Fix: validate drawer handler existence (#491)

src/main/java/com/buuz135/functionalstorage/block/tile/ControllableDrawerTile.java

@@ -23,6 +23,7 @@
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockState;
 import net.minecraftforge.api.distmarker.Dist;
@@ -76,7 +77,35 @@ public ControllableDrawerTile(BasicTileBlock<T> base, BlockEntityType<T> entityT
         }
 
     }
-
+    @Override
+    public void onLoad() {
+        super.onLoad();
+        if (level == null || level.isClientSide()) return;
+
+        // Loaded at a new location after block movement
+        // If controllerPos exists but current position is missing from Controller list -> Moved
+        if (controllerPos != null) {
+            BlockEntity be = level.getBlockEntity(controllerPos);
+            if (be instanceof StorageControllerTile<?> controllerTile) {
+                boolean isInController = controllerTile.getConnectedDrawers()
+                        .getConnectedDrawers()
+                        .contains(this.getBlockPos().asLong());
+
+                if (!isInController) {
+                    // Moved Drawer: Remove old link + Force cache reconstruction
+                    controllerTile.getConnectedDrawers()
+                            .getConnectedDrawers()
+                            .removeIf(aLong -> aLong == this.getBlockPos().asLong());
+                    this.controllerPos = null;
+                    controllerTile.getConnectedDrawers().rebuild(); // selectors[] 재구성
+                    controllerTile.markForUpdate();
+                }
+            } else {
+                // No Controller found
+                this.controllerPos = null;
+            }
+        }
+    }
     @Override
     @OnlyIn(Dist.CLIENT)
     public void initClient() {
@@ -298,11 +327,6 @@ public InventoryComponent<ControllableDrawerTile<T>> getStorageUpgrades() {
         return storageUpgrades;
     }
 
-    @Override
-    public void invalidateCaps() {
-        super.invalidateCaps();
-    }
-
     public boolean isEverythingEmpty() {
         for (int i = 0; i < getStorageUpgrades().getSlots(); i++) {
             if (!getStorageUpgrades().getStackInSlot(i).isEmpty()) {
@@ -316,6 +340,17 @@ public boolean isEverythingEmpty() {
         }
         return true;
     }
+    @Override
+    public void invalidateCaps() {
+        super.invalidateCaps();
+        // Rebuild Controller cache immediately on caps invalidation
+        if (level != null && !level.isClientSide() && controllerPos != null) {
+            BlockEntity be = level.getBlockEntity(controllerPos);
+            if (be instanceof StorageControllerTile<?> controllerTile) {
+                controllerTile.getConnectedDrawers().rebuild();
+            }
+        }
+    }
 
     public abstract InventoryComponent<ControllableDrawerTile<T>> getStorageUpgradesConstructor();
 

src/main/java/com/buuz135/functionalstorage/inventory/ControllerInventoryHandler.java

@@ -75,7 +75,15 @@ private HandlerSlotSelector selectorForSlot(int slot) {
     @Override
     public ItemStack getStackInSlot(int slot) {
         HandlerSlotSelector selector = selectorForSlot(slot);
-        return null != selector ? selector.getStackInSlot() : ItemStack.EMPTY;
+        if (null == selector) return ItemStack.EMPTY;
+
+        // Block access to invalid handlers
+        if (!getDrawers().getItemHandlers().contains(selector.handler)) {
+            invalidateSlots();
+            return ItemStack.EMPTY;
+        }
+
+        return selector.getStackInSlot();
     }
 
     @NotNull
@@ -89,7 +97,16 @@ public ItemStack insertItem(int slot, @NotNull ItemStack stack, boolean simulate
     @Override
     public ItemStack extractItem(int slot, int amount, boolean simulate) {
         HandlerSlotSelector selector = selectorForSlot(slot);
-        return null != selector ? selector.extractItem(amount, simulate) : ItemStack.EMPTY;
+        if (null == selector) return ItemStack.EMPTY;
+
+        //Verify if the handler is still valid before extraction
+        if (!getDrawers().getItemHandlers().contains(selector.handler)) {
+            // Invalid handler: Rebuild slots and return empty stack
+            invalidateSlots();
+            return ItemStack.EMPTY;
+        }
+
+        return selector.extractItem(amount, simulate);
     }
 
     @Override

src/main/java/com/buuz135/functionalstorage/util/ConnectedDrawers.java

@@ -60,6 +60,15 @@ public void rebuild() {
             }
             var area = new AABB(controllerTile.getBlockPos()).inflate(FunctionalStorageConfig.DRAWER_CONTROLLER_LINKING_RANGE + extraRange);
             this.connectedDrawers.removeIf(aLong -> !area.contains(Vec3.atCenterOf(BlockPos.of(aLong))));
+
+            //Check if the Drawer is present within the range.
+            this.connectedDrawers.removeIf(aLong -> {
+                BlockEntity entity = level.getBlockEntity(BlockPos.of(aLong));
+                return !(entity instanceof ItemControllableDrawerTile<?>)
+                        && !(entity instanceof FluidDrawerTile)
+                        && !(entity instanceof StorageControllerExtensionTile);
+            });
+
             this.connectedDrawers.sort(Comparator.comparingDouble(value -> BlockPos.of(value).distSqr(controllerTile.getBlockPos())));
             for (Long connectedDrawer : this.connectedDrawers) {
                 BlockPos pos = BlockPos.of(connectedDrawer);