fix advancements

src/api/java/appeng/api/config/FuzzyMode.java

@@ -23,18 +23,38 @@
 
 package appeng.api.config;
 
+public enum FuzzyMode {
+    /**
+     * Matches any item from undamaged to including 0% durability, but not negative durability (where item damage
+     * exceeds maxdamage).
+     */
+    IGNORE_ALL(-1),
+    /**
+     * Matches items that have less than 100% durability (that is, at least 1 damage point) if a damaged item is used as
+     * the filter, or undamaged items otherwise.
+     */
+    PERCENT_99(0),
+    /**
+     * If an item with less than 75% durability is used as the filter, items with less than 75% durability are matched.
+     * Otherwise items with 75% durability or more are matched.
+     */
+    PERCENT_75(25),
+    /**
+     * If an item with less than 50% durability is used as the filter, items with less than 50% durability are matched.
+     * Otherwise items with 50% durability or more are matched.
+     */
+    PERCENT_50(50),
+    /**
+     * If an item with less than 25% durability is used as the filter, items with less than 50% durability are matched.
+     * Otherwise items with 25% durability or more are matched.
+     */
+    PERCENT_25(75);
 
-public enum FuzzyMode
-{
-	// Note that percentage damaged, is the inverse of percentage durability.
-	IGNORE_ALL( -1 ),
-	PERCENT_99( 0 ),
-	PERCENT_75( 25 ),
-	PERCENT_50( 50 ),
-	PERCENT_25( 75 );
-
-	public final float breakPoint;
-	public final float percentage;
+    public final float breakPoint;
+    /**
+     * Note this is percentage "damaged". It's the inverse of percentage durability.
+     */
+    public final float percentage;
 
 	FuzzyMode( final float p )
 	{

src/api/java/appeng/api/storage/data/IAEItemStack.java

@@ -112,4 +112,13 @@ public interface IAEItemStack extends IAEStack<IAEItemStack>
 	 * @return definition stack
 	 */
 	ItemStack getDefinition();
+
+	/**
+	 * Compare this AE item stack to another item stack, but ignores the amount. It checks the item type, NBT and damage
+	 * values.
+	 *
+	 * @param is An item stack
+	 */
+	boolean equals(ItemStack is);
+
 }

src/api/java/appeng/api/storage/data/IAEStack.java

@@ -23,27 +23,24 @@
 
 package appeng.api.storage.data;
 
-
 import java.io.IOException;
 
 import io.netty.buffer.ByteBuf;
-
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.network.PacketBuffer;
 
 import appeng.api.config.FuzzyMode;
 import appeng.api.storage.IStorageChannel;
 
-
-public interface IAEStack<T extends IAEStack<T>>
-{
+public interface IAEStack<T extends IAEStack<T>> {
 
 	/**
 	 * add two stacks together
 	 *
 	 * @param is added item
 	 */
-	void add( T is );
+	void add(T is);
 
 	/**
 	 * number of items in the stack.
@@ -57,7 +54,7 @@ public interface IAEStack<T extends IAEStack<T>>
 	 *
 	 * @param stackSize , ItemStack.stackSize = N
 	 */
-	T setStackSize( long stackSize );
+	T setStackSize(long stackSize);
 
 	/**
 	 * Same as getStackSize, but for requestable items. ( LP )
@@ -71,7 +68,7 @@ public interface IAEStack<T extends IAEStack<T>>
 	 *
 	 * @return basically itemStack.stackSize = N but for setStackSize items.
 	 */
-	T setCountRequestable( long countRequestable );
+	T setCountRequestable(long countRequestable);
 
 	/**
 	 * true, if the item can be crafted.
@@ -85,7 +82,7 @@ public interface IAEStack<T extends IAEStack<T>>
 	 *
 	 * @param isCraftable can item be crafted
 	 */
-	T setCraftable( boolean isCraftable );
+	T setCraftable(boolean isCraftable);
 
 	/**
 	 * clears, requestable, craftable, and stack sizes.
@@ -104,33 +101,33 @@ public interface IAEStack<T extends IAEStack<T>>
 	 *
 	 * @param i additional stack size
 	 */
-	void incStackSize( long i );
+	void incStackSize(long i);
 
 	/**
 	 * removes some from the stack size.
 	 */
-	void decStackSize( long i );
+	void decStackSize(long i);
 
 	/**
 	 * adds items to the requestable
 	 *
 	 * @param i increased amount of requested items
 	 */
-	void incCountRequestable( long i );
+	void incCountRequestable(long i);
 
 	/**
 	 * removes items from the requestable
 	 *
 	 * @param i decreased amount of requested items
 	 */
-	void decCountRequestable( long i );
+	void decCountRequestable(long i);
 
 	/**
-	 * write to a NBTTagCompound.
+	 * write to a CompoundNBT.
 	 *
 	 * @param i to be written data
 	 */
-	void writeToNBT( NBTTagCompound i );
+	void writeToNBT( NBTTagCompound i);
 
 	/**
 	 * Compare stacks using precise logic.
@@ -146,17 +143,18 @@ public interface IAEStack<T extends IAEStack<T>>
 	 * @return true if they are the same.
 	 */
 	@Override
-	boolean equals( Object obj );
+	boolean equals(Object obj);
 
 	/**
-	 * Compare the same subtype of {@link IAEStack} with another using a fuzzy comparison.
+	 * Compare the same subtype of {@link IAEStack} with another using a fuzzy
+	 * comparison.
 	 *
 	 * @param other The stack to compare.
-	 * @param mode Which {@link FuzzyMode} should be used.
+	 * @param mode  Which {@link FuzzyMode} should be used.
 	 *
 	 * @return true if two stacks are equal based on AE Fuzzy Comparison.
 	 */
-	boolean fuzzyComparison( T other, FuzzyMode mode );
+	boolean fuzzyComparison(T other, FuzzyMode mode);
 
 	/**
 	 * Slower for disk saving, but smaller/more efficient for packets.
@@ -165,7 +163,7 @@ public interface IAEStack<T extends IAEStack<T>>
 	 *
 	 * @throws IOException
 	 */
-	void writeToPacket( ByteBuf data ) throws IOException;
+	void writeToPacket( ByteBuf data) throws IOException;
 
 	/**
 	 * Clone the Item / Fluid Stack
@@ -182,17 +180,7 @@ public interface IAEStack<T extends IAEStack<T>>
 	T empty();
 
 	/**
-	 * @return true if the stack is a {@link IAEItemStack}
-	 */
-	boolean isItem();
-
-	/**
-	 * @return true if the stack is a {@link IAEFluidStack}
-	 */
-	boolean isFluid();
-
-	/**
-	 * @return ITEM or FLUID
+	 * @return The {@link IStorageChannel} backing this stack.
 	 */
 	IStorageChannel<T> getChannel();
 
@@ -202,4 +190,4 @@ public interface IAEStack<T extends IAEStack<T>>
 	 * @return itemstack
 	 */
 	ItemStack asItemStackRepresentation();
-}
+}

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

@@ -387,13 +387,29 @@ public abstract class AEBaseGui extends GuiContainer implements IMTModGuiContain
 			{
 				if( !itemstack.isEmpty() )
 				{
+					Set<IItemHandler> visitedInterfaces = new HashSet<>();
 					for( final Slot dr : this.drag_click )
 					{
-						if( slot.getStack().isEmpty() )
+						IItemHandler interfaceHandler = ( (SlotDisconnected) slot ).getSlot().getInventory();
+						if (visitedInterfaces.contains( interfaceHandler )) break;
+						visitedInterfaces.add( interfaceHandler );
+						boolean canInsert = true;
+						for( int s = 0; s < interfaceHandler.getSlots(); s++ )
 						{
-							InventoryAction action = InventoryAction.SPLIT_OR_PLACE_SINGLE;
-							final PacketInventoryAction p = new PacketInventoryAction( action, dr.getSlotIndex(), ( (SlotDisconnected) slot ).getSlot().getId() );
-							NetworkHandler.instance().sendToServer( p );
+							if( ItemStack.areItemStacksEqual( interfaceHandler.getStackInSlot( s ), itemstack ) )
+							{
+								canInsert = false;
+								break;
+							}
+						}
+						if( canInsert )
+						{
+							if( slot.getStack().isEmpty() )
+							{
+								InventoryAction action = InventoryAction.SPLIT_OR_PLACE_SINGLE;
+								final PacketInventoryAction p = new PacketInventoryAction( action, dr.getSlotIndex(), ( (SlotDisconnected) slot ).getSlot().getId() );
+								NetworkHandler.instance().sendToServer( p );
+							}
 						}
 					}
 				}
@@ -522,12 +538,23 @@ public abstract class AEBaseGui extends GuiContainer implements IMTModGuiContain
 				case PICKUP: // pickup / set-down.
 					if( slot.getStack().isEmpty() && !player.inventory.getItemStack().isEmpty() )
 					{
-						action = InventoryAction.SPLIT_OR_PLACE_SINGLE;
-					}
-					if( !slot.getStack().isEmpty() && player.inventory.getItemStack().getCount() <= 1 )
-					{
-						action = InventoryAction.PICKUP_OR_SET_DOWN;
+						boolean canInsert = true;
+						IItemHandler interfaceHandler = ( (SlotDisconnected) slot ).getSlot().getInventory();
+						for( int s = 0; s < interfaceHandler.getSlots(); s++ )
+						{
+							if( ItemStack.areItemStacksEqual( interfaceHandler.getStackInSlot( s ), player.inventory.getItemStack() ) )
+							{
+								canInsert = false;
+								break;
+							}
+						}
+						if( canInsert )
+						{
+							action = InventoryAction.SPLIT_OR_PLACE_SINGLE;
+						}
+						break;
 					}
+					if( !slot.getStack().isEmpty() && player.inventory.getItemStack().getCount() <= 1 ) action = InventoryAction.PICKUP_OR_SET_DOWN;
 					break;
 				case QUICK_MOVE:
 					action = ( mouseButton == 1 ) ? InventoryAction.PICKUP_SINGLE : InventoryAction.SHIFT_CLICK;

src/main/java/appeng/client/gui/implementations/GuiInterfaceTerminal.java

@@ -123,6 +123,14 @@ public class GuiInterfaceTerminal extends AEBaseGui
 		super.onGuiClosed();
 	}
 
+	@Override
+	protected boolean isPointInRegion( int rectX, int rectY, int rectWidth, int rectHeight, int pointX, int pointY )
+	{
+		if( searchFieldInputs.isMouseIn( pointX, pointY ) ) drawTooltip( pointX - guiLeft - offsetX, pointY - guiTop , "Inputs OR names" );
+		else if( searchFieldOutputs.isMouseIn( pointX, pointY ) ) drawTooltip( pointX - guiLeft - offsetX, pointY - guiTop, "Outputs OR names" );
+		return super.isPointInRegion( rectX, rectY, rectWidth, rectHeight, pointX, pointY );
+	}
+
 	@Override
 	public void drawFG( final int offsetX, final int offsetY, final int mouseX, final int mouseY )
 	{
@@ -178,10 +186,6 @@ public class GuiInterfaceTerminal extends AEBaseGui
 			}
 			offset += 18;
 		}
-
-		if( searchFieldInputs.isMouseIn( mouseX, mouseY ) ) drawTooltip( mouseX - guiLeft - offsetX, mouseY - guiTop, "Inputs OR names" );
-		else if( searchFieldOutputs.isMouseIn( mouseX, mouseY ) ) drawTooltip( mouseX - guiLeft - offsetX, mouseY - guiTop, "Outputs OR names" );
-
 	}
 
 	@Override
@@ -213,8 +217,7 @@ public class GuiInterfaceTerminal extends AEBaseGui
 		{
 			BlockPos blockPos = blockPosHashMap.get( guiButtonHashMap.get( this.selectedButton ) );
 			BlockPos blockPos2 = mc.player.getPosition();
-			int dimension = mc.world.provider.getDimension();
-			hilightBlock( blockPos, System.currentTimeMillis() + 500 * BlockPosUtils.getDistance(blockPos, blockPos2), dimension );
+			hilightBlock( blockPos, System.currentTimeMillis() + 500 * BlockPosUtils.getDistance(blockPos, blockPos2) );
 			mc.player.sendStatusMessage( new TextComponentString( "The interface is now highlighted at " + "X: " + blockPos.getX() + " Y: " + blockPos.getY() + " Z: " + blockPos.getZ() ), false );
 			mc.player.closeScreen();
 		}
@@ -373,7 +376,6 @@ public class GuiInterfaceTerminal extends AEBaseGui
 			// Shortcut to skip any filter if search term is ""/empty
 
 			boolean found = (searchFieldInputs.isEmpty() && searchFieldOutputs.isEmpty() && !partInterfaceTerminal.onlyInterfacesWithFreeSlots);
-			boolean interfaceHasFreeSlots = false;
 
 			// Search if the current inventory holds a pattern containing the search term.
 			if( !found )
@@ -386,15 +388,25 @@ public class GuiInterfaceTerminal extends AEBaseGui
 						found = ( this.itemStackMatchesSearchTerm( itemStack, searchFieldInputs, 0 ) );
 					else if( !searchFieldOutputs.isEmpty() )
 						found = ( this.itemStackMatchesSearchTerm( itemStack, searchFieldOutputs, 1 ) );
-					// If only Interfaces with empty slots should be shown, check that here
-					if(itemStack.isEmpty())
-						interfaceHasFreeSlots = true;
 					if( found )
 					{
 						break;
 					}
 				}
+			} 
+
+			// If only Interfaces with empty slots should be shown, check that here
+			boolean interfaceHasFreeSlots = false;
+			if (partInterfaceTerminal.onlyInterfacesWithFreeSlots) {
+				for( final ItemStack itemStack : entry.getInventory() )
+				{
+					if(itemStack.isEmpty()){
+						interfaceHasFreeSlots = true;
+						break;
+					}
+				}
 			}
+
 			// if found, filter skipped or machine name matching the search term, add it
 			if( found || (entry.getName().toLowerCase().contains( searchFieldInputs ) && entry.getName().toLowerCase().contains( searchFieldOutputs )))
 			{

src/main/java/appeng/client/render/BlockPosHighlighter.java

@@ -8,14 +8,9 @@ public class BlockPosHighlighter
     private static BlockPos hilightedBlock;
     private static long expireHilight;
 
-
-
-    private static int dimension;
-
-    public static void hilightBlock( BlockPos c, long expireHilight, int dimension ) {
+    public static void hilightBlock( BlockPos c, long expireHilight ) {
         hilightedBlock = c;
         BlockPosHighlighter.expireHilight = expireHilight;
-        BlockPosHighlighter.dimension = dimension;
     }
 
     public static BlockPos getHilightedBlock() {
@@ -26,9 +21,5 @@ public class BlockPosHighlighter
         return expireHilight;
     }
 
-    public static int getDimension()
-    {
-        return dimension;
-    }
 
 }

src/main/java/appeng/client/render/TesrRenderHelper.java

@@ -19,7 +19,6 @@
 package appeng.client.render;
 
 
-import appeng.api.storage.data.IAEFluidStack;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.client.renderer.GlStateManager;
@@ -31,7 +30,6 @@ import net.minecraft.util.EnumFacing;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.util.IWideReadableNumberConverter;
 import appeng.util.ReadableNumberConverter;
-import net.minecraftforge.fluids.FluidStack;
 
 
 /**
@@ -145,23 +143,4 @@ public class TesrRenderHelper
 
 	}
 
-	public static void renderFluid2dWithAmount( IAEFluidStack fluidStack, float scale, float spacing )
-	{
-		final ItemStack renderStack = fluidStack.asItemStackRepresentation();
-
-		TesrRenderHelper.renderItem2d( renderStack, scale );
-
-		final long stackSize = fluidStack.getStackSize() / 1000;
-		final String renderedStackSize = NUMBER_CONVERTER.toWideReadableForm( stackSize ) + "B";
-
-		// Render the item count
-		final FontRenderer fr = Minecraft.getMinecraft().fontRenderer;
-		final int width = fr.getStringWidth( renderedStackSize );
-		GlStateManager.translate( 0.0f, spacing, 0 );
-		GlStateManager.scale( 1.0f / 62.0f, 1.0f / 62.0f, 1.0f / 62.0f );
-		GlStateManager.translate( -0.5f * width, 0.0f, 0.5f );
-		fr.drawString( renderedStackSize, 0, 0, 0 );
-
-	}
-
 }

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

@@ -215,48 +215,35 @@ public final class ContainerInterfaceTerminal extends AEBaseContainer
 			final IItemHandler theSlot = new WrapperFilteredItemHandler( new WrapperRangeItemHandler( inv.server, slot, slot + 1 ), new PatternSlotFilter() );
 			final InventoryAdaptor interfaceSlot = new AdaptorItemHandler( theSlot );
 
