Changed to Null ItemStack instead of null.

gradle.properties

@@ -1,4 +1,4 @@
-aeversion=rv4
+aeversion=rv5
 aechannel=alpha
 aebuild=0
 aegroup=appeng
@@ -9,7 +9,7 @@ aebasename=appliedenergistics2
 #########################################################
 minecraft_version=1.11
 mcp_mappings=snapshot_20161206
-forge_version=13.19.1.2188
+forge_version=13.19.1.2189
 
 #########################################################
 # Installable                                           #

src/main/java/appeng/block/networking/BlockCableBus.java

@@ -237,7 +237,7 @@ public class BlockCableBus extends AEBaseTileBlock
 			return sp.facade.getItemStack();
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/client/gui/Size1Slot.java

@@ -40,7 +40,7 @@ class Size1Slot extends Slot
 			return modifiedStack;
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/client/me/SlotDisconnected.java

@@ -91,7 +91,7 @@ public class SlotDisconnected extends AppEngSlot
 	@Override
 	public ItemStack decrStackSize( final int par1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/container/AEBaseContainer.java

@@ -455,7 +455,7 @@ public abstract class AEBaseContainer extends Container
 	{
 		if( Platform.isClient() )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		boolean hasMETiles = false;
@@ -470,14 +470,14 @@ public abstract class AEBaseContainer extends Container
 
 		if( hasMETiles && Platform.isClient() )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final AppEngSlot clickSlot = (AppEngSlot) this.inventorySlots.get( idx ); // require AE SLots!
 
 		if( clickSlot instanceof SlotDisabled || clickSlot instanceof SlotInaccessible )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 		if( clickSlot != null && clickSlot.getHasStack() )
 		{
@@ -485,7 +485,7 @@ public abstract class AEBaseContainer extends Container
 
 			if( tis == null )
 			{
-				return null;
+				return ItemStack.EMPTY;
 			}
 
 			final List<Slot> selectedSlots = new ArrayList<Slot>();
@@ -602,7 +602,7 @@ public abstract class AEBaseContainer extends Container
 
 									this.updateSlot( clickSlot );
 									this.updateSlot( d );
-									return null;
+									return ItemStack.EMPTY;
 								}
 								else
 								{
@@ -656,7 +656,7 @@ public abstract class AEBaseContainer extends Container
 
 									this.updateSlot( clickSlot );
 									this.updateSlot( d );
-									return null;
+									return ItemStack.EMPTY;
 								}
 								else
 								{
@@ -692,7 +692,7 @@ public abstract class AEBaseContainer extends Container
 
 								this.updateSlot( clickSlot );
 								this.updateSlot( d );
-								return null;
+								return ItemStack.EMPTY;
 							}
 							else
 							{
@@ -707,7 +707,7 @@ public abstract class AEBaseContainer extends Container
 		}
 
 		this.updateSlot( clickSlot );
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/container/implementations/ContainerQuartzKnife.java

@@ -128,9 +128,9 @@ public class ContainerQuartzKnife extends AEBaseContainer implements IAEAppEngIn
 	public ItemStack getStackInSlot( final int var1 )
 	{
 		final ItemStack input = this.inSlot.getStackInSlot( 0 );
-		if( input == null )
+		if( input == ItemStack.EMPTY )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		if( SlotRestrictedInput.isMetalIngot( input ) )
@@ -147,7 +147,7 @@ public class ContainerQuartzKnife extends AEBaseContainer implements IAEAppEngIn
 			}
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override
@@ -161,7 +161,7 @@ public class ContainerQuartzKnife extends AEBaseContainer implements IAEAppEngIn
 				return is;
 			}
 		}
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	private boolean makePlate()
@@ -185,7 +185,7 @@ public class ContainerQuartzKnife extends AEBaseContainer implements IAEAppEngIn
 	@Override
 	public ItemStack removeStackFromSlot( final int var1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/container/slot/AppEngSlot.java

