Made upgrades stackable

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### 1.3.1
 - Updated Forge to 2180 (raoulvdberge)
+- Made Upgrades stackable (raoulvdberge)
 - Fixed Disk Drive not noticing a Storage Disk being shift clicked out of the GUI (raoulvdberge)
 
 ### 1.3

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerBase.java

@@ -30,6 +30,95 @@ public abstract class ContainerBase extends Container {
         return tile;
     }
 
+    // @todo Forge issue #3498
+    @Override
+    protected boolean mergeItemStack(ItemStack stack, int startIndex, int endIndex, boolean reverseDirection) {
+        boolean flag = false;
+        int i = startIndex;
+
+        if (reverseDirection) {
+            i = endIndex - 1;
+        }
+
+        if (stack.isStackable()) {
+            while (!stack.isEmpty()) {
+                if (reverseDirection) {
+                    if (i < startIndex) {
+                        break;
+                    }
+                } else if (i >= endIndex) {
+                    break;
+                }
+
+                Slot slot = (Slot) this.inventorySlots.get(i);
+                ItemStack itemstack = slot.getStack();
+
+                if (!itemstack.isEmpty() && itemstack.getItem() == stack.getItem() && (!stack.getHasSubtypes() || stack.getMetadata() == itemstack.getMetadata()) && ItemStack.areItemStackTagsEqual(stack, itemstack)) {
+                    int j = itemstack.getCount() + stack.getCount();
+
+                    if (j <= slot.getSlotStackLimit()) {
+                        stack.setCount(0);
+                        itemstack.setCount(j);
+                        slot.onSlotChanged();
+                        flag = true;
+                    } else if (itemstack.getCount() < slot.getSlotStackLimit()) {
+                        stack.shrink(slot.getSlotStackLimit() - itemstack.getCount());
+                        itemstack.setCount(slot.getSlotStackLimit());
+                        slot.onSlotChanged();
+                        flag = true;
+                    }
+                }
+
+                if (reverseDirection) {
+                    --i;
+                } else {
+                    ++i;
+                }
+            }
+        }
+
+        if (!stack.isEmpty()) {
+            if (reverseDirection) {
+                i = endIndex - 1;
+            } else {
+                i = startIndex;
+            }
+
+            while (true) {
+                if (reverseDirection) {
+                    if (i < startIndex) {
+                        break;
+                    }
+                } else if (i >= endIndex) {
+                    break;
+                }
+
+                Slot slot1 = (Slot) this.inventorySlots.get(i);
+                ItemStack itemstack1 = slot1.getStack();
+
+                if (itemstack1.isEmpty() && slot1.isItemValid(stack)) {
+                    if (stack.getCount() > slot1.getSlotStackLimit()) {
+                        slot1.putStack(stack.splitStack(slot1.getSlotStackLimit()));
+                    } else {
+                        slot1.putStack(stack.splitStack(stack.getCount()));
+                    }
+
+                    slot1.onSlotChanged();
+                    flag = true;
+                    break;
+                }
+
+                if (reverseDirection) {
+                    --i;
+                } else {
+                    ++i;
+                }
+            }
+        }
+
+        return flag;
+    }
+
     protected void addPlayerInventory(int xInventory, int yInventory) {
         int id = 0;
 

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerConstructor.java

@@ -1,18 +1,18 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterType;
 import com.raoulvdberge.refinedstorage.tile.TileConstructor;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerConstructor extends ContainerBase {
     public ContainerConstructor(TileConstructor constructor, EntityPlayer player) {
         super(constructor, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(constructor.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(constructor.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         addSlotToContainer(new SlotFilterType(constructor, 0, 80, 20));

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerCrafter.java

@@ -1,21 +1,21 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.tile.TileCrafter;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerCrafter extends ContainerBase {
     public ContainerCrafter(TileCrafter crafter, EntityPlayer player) {
         super(crafter, player);
 
         for (int i = 0; i < 9; ++i) {
-            addSlotToContainer(new SlotItemHandler(crafter.getPatternItems(), i, 8 + (18 * i), 20));
+            addSlotToContainer(new SlotBase(crafter.getPatternItems(), i, 8 + (18 * i), 20));
         }
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(crafter.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(crafter.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         addPlayerInventory(8, 55);