-			IItemHandler interfaceHandler = inv.server;
-			boolean canInsert = true;
-
-			switch ( action )
+			switch( action )
 			{
 				case PICKUP_OR_SET_DOWN:
+
 					if( hasItemInHand )
 					{
-						for( int s = 0; s < interfaceHandler.getSlots(); s++ )
+						ItemStack inSlot = theSlot.getStackInSlot( 0 );
+						if( inSlot.isEmpty() )
 						{
-							if( Platform.itemComparisons().isSameItem( interfaceHandler.getStackInSlot( s ), player.inventory.getItemStack() ) )
-							{
-								canInsert = false;
-								break;
-							}
+							player.inventory.setItemStack( interfaceSlot.addItems( player.inventory.getItemStack() ) );
 						}
-						if( canInsert )
+						else
 						{
-							ItemStack inSlot = theSlot.getStackInSlot( 0 );
-							if( inSlot.isEmpty() )
+							inSlot = inSlot.copy();
+							final ItemStack inHand = player.inventory.getItemStack().copy();
+
+							ItemHandlerUtil.setStackInSlot( theSlot, 0, ItemStack.EMPTY );
+							player.inventory.setItemStack( ItemStack.EMPTY );
+
+							player.inventory.setItemStack( interfaceSlot.addItems( inHand.copy() ) );
+
+							if( player.inventory.getItemStack().isEmpty() )
 							{
-								player.inventory.setItemStack( interfaceSlot.addItems( player.inventory.getItemStack() ) );
+								player.inventory.setItemStack( inSlot );
 							}
 							else
 							{
-								inSlot = inSlot.copy();
-								final ItemStack inHand = player.inventory.getItemStack().copy();
-
-								ItemHandlerUtil.setStackInSlot( theSlot, 0, ItemStack.EMPTY );
-								player.inventory.setItemStack( ItemStack.EMPTY );
-
-								player.inventory.setItemStack( interfaceSlot.addItems( inHand.copy() ) );
-
-								if( player.inventory.getItemStack().isEmpty() )
-								{
-									player.inventory.setItemStack( inSlot );
-								}
-								else
-								{
-									player.inventory.setItemStack( inHand );
-									ItemHandlerUtil.setStackInSlot( theSlot, 0, inSlot );
-								}
+								player.inventory.setItemStack( inHand );
+								ItemHandlerUtil.setStackInSlot( theSlot, 0, inSlot );
 							}
 						}
 					}
@@ -267,27 +254,17 @@ public final class ContainerInterfaceTerminal extends AEBaseContainer
 
 					break;
 				case SPLIT_OR_PLACE_SINGLE:
+
 					if( hasItemInHand )
 					{
-						for( int s = 0; s < interfaceHandler.getSlots(); s++ )
+						ItemStack extra = playerHand.removeItems( 1, ItemStack.EMPTY, null );
+						if( !extra.isEmpty() && !interfaceSlot.containsItems())
 						{
-							if( Platform.itemComparisons().isSameItem( interfaceHandler.getStackInSlot( s ), player.inventory.getItemStack() ) )
-							{
-								canInsert = false;
-								break;
-							}
+							extra = interfaceSlot.addItems( extra );
 						}
-						if( canInsert )
+						if( !extra.isEmpty() )
 						{
-							ItemStack extra = playerHand.removeItems( 1, ItemStack.EMPTY, null );
-							if( !extra.isEmpty() && !interfaceSlot.containsItems() )
-							{
-								extra = interfaceSlot.addItems( extra );
-							}
-							if( !extra.isEmpty() )
-							{
-								playerHand.addItems( extra );
-							}
+							playerHand.addItems( extra );
 						}
 					}
 					else if( !is.isEmpty() )

src/main/java/appeng/fluids/client/gui/GuiFluidLevelEmitter.java

@@ -90,13 +90,6 @@ public class GuiFluidLevelEmitter extends GuiUpgradeable
 		this.level.drawTextBox();
 	}
 
-	@Override
-	public void drawFG( int offsetX, int offsetY, int mouseX, int mouseY )
-	{
-		if( isPointInRegion( 24, 43,89,this.fontRenderer.FONT_HEIGHT,mouseX,mouseY ) ) drawTooltip( mouseX - guiLeft - 7, mouseY - guiTop + 25, "Amount in millibuckets" );
-		super.drawFG( offsetX, offsetY, mouseX, mouseY );
-	}
-
 	@Override
 	protected boolean drawUpgrades()
 	{

src/main/java/appeng/fluids/util/AEFluidStack.java

@@ -32,6 +32,7 @@ import io.netty.buffer.ByteBuf;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.CompressedStreamTools;
 import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.network.PacketBuffer;
 import net.minecraftforge.fluids.Fluid;
 import net.minecraftforge.fluids.FluidStack;
 
@@ -216,18 +217,6 @@ public final class AEFluidStack extends AEStack<IAEFluidStack> implements IAEFlu
 		return dup;
 	}
 
-	@Override
-	public boolean isItem()
-	{
-		return false;
-	}
-
-	@Override
-	public boolean isFluid()
-	{
-		return true;
-	}
-
 	@Override
 	public IStorageChannel<IAEFluidStack> getChannel()
 	{
@@ -318,17 +307,17 @@ public final class AEFluidStack extends AEStack<IAEFluidStack> implements IAEFlu
 	}
 
 	@Override
-	public void writeToPacket( final ByteBuf buffer ) throws IOException
+	public void writeToPacket( final ByteBuf i ) throws IOException
 	{
 		final byte mask = (byte) ( ( this.getType( this.getStackSize() ) << 2 ) | ( this
 				.getType( this.getCountRequestable() ) << 4 ) | ( (byte) ( this.isCraftable() ? 1 : 0 ) << 6 ) | ( this.hasTagCompound() ? 1 : 0 ) << 7 );
 
-		buffer.writeByte( mask );
+		i.writeByte( mask );
 
-		this.writeToStream( buffer );
+		this.writeToStream( i );
 
-		this.putPacketValue( buffer, this.getStackSize() );
-		this.putPacketValue( buffer, this.getCountRequestable() );
+		this.putPacketValue( i, this.getStackSize() );
+		this.putPacketValue( i, this.getCountRequestable() );
 	}
 
 	private void writeToStream( final ByteBuf buffer ) throws IOException

src/main/java/appeng/helpers/HighlighterHandler.java

@@ -26,11 +26,10 @@ public class HighlighterHandler
             return;
         }
         Minecraft mc = Minecraft.getMinecraft();
-        int dimension = mc.world.provider.getDimension();
         long time = System.currentTimeMillis();
 
-        if (time > BlockPosHighlighter.getExpireHilight() || dimension != BlockPosHighlighter.getDimension()) {
-            BlockPosHighlighter.hilightBlock(null, -1, BlockPosHighlighter.getDimension() );
+        if (time > BlockPosHighlighter.getExpireHilight()) {
+            BlockPosHighlighter.hilightBlock(null, -1);
             return;
         }
 

src/main/java/appeng/parts/reporting/AbstractPartMonitor.java

@@ -21,10 +21,6 @@ package appeng.parts.reporting;
 
 import java.io.IOException;
 
-import appeng.api.storage.channels.IFluidStorageChannel;
-import appeng.api.storage.data.IAEFluidStack;
-import appeng.fluids.util.AEFluidStack;
-import appeng.util.item.AEStack;
 import io.netty.buffer.ByteBuf;
 
 import net.minecraft.client.renderer.GlStateManager;
@@ -35,9 +31,6 @@ import net.minecraft.util.EnumFacing;
 import net.minecraft.util.EnumHand;
 import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
-import net.minecraftforge.fluids.FluidStack;
-import net.minecraftforge.fluids.capability.CapabilityFluidHandler;
-import net.minecraftforge.fluids.capability.IFluidHandlerItem;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 
@@ -77,9 +70,7 @@ import appeng.util.item.AEItemStack;
 public abstract class AbstractPartMonitor extends AbstractPartDisplay implements IPartStorageMonitor, IStackWatcherHost
 {
 	private static final IWideReadableNumberConverter NUMBER_CONVERTER = ReadableNumberConverter.INSTANCE;
-
 	private IAEItemStack configuredItem;
-	private IAEFluidStack configuredFluid;
 	private String lastHumanReadableText;
 	private boolean isLocked;
 	private IStackWatcher myWatcher;
@@ -99,9 +90,6 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 
 		final NBTTagCompound myItem = data.getCompoundTag( "configuredItem" );
 		this.configuredItem = AEItemStack.fromNBT( myItem );
-
-		final NBTTagCompound myFluid = data.getCompoundTag( "configuredFluid" );
-		this.configuredFluid = AEFluidStack.fromNBT( myFluid );
 	}
 
 	@Override
@@ -116,15 +104,8 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 		{
 			this.configuredItem.writeToNBT( myItem );
 		}
-		final NBTTagCompound myFluid = new NBTTagCompound();
-		if( this.configuredFluid != null )
-		{
-			this.configuredFluid.writeToNBT( myFluid );
-		}
 
 		data.setTag( "configuredItem", myItem );
-		data.setTag( "configuredFluid", myFluid );
-
 	}
 
 	@Override
@@ -133,17 +114,11 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 		super.writeToStream( data );
 
 		data.writeBoolean( this.isLocked );
-		//is configured
-		data.writeBoolean( this.configuredItem != null);
-		data.writeBoolean( this.configuredFluid != null);
+		data.writeBoolean( this.configuredItem != null );
 		if( this.configuredItem != null )
 		{
 			this.configuredItem.writeToPacket( data );
 		}
-		else if( this.configuredFluid != null )
-		{
-			this.configuredFluid.writeToPacket( data );
-		}
 	}
 
 	@Override
@@ -156,22 +131,14 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 
 		this.isLocked = isLocked;
 
-		final boolean isItem = data.readBoolean();
-		final boolean isFluid = data.readBoolean();
-		if( isItem )
+		final boolean val = data.readBoolean();
+		if( val )
 		{
 			this.configuredItem = AEItemStack.fromPacket( data );
-			this.configuredFluid = null;
-		}
-		else if( isFluid )
-		{
-			this.configuredFluid = AEFluidStack.fromPacket( data );
-			this.configuredItem = null;
 		}
 		else
 		{
 			this.configuredItem = null;
-			this.configuredFluid = null;
 		}
 
 		return needRedraw;
@@ -198,25 +165,7 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 		if( !this.isLocked )
 		{
 			final ItemStack eq = player.getHeldItem( hand );
-			FluidStack fluidInTank = null;
-
-			if( eq.hasCapability( CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null ) )
-			{
-				IFluidHandlerItem fluidHandlerItem = ( eq.getCapability( CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null ) );
-				fluidInTank = fluidHandlerItem.drain( Integer.MAX_VALUE, false );
-			}
-
-			if (fluidInTank == null)
-			{
-				this.configuredFluid = null;
-				this.configuredItem = AEItemStack.fromItemStack( eq );
-			}
-			else if( fluidInTank.amount > 0 )
-			{
-				this.configuredFluid = AEFluidStack.fromFluidStack( fluidInTank );
-				this.configuredItem = null;
-			}
-
+			this.configuredItem = AEItemStack.fromItemStack( eq );
 			this.configureWatchers();
 			this.getHost().markForSave();
 			this.getHost().markForUpdate();
@@ -278,16 +227,6 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 				this.updateReportingValue(
 						this.getProxy().getStorage().getInventory( AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ) ) );
 			}
-			else if ( this.configuredFluid != null )
-			{
-				if( this.myWatcher != null )
-				{
-					this.myWatcher.add( this.configuredFluid );
-				}
-
-				this.updateReportingValue(
-						this.getProxy().getStorage().getInventory( AEApi.instance().storage().getStorageChannel( IFluidStorageChannel.class ) ) );
-			}
 		}
 		catch( final GridAccessException e )
 		{
@@ -295,12 +234,11 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 		}
 	}
 
-	private <T extends IAEStack<T>> void updateReportingValue ( final IMEMonitor<T> monitor )
+	private void updateReportingValue( final IMEMonitor<IAEItemStack> itemInventory )
 	{
-
-		if( this.configuredItem != null)
+		if( this.configuredItem != null )
 		{
-			final IAEItemStack result = (IAEItemStack) monitor.getStorageList().findPrecise( (T) this.configuredItem );
+			final IAEItemStack result = itemInventory.getStorageList().findPrecise( this.configuredItem );
 			if( result == null )
 			{
 				this.configuredItem.setStackSize( 0 );
@@ -310,18 +248,6 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 				this.configuredItem.setStackSize( result.getStackSize() );
 			}
 		}
-		else if( this.configuredFluid != null)
-		{
-			final IAEFluidStack result = (IAEFluidStack) monitor.getStorageList().findPrecise( (T) this.configuredFluid );
-			if( result == null )
-			{
-				this.configuredFluid.setStackSize( 0 );
-			}
-			else
-			{
-				this.configuredFluid.setStackSize( result.getStackSize() );
-			}
-		}
 	}
 
 	@Override
@@ -334,7 +260,7 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 			return;
 		}
 
-		IAEStack<?> ais = this.getDisplayed();
+		final IAEItemStack ais = this.getDisplayed();
 
 		if( ais == null )
 		{
@@ -348,10 +274,8 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 
 		TesrRenderHelper.moveToFace( facing );
 		TesrRenderHelper.rotateToFace( facing, this.getSpin() );
-		if (ais instanceof IAEItemStack)
-			TesrRenderHelper.renderItem2dWithAmount( (IAEItemStack) ais, 0.8f, 0.17f );
-		if (ais instanceof IAEFluidStack)
-			TesrRenderHelper.renderFluid2dWithAmount( (IAEFluidStack) ais, 0.8f, 0.17f );
+		TesrRenderHelper.renderItem2dWithAmount( ais, 0.8f, 0.17f );
+
 		GlStateManager.popMatrix();
 
 	}
@@ -363,13 +287,9 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 	}
 
 	@Override
-	public IAEStack<?> getDisplayed()
+	public IAEItemStack getDisplayed()
 	{
-		if (this.configuredItem != null)
 		return this.configuredItem;
-		else if (this.configuredFluid != null)
-			return this.configuredFluid;
-		return null;
 	}
 
 	@Override
@@ -402,26 +322,6 @@ public abstract class AbstractPartMonitor extends AbstractPartDisplay implements
 			final long stackSize = this.configuredItem.getStackSize();
 			final String humanReadableText = NUMBER_CONVERTER.toWideReadableForm( stackSize );
 
-			if( !humanReadableText.equals( this.lastHumanReadableText ) )
-			{
-				this.lastHumanReadableText = humanReadableText;
-				this.getHost().markForUpdate();
-			}
-		}
-		else if( this.configuredFluid != null )
-		{
-			if( fullStack == null )
-			{
-				this.configuredFluid.setStackSize( 0 );
-			}
-			else
-			{
-				this.configuredFluid.setStackSize( fullStack.getStackSize() );
-			}
-
-			final long stackSize = this.configuredFluid.getStackSize() / 1000;
-			final String humanReadableText = NUMBER_CONVERTER.toWideReadableForm( stackSize ) + "B";
-
 			if( !humanReadableText.equals( this.lastHumanReadableText ) )
 			{
 				this.lastHumanReadableText = humanReadableText;

src/main/java/appeng/parts/reporting/PartConversionMonitor.java

@@ -19,31 +19,15 @@
 package appeng.parts.reporting;
 
 
-import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
-import java.util.Objects;
 
-import appeng.api.config.Actionable;
-import appeng.api.storage.channels.IFluidStorageChannel;
-import appeng.api.storage.data.IAEFluidStack;
-import appeng.api.storage.data.IAEStack;
-import appeng.core.AELog;
-import appeng.core.sync.network.NetworkHandler;
-import appeng.core.sync.packets.PacketInventoryAction;
-import appeng.fluids.util.AEFluidStack;
-import appeng.helpers.InventoryAction;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumHand;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.Vec3d;
-import net.minecraftforge.fluids.FluidStack;
-import net.minecraftforge.fluids.FluidUtil;
-import net.minecraftforge.fluids.capability.CapabilityFluidHandler;
-import net.minecraftforge.fluids.capability.IFluidHandlerItem;
 import net.minecraftforge.items.IItemHandler;
 import net.minecraftforge.items.wrapper.PlayerMainInvWrapper;
 