@@ -85,12 +85,12 @@ public class AppEngSlot extends Slot
 	{
 		if( !this.isEnabled() )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		if( this.inventory.getSizeInventory() <= this.getSlotIndex() )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		if( this.isDisplay() )

src/main/java/appeng/container/slot/NullSlot.java

@@ -54,7 +54,7 @@ public class NullSlot extends Slot
 	@Override
 	public ItemStack getStack()
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override
@@ -78,7 +78,7 @@ public class NullSlot extends Slot
 	@Override
 	public ItemStack decrStackSize( final int par1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/container/slot/SlotCraftingTerm.java

@@ -200,7 +200,7 @@ public class SlotCraftingTerm extends AppEngCraftingSlot
 							return request;
 						}
 					}
-					return null;
+					return ItemStack.EMPTY;
 				}
 
 				is = r.getCraftingResult( ic );
@@ -231,7 +231,7 @@ public class SlotCraftingTerm extends AppEngCraftingSlot
 			return is;
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	private boolean preCraft( final EntityPlayer p, final IMEMonitor<IAEItemStack> inv, final ItemStack[] set, final ItemStack result )

src/main/java/appeng/container/slot/SlotFake.java

@@ -41,7 +41,7 @@ public class SlotFake extends AppEngSlot
 	@Override
 	public ItemStack decrStackSize( final int par1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/core/features/ColoredItemDefinition.java

@@ -70,7 +70,7 @@ public final class ColoredItemDefinition implements AEColoredItemDefinition
 
 		if( is == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		return is.stack( stackSize );

src/main/java/appeng/core/features/registries/P2PTunnelRegistry.java

@@ -162,7 +162,7 @@ public final class P2PTunnelRegistry implements IP2PTunnelRegistry
 
 		if( item == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final ItemStack myItemStack = new ItemStack( item, 1, meta );

src/main/java/appeng/core/features/registries/grinder/GrinderRecipeManager.java

@@ -233,7 +233,7 @@ public final class GrinderRecipeManager implements IGrinderRegistry, IOreListene
 		{
 			return is.copy();
 		}
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	private int getDustToOreRatio( final String name )

src/main/java/appeng/debug/TileItemGen.java

@@ -93,7 +93,7 @@ public class TileItemGen extends AEBaseTile implements IInventory
 	@Override
 	public ItemStack removeStackFromSlot( final int i )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/helpers/PatternHelper.java

@@ -316,7 +316,7 @@ public class PatternHelper implements ICraftingPatternDetails, Comparable<Patter
 		{
 			if( !this.isValidItemForSlot( x, craftingInv.getStackInSlot( x ), w ) )
 			{
-				return null;
+				return ItemStack.EMPTY;
 			}
 		}
 
@@ -325,7 +325,7 @@ public class PatternHelper implements ICraftingPatternDetails, Comparable<Patter
 			return this.outputs[0].getItemStack();
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	private TestStatus getStatus( final int slotIndex, final ItemStack i )

src/main/java/appeng/items/materials/MaterialType.java

@@ -144,7 +144,7 @@ public enum MaterialType
 		this( metaValue, modelName, features );
 		this.droppedEntity = c;
 
-		EntityRegistry.registerModEntity( new ResourceLocation( this.droppedEntity.getName() ), this.droppedEntity, this.droppedEntity.getSimpleName(),
+		EntityRegistry.registerModEntity( new ResourceLocation( this.droppedEntity.getName() ), this.droppedEntity, "appliedenergistics2:" + this.droppedEntity.getSimpleName(),
 				EntityIds.get( this.droppedEntity ), AppEng.instance(), 16, 4,
 				true );
 	}
@@ -154,7 +154,7 @@ public enum MaterialType
 		this( metaValue, modelName, features );
 		this.oreName = oreDictionary;
 		this.droppedEntity = c;
-		EntityRegistry.registerModEntity( new ResourceLocation( this.droppedEntity.getName() ), this.droppedEntity, this.droppedEntity.getSimpleName(),
+		EntityRegistry.registerModEntity( new ResourceLocation( this.droppedEntity.getName() ), this.droppedEntity, "appliedenergistics2:" + this.droppedEntity.getSimpleName(),
 				EntityIds.get( this.droppedEntity ), AppEng.instance(), 16, 4,
 				true );
 	}

src/main/java/appeng/items/misc/ItemCrystalSeed.java

@@ -64,7 +64,7 @@ public class ItemCrystalSeed extends AEBaseItem implements IGrowableCrystal
 	{
 		this.setHasSubtypes( true );
 
