Fix TraderControllerClass.ExecutePossibleAction to not drop unsimulated operations on the floor

Patches/FixTraderControllerSimulateFalsePatch.cs

@@ -0,0 +1,82 @@
+using Aki.Reflection.Patching;
+using Diz.LanguageExtensions;
+using EFT.InventoryLogic;
+using HarmonyLib;
+using System.Reflection;
+
+namespace UIFixes
+{
+    public class FixTraderControllerSimulateFalsePatch : ModulePatch
+    {
+        protected override MethodBase GetTargetMethod()
+        {
+            return AccessTools.Method(typeof(TraderControllerClass), nameof(TraderControllerClass.ExecutePossibleAction), [typeof(ItemContextAbstractClass), typeof(Item), typeof(bool), typeof(bool)]);
+        }
+
+        // Recreatign this function to add the comment section, so calling this with simulate = false doesn't break everything
+        [PatchPrefix]
+        [HarmonyPriority(Priority.Last)]
+        public static bool Prefix(TraderControllerClass __instance, ItemContextAbstractClass itemContext, Item targetItem, bool partialTransferOnly, bool simulate, ref GStruct413 __result)
+        {
+            TraderControllerClass.Struct754 opStruct;
+            opStruct.targetItem = targetItem;
+            opStruct.gclass2758_0 = __instance;
+            opStruct.simulate = simulate;
+            opStruct.item = itemContext.Item;
+
+            Error error = new GClass3293(opStruct.item);
+            bool mergeAvailable = itemContext.MergeAvailable;
+            bool splitAvailable = itemContext.SplitAvailable;
+            partialTransferOnly &= splitAvailable;
+
+            if (mergeAvailable)
+            {
+                if (partialTransferOnly)
+                {
+                    __result = __instance.method_24(ref error, ref opStruct);
+                    return false;
+                }
+
+                GStruct413 operation = __instance.method_22(ref error, ref opStruct);
+                if (operation.Succeeded)
+                {
+                    __result = operation;
+                    return false;
+                }
+            }
+
+            if (opStruct.targetItem is GInterface306 applicable)
+            {
+                GStruct413 operation = __instance.method_23(applicable, ref error, ref opStruct);
+                if (operation.Succeeded)
+                {
+                    if (itemContext.IsOperationAllowed(operation.Value))
+                    {
+                        __result = operation;
+                        return false;
+                    }
+                    // Begin added section
+                    else if (!simulate && operation.Value != null)
+                    {
+                        // BSG dropped this operation on the floor, but it needs to be rolled back if it's not going to be returned
+                        operation.Value.RollBack();
+                    }
+                    // End added section
+                }
+            }
+
+            if (mergeAvailable && splitAvailable)
+            {
+                GStruct413 operation = __instance.method_24(ref error, ref opStruct);
+                if (operation.Succeeded)
+                {
+                    __result = operation;
+                    return false;
+                }
+            }
+
+            __result = error;
+            return false;
+        }
+    }
+}

Plugin.cs

@@ -53,6 +53,7 @@ namespace UIFixes
             new FixUnloadLastBulletPatch().Enable();
             StackMoveGreedyPatches.Enable();
             UnloadAmmoPatches.Enable();
+            new FixTraderControllerSimulateFalsePatch().Enable();
         }
 
         public static bool InRaid()