@@ -108,13 +92,6 @@ public class PartConversionMonitor extends AbstractPartMonitor
 		}
 
 		final ItemStack eq = player.getHeldItem( hand );
-		FluidStack fluidInTank = null;
-		if( eq.hasCapability( CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null ) )
-		{
-			IFluidHandlerItem fluidHandlerItem = ( eq.getCapability( CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null ) );
-			fluidInTank = fluidHandlerItem.drain( Integer.MAX_VALUE, false );
-		}
-
 		if( this.isLocked() )
 		{
 			if( eq.isEmpty() )
@@ -126,49 +103,18 @@ public class PartConversionMonitor extends AbstractPartMonitor
 				// wrench it
 				return super.onPartActivate( player, hand, pos );
 			}
-			else if( fluidInTank != null && fluidInTank.amount > 0 )
-			{
-				if( this.getDisplayed() != null && getDisplayed().equals( AEFluidStack.fromFluidStack( fluidInTank ) ) )
-				{
-					this.drainFluidContainer( player, hand );
-				}
-			}
 			else
 			{
 				this.insertItem( player, hand, false );
 			}
-
 		}
-
-		//If its a fluid container, grab its fluidstack. if its empty pass its itemstack;
-
-		if (eq.isEmpty()){
-			return super.onPartActivate( player, hand, pos );
-		}
-		if( fluidInTank != null && fluidInTank.amount > 0 )
+		else if( this.getDisplayed() != null && this.getDisplayed().equals( eq ) )
 		{
-			if( getDisplayed() instanceof IAEItemStack || getDisplayed() == null )
-			{
-				return super.onPartActivate( player, hand, pos );
-			}
-			if( ( (IAEFluidStack) this.getDisplayed() ).equals( AEFluidStack.fromFluidStack( fluidInTank ) ) )
-			{
-				this.drainFluidContainer( player, hand );
-			}
-			else {
-				return super.onPartActivate( player, hand, pos );
-			}
+			this.insertItem( player, hand, false );
 		}
 		else
 		{
-			if( getDisplayed() instanceof IAEFluidStack || getDisplayed() == null )
-			{
-				return super.onPartActivate( player, hand, pos );
-			}
-			if( ( (IAEItemStack) this.getDisplayed() ).equals( eq ) )
-			{
-				this.insertItem( player, hand, false );
-			}
+			return super.onPartActivate( player, hand, pos );
 		}
 
 		return true;
@@ -192,14 +138,9 @@ public class PartConversionMonitor extends AbstractPartMonitor
 			return false;
 		}
 
-		ItemStack eq = player.getHeldItem( hand );
-		if( this.getDisplayed() != null && this.getDisplayed() instanceof IAEItemStack )
+		if( this.getDisplayed() != null )
 		{
-			this.extractItem( player, ( (IAEItemStack) this.getDisplayed() ).getDefinition().getMaxStackSize() );
-		}
-		else if( this.getDisplayed() != null && this.getDisplayed() instanceof IAEFluidStack )
-		{
-			this.fillFluidContainer( player,hand );
+			this.extractItem( player, this.getDisplayed().getDefinition().getMaxStackSize() );
 		}
 
 		return true;
@@ -242,9 +183,9 @@ public class PartConversionMonitor extends AbstractPartMonitor
 
 			if( allItems )
 			{
-				if( this.getDisplayed() != null && this.getDisplayed() instanceof IAEItemStack)
+				if( this.getDisplayed() != null )
 				{
-					final IAEItemStack input = (IAEItemStack) this.getDisplayed().copy();
+					final IAEItemStack input = this.getDisplayed().copy();
 					IItemHandler inv = new PlayerMainInvWrapper( player.inventory );
 
 					for( int x = 0; x < inv.getSlots(); x++ )
@@ -280,9 +221,7 @@ public class PartConversionMonitor extends AbstractPartMonitor
 
 	private void extractItem( final EntityPlayer player, int count )
 	{
-		if (!(this.getDisplayed() instanceof IAEItemStack))
-			return;
-		final IAEItemStack input = (IAEItemStack) this.getDisplayed();
+		final IAEItemStack input = this.getDisplayed();
 		if( input != null )
 		{
 			try
@@ -326,141 +265,6 @@ public class PartConversionMonitor extends AbstractPartMonitor
 		}
 	}
 
-	private void drainFluidContainer( final EntityPlayer player, final EnumHand hand ) {
-		try
-		{
-			final ItemStack held = player.getHeldItem( hand );
-			if( held.getCount() != 1 )
-			{
-				// only support stacksize 1 for now
-				return;
-			}
-
-			final IFluidHandlerItem fh = FluidUtil.getFluidHandler( held );
-			if( fh == null )
-			{
-				// only fluid handlers items
-				return;
-			}
-
-			// See how much we can drain from the item
-			final FluidStack extract = fh.drain( Integer.MAX_VALUE, false );
-			if( extract == null || extract.amount < 1 )
-			{
-				return;
-			}
-
-			// Check if we can push into the system
-			final IEnergySource energy = this.getProxy().getEnergy();
-			final IMEMonitor<IAEFluidStack> cell = this.getProxy()
-					.getStorage()
-					.getInventory(
-							AEApi.instance().storage().getStorageChannel( IFluidStorageChannel.class ) );
-			final IAEFluidStack notStorable = Platform.poweredInsert( energy, cell, AEFluidStack.fromFluidStack( extract ), new PlayerSource( player, this ), Actionable.SIMULATE );
-
-			if( notStorable != null && notStorable.getStackSize() > 0 )
-			{
-				final int toStore = (int) ( extract.amount - notStorable.getStackSize() );
-				final FluidStack storable = fh.drain( toStore, false );
-
-				if( storable == null || storable.amount == 0 )
-				{
-					return;
-				}
-				else
-				{
-					extract.amount = storable.amount;
-				}
-			}
-
-			// Actually drain
-			final FluidStack drained = fh.drain( extract, true );
-			extract.amount = drained.amount;
-
-			final IAEFluidStack notInserted = Platform.poweredInsert( energy, cell, AEFluidStack.fromFluidStack( extract ), new PlayerSource( player, this ) );
-
-			if( notInserted != null && notInserted.getStackSize() > 0 )
-			{
-				AELog.error( "Fluid item [%s] reported a different possible amount to drain than it actually provided.", held.getDisplayName() );
-			}
-
-			player.setHeldItem( hand, fh.getContainer() );
-		}
-		catch( GridAccessException e )
-		{
-			e.printStackTrace();
-		}
-	}
-
-	private void fillFluidContainer( final EntityPlayer player, final EnumHand hand  )
-	{
-		try
-		{
-			final ItemStack held = player.getHeldItem( hand );
-			if( held.getCount() != 1 )
-			{
-				// only support stacksize 1 for now
-				return;
-			}
-
-			final IFluidHandlerItem fh = FluidUtil.getFluidHandler( held );
-			if( fh == null )
-			{
-				// only fluid handlers items
-				return;
-			}
-
-			final IAEFluidStack stack = (IAEFluidStack) this.getDisplayed().copy();
-
-			// Check how much we can store in the item
-			stack.setStackSize( Integer.MAX_VALUE );
-			int amountAllowed = fh.fill( stack.getFluidStack(), false );
-			stack.setStackSize( amountAllowed );
-
-			// Check if we can pull out of the system
-			final IEnergySource energy = this.getProxy().getEnergy();
-			final IMEMonitor<IAEFluidStack> cell = this.getProxy()
-					.getStorage()
-					.getInventory(
-							AEApi.instance().storage().getStorageChannel( IFluidStorageChannel.class ) );
-			final IAEFluidStack canPull = Platform.poweredExtraction( energy, cell, stack, new PlayerSource( player, this ), Actionable.SIMULATE );
-			if( canPull == null || canPull.getStackSize() < 1 )
-			{
-				return;
-			}
-
-			// How much could fit into the container
-			final int canFill = fh.fill( canPull.getFluidStack(), false );
-			if( canFill == 0 )
-			{
-				return;
-			}
-
-			// Now actually pull out of the system
-			stack.setStackSize( canFill );
-			final IAEFluidStack pulled = Platform.poweredExtraction( energy, cell, stack, new PlayerSource( player, this ) );
-			if( pulled == null || pulled.getStackSize() < 1 )
-			{
-				// Something went wrong
-				AELog.error( "Unable to pull fluid out of the ME system even though the simulation said yes " );
-				return;
-			}
-
-			// Actually fill
-			final int used = fh.fill( pulled.getFluidStack(), true );
-
-			if( used != canFill )
-			{
-				AELog.error( "Fluid item [%s] reported a different possible amount than it actually accepted.", held.getDisplayName() );
-			}
-			player.setHeldItem( hand, fh.getContainer() );
-		}
-		catch( GridAccessException e )
-		{
-			e.printStackTrace();
-		}
-	}
-
 	@Override
 	public IPartModel getStaticModels()
 	{

src/main/java/appeng/util/UUIDMatcher.java

@@ -48,4 +48,4 @@ public final class UUIDMatcher
 	{
 		return PATTERN.matcher( potential ).matches();
 	}
-}
+}

src/main/java/appeng/util/item/AEItemStack.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of Applied Energistics 2.
- * Copyright (c) 2013 - 2014, AlgorithmX2, All rights reserved.
+ * Copyright (c) 2013 - 2020, 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
@@ -18,7 +18,6 @@
 
 package appeng.util.item;
 
-
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -26,348 +25,287 @@ import java.util.Optional;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import appeng.api.AEApi;
 import io.netty.buffer.ByteBuf;
-
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
-import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.common.network.ByteBufUtils;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 import net.minecraftforge.items.ItemHandlerHelper;
 
-import appeng.api.AEApi;
 import appeng.api.config.FuzzyMode;
 import appeng.api.storage.IStorageChannel;
 import appeng.api.storage.channels.IItemStorageChannel;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.util.Platform;
 
+public final class AEItemStack extends AEStack<IAEItemStack> implements IAEItemStack {
 
-public final class AEItemStack extends AEStack<IAEItemStack> implements IAEItemStack
-{
-	private AESharedItemStack sharedStack;
-	private Optional<OreReference> oreReference;
+    private final AESharedItemStack sharedStack;
+    private Optional<OreReference> oreReference;
 
-	@SideOnly( Side.CLIENT )
-	private String displayName;
-	@SideOnly( Side.CLIENT )
-	private List<String> tooltip;
-	@SideOnly( Side.CLIENT )
-	private ResourceLocation uniqueID;
+    @SideOnly( Side.CLIENT )
+    private String displayName;
+    @SideOnly( Side.CLIENT )
+    private List<String> tooltip;
 
-	private AEItemStack( final AEItemStack is )
-	{
-		this.setStackSize( is.getStackSize() );
-		this.setCraftable( is.isCraftable() );
-		this.setCountRequestable( is.getCountRequestable() );
-		this.sharedStack = is.sharedStack;
-		this.oreReference = is.oreReference;
-	}
+    private AEItemStack(final AEItemStack is) {
+        this.setStackSize(is.getStackSize());
+        this.setCraftable(is.isCraftable());
+        this.setCountRequestable(is.getCountRequestable());
+        this.sharedStack = is.sharedStack;
+        this.oreReference = is.oreReference;
+    }
 
-	private AEItemStack( final AESharedItemStack is, long size )
-	{
-		this.sharedStack = is;
-		this.setStackSize( size );
-		this.setCraftable( false );
-		this.setCountRequestable( 0 );
-		this.oreReference = OreHelper.INSTANCE.getOre( is.getDefinition() );
-	}
+    private AEItemStack(final AESharedItemStack is, long size) {
+        this.sharedStack = is;
+        this.setStackSize(size);
+        this.setCraftable(false);
+        this.setCountRequestable(0);
+        this.oreReference = OreHelper.INSTANCE.getOre( is.getDefinition() );
+    }
 
-	@Nullable
-	public static AEItemStack fromItemStack( @Nonnull final ItemStack stack )
-	{
-		if( stack.isEmpty() )
-		{
-			return null;
-		}
+    @Nullable
+    public static AEItemStack fromItemStack(@Nonnull final ItemStack stack) {
+        if (stack.isEmpty()) {
+            return null;
+        }
 
-		return new AEItemStack( AEItemStackRegistry.getRegisteredStack( stack ), stack.getCount() );
-	}
+        return new AEItemStack(AEItemStackRegistry.getRegisteredStack(stack), stack.getCount());
+    }
 
-	public static IAEItemStack fromNBT( final NBTTagCompound i )
-	{
-		if( i == null )
-		{
-			return null;
-		}
+    public static IAEItemStack fromNBT( final NBTTagCompound i )
+    {
+        if( i == null )
+        {
+            return null;
+        }
 
-		final ItemStack itemstack = new ItemStack( i );
-		if( itemstack.isEmpty() )
-		{
-			return null;
-		}
+        final ItemStack itemstack = new ItemStack( i );
+        if( itemstack.isEmpty() )
+        {
+            return null;
+        }
 
-		final AEItemStack item = AEItemStack.fromItemStack( itemstack );
-		item.setStackSize( i.getLong( "Cnt" ) );
-		item.setCountRequestable( i.getLong( "Req" ) );
-		item.setCraftable( i.getBoolean( "Craft" ) );
-		return item;
-	}
+        final AEItemStack item = AEItemStack.fromItemStack( itemstack );
+        item.setStackSize( i.getLong( "Cnt" ) );
+        item.setCountRequestable( i.getLong( "Req" ) );
+        item.setCraftable( i.getBoolean( "Craft" ) );
+        return item;
+    }
 
-	@Override
-	public void writeToNBT( final NBTTagCompound i )
-	{
-		this.getDefinition().writeToNBT( i );
-		i.setLong( "Cnt", this.getStackSize() );
-		i.setLong( "Req", this.getCountRequestable() );
-		i.setBoolean( "Craft", this.isCraftable() );
-	}
+    @Override
+    public void writeToNBT( final NBTTagCompound i )
+    {
+        this.getDefinition().writeToNBT( i );
+        i.setLong( "Cnt", this.getStackSize() );
+        i.setLong( "Req", this.getCountRequestable() );
+        i.setBoolean( "Craft", this.isCraftable() );
+    }
 
-	public static AEItemStack fromPacket( final ByteBuf data )
-	{
-		final byte mask = data.readByte();
-		final byte stackType = (byte) ( ( mask & 0x0C ) >> 2 );
-		final byte countReqType = (byte) ( ( mask & 0x30 ) >> 4 );
-		final boolean isCraftable = ( mask & 0x40 ) > 0;
+    public static AEItemStack fromPacket( final ByteBuf data )
+    {
+        final byte mask = data.readByte();
+        final byte stackType = (byte) ( ( mask & 0x0C ) >> 2 );
+        final byte countReqType = (byte) ( ( mask & 0x30 ) >> 4 );
+        final boolean isCraftable = ( mask & 0x40 ) > 0;
 
-		final ItemStack itemstack = new ItemStack( ByteBufUtils.readTag( data ) );
-		final long stackSize = getPacketValue( stackType, data );
-		final long countRequestable = getPacketValue( countReqType, data );
+        final ItemStack itemstack = new ItemStack( ByteBufUtils.readTag( data ) );
+        final long stackSize = getPacketValue( stackType, data );
+        final long countRequestable = getPacketValue( countReqType, data );
 
-		if( itemstack.isEmpty() )
-		{
-			return null;
-		}
+        if( itemstack.isEmpty() )
+        {
+            return null;
+        }
 
-		final AEItemStack item = new AEItemStack( AEItemStackRegistry.getRegisteredStack( itemstack ), stackSize );
-		item.setCountRequestable( countRequestable );
-		item.setCraftable( isCraftable );
-		return item;
-	}
+        final AEItemStack item = new AEItemStack( AEItemStackRegistry.getRegisteredStack( itemstack ), stackSize );
+        item.setCountRequestable( countRequestable );
+        item.setCraftable( isCraftable );
+        return item;
+    }
 
-	@Override
-	public void writeToPacket( final ByteBuf i )
-	{
-		final byte mask = (byte) ( ( this.getType( this.getStackSize() ) << 2 ) | ( this
-				.getType( this.getCountRequestable() ) << 4 ) | ( (byte) ( this.isCraftable() ? 1 : 0 ) << 6 ) | ( this.hasTagCompound() ? 1 : 0 ) << 7 );
+    @Override
+    public void writeToPacket( final ByteBuf i )
+    {
+        final byte mask = (byte) ( ( this.getType( this.getStackSize() ) << 2 ) | ( this
+                .getType( this.getCountRequestable() ) << 4 ) | ( (byte) ( this.isCraftable() ? 1 : 0 ) << 6 ) | ( this.hasTagCompound() ? 1 : 0 ) << 7 );
 
-		i.writeByte( mask );
-		ByteBufUtils.writeTag( i, this.getDefinition().serializeNBT() );
-		this.putPacketValue( i, this.getStackSize() );
-		this.putPacketValue( i, this.getCountRequestable() );
-	}
+        i.writeByte( mask );
+        ByteBufUtils.writeTag( i, this.getDefinition().serializeNBT() );
+        this.putPacketValue( i, this.getStackSize() );
+        this.putPacketValue( i, this.getCountRequestable() );
+    }
 
-	@Override
-	public void add( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+    /**
+     * We're assuming that using capNBT here is safe, because {@link #getDefinition()} should have been created by
+     * {@link ItemStack#copy()}, and then never mutated. Copying an item stack will automatically serialize the
+     * capabilities of the source stack and initialize the target stacks capNBT field using that tag, which we are then
+     * reusing here.
+     */
 
-		this.incStackSize( option.getStackSize() );
-		this.setCountRequestable( this.getCountRequestable() + option.getCountRequestable() );
-		this.setCraftable( this.isCraftable() || option.isCraftable() );
-	}
+    @Override
+    public void add(final IAEItemStack option) {
+        if (option == null) {
+            return;
+        }
 