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerDestructor.java

@@ -1,18 +1,18 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterType;
 import com.raoulvdberge.refinedstorage.tile.TileDestructor;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerDestructor extends ContainerBase {
     public ContainerDestructor(TileDestructor destructor, EntityPlayer player) {
         super(destructor, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(destructor.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(destructor.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         for (int i = 0; i < 9; ++i) {

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerDiskDrive.java

@@ -1,11 +1,11 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterType;
 import com.raoulvdberge.refinedstorage.tile.TileDiskDrive;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerDiskDrive extends ContainerBase {
     public ContainerDiskDrive(TileDiskDrive drive, EntityPlayer player) {
@@ -15,7 +15,7 @@ public class ContainerDiskDrive extends ContainerBase {
         int y = 54;
 
         for (int i = 0; i < 8; ++i) {
-            addSlotToContainer(new SlotItemHandler(drive.getDisks(), i, x + ((i % 2) * 18), y + Math.floorDiv(i, 2) * 18));
+            addSlotToContainer(new SlotBase(drive.getDisks(), i, x + ((i % 2) * 18), y + Math.floorDiv(i, 2) * 18));
         }
 
         for (int i = 0; i < 9; ++i) {

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerDiskManipulator.java

@@ -1,26 +1,26 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterType;
 import com.raoulvdberge.refinedstorage.tile.TileDiskManipulator;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerDiskManipulator extends ContainerBase {
     public ContainerDiskManipulator(TileDiskManipulator manipulator, EntityPlayer player) {
         super(manipulator, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(manipulator.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(manipulator.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         for (int i = 0; i < 3; ++i) {
-            addSlotToContainer(new SlotItemHandler(manipulator.getInputDisks(), i, 44, 57 + (i * 18)));
+            addSlotToContainer(new SlotBase(manipulator.getInputDisks(), i, 44, 57 + (i * 18)));
         }
 
         for (int i = 0; i < 3; ++i) {
-            addSlotToContainer(new SlotItemHandler(manipulator.getOutputDisks(), i, 116, 57 + (i * 18)));
+            addSlotToContainer(new SlotBase(manipulator.getOutputDisks(), i, 116, 57 + (i * 18)));
         }
 
         for (int i = 0; i < 9; ++i) {

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerExporter.java

@@ -1,18 +1,18 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterType;
 import com.raoulvdberge.refinedstorage.tile.TileExporter;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerExporter extends ContainerBase {
     public ContainerExporter(TileExporter exporter, EntityPlayer player) {
         super(exporter, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(exporter.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(exporter.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         for (int i = 0; i < 9; ++i) {

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerFluidInterface.java

@@ -1,21 +1,21 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterFluid;
 import com.raoulvdberge.refinedstorage.tile.TileFluidInterface;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerFluidInterface extends ContainerBase {
     public ContainerFluidInterface(TileFluidInterface fluidInterface, EntityPlayer player) {
         super(fluidInterface, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(fluidInterface.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(fluidInterface.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
-        addSlotToContainer(new SlotItemHandler(fluidInterface.getIn(), 0, 44, 32));
+        addSlotToContainer(new SlotBase(fluidInterface.getIn(), 0, 44, 32));
         addSlotToContainer(new SlotFilterFluid(!fluidInterface.getWorld().isRemote, fluidInterface.getOut(), 0, 116, 32));
 
         addPlayerInventory(8, 122);

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerGrid.java

@@ -12,7 +12,6 @@ import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.inventory.IContainerListener;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerGrid extends ContainerBase {
     private IGrid grid;
@@ -60,13 +59,13 @@ public class ContainerGrid extends ContainerBase {
 
             addSlotToContainer(patternResultSlot = new SlotDisabled(((TileGrid) grid).getResult(), 0, 112 + 4, 110 + 4));
 