-		EntityRegistry.registerModEntity( new ResourceLocation( EntityGrowingCrystal.class.getName() ), EntityGrowingCrystal.class, EntityGrowingCrystal.class.getSimpleName(), EntityIds.get( EntityGrowingCrystal.class ), AppEng.instance(), 16, 4, true );
+		EntityRegistry.registerModEntity( new ResourceLocation( EntityGrowingCrystal.class.getName() ), EntityGrowingCrystal.class, "appliedenergistics2:" + EntityGrowingCrystal.class.getSimpleName(), EntityIds.get( EntityGrowingCrystal.class ), AppEng.instance(), 16, 4, true );
 	}
 
 	@Nullable
@@ -139,7 +139,7 @@ public class ItemCrystalSeed extends AEBaseItem implements IGrowableCrystal
 		}
 		if( newDamage > FINAL_STAGE )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		this.setProgress( is, newDamage );

src/main/java/appeng/items/misc/ItemEncodedPattern.java

@@ -175,14 +175,14 @@ public class ItemEncodedPattern extends AEBaseItem implements ICraftingPatternIt
 		final World w = AppEng.proxy.getWorld();
 		if( w == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final ICraftingPatternDetails details = this.getPatternForItem( item, w );
 
 		if( details == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		SIMPLE_CACHE.put( item, out = details.getCondensedOutputs()[0].getItemStack() );

src/main/java/appeng/items/parts/ItemFacade.java

@@ -155,13 +155,13 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 	{
 		if( l == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final Block b = Block.getBlockFromItem( l.getItem() );
 		if( b == null || l.hasTagCompound() )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final int metadata = l.getItem().getMetadata( l.getItemDamage() );
@@ -180,7 +180,7 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 		catch( Exception e )
 		{
 			AELog.debug( e, "Cannot create a facade for " + b.getRegistryName() );
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final boolean defaultValue = ( b.isFullyOpaque( blockState ) && hasSimpleModel( blockState ) && !b.getTickRandomly() && !hasTile && !disableOre ) || enableGlass;
@@ -198,7 +198,7 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 			is.setTagCompound( data );
 			return is;
 		}
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override
@@ -220,7 +220,7 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 
 		if( nbt == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		ResourceLocation itemId;
@@ -232,12 +232,12 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 			int[] data = nbt.getIntArray( "x" );
 			if( data.length != 2 )
 			{
-				return null;
+				return ItemStack.EMPTY;
 			}
 
 			Item item = Item.REGISTRY.getObjectById( data[0] );
 			if ( item == null ) {
-				return null;
+				return ItemStack.EMPTY;
 			}
 
 			itemId = item.getRegistryName();
@@ -252,7 +252,7 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 
 		if( baseItem == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		return new ItemStack( baseItem, 1, itemDamage );
@@ -315,7 +315,7 @@ public class ItemFacade extends AEBaseItem implements IFacadeItem, IAlphaPassIte
 		// Convert back to a registry name...
 		Item item = Item.REGISTRY.getObjectById( ids[0] );
 		if ( item == null ) {
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final NBTTagCompound facadeTag = new NBTTagCompound();

src/main/java/appeng/items/tools/powered/ToolColorApplicator.java

@@ -288,7 +288,7 @@ public class ToolColorApplicator extends AEBasePoweredItem implements IStorageCe
 
 				if( list.size() <= 0 )
 				{
-					return null;
+					return ItemStack.EMPTY;
 				}
 
