match tilesheets without extension to .png files automatically if possible

2 files changed, 14 insertions, 4 deletions

diff --git a/docs/release-notes.md b/docs/release-notes.md
index b6b14f97..701471ee 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -21,6 +21,7 @@
 * For modders:
   * Added asset propagation for `Data\Concessions`.
   * Added SMAPI version and bitness to the console title before startup to simplify troubleshooting.
+  * If a map loads a tilesheet path with no file extension, SMAPI now automatically links it to a `.png` version in the map folder if possible.
   * Improved error-handling during asset propagation.
   * Fixed `Context.IsMainPlayer` returning true for a farmhand in split-screen mode before the screen is initialized.
   * Fixed error when editing bundle data while a split-screen player is joining.
diff --git a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
index 9af14cb5..0cd431e8 100644
--- a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
+++ b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
@@ -34,6 +34,9 @@ namespace StardewModdingAPI.Framework.ContentManagers
         /// <summary>The language code for language-agnostic mod assets.</summary>
         private readonly LanguageCode DefaultLanguage = Constants.DefaultLanguage;
 
+        /// <summary>If a map tilesheet's image source has no file extensions, the file extensions to check for in the local mod folder.</summary>
+        private readonly string[] LocalTilesheetExtensions = { ".png", ".xnb" };
+
 
         /*********
         ** Public methods
@@ -215,11 +218,17 @@ namespace StardewModdingAPI.Framework.ContentManagers
             FileInfo file = new FileInfo(Path.Combine(this.FullRootDirectory, path));
 
             // try with default extension
-            if (!file.Exists && file.Extension.ToLower() != ".xnb")
+            if (!file.Exists && file.Extension == string.Empty)
             {
-                FileInfo result = new FileInfo(file.FullName + ".xnb");
-                if (result.Exists)
-                    file = result;
+                foreach (string extension in this.LocalTilesheetExtensions)
+                {
+                    FileInfo result = new FileInfo(file.FullName + extension);
+                    if (result.Exists)
+                    {
+                        file = result;
+                        break;
+                    }
+                }
             }
 
             return file;