-            addSlotToContainer(new SlotItemHandler(((TileGrid) grid).getPatterns(), 0, 152, 96));
+            addSlotToContainer(new SlotBase(((TileGrid) grid).getPatterns(), 0, 152, 96));
             addSlotToContainer(new SlotOutput(((TileGrid) grid).getPatterns(), 1, 152, 132));
         }
 
         if (grid.getType() != EnumGridType.FLUID) {
             for (int i = 0; i < 4; ++i) {
-                addSlotToContainer(new SlotItemHandler(grid.getFilter(), i, 204, 6 + (18 * i)));
+                addSlotToContainer(new SlotBase(grid.getFilter(), i, 204, 6 + (18 * i)));
             }
         }
     }

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerImporter.java

@@ -1,18 +1,18 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilterType;
 import com.raoulvdberge.refinedstorage.tile.TileImporter;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerImporter extends ContainerBase {
     public ContainerImporter(TileImporter importer, EntityPlayer player) {
         super(importer, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(importer.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(importer.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         for (int i = 0; i < 9; ++i) {

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerInterface.java

@@ -1,19 +1,19 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilter;
 import com.raoulvdberge.refinedstorage.container.slot.SlotOutput;
 import com.raoulvdberge.refinedstorage.tile.TileInterface;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerInterface extends ContainerBase {
     public ContainerInterface(TileInterface tile, EntityPlayer player) {
         super(tile, player);
 
         for (int i = 0; i < 9; ++i) {
-            addSlotToContainer(new SlotItemHandler(tile.getImportItems(), i, 8 + (18 * i), 20));
+            addSlotToContainer(new SlotBase(tile.getImportItems(), i, 8 + (18 * i), 20));
         }
 
         for (int i = 0; i < 9; ++i) {
@@ -25,7 +25,7 @@ public class ContainerInterface extends ContainerBase {
         }
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(tile.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(tile.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         addPlayerInventory(8, 134);

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerNetworkTransmitter.java

@@ -1,18 +1,18 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.tile.TileNetworkTransmitter;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerNetworkTransmitter extends ContainerBase {
     public ContainerNetworkTransmitter(TileNetworkTransmitter networkTransmitter, EntityPlayer player) {
         super(networkTransmitter, player);
 
-        addSlotToContainer(new SlotItemHandler(networkTransmitter.getNetworkCard(), 0, 8, 20));
+        addSlotToContainer(new SlotBase(networkTransmitter.getNetworkCard(), 0, 8, 20));
 
-        addSlotToContainer(new SlotItemHandler(networkTransmitter.getUpgrades(), 0, 187, 6));
+        addSlotToContainer(new SlotBase(networkTransmitter.getUpgrades(), 0, 187, 6));
 
         addPlayerInventory(8, 55);
     }

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerProcessingPatternEncoder.java

@@ -1,12 +1,12 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotFilter;
 import com.raoulvdberge.refinedstorage.container.slot.SlotOutput;
 import com.raoulvdberge.refinedstorage.tile.TileProcessingPatternEncoder;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 import java.util.Collection;
 
@@ -14,7 +14,7 @@ public class ContainerProcessingPatternEncoder extends ContainerBase {
     public ContainerProcessingPatternEncoder(TileProcessingPatternEncoder encoder, EntityPlayer player) {
         super(encoder, player);
 
-        addSlotToContainer(new SlotItemHandler(encoder.getPatterns(), 0, 152, 18));
+        addSlotToContainer(new SlotBase(encoder.getPatterns(), 0, 152, 18));
         addSlotToContainer(new SlotOutput(encoder.getPatterns(), 1, 152, 58));
 
         int ox = 8;

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerSolderer.java

@@ -1,12 +1,12 @@
 package com.raoulvdberge.refinedstorage.container;
 
 import com.raoulvdberge.refinedstorage.RSItems;
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.container.slot.SlotOutput;
 import com.raoulvdberge.refinedstorage.tile.TileSolderer;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerSolderer extends ContainerBase {
     public ContainerSolderer(TileSolderer solderer, EntityPlayer player) {
@@ -16,7 +16,7 @@ public class ContainerSolderer extends ContainerBase {
         int y = 20;
 
         for (int i = 0; i < 3; ++i) {
-            addSlotToContainer(new SlotItemHandler(solderer.getItems(), i, x, y));
+            addSlotToContainer(new SlotBase(solderer.getItems(), i, x, y));
 
             y += 18;
         }
@@ -24,7 +24,7 @@ public class ContainerSolderer extends ContainerBase {
         addSlotToContainer(new SlotOutput(solderer.getResult(), 0, 127, 38));
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(solderer.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(solderer.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         addPlayerInventory(8, 89);

src/main/java/com/raoulvdberge/refinedstorage/container/ContainerWirelessTransmitter.java