-	@Override
-	public boolean fuzzyComparison( final IAEItemStack other, final FuzzyMode mode )
-	{
-		if( mode == FuzzyMode.IGNORE_ALL && OreHelper.INSTANCE.sameOre( this, other ) )
-		{
-			return true;
-		}
+        this.incStackSize(option.getStackSize());
+        this.setCountRequestable(this.getCountRequestable() + option.getCountRequestable());
+        this.setCraftable(this.isCraftable() || option.isCraftable());
+    }
 
-		final ItemStack itemStack = this.getDefinition();
-		final ItemStack otherStack = other.getDefinition();
+    @Override
+    public boolean fuzzyComparison(final IAEItemStack other, final FuzzyMode mode) {
+        final ItemStack itemStack = this.getDefinition();
+        final ItemStack otherStack = other.getDefinition();
 
-		return this.fuzzyItemStackComparison( itemStack, otherStack, mode );
-	}
+        return this.fuzzyItemStackComparison(itemStack, otherStack, mode);
+    }
 
-	@Override
-	public IAEItemStack copy()
-	{
-		return new AEItemStack( this );
-	}
+    @Override
+    public IAEItemStack copy() {
+        return new AEItemStack(this);
+    }
 
-	@Override
-	public boolean isItem()
-	{
-		return true;
-	}
+    @Override
+    public IStorageChannel<IAEItemStack> getChannel() {
+        return AEApi.instance().storage().getStorageChannel(IItemStorageChannel.class);
+    }
 
-	@Override
-	public boolean isFluid()
-	{
-		return false;
-	}
+    @Override
+    public ItemStack createItemStack() {
+        return ItemHandlerHelper.copyStackWithSize(this.getDefinition(),
+                (int) Math.min(Integer.MAX_VALUE, this.getStackSize()));
+    }
 
-	@Override
-	public IStorageChannel<IAEItemStack> getChannel()
-	{
-		return AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class );
-	}
+    @Override
+    public Item getItem() {
+        return this.getDefinition().getItem();
+    }
 
-	@Override
-	public ItemStack createItemStack()
-	{
-		return ItemHandlerHelper.copyStackWithSize( this.getDefinition(), (int) Math.min( Integer.MAX_VALUE, this.getStackSize() ) );
-	}
+    @Override
+    public int getItemDamage() {
+        return this.sharedStack.getItemDamage();
+    }
 
-	@Override
-	public Item getItem()
-	{
-		return this.getDefinition().getItem();
-	}
+    public Optional<OreReference> getOre()
+    {
+        return this.oreReference;
+    }
 
-	@Override
-	public int getItemDamage()
-	{
-		return this.sharedStack.getItemDamage();
-	}
+    @Override
+    public boolean sameOre( final IAEItemStack is )
+    {
+        return OreHelper.INSTANCE.sameOre( this, is );
+    }
 
-	@Override
-	public boolean sameOre( final IAEItemStack is )
-	{
-		return OreHelper.INSTANCE.sameOre( this, is );
-	}
+    @Override
+    public boolean isSameType(final IAEItemStack otherStack) {
+        if (otherStack == null) {
+            return false;
+        }
 
-	@Override
-	public boolean isSameType( final IAEItemStack otherStack )
-	{
-		if( otherStack == null )
-		{
-			return false;
-		}
+        return Objects.equals(this.sharedStack, ((AEItemStack) otherStack).sharedStack);
+    }
 
-		return Objects.equals( this.sharedStack, ( (AEItemStack) otherStack ).sharedStack );
-	}
+    @Override
+    public boolean isSameType(final ItemStack otherStack) {
+        if (otherStack.isEmpty()) {
+            return false;
+        }
+        int oldSize = otherStack.getCount();
 
-	@Override
-	public boolean isSameType( final ItemStack otherStack )
-	{
-		if( otherStack.isEmpty() )
-		{
-			return false;
-		}
-		int oldSize = otherStack.getCount();
+        otherStack.setCount(1);
+        boolean ret = ItemStack.areItemStacksEqual(this.getDefinition(), otherStack);
+        otherStack.setCount(oldSize);
 
-		otherStack.setCount( 1 );
-		boolean ret = ItemStack.areItemStacksEqual( this.getDefinition(), otherStack );
-		otherStack.setCount( oldSize );
+        return ret;
+    }
 
-		return ret;
-	}
+    @Override
+    public int hashCode() {
+        return this.sharedStack.hashCode();
+    }
 
-	@Override
-	public int hashCode()
-	{
-		return this.sharedStack.hashCode();
-	}
+    @Override
+    public boolean equals(final Object ia) {
+        if (ia instanceof AEItemStack) {
+            return this.isSameType((AEItemStack) ia);
+        } else if (ia instanceof ItemStack) {
+            // this actually breaks the equals contract (being equals to unrelated classes)
+            return equals((ItemStack) ia);
+        }
+        return false;
+    }
 
-	@Override
-	public boolean equals( final Object ia )
-	{
-		if( ia instanceof AEItemStack )
-		{
-			return this.isSameType( (AEItemStack) ia );
-		}
-		else if( ia instanceof ItemStack )
-		{
-			return this.isSameType( (ItemStack) ia );
-		}
-		return false;
-	}
+    @Override
+    public String toString() {
+        return this.getStackSize() + "x" + this.getDefinition().getItem().getRegistryName();
+    }
 
-	@Override
-	public String toString()
-	{
-		return this.getStackSize() + "x" + this.getDefinition().getItem().getUnlocalizedName() + "@" + this.getDefinition().getItemDamage();
-	}
+    @SideOnly( Side.CLIENT )
+    public List<String> getToolTip() {
+        if (this.tooltip == null) {
+            this.tooltip = Platform.getTooltip(this.asItemStackRepresentation());
+        }
+        return this.tooltip;
+    }
 
-	@SideOnly( Side.CLIENT )
-	public List<String> getToolTip()
-	{
-		if( this.tooltip == null )
-		{
-			this.tooltip = Platform.getTooltip( this.asItemStackRepresentation() );
-		}
-		return this.tooltip;
-	}
+    @SideOnly( Side.CLIENT )
+    public String getDisplayName() {
+        if (this.displayName == null) {
+            this.displayName = Platform.getItemDisplayName(this.asItemStackRepresentation());
+        }
+        return this.displayName;
+    }
 
-	@SideOnly( Side.CLIENT )
-	public String getDisplayName()
-	{
-		if( this.displayName == null )
-		{
-			this.displayName = Platform.getItemDisplayName( this.asItemStackRepresentation() );
-		}
-		return this.displayName;
-	}
+    @SideOnly( Side.CLIENT )
+    public String getModID() {
+        return this.getDefinition().getItem().getRegistryName().getResourceDomain();
+    }
 
-	@SideOnly( Side.CLIENT )
-	public String getModID()
-	{
-		if( this.uniqueID == null )
-		{
-			this.uniqueID = Item.REGISTRY.getNameForObject( this.getDefinition().getItem() );
-		}
+    @Override
+    public boolean hasTagCompound() {
+        return this.getDefinition().hasTagCompound();
+    }
 
-		if( this.uniqueID == null )
-		{
-			return "** Null";
-		}
+    @Override
+    public ItemStack asItemStackRepresentation() {
+        return this.getDefinition().copy();
+    }
 
-		return this.uniqueID.getResourceDomain() == null ? "** Null" : this.uniqueID.getResourceDomain();
-	}
+    @Override
+    public ItemStack getDefinition() {
+        return this.sharedStack.getDefinition();
+    }
 
-	public Optional<OreReference> getOre()
-	{
-		return this.oreReference;
-	}
+    public boolean equals(final ItemStack is) {
+        return this.isSameType(is);
+    }
 
-	@Override
-	public boolean hasTagCompound()
-	{
-		return this.getDefinition().hasTagCompound();
-	}
+    AESharedItemStack getSharedStack() {
+        return this.sharedStack;
+    }
 
-	@Override
-	public ItemStack asItemStackRepresentation()
-	{
-		return this.getDefinition().copy();
-	}
+    private boolean fuzzyItemStackComparison(ItemStack a, ItemStack b, FuzzyMode mode) {
+        if (a.getItem() == b.getItem()) {
+            if (a.getItem().isDamageable()) {
+                if (mode == FuzzyMode.IGNORE_ALL) {
+                    return true;
+                } else if (mode == FuzzyMode.PERCENT_99) {
+                    return (a.getItemDamage() > 1) == (b.getItemDamage() > 1);
+                } else {
+                    final float percentDamageOfA = (float) a.getItemDamage() / a.getMaxDamage();
+                    final float percentDamageOfB = (float) b.getItemDamage() / b.getMaxDamage();
 
-	@Override
-	public ItemStack getDefinition()
-	{
-		return this.sharedStack.getDefinition();
-	}
-
-	AESharedItemStack getSharedStack()
-	{
-		return this.sharedStack;
-	}
-
-	private boolean fuzzyItemStackComparison( ItemStack a, ItemStack b, FuzzyMode mode )
-	{
-		if( a.getItem() == b.getItem() )
-		{
-			if( a.getItem().isDamageable() )
-			{
-				if( mode == FuzzyMode.IGNORE_ALL )
-				{
-					return true;
-				}
-				else if( mode == FuzzyMode.PERCENT_99 )
-				{
-					return ( a.getItemDamage() > 1 ) == ( b.getItemDamage() > 1 );
-				}
-				else
-				{
-					final float percentDamageOfA = (float) a.getItemDamage() / (float) a.getMaxDamage();
-					final float percentDamageOfB = (float) b.getItemDamage() / (float) b.getMaxDamage();
-
-					return ( percentDamageOfA > mode.breakPoint ) == ( percentDamageOfB > mode.breakPoint );
-				}
-			}
-
-			return a.getMetadata() == b.getMetadata();
-		}
-
-		return false;
-	}
+                    return (percentDamageOfA > mode.breakPoint) == (percentDamageOfB > mode.breakPoint);
+                }
+            }
+        }
 
+        return false;
+    }
 }

src/main/java/appeng/util/item/AEItemStackRegistry.java

@@ -23,7 +23,6 @@
 
 package appeng.util.item;
 
-
 import java.lang.ref.WeakReference;
 import java.util.WeakHashMap;
 
@@ -31,56 +30,34 @@ import javax.annotation.Nonnull;
 
 import net.minecraft.item.ItemStack;
 
-import appeng.util.Platform;
+public final class AEItemStackRegistry {
+    private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> REGISTRY = new WeakHashMap<>();
 
+    private AEItemStackRegistry() {
+    }
 
-public final class AEItemStackRegistry
-{
-	private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> SERVER_REGISTRY = new WeakHashMap<>();
-	private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> CLIENT_REGISTRY = new WeakHashMap<>();
+    static synchronized AESharedItemStack getRegisteredStack(final @Nonnull ItemStack itemStack) {
+        if (itemStack.isEmpty()) {
+            throw new IllegalArgumentException("stack cannot be empty");
+        }
 
-	private AEItemStackRegistry()
-	{
-	}
+        int oldStackSize = itemStack.getCount();
+        itemStack.setCount(1);
 
-	private static WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> registry()
-	{
-		if( Platform.isClient() )
-		{
-			return CLIENT_REGISTRY;
-		}
-		else
-		{
-			return SERVER_REGISTRY;
-		}
-	}
+        AESharedItemStack search = new AESharedItemStack(itemStack);
+        WeakReference<AESharedItemStack> weak = REGISTRY.get(search);
+        AESharedItemStack ret = null;
 
-	static synchronized AESharedItemStack getRegisteredStack( final @Nonnull ItemStack itemStack )
-	{
-		if( itemStack.isEmpty() )
-		{
-			throw new IllegalArgumentException( "stack cannot be empty" );
-		}
+        if (weak != null) {
+            ret = weak.get();
+        }
 
-		int oldStackSize = itemStack.getCount();
-		itemStack.setCount( 1 );
+        if (ret == null) {
+            ret = new AESharedItemStack(itemStack.copy());
+            REGISTRY.put(ret, new WeakReference<>(ret));
+        }
+        itemStack.setCount(oldStackSize);
 
-		AESharedItemStack search = new AESharedItemStack( itemStack );
-		WeakReference<AESharedItemStack> weak = registry().get( search );
-		AESharedItemStack ret = null;
-
-		if( weak != null )
-		{
-			ret = weak.get();
-		}
-
-		if( ret == null )
-		{
-			ret = new AESharedItemStack( itemStack.copy() );
-			registry().put( ret, new WeakReference<>( ret ) );
-		}
-		itemStack.setCount( oldStackSize );
-
-		return ret;
-	}
+        return ret;
+    }
 }

src/main/java/appeng/util/item/AESharedItemStack.java

@@ -18,263 +18,76 @@
 
 package appeng.util.item;
 
-
 import java.util.Objects;
 
 import com.google.common.base.Preconditions;
 
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
-import net.minecraft.nbt.NBTTagCompound;
 
-import appeng.api.config.FuzzyMode;
+final class AESharedItemStack {
 
+    private final ItemStack itemStack;
+    private final int itemId;
+    private final int itemDamage;
+    private final int hashCode;
 
-final class AESharedItemStack implements Comparable<AESharedItemStack>
-{
-	private static final NBTTagCompound LOW_TAG = new NBTTagCompound();
-	private static final NBTTagCompound HIGH_TAG = new NBTTagCompound();
+    public AESharedItemStack(final ItemStack itemStack) {
+        this(itemStack, itemStack.getItemDamage());
+    }
 
-	private final ItemStack itemStack;
-	private final int itemId;
-	private final int itemDamage;
-	private final int hashCode;
+    /**
+     * A constructor to explicitly set the damage value and not fetch it from the {@link ItemStack}
+     * 
+     * @param itemStack The {@link ItemStack} to filter
+     * @param damage    The damage of the item
+     */
+    private AESharedItemStack(ItemStack itemStack, int damage) {
+        this.itemStack = itemStack;
+        this.itemId = Item.getIdFromItem(itemStack.getItem());
+        this.itemDamage = damage;
 
-	public AESharedItemStack( final ItemStack itemStack )
-	{
-		this.itemStack = itemStack;
-		this.itemId = Item.getIdFromItem( itemStack.getItem() );
-		this.itemDamage = itemStack.getItemDamage();
-		this.hashCode = this.makeHashCode();
-	}
+        // Ensure this is always called last.
+        this.hashCode = this.makeHashCode();
+    }
 
-	Bounds getBounds( final FuzzyMode fuzzy, final boolean ignoreMeta )
-	{
-		return new Bounds( this.itemStack, fuzzy, ignoreMeta );
-	}
+    ItemStack getDefinition() {
+        return this.itemStack;
+    }
 
-	ItemStack getDefinition()
-	{
-		return this.itemStack;
-	}
+    int getItemDamage() {
+        return this.itemDamage;
+    }
 
-	int getItemDamage()
-	{
-		return this.itemDamage;
-	}
+    @Override
+    public int hashCode() {
+        return this.hashCode;
+    }
 
-	int getItemID()
-	{
-		return this.itemId;
-	}
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof AESharedItemStack)) {
+            return false;
+        }
 
-	@Override
-	public int hashCode()
-	{
-		return this.hashCode;
-	}
+        final AESharedItemStack other = (AESharedItemStack) obj;
+        Preconditions.checkState(this.itemStack.getCount() == 1, "ItemStack#getCount() has to be 1");
+        Preconditions.checkArgument(other.getDefinition().getCount() == 1, "ItemStack#getCount() has to be 1");
 
-	@Override
-	public boolean equals( final Object obj )
-	{
-		if( obj instanceof AESharedItemStack )
-		{
-			final AESharedItemStack other = (AESharedItemStack) obj;
+        if (this.itemStack == other.itemStack) {
+            return true;
+        }
+        return ItemStack.areItemStacksEqual(this.itemStack, other.itemStack);
+    }
 
-			Preconditions.checkState( this.itemStack.getCount() == 1, "ItemStack#getCount() has to be 1" );
-			Preconditions.checkArgument( other.getDefinition().getCount() == 1, "ItemStack#getCount() has to be 1" );
+    private int makeHashCode() {
+        return Objects.hash(
+                this.itemId,
+                this.itemDamage,
+                this.itemStack.hasTagCompound() ? this.itemStack.getTagCompound() : 0);
+    }
 
