Keep destroyed warehouse contents in memory so the rubble can be looted

destroyOrDerank nulled city.warehouse on destruction, so the loot click
found no warehouse and returned silently. The destroyed Warehouse is now
held in Warehouse.destroyedWarehouses keyed by the rubble building UUID
until it is looted empty, the rubble is destroyed, or the city places a
new warehouse. Contents are not persisted across a reboot.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/gameManager/BuildingManager.java

@@ -211,12 +211,7 @@ public enum BuildingManager {
                 break;
             case WAREHOUSE:
 
-                City city = building.getCity();
-
-                if (city == null)
-                    return true;
-
-                Warehouse warehouse = city.warehouse;
+                Warehouse warehouse = Warehouse.destroyedWarehouses.get(building.getObjectUUID());
 
                 if (warehouse == null)
                     return false;
@@ -241,6 +236,9 @@ public enum BuildingManager {
                     }
 
                 }
+
+                if (Warehouse.isEmpty(warehouse))
+                    Warehouse.destroyedWarehouses.remove(building.getObjectUUID());
                 break;
 
         }

src/engine/net/client/handlers/DestroyBuildingHandler.java

@@ -97,6 +97,7 @@ public class DestroyBuildingHandler extends AbstractClientMsgHandler {
             if (city == null)
                 return true;
 
+            Warehouse.destroyedWarehouses.remove(building.getObjectUUID());
             DbManager.WarehouseQueries.DELETE_WAREHOUSE(city.warehouse);
 
             city.warehouse = null;

src/engine/net/client/handlers/ManageCityAssetMsgHandler.java

@@ -141,17 +141,9 @@ public class ManageCityAssetMsgHandler extends AbstractClientMsgHandler {
                                     return true;
                                 }
 
-                                City city = building.getCity();
+                                Warehouse warehouse = Warehouse.destroyedWarehouses.get(building.getObjectUUID());
 
-                                if (city == null)
-                                    return true;
-
-                                Warehouse warehouse = city.warehouse;
-
-                                if (warehouse == null)
-                                    return true;
-
-                                if (Warehouse.isEmpty(warehouse)) {
+                                if (warehouse == null || Warehouse.isEmpty(warehouse)) {
                                     ErrorPopupMsg.sendErrorPopup(player, 167); // no more resources.
                                     return true;
                                 }

src/engine/net/client/handlers/PlaceAssetMsgHandler.java

@@ -1341,6 +1341,7 @@ public class PlaceAssetMsgHandler extends AbstractClientMsgHandler {
         }
 
         Warehouse warehouse = new Warehouse(warehouseBuilding);
+        Warehouse.destroyedWarehouses.values().removeIf(destroyed -> destroyed.city == city);
         city.warehouse = warehouse;
         DbManager.WarehouseQueries.UPDATE_WAREHOUSE(warehouse);
 

src/engine/objects/Building.java

@@ -433,6 +433,7 @@ public class Building extends AbstractWorldObject {
         // Special handling of warehouses
 
         if (blueprint.getBuildingGroup() == BuildingGroup.WAREHOUSE) {
+            Warehouse.destroyedWarehouses.put(this.getObjectUUID(), city.warehouse);
             DbManager.WarehouseQueries.DELETE_WAREHOUSE(city.warehouse);
             city.warehouse = null;
         }

src/engine/objects/Warehouse.java

@@ -31,6 +31,9 @@ import java.util.concurrent.ConcurrentHashMap;
 
 public class Warehouse {
 
+    // Destroyed warehouses keyed by rubble building UUID; memory only so the rubble can be looted
+    public static final ConcurrentHashMap<Integer, Warehouse> destroyedWarehouses = new ConcurrentHashMap<>();
+
     public EnumSet<mbEnums.ResourceType> locked = EnumSet.noneOf(mbEnums.ResourceType.class);
     public Building building;
     public City city;