midas_touch: prevent item duplication (LostArtefacts#1416)

This retains the Midas Touch item number that Lara is interacting with
until the puzzle item is added to inventory, so to avoid adjacent
objects triggering the pickup together.

Resolves LostArtefacts#1415.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## [Unreleased](https://github.com/LostArtefacts/TR1X/compare/stable...develop) - ××××-××-××
 - added deadly water feature from TR2+ for custom levels (#1404)
+- fixed adjacent Midas Touch objects potentially allowing gold bar duplication in custom levels (#1415)
 
 ## [4.2](https://github.com/LostArtefacts/TR1X/compare/4.1.2...4.2) - 2024-07-14
 - added creating minidump files on crashes

src/game/objects/traps/midas_touch.c

@@ -62,11 +62,12 @@ void MidasTouch_Collision(
         break;
     }
 
-    if (lara_item->current_anim_state == LS_USE_MIDAS) {
-        if (Item_TestFrameEqual(lara_item, LF_PICKUP_GOLD_BAR)) {
-            Overlay_AddPickup(O_PUZZLE_ITEM1);
-            Inv_AddItem(O_PUZZLE_ITEM1);
-        }
+    if (lara_item->current_anim_state == LS_USE_MIDAS
+        && g_Lara.interact_target.item_num == item_num
+        && Item_TestFrameEqual(lara_item, LF_PICKUP_GOLD_BAR)) {
+        Overlay_AddPickup(O_PUZZLE_ITEM1);
+        Inv_AddItem(O_PUZZLE_ITEM1);
+        g_Lara.interact_target.item_num = NO_OBJECT;
     }
 
     if (!lara_item->gravity_status && lara_item->current_anim_state == LS_STOP
@@ -100,7 +101,6 @@ void MidasTouch_Collision(
         Item_SwitchToObjAnim(lara_item, EXTRA_ANIM_PLACE_BAR, 0, O_LARA_EXTRA);
         g_Lara.gun_status = LGS_HANDS_BUSY;
         g_Lara.interact_target.is_moving = false;
-        g_Lara.interact_target.item_num = NO_OBJECT;
     }
 
     if (!g_Input.action || g_Lara.gun_status != LGS_ARMLESS