-			if( this.itemStack == other.itemStack )
-			{
-				return true;
-			}
-			return ItemStack.areItemStacksEqual( this.itemStack, other.itemStack );
-		}
-		return false;
-	}
-
-	@Override
-	public int compareTo( final AESharedItemStack b )
-	{
-		Preconditions.checkState( this.itemStack.getCount() == 1, "ItemStack#getCount() has to be 1" );
-		Preconditions.checkArgument( b.getDefinition().getCount() == 1, "ItemStack#getCount() has to be 1" );
-
-		if( this.itemStack == b.getDefinition() )
-		{
-			return 0;
-		}
-
-		final int id = this.itemId - b.itemId;
-		if( id != 0 )
-		{
-			return id;
-		}
-
-		final int damageValue = this.itemDamage - b.itemDamage;
-		if( damageValue != 0 )
-		{
-			return damageValue;
-		}
-
-		final int nbt = this.compareNBT( b.getDefinition() );
-		if( nbt != 0 )
-		{
-			return nbt;
-		}
-
-		if( !this.itemStack.areCapsCompatible( b.getDefinition() ) )
-		{
-			return System.identityHashCode( this.itemStack ) - System.identityHashCode( b.getDefinition() );
-		}
-		return 0;
-	}
-
-	private int compareNBT( final ItemStack b )
-	{
-		if( this.itemStack.getTagCompound() == b.getTagCompound() )
-		{
-			return 0;
-		}
-		if( this.itemStack.getTagCompound() == LOW_TAG || b.getTagCompound() == HIGH_TAG )
-		{
-			return -1;
-		}
-		if( this.itemStack.getTagCompound() == HIGH_TAG || b.getTagCompound() == LOW_TAG )
-		{
-			return 1;
-		}
-		return System.identityHashCode( this.itemStack.getTagCompound() ) - System.identityHashCode( b.getTagCompound() );
-	}
-
-	private int makeHashCode()
-	{
-		return Objects.hash( this.itemId, this.itemDamage, this.itemStack.hasTagCompound() ? this.itemStack.getTagCompound() : 0 );
-	}
-
-	/**
-	 * Creates the lower and upper bounds for a specific shared itemstack.
-	 */
-	public static final class Bounds
-	{
-		/**
-		 * Bounds enforced by {@link ItemStack#isEmpty()}
-		 */
-		private static final int MIN_DAMAGE_VALUE = 0;
-		private static final int MAX_DAMAGE_VALUE = 65535;
-
-		private final AESharedItemStack lower;
-		private final AESharedItemStack upper;
-
-		public Bounds( final ItemStack stack, final FuzzyMode fuzzy, final boolean ignoreMeta )
-		{
-			Preconditions.checkState( !stack.isEmpty(), "ItemStack#isEmpty() has to be false" );
-			Preconditions.checkState( stack.getCount() == 1, "ItemStack#getCount() has to be 1" );
-
-			final NBTTagCompound tag = stack.hasTagCompound() ? stack.getTagCompound() : null;
-
-			this.lower = this.makeLowerBound( stack, tag, fuzzy, ignoreMeta );
-			this.upper = this.makeUpperBound( stack, tag, fuzzy, ignoreMeta );
-		}
-
-		public AESharedItemStack lower()
-		{
-			return this.lower;
-		}
-
-		public AESharedItemStack upper()
-		{
-			return this.upper;
-		}
-
-		private AESharedItemStack makeLowerBound( final ItemStack itemStack, final NBTTagCompound tag, final FuzzyMode fuzzy, final boolean ignoreMeta )
-		{
-			final ItemStack newDef = itemStack.copy();
-
-			if( ignoreMeta )
-			{
-				newDef.setItemDamage( MIN_DAMAGE_VALUE );
-				newDef.setTagCompound( tag );
-			}
-			else
-			{
-				if( newDef.getItem().isDamageable() )
-				{
-					if (itemStack.getMaxDamage() == 0)
-					{
-						newDef.setItemDamage(itemStack.getItemDamage() );
-					}
-					else if ( fuzzy == FuzzyMode.IGNORE_ALL )
-					{
-						newDef.setItemDamage( MIN_DAMAGE_VALUE );
-					}
-					else if( fuzzy == FuzzyMode.PERCENT_99 )
-					{
-						if( itemStack.getItemDamage() == MIN_DAMAGE_VALUE )
-						{
-							newDef.setItemDamage( MIN_DAMAGE_VALUE );
-						}
-						else
-						{
-							newDef.setItemDamage( MIN_DAMAGE_VALUE + 1 );
-						}
-					}
-					else
-					{
-						final int breakpoint = fuzzy.calculateBreakPoint( itemStack.getMaxDamage() );
-						final int damage = breakpoint <= itemStack.getItemDamage() ? breakpoint : 0;
-						newDef.setItemDamage( damage );
-					}
-				}
-				newDef.setTagCompound( LOW_TAG );
-			}
-
-			return new AESharedItemStack( newDef );
-		}
-
-		private AESharedItemStack makeUpperBound( final ItemStack itemStack, final NBTTagCompound tag, final FuzzyMode fuzzy, final boolean ignoreMeta )
-		{
-			final ItemStack newDef = itemStack.copy();
-
-			if( ignoreMeta )
-			{
-				newDef.setItemDamage( MAX_DAMAGE_VALUE );
-				newDef.setTagCompound( tag );
-			}
-			else
-			{
-				if( newDef.getItem().isDamageable() )
-				{
-					if (itemStack.getMaxDamage() == 0)
-					{
-						newDef.setItemDamage(itemStack.getItemDamage() );
-					}
-					else if ( fuzzy == FuzzyMode.IGNORE_ALL )
-					{
-						newDef.setItemDamage( itemStack.getMaxDamage() + 1 );
-					}
-					else if( fuzzy == FuzzyMode.PERCENT_99 )
-					{
-						if( itemStack.getItemDamage() == MIN_DAMAGE_VALUE )
-						{
-							newDef.setItemDamage( MIN_DAMAGE_VALUE );
-						}
-						else
-						{
-							newDef.setItemDamage( itemStack.getMaxDamage() + 1 );
-						}
-					}
-					else
-					{
-						final int breakpoint = fuzzy.calculateBreakPoint( itemStack.getMaxDamage() );
-						final int damage = itemStack.getItemDamage() < breakpoint ? breakpoint - 1 : itemStack.getMaxDamage() + 1;
-						newDef.setItemDamage( damage );
-					}
-				}
-				newDef.setTagCompound( HIGH_TAG );
-			}
-
-			return new AESharedItemStack( newDef );
-		}
-
-	}
 }

src/main/java/appeng/util/item/AEStack.java

@@ -18,169 +18,152 @@
 
 package appeng.util.item;
 
-
+import appeng.api.storage.data.IAEStack;
 import io.netty.buffer.ByteBuf;
 
-import appeng.api.storage.data.IAEStack;
 
+public abstract class AEStack<T extends IAEStack<T>> implements IAEStack<T> {
 
-public abstract class AEStack<StackType extends IAEStack<StackType>> implements IAEStack<StackType>
-{
+    private boolean isCraftable;
+    private long stackSize;
+    private long countRequestable;
 
-	private boolean isCraftable;
-	private long stackSize;
-	private long countRequestable;
+    @Override
+    public long getStackSize() {
+        return this.stackSize;
+    }
 
-	protected static long getPacketValue( final byte type, final ByteBuf tag )
-	{
-		if( type == 0 )
-		{
-			long l = tag.readByte();
-			l -= Byte.MIN_VALUE;
-			return l;
-		}
-		else if( type == 1 )
-		{
-			long l = tag.readShort();
-			l -= Short.MIN_VALUE;
-			return l;
-		}
-		else if( type == 2 )
-		{
-			long l = tag.readInt();
-			l -= Integer.MIN_VALUE;
-			return l;
-		}
+    @Override
+    public T setStackSize(final long ss) {
+        this.stackSize = ss;
+        return (T) this;
+    }
 
-		return tag.readLong();
-	}
+    @Override
+    public long getCountRequestable() {
+        return this.countRequestable;
+    }
 
-	@Override
-	public long getStackSize()
-	{
-		return this.stackSize;
-	}
+    @Override
+    public T setCountRequestable(final long countRequestable) {
+        this.countRequestable = countRequestable;
+        return (T) this;
+    }
 
-	@Override
-	public StackType setStackSize( final long ss )
-	{
-		this.stackSize = ss;
-		return (StackType) this;
-	}
+    @Override
+    public boolean isCraftable() {
+        return this.isCraftable;
+    }
 
-	@Override
-	public long getCountRequestable()
-	{
-		return this.countRequestable;
-	}
+    @Override
+    public T setCraftable(final boolean isCraftable) {
+        this.isCraftable = isCraftable;
+        return (T) this;
+    }
 
-	@Override
-	public StackType setCountRequestable( final long countRequestable )
-	{
-		this.countRequestable = countRequestable;
-		return (StackType) this;
-	}
+    @Override
+    public T reset() {
+        this.stackSize = 0;
+        this.setCountRequestable(0);
+        this.setCraftable(false);
+        return (T) this;
+    }
 
-	@Override
-	public boolean isCraftable()
-	{
-		return this.isCraftable;
-	}
+    @Override
+    public T empty() {
+        final T dup = this.copy();
+        dup.reset();
+        return dup;
+    }
 
-	@Override
-	public StackType setCraftable( final boolean isCraftable )
-	{
-		this.isCraftable = isCraftable;
-		return (StackType) this;
-	}
+    @Override
+    public boolean isMeaningful() {
+        return this.stackSize != 0 || this.countRequestable > 0 || this.isCraftable;
+    }
 
-	@Override
-	public StackType reset()
-	{
-		this.stackSize = 0;
-		// priority = Integer.MIN_VALUE;
-		this.setCountRequestable( 0 );
-		this.setCraftable( false );
-		return (StackType) this;
-	}
+    @Override
+    public void incStackSize(final long i) {
+        this.stackSize += i;
+    }
 
-	@Override
-	public StackType empty()
-	{
-		final StackType dup = this.copy();
-		dup.reset();
-		return dup;
-	}
+    @Override
+    public void decStackSize(final long i) {
+        this.stackSize -= i;
+    }
 
-	@Override
-	public boolean isMeaningful()
-	{
-		return this.stackSize != 0 || this.countRequestable > 0 || this.isCraftable;
-	}
+    @Override
+    public void incCountRequestable(final long i) {
+        this.countRequestable += i;
+    }
 
-	@Override
-	public void incStackSize( final long i )
-	{
-		this.stackSize += i;
-	}
+    @Override
+    public void decCountRequestable(final long i) {
+        this.countRequestable -= i;
+    }
 
-	@Override
-	public void decStackSize( final long i )
-	{
-		this.stackSize -= i;
-	}
+    protected abstract boolean hasTagCompound();
 
-	@Override
-	public void incCountRequestable( final long i )
-	{
-		this.countRequestable += i;
-	}
+    protected static long getPacketValue( final byte type, final ByteBuf tag )
+    {
+        if( type == 0 )
+        {
+            long l = tag.readByte();
+            l -= Byte.MIN_VALUE;
+            return l;
+        }
+        else if( type == 1 )
+        {
+            long l = tag.readShort();
+            l -= Short.MIN_VALUE;
+            return l;
+        }
+        else if( type == 2 )
+        {
+            long l = tag.readInt();
+            l -= Integer.MIN_VALUE;
+            return l;
+        }
 
-	@Override
-	public void decCountRequestable( final long i )
-	{
-		this.countRequestable -= i;
-	}
+        return tag.readLong();
+    }
 
-	protected byte getType( final long num )
-	{
-		if( num <= 255 )
-		{
-			return 0;
-		}
-		else if( num <= 65535 )
-		{
-			return 1;
-		}
-		else if( num <= 4294967295L )
-		{
-			return 2;
-		}
-		else
-		{
-			return 3;
-		}
-	}
+    protected void putPacketValue( final ByteBuf tag, final long num )
+    {
+        if( num <= 255 )
+        {
+            tag.writeByte( (byte) ( num + Byte.MIN_VALUE ) );
+        }
+        else if( num <= 65535 )
+        {
+            tag.writeShort( (short) ( num + Short.MIN_VALUE ) );
+        }
+        else if( num <= 4294967295L )
+        {
+            tag.writeInt( (int) ( num + Integer.MIN_VALUE ) );
+        }
+        else
+        {
+            tag.writeLong( num );
+        }
+    }
 
-	protected abstract boolean hasTagCompound();
-
-	protected void putPacketValue( final ByteBuf tag, final long num )
-	{
-		if( num <= 255 )
-		{
-			tag.writeByte( (byte) ( num + Byte.MIN_VALUE ) );
-		}
-		else if( num <= 65535 )
-		{
-			tag.writeShort( (short) ( num + Short.MIN_VALUE ) );
-		}
-		else if( num <= 4294967295L )
-		{
-			tag.writeInt( (int) ( num + Integer.MIN_VALUE ) );
-		}
-		else
-		{
-			tag.writeLong( num );
-		}
-	}
+    protected byte getType( final long num )
+    {
+        if( num <= 255 )
+        {
+            return 0;
+        }
+        else if( num <= 65535 )
+        {
+            return 1;
+        }
+        else if( num <= 4294967295L )
+        {
+            return 2;
+        }
+        else
+        {
+            return 3;
+        }
+    }
 }

src/main/java/appeng/util/item/FuzzyItemVariantList.java

@@ -0,0 +1,179 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2021, TeamAppliedEnergistics, 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.util.item;
+
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Map;
+
+import com.google.common.base.Preconditions;
+
+import net.minecraft.item.ItemStack;
+
+import it.unimi.dsi.fastutil.objects.Object2ObjectAVLTreeMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectSortedMap;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+/**
+ * This variant list is optimized for damageable items, and supports selecting durability ranges with
+ * {@link #findFuzzy(IAEItemStack, FuzzyMode)}.
+ */
+class FuzzyItemVariantList extends ItemVariantList {
+
+    static final SharedStackComparator COMPARATOR = new SharedStackComparator();
+
+    // NOTE: We only use Object as they key here so we can pass our special DamageBounds to the subMap method.
+    // We NEVER put any keys in this map that are not AESharedItemStacks.
+    private final Object2ObjectSortedMap<Object, IAEItemStack> records = new Object2ObjectAVLTreeMap<>(COMPARATOR);
+
+    @Override
+    public Collection<IAEItemStack> findFuzzy(final IAEItemStack filter, final FuzzyMode fuzzy) {
+        ItemStack itemStack = filter.getDefinition();
+
+        ItemDamageBound lowerBound = makeLowerBound(itemStack, fuzzy);
+        ItemDamageBound upperBound = makeUpperBound(itemStack, fuzzy);
+        Preconditions.checkState(lowerBound.itemDamage > upperBound.itemDamage);
+
+        return this.records.subMap(lowerBound, upperBound).values();
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    Map<AESharedItemStack, IAEItemStack> getRecords() {
+        // We ensure on our end that we NEVER use anything but AESharedItemStack as the key in this map
+        return (Map<AESharedItemStack, IAEItemStack>) (Object) this.records;
+    }
+
+    static class ItemDamageBound {
+        final int itemDamage;
+
+        public ItemDamageBound(int itemDamage) {
+            this.itemDamage = itemDamage;
+        }
+    }
+
+    /**
+     * This comparator creates a strict and total ordering over all {@link AESharedItemStack} of the same item. To
+     * support selecting ranges of durability, it is defined for type {@link Object} and also accepts
+     * {@link ItemDamageBound} as an argument to compare against.
+     */
+    static class SharedStackComparator implements Comparator<Object> {
+        @Override
+        public int compare(Object a, Object b) {
+            // Either argument can either be a damage bound or a shared item stack
+            // Since we never put damage bounds into the map as keys, only one
+            // of the two arguments can possibly be a bound
+            ItemDamageBound boundA = null;
+            AESharedItemStack stackA = null;
+            int itemDamageA;
+            if (a instanceof ItemDamageBound) {
+                boundA = (ItemDamageBound) a;
+                itemDamageA = boundA.itemDamage;
+            } else {
+                stackA = (AESharedItemStack) a;
+                itemDamageA = stackA.getItemDamage();
+            }
+            ItemDamageBound boundB = null;
+            AESharedItemStack stackB = null;
+            int itemDamageB;
+            if (b instanceof ItemDamageBound) {
+                boundB = (ItemDamageBound) b;
+                itemDamageB = boundB.itemDamage;
+            } else {
+                stackB = (AESharedItemStack) b;
+                itemDamageB = stackB.getItemDamage();
+            }
+
+            // When either argument is a damage bound, we just compare the damage values because it is used
+            // only to get a certain damage range out of the map.
+            if (boundA != null || boundB != null) {
+                return Integer.compare(itemDamageB, itemDamageA);
+            }
+
+            ItemStack itemStackA = stackA.getDefinition();
+            ItemStack itemStackB = stackB.getDefinition();
+            Preconditions.checkState(itemStackA.getCount() == 1, "ItemStack#getCount() has to be 1");
+            Preconditions.checkArgument(itemStackB.getCount() == 1, "ItemStack#getCount() has to be 1");
+
+            if (itemStackA == itemStackB) {
+                return 0;
+            }
+
+            // Damaged items are sorted before undamaged items
+            final int damageValue = Integer.compare(itemDamageB, itemDamageA);
+            if (damageValue != 0) {
+                return damageValue;
+            }
+
+            // As a final tie breaker, order by the object identity of the item stack
+            // While this will order seemingly at random, we only need the order of
+            // damage values to be predictable, while still having to satisfy the
+            // complete order requirements of the sorted map
+            return Long.compare(System.identityHashCode(itemStackA), System.identityHashCode(itemStackB));
+        }
+    }
+
+    /**
+     * Minecraft reverses the damage values. So anything with a damage of 0 is undamaged and increases the more damaged
+     * the item is.
+     * <p>
+     * Further the used subMap follows [MAX_DAMAGE, MIN_DAMAGE), so to include undamaged items, we have to start with a
+     * lower damage value than 0, while it is fine to use {@link ItemStack#getMaxDamage()} for the upper bound.
+     */
+    private static final int MIN_DAMAGE_VALUE = -1;
+
+    /*
+     * Keep in mind that the stack order is from most damaged to least damaged, so this lower bound will actually be a
+     * higher number than the upper bound.
+     */
+    static ItemDamageBound makeLowerBound(final ItemStack stack, final FuzzyMode fuzzy) {
+        Preconditions.checkState(((stack.getMaxDamage() == 0 && stack.getItemDamage() > 0 ) || stack.isItemStackDamageable()), "ItemStack#isDamageable() has to be true");
+
+        int damage;
+        if (fuzzy == FuzzyMode.IGNORE_ALL) {
+            damage = stack.getMaxDamage();
+        } else {
+            final int breakpoint = fuzzy.calculateBreakPoint(stack.getMaxDamage());
+            damage = stack.getItemDamage() <= breakpoint ? breakpoint : stack.getMaxDamage();
+        }
+
+        return new ItemDamageBound(damage);
+    }
+
+    /*
+     * Keep in mind that the stack order is from most damaged to least damaged, so this upper bound will actually be a
+     * lower number than the lower bound. It also is exclusive.
+     */
+    static ItemDamageBound makeUpperBound(final ItemStack stack, final FuzzyMode fuzzy) {
+        Preconditions.checkState(((stack.getMaxDamage() == 0 && stack.getItemDamage() > 0 ) || stack.isItemStackDamageable()), "ItemStack#isDamageable() has to be true");
+
+        int damage;
+        if (fuzzy == FuzzyMode.IGNORE_ALL) {
+            damage = MIN_DAMAGE_VALUE;
+        } else {
+            final int breakpoint = fuzzy.calculateBreakPoint(stack.getMaxDamage());
+            damage = stack.getItemDamage() <= breakpoint ? MIN_DAMAGE_VALUE : breakpoint;
+        }
+
+        return new ItemDamageBound(damage);
+    }
+
+}

src/main/java/appeng/util/item/ItemList.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of Applied Energistics 2.
- * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
+ * Copyright (c) 2013 - 2020, 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
@@ -18,212 +18,196 @@
 
 package appeng.util.item;
 
