Fix remove(slot) method

- Add Remove/AddItemTransactionBlock

game/src/main/org/apollo/game/model/inv/Inventory.java

@@ -421,7 +421,10 @@ public final class Inventory {
 	public Optional<Item> remove(int slot) {
 		Item item = get(slot);
 		if (item != null) {
-			remove(item);
+			int amount = remove(item);
+			if (amount != item.getAmount()) {
+				return Optional.of(new Item(item.getId(), amount));
+			}
 			return Optional.of(item);
 		}
 		return Optional.empty();

game/src/main/org/apollo/game/model/inv/transaction/block/AddItemTransactionBlock.java

@@ -0,0 +1,43 @@
+package org.apollo.game.model.inv.transaction.block;
+
+import org.apollo.game.model.Item;
+import org.apollo.game.model.inv.Inventory;
+import org.apollo.game.model.inv.transaction.TransactionBlock;
+
+/**
+ * A TransactionBlock which adds an Item to an Inventory.
+ */
+public final class AddItemTransactionBlock implements TransactionBlock {
+
+	/**
+	 * The Inventory the Item is being added to.
+	 */
+	private final Inventory inventory;
+
+	/**
+	 * The Item we are adding to the Inventory.
+	 */
+	private final Item item;
+
+	/**
+	 * Creates a new {@link AddItemTransactionBlock}.
+	 *
+	 * @param inventory The Inventory we are adding the specified Item to.
+	 * @param item The Item to add to the Inventory.
+	 */
+	public AddItemTransactionBlock(Inventory inventory, Item item) {
+		this.inventory = inventory;
+		this.item = item;
+	}
+
+	@Override
+	public boolean commit() {
+		return !inventory.add(item).isPresent();
+	}
+
+	@Override
+	public void revert() {
+		inventory.remove(item);
+	}
+
+}

game/src/main/org/apollo/game/model/inv/transaction/block/RemoveItemTransactionBlock.java

@@ -0,0 +1,35 @@
+package org.apollo.game.model.inv.transaction.block;
+
+import java.util.Optional;
+
+import org.apollo.game.model.Item;
+import org.apollo.game.model.inv.Inventory;
+import org.apollo.game.model.inv.transaction.TransactionBlock;
+
+public final class RemoveItemTransactionBlock implements TransactionBlock {
+
+	private final Inventory inventory;
+
+	private final Item item;
+
+	private Optional<Item> removed = Optional.empty();
+
+	public RemoveItemTransactionBlock(Inventory inventory, Item item) {
+		this.inventory = inventory;
+		this.item = item;
+	}
+
+	@Override
+	public boolean commit() {
+		int slot = inventory.slotOf(item.getId());
+		removed = inventory.remove(slot);
+		return removed.get().equals(item);
+	}
+
+	@Override
+	public void revert() {
+		removed.ifPresent(inventory::add);
+		removed = Optional.empty();
+	}
+
+}