 				IAEItemStack where = list.getFirst();

src/main/java/appeng/items/tools/powered/powersink/AERootPoweredItem.java

@@ -66,7 +66,8 @@ public abstract class AERootPoweredItem extends AEBaseItem implements IAEItemPow
 
 		final double percent = internalCurrentPower / internalMaxPower;
 
-		lines.add( GuiText.StoredEnergy.getLocal() + ':' + MessageFormat.format( " {0,number,#} ", internalCurrentPower ) + Platform.gui_localize( PowerUnits.AE.unlocalizedName ) + " - " + MessageFormat.format( " {0,number,#.##%} ", percent ) );
+		lines.add( GuiText.StoredEnergy.getLocal() + ':' + MessageFormat.format( " {0,number,#} ", internalCurrentPower ) + Platform
+				.gui_localize( PowerUnits.AE.unlocalizedName ) + " - " + MessageFormat.format( " {0,number,#.##%} ", percent ) );
 	}
 
 	@Override

src/main/java/appeng/items/tools/powered/powersink/PoweredItemCapabilities.java

@@ -64,9 +64,7 @@ class PoweredItemCapabilities implements ICapabilityProvider, IEnergyStorage
 	@Override
 	public boolean hasCapability( Capability<?> capability, @Nullable EnumFacing facing )
 	{
-		return capability == CapabilityEnergy.ENERGY
-				|| capability == Capabilities.TESLA_CONSUMER
-				|| capability == Capabilities.TESLA_HOLDER;
+		return capability == CapabilityEnergy.ENERGY || capability == Capabilities.TESLA_CONSUMER || capability == Capabilities.TESLA_HOLDER;
 	}
 
 	@SuppressWarnings( "unchecked" )

src/main/java/appeng/parts/p2p/PartP2PItems.java

@@ -281,7 +281,7 @@ public class PartP2PItems extends PartP2PTunnel<PartP2PItems> implements /* IPip
 	@Override
 	public ItemStack removeStackFromSlot( final int i )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/recipes/game/DisassembleRecipe.java

@@ -171,7 +171,7 @@ public final class DisassembleRecipe implements IRecipe
 	@Override
 	public ItemStack getRecipeOutput() // no default output..
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/recipes/game/FacadeRecipe.java

@@ -88,7 +88,7 @@ public final class FacadeRecipe implements IRecipe
 	@Override
 	public ItemStack getRecipeOutput() // no default output..
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/tile/AEBaseInvTile.java

@@ -111,7 +111,7 @@ public abstract class AEBaseInvTile extends AEBaseTile implements ISidedInventor
 	@Override
 	public ItemStack removeStackFromSlot( final int i )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/tile/AEBaseTile.java

@@ -110,7 +110,7 @@ public class AEBaseTile extends TileEntity implements IOrientable, ICommonTile,
 		final IStackSrc src = ITEM_STACKS.get( obj.getClass() );
 		if( src == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 		return src.stack( 1 );
 	}

src/main/java/appeng/tile/inventory/AppEngInternalAEInventory.java

@@ -174,13 +174,13 @@ public class AppEngInternalAEInventory implements IInventory, Iterable<ItemStack
 			return ns;
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override
 	public ItemStack removeStackFromSlot( final int var1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/tile/inventory/AppEngInternalInventory.java

@@ -99,7 +99,7 @@ public class AppEngInternalInventory implements IInventory, Iterable<ItemStack>
 			return ns;
 		}
 
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	protected boolean eventsEnabled()
@@ -110,7 +110,7 @@ public class AppEngInternalInventory implements IInventory, Iterable<ItemStack>
 	@Override
 	public ItemStack removeStackFromSlot( final int var1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/tile/inventory/AppEngNullInventory.java

@@ -46,19 +46,19 @@ public class AppEngNullInventory implements IInventory
 	@Override
 	public ItemStack getStackInSlot( final int var1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override
 	public ItemStack decrStackSize( final int slot, final int qty )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override
 	public ItemStack removeStackFromSlot( final int var1 )
 	{
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/tile/misc/TileCondenser.java