-
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.ConcurrentModificationException;
 import java.util.Iterator;
-import java.util.NavigableMap;
-import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.NoSuchElementException;
+import java.util.concurrent.atomic.AtomicInteger;
 
-import net.minecraftforge.oredict.OreDictionary;
+import net.minecraft.item.Item;
+
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
 
 import appeng.api.config.FuzzyMode;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.api.storage.data.IItemList;
-import appeng.util.item.AESharedItemStack.Bounds;
 
+public final class ItemList implements IItemList<IAEItemStack> {
 
-public final class ItemList implements IItemList<IAEItemStack>
-{
+    private final Reference2ObjectMap<Item, ItemVariantList> records = new Reference2ObjectOpenHashMap<>();
+    /**
+     * We increment this version field everytime an attempt to mutate this item list (or potentially one of its
+     * sub-lists) is made. Iterators will copy the version when they are created and compare it against the current
+     * version whenever they advance to trigger a {@link ConcurrentModificationException}.
+     */
+    private final AtomicInteger version = new AtomicInteger(0);
 
-	private final NavigableMap<AESharedItemStack, IAEItemStack> records = new ConcurrentSkipListMap<>();
+    @Override
+    public IAEItemStack findPrecise(final IAEItemStack itemStack) {
+        if (itemStack == null) {
+            return null;
+        }
 
-	@Override
-	public void add( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        ItemVariantList record = this.records.get(itemStack.getItem());
+        return record != null ? record.findPrecise(itemStack) : null;
+    }
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+    @Override
+    public Collection<IAEItemStack> findFuzzy(final IAEItemStack filter, final FuzzyMode fuzzy) {
+        if (filter == null) {
+            return Collections.emptyList();
+        }
 
-		if( st != null )
-		{
-			st.add( option );
-			return;
-		}
+        ItemVariantList record = this.records.get(filter.getItem());
+        return record != null ? record.findFuzzy(filter, fuzzy) : Collections.emptyList();
+    }
 
-		final IAEItemStack opt = option.copy();
+    @Override
+    public boolean isEmpty() {
+        return !this.iterator().hasNext();
+    }
 
-		this.putItemRecord( opt );
-	}
+    @Override
+    public void add(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-	@Override
-	public IAEItemStack findPrecise( final IAEItemStack itemStack )
-	{
-		if( itemStack == null )
-		{
-			return null;
-		}
+        if (itemStack == null) {
+            return;
+        }
 
-		return this.records.get( ( (AEItemStack) itemStack ).getSharedStack() );
-	}
+        this.getOrCreateRecord(itemStack.getItem()).add(itemStack);
+    }
 
-	@Override
-	public Collection<IAEItemStack> findFuzzy( final IAEItemStack filter, final FuzzyMode fuzzy )
-	{
-		if( filter == null )
-		{
-			return Collections.emptyList();
-		}
+    @Override
+    public void addStorage(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-		final AEItemStack ais = (AEItemStack) filter;
+        if (itemStack == null) {
+            return;
+        }
 
-		return ais.getOre().map( or ->
-		{
-			if( or.getAEEquivalents().size() == 1 )
-			{
-				final IAEItemStack is = or.getAEEquivalents().get( 0 );
+        this.getOrCreateRecord(itemStack.getItem()).addStorage(itemStack);
+    }
 
-				return this.findFuzzyDamage( is, fuzzy, is.getItemDamage() == OreDictionary.WILDCARD_VALUE );
-			}
-			else
-			{
-				final Collection<IAEItemStack> output = new ArrayList<>();
+    @Override
+    public void addCrafting(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-				for( final IAEItemStack is : or.getAEEquivalents() )
-				{
-					output.addAll( this.findFuzzyDamage( is, fuzzy, is.getItemDamage() == OreDictionary.WILDCARD_VALUE ) );
-				}
+        if (itemStack == null) {
+            return;
+        }
 
-				return output;
-			}
-		} ).orElse( this.findFuzzyDamage( ais, fuzzy, false ) );
-	}
+        this.getOrCreateRecord(itemStack.getItem()).addCrafting(itemStack);
+    }
 
-	@Override
-	public boolean isEmpty()
-	{
-		return !this.iterator().hasNext();
-	}
+    @Override
+    public void addRequestable(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-	@Override
-	public void addStorage( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        if (itemStack == null) {
+            return;
+        }
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+        this.getOrCreateRecord(itemStack.getItem()).addRequestable(itemStack);
+    }
 
-		if( st != null )
-		{
-			st.incStackSize( option.getStackSize() );
-			return;
-		}
+    @Override
+    public IAEItemStack getFirstItem() {
+        for (final IAEItemStack stackType : this) {
+            return stackType;
+        }
 
-		final IAEItemStack opt = option.copy();
+        return null;
+    }
 
-		this.putItemRecord( opt );
-	}
+    @Override
+    public int size() {
+        int size = 0;
+        for (ItemVariantList entry : records.values()) {
+            size += entry.size();
+        }
 
-	/*
-	 * public void clean() { Iterator<StackType> i = iterator(); while (i.hasNext()) { StackType AEI =
-	 * i.next(); if ( !AEI.isMeaningful() ) i.remove(); } }
-	 */
+        return size;
+    }
 
-	@Override
-	public void addCrafting( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+    @Override
+    public Iterator<IAEItemStack> iterator() {
+        return new ChainedIterator(this.records.values().iterator(), version);
+    }
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+    @Override
+    public void resetStatus() {
+        for (final IAEItemStack i : this) {
+            i.reset();
+        }
+    }
 
-		if( st != null )
-		{
-			st.setCraftable( true );
-			return;
-		}
+    private ItemVariantList getOrCreateRecord(Item item) {
+        return this.records.computeIfAbsent(item, this::makeRecordMap);
+    }
 
-		final IAEItemStack opt = option.copy();
-		opt.setStackSize( 0 );
-		opt.setCraftable( true );
+    private ItemVariantList makeRecordMap(Item item) {
+        if (item.isDamageable()) {
+            return new FuzzyItemVariantList();
+        } else {
+            return new NormalItemVariantList();
+        }
+    }
 
-		this.putItemRecord( opt );
-	}
+    /**
+     * Iterates over multiple item lists as if they were one list.
+     */
+    private static class ChainedIterator implements Iterator<IAEItemStack> {
 
-	@Override
-	public void addRequestable( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        private final AtomicInteger parentVersion;
+        private final int version;
+        private final Iterator<ItemVariantList> parent;
+        private Iterator<IAEItemStack> next;
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+        public ChainedIterator(Iterator<ItemVariantList> iterator, AtomicInteger parentVersion) {
+            this.parent = iterator;
+            this.parentVersion = parentVersion;
+            this.version = parentVersion.get();
+            this.ensureItems();
+        }
 
-		if( st != null )
-		{
-			st.setCountRequestable( st.getCountRequestable() + option.getCountRequestable() );
-			return;
-		}
+        @Override
+        public boolean hasNext() {
+            return next != null && next.hasNext();
+        }
 
-		final IAEItemStack opt = option.copy();
-		opt.setStackSize( 0 );
-		opt.setCraftable( false );
-		opt.setCountRequestable( option.getCountRequestable() );
+        @Override
+        public IAEItemStack next() {
+            if (this.next == null) {
+                throw new NoSuchElementException();
+            }
+            if (this.version != this.parentVersion.get()) {
+                throw new ConcurrentModificationException();
+            }
 
-		this.putItemRecord( opt );
-	}
+            IAEItemStack result = this.next.next();
+            this.ensureItems();
+            return result;
+        }
 
-	@Override
-	public IAEItemStack getFirstItem()
-	{
-		for( final IAEItemStack stackType : this )
-		{
-			return stackType;
-		}
+        private void ensureItems() {
+            if (hasNext()) {
+                return; // Still items left in the current one
+            }
 
-		return null;
-	}
+            // Find the next iterator willing to return some items...
+            while (this.parent.hasNext()) {
+                this.next = this.parent.next().iterator();
 
-	@Override
-	public int size()
-	{
-		return this.records.size();
-	}
+                if (this.next.hasNext()) {
+                    return; // Found one!
+                }
+            }
 
-	@Override
-	public Iterator<IAEItemStack> iterator()
-	{
-		return new MeaningfulItemIterator<>( this.records.values().iterator() );
-	}
-
-	@Override
-	public void resetStatus()
-	{
-		for( final IAEItemStack i : this )
-		{
-			i.reset();
-		}
-	}
-
-	private IAEItemStack putItemRecord( final IAEItemStack itemStack )
-	{
-		return this.records.put( ( (AEItemStack) itemStack ).getSharedStack(), itemStack );
-	}
-
-	private Collection<IAEItemStack> findFuzzyDamage( final IAEItemStack filter, final FuzzyMode fuzzy, final boolean ignoreMeta )
-	{
-		final AEItemStack itemStack = (AEItemStack) filter;
-		final Bounds bounds = itemStack.getSharedStack().getBounds( fuzzy, ignoreMeta );
-
-		return this.records.subMap( bounds.lower(), true, bounds.upper(), true ).descendingMap().values();
-	}
+            // No more items
+            this.next = null;
+        }
+    }
 }

src/main/java/appeng/util/item/ItemModList.java

@@ -1,87 +0,0 @@
-/*
- * 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.util.item;
-
-
-import java.util.Collection;
-
-import appeng.api.AEApi;
-import appeng.api.config.FuzzyMode;
-import appeng.api.storage.channels.IItemStorageChannel;
-import appeng.api.storage.data.IAEItemStack;
-import appeng.api.storage.data.IItemContainer;
-
-
-public class ItemModList implements IItemContainer<IAEItemStack>
-{
-
-	private final IItemContainer<IAEItemStack> backingStore;
-	private final IItemContainer<IAEItemStack> overrides = AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ).createList();
-
-	public ItemModList( final IItemContainer<IAEItemStack> backend )
-	{
-		this.backingStore = backend;
-	}
-
-	@Override
-	public void add( final IAEItemStack option )
-	{
-		IAEItemStack over = this.overrides.findPrecise( option );
-		if( over == null )
-		{
-			over = this.backingStore.findPrecise( option );
-			if( over == null )
-			{
-				this.overrides.add( option );
-			}
-			else
-			{
-				option.add( over );
-				this.overrides.add( option );
-			}
-		}
-		else
-		{
-			this.overrides.add( option );
-		}
-	}
-
-	@Override
-	public IAEItemStack findPrecise( final IAEItemStack i )
-	{
-		final IAEItemStack over = this.overrides.findPrecise( i );
-		if( over == null )
-		{
-			return this.backingStore.findPrecise( i );
-		}
-		return over;
-	}
-
-	@Override
-	public Collection<IAEItemStack> findFuzzy( final IAEItemStack input, final FuzzyMode fuzzy )
-	{
-		return this.overrides.findFuzzy( input, fuzzy );
-	}
-
-	@Override
-	public boolean isEmpty()
-	{
-		return this.overrides.isEmpty() && this.backingStore.isEmpty();
-	}
-}

src/main/java/appeng/util/item/ItemVariantList.java

@@ -0,0 +1,118 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2021, TeamAppliedEnergistics, 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.util.item;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+/**
+ * Stores variants of a single type of {@link net.minecraft.item.Item}, i.e. versions with different durability, or
+ * different NBT or capabilities.
+ */
+abstract class ItemVariantList {
+
+    public void add(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.add(option);
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+
+        this.putItemRecord(opt);
+    }
+
+    public IAEItemStack findPrecise(final IAEItemStack itemStack) {
+        return this.getRecords().get(((AEItemStack) itemStack).getSharedStack());
+    }
+
+    public void addStorage(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.incStackSize(option.getStackSize());
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+
+        this.putItemRecord(opt);
+    }
+
+    public void addCrafting(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.setCraftable(true);
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+        opt.setStackSize(0);
+        opt.setCraftable(true);
+
+        this.putItemRecord(opt);
+    }
+
+    public void addRequestable(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.setCountRequestable(st.getCountRequestable() + option.getCountRequestable());
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+        opt.setStackSize(0);
+        opt.setCraftable(false);
+        opt.setCountRequestable(option.getCountRequestable());
+
+        this.putItemRecord(opt);
+    }
+
+    public int size() {
+        int size = 0;
+        for (IAEItemStack entry : getRecords().values()) {
+            if (entry.isMeaningful()) {
+                size++;
+            }
+        }
+
+        return size;
+    }
+
+    public Iterator<IAEItemStack> iterator() {
+        return new MeaningfulItemIterator<>(this.getRecords().values());
+    }
+
+    private void putItemRecord(final IAEItemStack itemStack) {
+        this.getRecords().put(((AEItemStack) itemStack).getSharedStack(), itemStack);
+    }
+
+    abstract Map<AESharedItemStack, IAEItemStack> getRecords();
+
+    public abstract Collection<IAEItemStack> findFuzzy(final IAEItemStack filter, final FuzzyMode fuzzy);
+
+}

src/main/java/appeng/util/item/MeaningfulItemIterator.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of Applied Energistics 2.
- * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
+ * Copyright (c) 2021, TeamAppliedEnergistics, 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
@@ -18,59 +18,53 @@
 
 package appeng.util.item;
 
-
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 
 import appeng.api.storage.data.IAEItemStack;
 
+/**
+ * This iterator will only return items from a collection that are meaningful (w.r.t.
+ * {@link IAEItemStack#isMeaningful()}. Items that are not meaningful are automatically removed from the collection as
+ * it is being iterated.
+ */
+public class MeaningfulItemIterator<T extends IAEItemStack> implements Iterator<T> {
+    private final Iterator<T> parent;
+    private T next;
 
-public class MeaningfulItemIterator<T extends IAEItemStack> implements Iterator<T>
-{
+    public MeaningfulItemIterator(final Collection<T> collection) {
+        this.parent = collection.iterator();
+        this.next = seekNext();
+    }
 
-	private final Iterator<T> parent;
-	private T next;
+    @Override
+    public boolean hasNext() {
+        return this.next != null;
+    }
 
-	public MeaningfulItemIterator( final Iterator<T> iterator )
-	{
-		this.parent = iterator;
-	}
+    @Override
+    public T next() {
+        if (this.next == null) {
+            throw new NoSuchElementException();
+        }
 
-	@Override
-	public boolean hasNext()
-	{
-		while( this.parent.hasNext() )
-		{
-			this.next = this.parent.next();
+        T result = this.next;
+        this.next = this.seekNext();
+        return result;
+    }
 
-			if( this.next.isMeaningful() )
-			{
-				return true;
-			}
-			else
-			{
-				this.parent.remove(); // self cleaning :3
-			}
-		}
+    private T seekNext() {
+        while (this.parent.hasNext()) {
+            T item = this.parent.next();
 
-		this.next = null;
-		return false;
-	}
+            if (item.isMeaningful()) {
+                return item;
+            } else {
+                this.parent.remove();
+            }
+        }
 
