fix error when mod edits bundle data while a split-screen player is joining

docs/release-notes.md

@@ -20,6 +20,7 @@
   * Added asset propagation for `Data\Concessions`.
   * 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.
 
 ## 3.9.5
 Released 21 March 2021 for Stardew Valley 1.5.4 or later.

src/SMAPI/Metadata/CoreAssetPropagator.cs

@@ -274,6 +274,7 @@ namespace StardewModdingAPI.Metadata
                     return true;
 
                 case "data\\bundles": // NetWorldState constructor
+                    if (Context.IsMainPlayer && Game1.netWorldState != null)
                     {
                         var bundles = this.Reflection.GetField<NetBundles>(Game1.netWorldState.Value, "bundles").GetValue();
                         var rewards = this.Reflection.GetField<NetIntDictionary<bool, NetBool>>(Game1.netWorldState.Value, "bundleRewards").GetValue();