@@ -172,7 +172,7 @@ public class TileCondenser extends AEBaseInvTile implements IConfigManagerHost,
 
 			case TRASH:
 			default:
-				return null;
+				return ItemStack.EMPTY;
 		}
 	}
 
@@ -314,7 +314,7 @@ public class TileCondenser extends AEBaseInvTile implements IConfigManagerHost,
 		public ItemStack getStackInSlot( int slot )
 		{
 			// The void slot never has any content
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		@Override
@@ -328,13 +328,13 @@ public class TileCondenser extends AEBaseInvTile implements IConfigManagerHost,
 			{
 				addPower( stack.getCount() );
 			}
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		@Override
 		public ItemStack extractItem( int slot, int amount, boolean simulate )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		@Override

src/main/java/appeng/tile/misc/TileInscriber.java

@@ -672,7 +672,7 @@ public class TileInscriber extends AENetworkPowerTile implements IGridTickable,
 			{
 				return inv.getStackInSlot( extractSlot );
 			}
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		@Override
@@ -708,7 +708,7 @@ public class TileInscriber extends AENetworkPowerTile implements IGridTickable,
 
 			if( slot != validExtractSlot || amount == 0 )
 			{
-				return null;
+				return ItemStack.EMPTY;
 			}
 
 			AdaptorIInventory adapter = new AdaptorIInventory( new WrapperInventoryRange( TileInscriber.this, extractSlot, 1, true ) );

src/main/java/appeng/tile/powersink/TeslaEnergyAdapter.java

@@ -1,3 +1,21 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2013 - 2014, AlgorithmX2, All rights reserved.
+ *
+ * Applied Energistics 2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Applied Energistics 2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
+ */
+
 package appeng.tile.powersink;
 
 

src/main/java/appeng/tile/storage/TileChest.java

@@ -700,7 +700,7 @@ public class TileChest extends AENetworkPowerTile implements IMEChest, ITerminal
 		{
 			return this.storageType;
 		}
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	@Override

src/main/java/appeng/util/Platform.java

@@ -1626,7 +1626,7 @@ public class Platform
 		{
 			if( providedTemplate == null )
 			{
-				return null;
+				return ItemStack.EMPTY;
 			}
 
 			final AEItemStack ae_req = AEItemStack.create( providedTemplate );
@@ -1679,7 +1679,7 @@ public class Platform
 				}
 			}
 		}
-		return null;
+		return ItemStack.EMPTY;
 	}
 
 	public static ItemStack cloneItemStack( final ItemStack a )
@@ -1691,7 +1691,7 @@ public class Platform
 	{
 		if( stackInSlot == null )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final Item i = stackInSlot.getItem();
@@ -1702,13 +1702,13 @@ public class Platform
 				stackInSlot.setCount( stackInSlot.getCount() - 1 );
 				return stackInSlot;
 			}
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		ItemStack ci = i.getContainerItem( stackInSlot.copy() );
 		if( ci != null && ci.isItemStackDamageable() && ci.getItemDamage() == ci.getMaxDamage() )
 		{
-			ci = null;
+			ci = ItemStack.EMPTY;
 		}
 
 		return ci;

src/main/java/appeng/util/inv/AdaptorIInventory.java

@@ -264,7 +264,7 @@ public class AdaptorIInventory extends InventoryAdaptor
 	{
 		if( itemsToAdd == null || itemsToAdd.getCount() == 0 )
 		{
-			return null;
+			return ItemStack.EMPTY;
 		}
 
 		final ItemStack left = itemsToAdd.copy();
@@ -292,7 +292,7 @@ public class AdaptorIInventory extends InventoryAdaptor
 
 					if( left.getCount() <= 0 )
 					{
-						return null;
+						return ItemStack.EMPTY;
 					}
 				}
 				else if( Platform.itemComparisons().isSameItem( is, left ) && is.getCount() < perOperationLimit )
@@ -310,7 +310,7 @@ public class AdaptorIInventory extends InventoryAdaptor
 					left.grow( -used );
 					if( left.getCount() <= 0 )
 					{
-						return null;
+						return ItemStack.EMPTY;
 					}
 				}
 			}