-	@Override
-	public T next()
-	{
-		if( this.next == null )
-		{
-			throw new NoSuchElementException();
-		}
-
-		return this.next;
-	}
-
-	@Override
-	public void remove()
-	{
-		this.parent.remove();
-	}
+        return null;
+    }
 }

src/main/java/appeng/util/item/NormalItemVariantList.java

@@ -0,0 +1,51 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2021, TeamAppliedEnergistics, 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.util.item;
+
+import java.util.Collection;
+import java.util.Map;
+
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+/**
+ * This variant list is optimized for items that cannot be damaged and thus do not support querying durability ranges
+ * via {@link #findFuzzy(IAEItemStack, FuzzyMode)}.
+ */
+class NormalItemVariantList extends ItemVariantList {
+
+    private final Reference2ObjectMap<AESharedItemStack, IAEItemStack> records = new Reference2ObjectOpenHashMap<>();
+
+    @Override
+    Map<AESharedItemStack, IAEItemStack> getRecords() {
+        return this.records;
+    }
+
+    /**
+     * For items that do not support durability, we just return all variants to a fuzzy search.
+     */
+    @Override
+    public Collection<IAEItemStack> findFuzzy(IAEItemStack filter, FuzzyMode fuzzy) {
+        return this.getRecords().values();
+    }
+
+}

src/test/java/appeng/util/EnumCyclerTest.java

@@ -0,0 +1,91 @@
+package appeng.util;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.EnumSet;
+
+import org.junit.jupiter.api.Test;
+
+class EnumCyclerTest {
+
+    @Test
+    void testRotateEnumForwardWithOnlySomeValidOptions() {
+        EnumSet<RotateTestEnum> validOptions = EnumSet.of(RotateTestEnum.A, RotateTestEnum.C, RotateTestEnum.E);
+        assertThat(EnumCycler.rotateEnum(RotateTestEnum.A, false, validOptions)).isEqualTo(RotateTestEnum.C);
+        assertThat(EnumCycler.rotateEnum(RotateTestEnum.C, false, validOptions)).isEqualTo(RotateTestEnum.E);
+        assertThat(EnumCycler.rotateEnum(RotateTestEnum.E, false, validOptions)).isEqualTo(RotateTestEnum.A);
+    }
+
+    @Test
+    void testRotateEnumBackwardsWithOnlySomeValidOptions() {
+        EnumSet<RotateTestEnum> validOptions = EnumSet.of(RotateTestEnum.A, RotateTestEnum.C, RotateTestEnum.E);
+        assertThat(EnumCycler.rotateEnum(RotateTestEnum.A, true, validOptions)).isEqualTo(RotateTestEnum.E);
+        assertThat(EnumCycler.rotateEnum(RotateTestEnum.C, true, validOptions)).isEqualTo(RotateTestEnum.A);
+        assertThat(EnumCycler.rotateEnum(RotateTestEnum.E, true, validOptions)).isEqualTo(RotateTestEnum.C);
+    }
+
+    /**
+     * When there are no valid options, the function should reject the arguments.
+     */
+    @Test
+    void testRotateEnumNoValidOptions() {
+        assertThrows(IllegalArgumentException.class, () -> {
+            EnumCycler.rotateEnum(TestEnum.A, false, EnumSet.noneOf(TestEnum.class));
+        });
+    }
+
+    /**
+     * When the current enum literal is not part of the valid options, it should just skip to the next valid option
+     * instead.
+     */
+    @Test
+    void testRotateEnumCurrentIsNotAValidOption() {
+        assertThat(EnumCycler.rotateEnum(TestEnum.B, false, EnumSet.of(TestEnum.A))).isEqualTo(TestEnum.A);
+        assertThat(EnumCycler.rotateEnum(TestEnum.B, true, EnumSet.of(TestEnum.A))).isEqualTo(TestEnum.A);
+    }
+
+    /**
+     * When there's only one valid option, it should just rotate back to it.
+     */
+    @Test
+    void testRotateEnumOnlyOneValidOption() {
+        assertThat(EnumCycler.rotateEnum(TestEnum.A, false, EnumSet.of(TestEnum.A))).isEqualTo(TestEnum.A);
+        assertThat(EnumCycler.rotateEnum(TestEnum.A, true, EnumSet.of(TestEnum.A))).isEqualTo(TestEnum.A);
+    }
+
+    @Test
+    void testNext() {
+        assertThat(EnumCycler.next(TestEnum.A)).isEqualTo(TestEnum.B);
+        assertThat(EnumCycler.next(TestEnum.B)).isEqualTo(TestEnum.C);
+        assertThat(EnumCycler.next(TestEnum.C)).isEqualTo(TestEnum.A);
+        assertThat(EnumCycler.next(SingleLiteralEnum.A)).isEqualTo(SingleLiteralEnum.A);
+    }
+
+    @Test
+    void testPrev() {
+        assertThat(EnumCycler.prev(TestEnum.A)).isEqualTo(TestEnum.C);
+        assertThat(EnumCycler.prev(TestEnum.B)).isEqualTo(TestEnum.A);
+        assertThat(EnumCycler.prev(TestEnum.C)).isEqualTo(TestEnum.B);
+        assertThat(EnumCycler.prev(SingleLiteralEnum.A)).isEqualTo(SingleLiteralEnum.A);
+    }
+
+    enum TestEnum {
+        A,
+        B,
+        C
+    }
+
+    enum RotateTestEnum {
+        A,
+        B,
+        C,
+        D,
+        E
+    }
+
+    enum SingleLiteralEnum {
+        A
+    }
+
+}

src/test/java/appeng/util/UUIDMatcherTest.java

@@ -1,61 +0,0 @@
-/*
- * 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.util;
-
-
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Test;
-
-
-/**
- * Tests for {@link UUIDMatcher}
- */
-public final class UUIDMatcherTest
-{
-	private static final String IS_UUID = "03ba29a1-d6bd-32ba-90b2-375e4d65abc9";
-	private static final String NO_UUID = "no";
-	private static final String INVALID_UUID = "g3ba29a1-d6bd-32ba-90b2-375e4d65abc9";
-
-	private final UUIDMatcher matcher;
-
-	public UUIDMatcherTest()
-	{
-		this.matcher = new UUIDMatcher();
-	}
-
-	@Test
-	public void testUUID_shouldPass()
-	{
-		assertTrue( this.matcher.isUUID( IS_UUID ) );
-	}
-
-	@Test
-	public void testNoUUD_shouldPass()
-	{
-		assertFalse( this.matcher.isUUID( NO_UUID ) );
-	}
-
-	@Test
-	public void testInvalidUUID_shouldPass()
-	{
-		assertFalse( this.matcher.isUUID( INVALID_UUID ) );
-	}
-}

src/test/java/appeng/util/WideReadableNumberConverterTest.java

@@ -21,7 +21,7 @@ package appeng.util;
 
 import static org.junit.Assert.assertEquals;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 
 /**

src/test/java/appeng/util/helpers/P2PHelperTest.java

@@ -22,7 +22,7 @@ package appeng.util.helpers;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import appeng.api.util.AEColor;
 

src/test/java/appeng/util/item/AESharedItemStackTest.java

@@ -0,0 +1,78 @@
+package appeng.util.item;
+
+import java.util.IdentityHashMap;
+import java.util.Map;
+
+import com.google.common.testing.EqualsTester;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+import net.minecraft.nbt.CompoundNBT;
+import net.minecraft.util.registry.Bootstrap;
+import net.minecraft.util.text.StringTextComponent;
+
+class AESharedItemStackTest {
+
+    @BeforeAll
+    static void bootstrap() {
+        Bootstrap.register();
+    }
+
+    // Test stack -> Name for debugging the tests
+    final Map<AESharedItemStack, String> stacks = new IdentityHashMap<>();
+
+    AESharedItemStackTest() {
+        TestItemWithCaps TEST_ITEM = new TestItemWithCaps();
+
+        ItemStack nameTag1 = new ItemStack(TEST_ITEM);
+        stacks.put(new AESharedItemStack(nameTag1), "no-nbt");
+
+        // NBT
+        ItemStack nameTag2 = new ItemStack(TEST_ITEM);
+        nameTag2.setDisplayName(new StringTextComponent("Hello World"));
+        stacks.put(new AESharedItemStack(nameTag2), "nbt1");
+
+        // Different NBT
+        ItemStack nameTag3 = new ItemStack(TEST_ITEM);
+        nameTag3.setDisplayName(new StringTextComponent("ABCDEFGH"));
+        stacks.put(new AESharedItemStack(nameTag3), "nbt2");
+
+        // NBT + Cap
+        CompoundNBT capNbt = new CompoundNBT();
+        capNbt.putInt("Parent", 1);
+        ItemStack nameTag4 = new ItemStack(TEST_ITEM, 1, capNbt);
+        nameTag4.setDisplayName(new StringTextComponent("Hello World"));
+        stacks.put(new AESharedItemStack(nameTag4), "nbt1+cap1");
+
+        // NBT + Different Cap
+        CompoundNBT capNbt2 = new CompoundNBT();
+        capNbt2.putInt("Parent", 123);
+        ItemStack nameTag5 = new ItemStack(TEST_ITEM, 1, capNbt2);
+        nameTag5.setDisplayName(new StringTextComponent("Hello World"));
+        stacks.put(new AESharedItemStack(nameTag5), "nbt1+cap2");
+    }
+
+    /**
+     * Tests equality between shared item stacks.
+     */
+    @Test
+    void testEquals() {
+        EqualsTester tester = new EqualsTester();
+        for (AESharedItemStack stack : stacks.keySet()) {
+            // Add the stack, and a pristine copy of the stack
+            tester.addEqualityGroup(stack, new AESharedItemStack(stack.getDefinition().copy()));
+        }
+
+        // Test that using the same item stack instance makes two separate shared stacks equal
+        ItemStack itemStack = new ItemStack(Items.CRAFTING_TABLE);
+        tester.addEqualityGroup(
+                new AESharedItemStack(itemStack),
+                new AESharedItemStack(itemStack));
+
+        tester.testEquals();
+    }
+
+}

src/test/java/appeng/util/item/FuzzyItemVariantListTest.java

@@ -0,0 +1,157 @@
+package appeng.util.item;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Arrays;
+
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+
+import appeng.api.config.FuzzyMode;
+
+public class FuzzyItemVariantListTest {
+
+    @Test
+    void testOrderForDamagedItems() {
+        // Diamond Sword @ 100% durability
+        ItemStack undamagedSword = new ItemStack(Items.DIAMOND_SWORD);
+        AESharedItemStack undamagedStack = new AESharedItemStack(undamagedSword);
+
+        // Unenchanted Diamond Sword @ 0% durability
+        ItemStack damagedSword = new ItemStack(Items.DIAMOND_SWORD);
+        damagedSword.setDamage(damagedSword.getMaxDamage());
+        AESharedItemStack damagedStack = new AESharedItemStack(damagedSword);
+
+        // Create a list of stacks and sort by their natural order
+        AESharedItemStack[] stacks = new AESharedItemStack[] {
+                damagedStack, undamagedStack
+        };
+        Arrays.sort(stacks, FuzzyItemVariantList.COMPARATOR);
+        assertThat(stacks).containsExactly(damagedStack, undamagedStack);
+    }
+
+    @Nested
+    class Bounds {
+        final ItemStack stack = new ItemStack(Items.DIAMOND_SWORD);
+        final ItemStack damagedStack;
+
+        {
+            damagedStack = stack.copy();
+            damagedStack.setDamage(damagedStack.getMaxDamage());
+        }
+
+        @Test
+        void testIgnoreAll() {
+            DamageBounds bounds = new DamageBounds(stack, FuzzyMode.IGNORE_ALL);
+            assertEquals(stack.getMaxDamage(), bounds.lower.itemDamage);
+            assertEquals(-1, bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_99 with an undamaged item should select only undamaged items, which translates to a damage range of
+         * [0, -1).
+         */
+        @Test
+        void test99PercentDurabilityWithUndamagedItem() {
+            DamageBounds bounds = new DamageBounds(stack, FuzzyMode.PERCENT_99);
+            assertEquals(0, bounds.lower.itemDamage);
+            assertEquals(-1, bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_99 with a damaged item should select only damaged items, which translates to a damage range of
+         * [maxDmg, 0).
+         */
+        @Test
+        void test99PercentDurabilityWithDamagedItem() {
+            DamageBounds bounds = new DamageBounds(damagedStack, FuzzyMode.PERCENT_99);
+            assertEquals(stack.getMaxDamage(), bounds.lower.itemDamage);
+            assertEquals(0, bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_75 with an undamaged item should select items that have 75% or more durability, which should
+         * translate to a damage range of [0.25*maxDmg, -1).
+         */
+        @Test
+        void test75PercentWithUndamagedItem() {
+            DamageBounds bounds = new DamageBounds(stack, FuzzyMode.PERCENT_75);
+            assertEquals((int) (0.25 * stack.getMaxDamage()), bounds.lower.itemDamage);
+            assertEquals(-1, bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_75 with a damaged item should select items that have less than 75% durability, which should translate
+         * to a damage range of [maxDmg, 0.25*maxDmg).
+         */
+        @Test
+        void test75PercentWithDamagedItem() {
+            DamageBounds bounds = new DamageBounds(damagedStack, FuzzyMode.PERCENT_75);
+            assertEquals(stack.getMaxDamage(), bounds.lower.itemDamage);
+            assertEquals((int) (0.25 * stack.getMaxDamage()), bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_50 with an undamaged item should select items that have 50% or more durability, which should
+         * translate to a damage range of [0.50*maxDmg, -1).
+         */
+        @Test
+        void test50PercentWithUndamagedItem() {
+            DamageBounds bounds = new DamageBounds(stack, FuzzyMode.PERCENT_50);
+            assertEquals((int) (0.50 * stack.getMaxDamage()), bounds.lower.itemDamage);
+            assertEquals(-1, bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_50 with a damaged item should select items that have less than 50% durability, which should translate
+         * to a damage range of [maxDmg, 0.50*maxDmg).
+         */
+        @Test
+        void test50PercentWithDamagedItem() {
+            DamageBounds bounds = new DamageBounds(damagedStack, FuzzyMode.PERCENT_50);
+            assertEquals(stack.getMaxDamage(), bounds.lower.itemDamage);
+            assertEquals((int) (0.50 * stack.getMaxDamage()), bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_25 with an undamaged item should select items that have 25% or more durability, which should
+         * translate to a damage range of [0.75*maxDmg, -1).
+         */
+        @Test
+        void test25PercentWithUndamagedItem() {
+            DamageBounds bounds = new DamageBounds(stack, FuzzyMode.PERCENT_25);
+            assertEquals((int) (0.75 * stack.getMaxDamage()), bounds.lower.itemDamage);
+            assertEquals(-1, bounds.upper.itemDamage);
+        }
+
+        /**
+         * PERCENT_25 with a damaged item should select items that have less than 25% durability, which should translate
+         * to a damage range of [maxDmg, 0.75*maxDmg).
+         */
+        @Test
+        void test25PercentWithDamagedItem() {
+            DamageBounds bounds = new DamageBounds(damagedStack, FuzzyMode.PERCENT_25);
+            assertEquals(stack.getMaxDamage(), bounds.lower.itemDamage);
+            assertEquals((int) (0.75 * stack.getMaxDamage()), bounds.upper.itemDamage);
+        }
+
+    }
+
+    private static class DamageBounds {
+        final FuzzyItemVariantList.ItemDamageBound lower;
+        final FuzzyItemVariantList.ItemDamageBound upper;
+
+        public DamageBounds(ItemStack stack, FuzzyMode mode) {
+            lower = FuzzyItemVariantList.makeLowerBound(stack, mode);
+            upper = FuzzyItemVariantList.makeUpperBound(stack, mode);
+
+            // This may be counter intuitive, but the map is sorted in descending order of item damage
+            assertThat(lower.itemDamage).isGreaterThan(upper.itemDamage);
+        }
+    }
+
+}

