microsoft.Xna.Framework.Graphics;
+using StardewModdingAPI.Framework.Reflection;
+using StardewValley;
+
+namespace StardewModdingAPI.Framework.ContentManagers
+{
+    /// <summary>An extension of <see cref="GameContentManager"/> specifically optimized for asset propagation.</summary>
+    /// <remarks>This avoids sharing an asset cache with <see cref="Game1.content"/> or mods, so that assets can be safely disposed when the vanilla game no longer references them.</remarks>
+    internal class GameContentManagerForAssetPropagation : GameContentManager
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>A unique value used in <see cref="Texture2D"/> to identify assets loaded through this instance.</summary>
+        private readonly string Tag = $"Pathoschild.SMAPI/LoadedBy:{nameof(GameContentManagerForAssetPropagation)}";
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <inheritdoc />
+        public GameContentManagerForAssetPropagation(string name, IServiceProvider serviceProvider, string rootDirectory, CultureInfo currentCulture, ContentCoordinator coordinator, IMonitor monitor, Reflector reflection, Action<BaseContentManager> onDisposing, Action onLoadingFirstAsset, bool aggressiveMemoryOptimizations)
+            : base(name, serviceProvider, rootDirectory, currentCulture, coordinator, monitor, reflection, onDisposing, onLoadingFirstAsset, aggressiveMemoryOptimizations) { }
+
+        /// <inheritdoc />
+        public override T Load<T>(string assetName, LanguageCode language, bool useCache)
+        {
+            T data = base.Load<T>(assetName, language, useCache);
+
+            if (data is Texture2D texture)
+                texture.Tag = this.Tag;
+
+            return data;
+        }
+
+        /// <summary>Get whether a texture was loaded by this content manager.</summary>
+        /// <param name="texture">The texture to check.</param>
+        public bool IsReponsibleFor(Texture2D texture)
+        {
+            return
+                texture?.Tag is string tag
+                && tag.Contains(this.Tag);
+        }
+    }
+}