@@ -1,17 +1,17 @@
 package com.raoulvdberge.refinedstorage.container;
 
+import com.raoulvdberge.refinedstorage.container.slot.SlotBase;
 import com.raoulvdberge.refinedstorage.tile.TileWirelessTransmitter;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.SlotItemHandler;
 
 public class ContainerWirelessTransmitter extends ContainerBase {
     public ContainerWirelessTransmitter(TileWirelessTransmitter wirelessTransmitter, EntityPlayer player) {
         super(wirelessTransmitter, player);
 
         for (int i = 0; i < 4; ++i) {
-            addSlotToContainer(new SlotItemHandler(wirelessTransmitter.getUpgrades(), i, 187, 6 + (i * 18)));
+            addSlotToContainer(new SlotBase(wirelessTransmitter.getUpgrades(), i, 187, 6 + (i * 18)));
         }
 
         addPlayerInventory(8, 55);
@@ -23,7 +23,7 @@ public class ContainerWirelessTransmitter extends ContainerBase {
 
         Slot slot = getSlot(index);
 
-        if (slot != null && slot.getHasStack()) {
+        if (slot.getHasStack()) {
             stack = slot.getStack();
 
             if (index < 4) {

src/main/java/com/raoulvdberge/refinedstorage/container/slot/SlotBase.java

@@ -0,0 +1,16 @@
+package com.raoulvdberge.refinedstorage.container.slot;
+
+import net.minecraftforge.items.IItemHandler;
+import net.minecraftforge.items.SlotItemHandler;
+
+// @todo: Forge issue #3497
+public class SlotBase extends SlotItemHandler {
+    public SlotBase(IItemHandler itemHandler, int index, int xPosition, int yPosition) {
+        super(itemHandler, index, xPosition, yPosition);
+    }
+
+    @Override
+    public int getSlotStackLimit() {
+        return getItemHandler().getSlotLimit(getSlotIndex());
+    }
+}

src/main/java/com/raoulvdberge/refinedstorage/container/slot/SlotFilter.java

@@ -9,12 +9,11 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockAccess;
 import net.minecraftforge.common.IPlantable;
 import net.minecraftforge.items.IItemHandler;
-import net.minecraftforge.items.SlotItemHandler;
 
 import javax.annotation.Nonnull;
 import java.lang.reflect.Field;
 
-public class SlotFilter extends SlotItemHandler {
+public class SlotFilter extends SlotBase {
     public static final int FILTER_ALLOW_SIZE = 1;
     public static final int FILTER_ALLOW_BLOCKS = 2;
 

src/main/java/com/raoulvdberge/refinedstorage/container/slot/SlotOutput.java

@@ -2,11 +2,10 @@ package com.raoulvdberge.refinedstorage.container.slot;
 
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.items.IItemHandler;
-import net.minecraftforge.items.SlotItemHandler;
 
 import javax.annotation.Nonnull;
 
-public class SlotOutput extends SlotItemHandler {
+public class SlotOutput extends SlotBase {
     public SlotOutput(IItemHandler inventory, int id, int x, int y) {
         super(inventory, id, x, y);
     }

src/main/java/com/raoulvdberge/refinedstorage/inventory/ItemHandlerUpgrade.java

@@ -65,6 +65,11 @@ public class ItemHandlerUpgrade extends ItemHandlerBasic {
         return 0;
     }
 
+    @Override
+    public int getSlotLimit(int slot) {
+        return 1;
+    }
+
     public int getItemInteractCount() {
         return hasUpgrade(ItemUpgrade.TYPE_STACK) ? 64 : 1;
     }

src/main/java/com/raoulvdberge/refinedstorage/item/ItemUpgrade.java

@@ -34,7 +34,6 @@ public class ItemUpgrade extends ItemBase {
 
         setHasSubtypes(true);
         setMaxDamage(0);
-        setMaxStackSize(1);
     }
 
     @Override