src/test/java/appeng/util/item/ItemListTest.java

@@ -0,0 +1,452 @@
+package appeng.util.item;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterators;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+import net.minecraft.util.text.StringTextComponent;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+public class ItemListTest {
+
+    ItemList itemList = new ItemList();
+
+    /**
+     * add should merge item stacks by adding stored/requestable counts, and setting craftable if it wasn't set before.
+     */
+    @Test
+    public void testAddMergesAllStackProperties() {
+        itemList.add(diamondSword(100, 1, 0, false));
+        assertPreciseStackProperties(diamondSwordFilter(100), 1, 0, false);
+
+        itemList.add(diamondSword(100, 0, 1, false));
+        assertPreciseStackProperties(diamondSwordFilter(100), 1, 1, false);
+
+        itemList.add(diamondSword(100, 0, 0, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 1, 1, true);
+    }
+
+    /**
+     * addStorage only considers {@link IAEItemStack#getStackSize()} and ignores other properties when merging stacks,
+     * but inherits all properties when it's adding a new item.
+     */
+    @Test
+    public void testAddStorageForNewItem() {
+        // TODO: This might actually be incorrect, given how addrequestable et al behave
+        itemList.addStorage(diamondSword(100, 1, 1, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 1, 1, true);
+    }
+
+    @Test
+    public void testAddStorageForExistingItem() {
+        itemList.addStorage(diamondSword(100, 1, 0, false));
+        itemList.addStorage(diamondSword(100, 1, 2, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 2, 0, false);
+    }
+
+    /**
+     * addRequestable only considers {@link IAEItemStack#getCountRequestable()} and sets the stored amount to 0 and
+     * craftable to false when adding an item.
+     */
+    @Test
+    public void testAddRequestableForNewItem() {
+        itemList.addRequestable(diamondSword(100, 1, 2, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 0, 2, false);
+    }
+
+    /**
+     * addRequestable only considers {@link IAEItemStack#getCountRequestable()} when merging into an existing item.
+     */
+    @Test
+    public void testAddRequestableForExistingItem() {
+        itemList.addRequestable(diamondSword(100, 0, 1, false));
+        itemList.addRequestable(diamondSword(100, 2, 1, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 0, 2, false);
+    }
+
+    /**
+     * addCraftable only considers {@link IAEItemStack#isCraftable()} and sets the stored and requestable amounts to 0
+     * when adding an item.
+     */
+    @Test
+    public void testAddCraftingForNewItem() {
+        itemList.addCrafting(diamondSword(100, 1, 2, true));
+        // TODO: I think it is unintended that the requestable amount is used
+        assertPreciseStackProperties(diamondSwordFilter(100), 0, 2, true);
+    }
+
+    /**
+     * addRequestable only considers {@link IAEItemStack#getCountRequestable()} when merging into an existing item.
+     */
+    @Test
+    public void testAddCraftingForExistingItem() {
+        itemList.addCrafting(diamondSword(100, 0, 0, false));
+        itemList.addCrafting(diamondSword(100, 1, 2, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 0, 0, true);
+    }
+
+    /**
+     * an empty craftable stack still creates an entry in the list
+     */
+    @Test
+    public void testAddEmptyStackThatIsCraftable() {
+        itemList.add(diamondSword(100, 0, 0, true));
+        assertPreciseStackProperties(diamondSwordFilter(100), 0, 0, true);
+    }
+
+    /**
+     * check that craftable isn't accidentally reset to false when merging stacks
+     */
+    @Test
+    public void testAddDoesNotResetCraftableBackToFalse() {
+        itemList.add(diamondSword(100, 0, 0, true));
+        itemList.add(diamondSword(100, 1, 0, false));
+        assertPreciseStackProperties(diamondSwordFilter(100), 1, 0, true);
+    }
+
+    /**
+     * stacks for the same item, but different damage values should not be merged
+     */
+    @Test
+    public void testAddDoesNotMergeAcrossDamageValues() {
+        itemList.add(diamondSword(100, 1, 0, false));
+        itemList.add(diamondSword(99, 1, 0, false));
+        assertPreciseStackProperties(diamondSwordFilter(100), 1, 0, false);
+        assertPreciseStackProperties(diamondSwordFilter(99), 1, 0, false);
+    }
+
+    private void assertPreciseStackProperties(IAEItemStack stack, long stored, long requestable, boolean craftable) {
+        IAEItemStack storedStack = itemList.findPrecise(stack);
+        assertEquals(stored, storedStack.getStackSize(), "stored amount");
+        assertEquals(requestable, storedStack.getCountRequestable(), "requestable amount");
+        assertEquals(craftable, storedStack.isCraftable(), "craftable");
+    }
+
+    /**
+     * Even if the stack has no stored or requestable amounts, it should be returned by the item list if it is
+     * craftable.
+     */
+    @Test
+    public void testSizeAndIterateForEmptyButCraftableStack() {
+        itemList.add(diamondSword(100, 0, 0, true));
+        assertListContent(diamondSword(100, 0, 0, true));
+    }
+
+    /**
+     * If the stack is not craftable, an empty stack is actually ignored.
+     */
+    @Test
+    public void testEmptyStackIsIgnored() {
+        itemList.add(diamondSword(100, 0, 0, false));
+        assertListContent();
+    }
+
+    @Test
+    public void testResetStatus() {
+        itemList.add(diamondSword(100, 1, 0, false));
+        itemList.add(nameTag(1, 0, false));
+        assertEquals(2, itemList.size());
+
+        itemList.resetStatus();
+
+        assertListContent(); // The list should now be empty
+    }
+
+    /**
+     * Tests that iteration across multiple items and variations of those items works.
+     */
+    @Test
+    public void testIterateAcrossMultipleItems() {
+        // Add damaged variants of the same item, including NBT variants
+        AEItemStack sword1 = diamondSword(100, 1, 0, false);
+        itemList.add(sword1);
+        AEItemStack sword2 = diamondSword(50, 1, 0, false);
+        itemList.add(sword2);
+        AEItemStack sword3 = diamondSword(25, 1, 0, false);
+        itemList.add(sword3);
+        AEItemStack sword4 = diamondSword(100, "master sword", 1, 0, false);
+        itemList.add(sword4);
+        // And a non-damagable item with different NBT
+        AEItemStack nameTag1 = nameTag(1, 0, false);
+        itemList.add(nameTag1);
+        AEItemStack nameTag2 = nameTag("bob", 1, 0, false);
+        itemList.add(nameTag2);
+
+        assertListContent(sword1, sword2, sword3, sword4, nameTag1, nameTag2);
+    }
+
+    @Test
+    void testConcurrentModificationByAddingItemType() {
+        AEItemStack sword = diamondSword(100, 1, 0, false);
+        itemList.add(sword);
+        AEItemStack nameTag = nameTag(1, 0, false);
+        itemList.add(nameTag);
+        AEItemStack craftingTable = AEItemStack.fromItemStack(new ItemStack(Items.CRAFTING_TABLE));
+
+        assertThrows(ConcurrentModificationException.class, () -> {
+            Iterator<IAEItemStack> it = itemList.iterator();
+            itemList.add(craftingTable);
+            assertThat(Iterators.toArray(it, IAEItemStack.class)).containsOnly(sword, nameTag);
+        });
+    }
+
+    /**
+     * Regression test for broken iterators that mutated state in {@see Iterator#hasNext}. This was the case for both
+     * the top-level and sub-iterator.
+     */
+    @Test
+    public void testIteratorHasNextDoesNotSkipItems() {
+        itemList.add(diamondSword(100, 1, 0, false));
+        itemList.add(diamondSword(50, 1, 0, false));
+
+        Iterator<IAEItemStack> it = itemList.iterator();
+        assertTrue(it.hasNext());
+        assertTrue(it.hasNext());
+        assertTrue(it.hasNext());
+    }
+
+    @Test
+    public void testGetFirstItemForEmptyList() {
+        assertNull(itemList.getFirstItem());
+    }
+
+    @Test
+    public void testGetFirstItem() {
+        AEItemStack itemStack = diamondSword(100, 1, 0, false);
+        itemList.add(itemStack);
+        // The order is no longer well defined w.r.t. the hashmap
+        assertEquals(itemStack, itemList.getFirstItem());
+    }
+
+    @Nested
+    class FindFuzzyDamageableItems {
+
+        // Swords to cover all durability values
+        AEItemStack swordAbove100 = diamondSword(101, 1, 0, false);
+        AEItemStack[] swords = new AEItemStack[101];
+        // Filters for inverting the filter as needed
+        AEItemStack undamagedFilter = diamondSwordFilter(100);
+        AEItemStack damagedFilter = diamondSwordFilter(0);
+
+        @BeforeEach
+        void addItems() {
+            itemList.add(swordAbove100);
+            for (int i = 0; i <= 100; i++) {
+                swords[i] = diamondSword(i, 1, 0, false);
+                assertEquals(i, getDurabilityPercent(swords[i]));
+                itemList.add(swords[i]);
+            }
+        }
+
+        @Test
+        public void testIgnoreAllWithUndamagedFilter() {
+            assertReturnedDurabilities(undamagedFilter, FuzzyMode.IGNORE_ALL, 0, 100, false);
+        }
+
+        @Test
+        public void testIgnoreAllWithDamagedFilter() {
+            assertReturnedDurabilities(damagedFilter, FuzzyMode.IGNORE_ALL, 0, 100, false);
+        }
+
+        @Test
+        public void testPercent99WithUndamagedFilter() {
+            assertReturnedDurabilities(undamagedFilter, FuzzyMode.PERCENT_99, 100, 100, false);
+        }
+
+        @Test
+        public void testPercent99WithDamagedFilter() {
+            assertReturnedDurabilities(damagedFilter, FuzzyMode.PERCENT_99, 0, 99, false);
+        }
+
+        @Test
+        public void testPercent75WithUndamagedFilter() {
+            assertReturnedDurabilities(undamagedFilter, FuzzyMode.PERCENT_75, 75, 100, false);
+        }
+
+        @Test
+        public void testPercent75WithDamagedFilter() {
+            assertReturnedDurabilities(damagedFilter, FuzzyMode.PERCENT_75, 0, 74, false);
+        }
+
+        @Test
+        public void testPercent50WithUndamagedFilter() {
+            assertReturnedDurabilities(undamagedFilter, FuzzyMode.PERCENT_50, 50, 100, false);
+        }
+
+        @Test
+        public void testPercent50WithDamagedFilter() {
+            assertReturnedDurabilities(damagedFilter, FuzzyMode.PERCENT_50, 0, 49, false);
+        }
+
+        @Test
+        public void testPercent25WithUndamagedFilter() {
+            assertReturnedDurabilities(undamagedFilter, FuzzyMode.PERCENT_25, 25, 100, false);
+        }
+
+        @Test
+        public void testPercent25WithDamagedFilter() {
+            assertReturnedDurabilities(damagedFilter, FuzzyMode.PERCENT_25, 0, 24, false);
+        }
+
+        private void assertReturnedDurabilities(IAEItemStack filter, FuzzyMode fuzzyMode, int minDurabilityInclusive,
+                int maxDurabilityInclusive, boolean above100) {
+            Collection<IAEItemStack> items = itemList.findFuzzy(filter, fuzzyMode);
+
+            // Build a list of the durabilities that got returned
+            List<Integer> durabilities = items.stream().map(this::getDurabilityPercent)
+                    .sorted()
+                    .collect(Collectors.toList());
+
+            // Build a sorted list of the durabilities we expect
+            List<Integer> expectedDurabilities = new ArrayList<>();
+            for (int i = minDurabilityInclusive; i <= maxDurabilityInclusive; i++) {
+                expectedDurabilities.add(getDurabilityPercent(swords[i]));
+            }
+            if (above100) {
+                expectedDurabilities.add(getDurabilityPercent(swordAbove100));
+            }
+            expectedDurabilities.sort(Integer::compare);
+
+            assertEquals(expectedDurabilities, durabilities);
+        }
+
+        private int getDurabilityPercent(IAEItemStack stack) {
+            if (stack == swordAbove100) {
+                return 101;
+            }
+            return (int) ((1.0f - (stack.getItemDamage() / (float) stack.getDefinition().getMaxDamage())) * 100);
+        }
+    }
+
+    @Test
+    void testFindFuzzyForNormalItems() {
+        AEItemStack item1 = nameTag(null, 1, 0, false);
+        itemList.add(item1);
+        AEItemStack item2 = nameTag("name1", 1, 0, false);
+        itemList.add(item2);
+        AEItemStack item3 = nameTag("name2", 1, 0, false);
+        itemList.add(item3);
+        // Add another item to ensure this is not returned
+        itemList.add(AEItemStack.fromItemStack(new ItemStack(Items.CRAFTING_TABLE)));
+
+        for (FuzzyMode fuzzyMode : FuzzyMode.values()) {
+            Collection<IAEItemStack> result = itemList.findFuzzy(nameTag(null, 0, 0, false), fuzzyMode);
+            assertThat(result).containsOnly(item1, item2, item3);
+        }
+    }
+
+    /**
+     * Tests how ItemList behaves w.r.t. null arguments, given that {@link AEItemStack#fromItemStack(ItemStack)} can
+     * return null for an empty stack, this sometimes leaks into method parameters. As such, methods should behave as if
+     * an empty item stack was passed.
+     */
+    @Nested
+    class NullArguments {
+        @BeforeEach
+        void addItem() {
+            itemList.add(diamondSword(100, 1, 0, false));
+        }
+
+        @Test
+        void testFindFuzzy() {
+            assertThat(itemList.findFuzzy(null, FuzzyMode.PERCENT_99)).isEmpty();
+        }
+
+        @Test
+        void testFindPrecise() {
+            assertThat(itemList.findPrecise(null)).isNull();
+        }
+
+        @Test
+        void testAdd() {
+            assertThat(itemList.size()).isEqualTo(1);
+            itemList.add(null);
+            assertThat(itemList.size()).isEqualTo(1);
+        }
+
+        @Test
+        void testAddStorage() {
+            assertThat(itemList.size()).isEqualTo(1);
+            itemList.addStorage(null);
+            assertThat(itemList.size()).isEqualTo(1);
+        }
+
+        @Test
+        void testAddRequestable() {
+            assertThat(itemList.size()).isEqualTo(1);
+            itemList.addRequestable(null);
+            assertThat(itemList.size()).isEqualTo(1);
+        }
+
+        @Test
+        void testAddCrafting() {
+            assertThat(itemList.size()).isEqualTo(1);
+            itemList.addCrafting(null);
+            assertThat(itemList.size()).isEqualTo(1);
+        }
+    }
+
+    private void assertListContent(AEItemStack... stacks) {
+        assertEquals(stacks.length == 0, itemList.isEmpty(), "isEmpty");
+        assertEquals(stacks.length, itemList.size());
+        assertEquals(ImmutableSet.copyOf(stacks), ImmutableSet.copyOf(itemList));
+    }
+
+    private AEItemStack diamondSwordFilter(int durabilityPercent) {
+        return diamondSword(durabilityPercent, 0, 0, false);
+    }
+
+    private AEItemStack diamondSword(int durabilityPercent, long stored, long requestable, boolean craftable) {
+        return diamondSword(durabilityPercent, null, stored, requestable, craftable);
+    }
+
+    private AEItemStack diamondSword(int durabilityPercent, String customName, long stored, long requestable,
+            boolean craftable) {
+        ItemStack is = new ItemStack(Items.DIAMOND_SWORD);
+        if (customName != null) {
+            is.setDisplayName(new StringTextComponent(customName));
+        }
+        int damage = (int) ((100 - durabilityPercent) / 100.0f * is.getMaxDamage());
+        is.setDamage(damage);
+        AEItemStack ais = AEItemStack.fromItemStack(is);
+        ais.setStackSize(stored);
+        ais.setCountRequestable(requestable);
+        ais.setCraftable(craftable);
+        return ais;
+    }
+
+    // customName can be used to create items that differ in NBT
+    private AEItemStack nameTag(long stored, long requestable, boolean craftable) {
+        return nameTag(null, stored, requestable, craftable);
+    }
+
+    private AEItemStack nameTag(String customName, long stored, long requestable, boolean craftable) {
+        ItemStack is = new ItemStack(Items.NAME_TAG);
+        if (customName != null) {
+            is.setDisplayName(new StringTextComponent(customName));
+        }
+        AEItemStack ais = AEItemStack.fromItemStack(is);
+        ais.setStackSize(stored);
+        ais.setCountRequestable(requestable);
+        ais.setCraftable(craftable);
+        return ais;
+    }
+
+}

src/test/java/appeng/util/item/TestItemWithCaps.java

@@ -0,0 +1,60 @@
+package appeng.util.item;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.CompoundNBT;
+import net.minecraft.nbt.IntNBT;
+import net.minecraft.util.Direction;
+import net.minecraftforge.common.capabilities.Capability;
+import net.minecraftforge.common.capabilities.ICapabilityProvider;
+import net.minecraftforge.common.util.INBTSerializable;
+import net.minecraftforge.common.util.LazyOptional;
+
+public class TestItemWithCaps extends Item {
+    public TestItemWithCaps() {
+        super(new Properties());
+        setRegistryName("appliedenergistics2:test_item");
+    }
+
+    @Nullable
+    @Override
+    public ICapabilityProvider initCapabilities(ItemStack stack, @Nullable CompoundNBT nbt) {
+        if (nbt == null) {
+            return null;
+        } else {
+            return new CapabilityProvider();
+        }
+    }
+
+    /**
+     * Simple capability provider that just has a single counter value to produce different NBT.
+     */
+    public static class CapabilityProvider implements ICapabilityProvider, INBTSerializable<IntNBT> {
+        private int counter;
+
+        @Nonnull
+        @Override
+        public <T> LazyOptional<T> getCapability(@Nonnull Capability<T> cap, @Nullable Direction side) {
+            return LazyOptional.empty();
+        }
+
+        @Nonnull
+        @Override
+        public <T> LazyOptional<T> getCapability(@Nonnull Capability<T> cap) {
+            return LazyOptional.empty();
+        }
+
+        @Override
+        public IntNBT serializeNBT() {
+            return IntNBT.valueOf(counter);
+        }
+
+        @Override
+        public void deserializeNBT(IntNBT nbt) {
+            counter = nbt.getInt();
+        }
+    }
+}