Update to 0.5.3, add inventory title tracking so we're working towards some of the inventory bugs with new ones.

Added proper update message (based on checkplys)

ISSUE_TEMPLATE.md

@@ -2,9 +2,11 @@
 
 ### What version of Spigot are you using? Type /ver
 
-### What plugins are you using? /plugins
+### What plugins are you using? Type /plugins
 
-### How does this error happen? login? using an item? 
+### Are you using any additional software like BungeeCord? If so, what software and version? (Please list your plugins as well)
+
+### How does this error happen? login? Using an item? 
 
 ### Is there an error in the console? Use pastebin.com. Is there a kick message?
 

README.md

@@ -1,17 +1,9 @@
-# ViaVersion 0.4.7
-**Allows the connection of 1.8 clients to 1.9**
+# ViaVersion 0.5.3
+**Allows the connection of 1.9 clients to 1.8**
 
 This plugin modifies netty to allow connection of 1.9 clients to 1.8,
 
-**Don't use late bind*
-
-**As of this point it doesn't have everything, I need to fix:**
-
-Attempt to make boats nicer when they don't work
-
-Remap spawn eggs
-
-If you have a bug with entities, please report the full stack trace
+###**Don't use late bind*
 
 
 This took hours of work, so if you enjoy this consider looking into contacting me and supporting my projects.
@@ -32,11 +24,17 @@ Contributors:
 --------
 
 **Myself** (harhar)
+
 **Matsv/StamBoom**
+
 **HugoDaBosss**
+
 **SanderGielisse**
+
 **Paulomart**
+
 **gigosaurus**
+
 **fillefilip8**
 
 **Chat: ** https://gitter.im/MylesIsCool/ViaVersion

pom.xml

@@ -5,9 +5,9 @@
 
     <groupId>us.myles</groupId>
     <artifactId>ViaVersion</artifactId>
-    <version>0.4.7</version>
+    <version>0.5.3</version>
     <build>
-        <finalName>ViaVersion-${version}</finalName>
+        <finalName>ViaVersion-${project.version}</finalName>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -27,6 +27,7 @@
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
+                <version>3.5.1</version>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
                     <source>1.7</source>

src/main/java/org/spacehq/mc/protocol/util/NetUtil.java

@@ -30,7 +30,7 @@ public class NetUtil {
             }
         }
 
-        if(fullChunk) {
+        if(fullChunk && column.getBiomeData() != null) {
             out.writeBytes(column.getBiomeData());
         }
 
@@ -103,7 +103,8 @@ public class NetUtil {
         }
 
         byte biomeData[] = null;
-        if(isFullChunk) {
+        if(isFullChunk && (pos + 256 <= input.length)) {
+
             biomeData = new byte[256];
             System.arraycopy(input, pos, biomeData, 0, biomeData.length);
         }

src/main/java/us/myles/ViaVersion/CancelException.java

@@ -1,4 +1,4 @@
 package us.myles.ViaVersion;
 
-public class CancelException extends Exception{
+public class CancelException extends Exception {
 }

src/main/java/us/myles/ViaVersion/ConnectionInfo.java

@@ -1,5 +1,7 @@
 package us.myles.ViaVersion;
 
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.socket.SocketChannel;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
@@ -12,6 +14,7 @@ public class ConnectionInfo {
     private Object lastPacket;
     private java.util.UUID UUID;
     private State state = State.HANDSHAKE;
+    private String openWindow;
     private int protocol = 0;
     private int compression = 0;
     private boolean active = true;
@@ -75,4 +78,26 @@ public class ConnectionInfo {
     public void setActive(boolean active) {
         this.active = active;
     }
+
+    public void sendRawPacket(final ByteBuf packet) {
+        final ChannelHandler handler = channel.pipeline().get("encoder");
+        channel.eventLoop().submit(new Runnable() {
+            @Override
+            public void run() {
+                channel.pipeline().context(handler).writeAndFlush(packet);
+            }
+        });
+    }
+
+    public String getOpenWindow() {
+        return openWindow;
+    }
+
+    public void setOpenWindow(String openWindow) {
+        this.openWindow = openWindow;
+    }
+
+    public void closeWindow() {
+        this.openWindow = null;
+    }
 }

src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -1,11 +1,14 @@
 package us.myles.ViaVersion;
 
+import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.socket.SocketChannel;
 import org.bukkit.Bukkit;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.configuration.file.YamlConfiguration;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
@@ -14,14 +17,19 @@ import org.bukkit.inventory.ItemStack;
 import org.bukkit.plugin.java.JavaPlugin;
 import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.ViaVersionAPI;
+import us.myles.ViaVersion.armor.ArmorListener;
 import us.myles.ViaVersion.commands.ViaVersionCommand;
 import us.myles.ViaVersion.handlers.ViaVersionInitializer;
+import us.myles.ViaVersion.listeners.CommandBlockListener;
+import us.myles.ViaVersion.update.UpdateListener;
+import us.myles.ViaVersion.update.UpdateUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
+import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.Field;
-import java.util.Collections;
 import java.util.List;
-import java.util.Set;
+import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
@@ -29,13 +37,17 @@ import java.util.concurrent.TimeUnit;
 
 public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
 
-    private final Set<UUID> portedPlayers = Collections.newSetFromMap(new ConcurrentHashMap<UUID, Boolean>());
+    private final Map<UUID, ConnectionInfo> portedPlayers = new ConcurrentHashMap<UUID, ConnectionInfo>();
+    private boolean debug = false;
+    private FileConfiguration config;
+    private File configFile;
 
     @Override
     public void onEnable() {
         ViaVersion.setInstance(this);
         if (System.getProperty("ViaVersion") != null) {
             getLogger().severe("ViaVersion is already loaded, we don't support reloads. Please reboot if you wish to update.");
+            getLogger().severe("Some features may not work.");
             return;
         }
 
@@ -47,13 +59,33 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
             getLogger().severe("Unable to inject handlers, are you on 1.8? ");
             e.printStackTrace();
         }
+
+        this.config = getFileConfiguration();
+        if (!config.contains("checkforupdates")) {
+            config.set("checkforupdates", true);
+            try {
+                config.save(configFile);
+            } catch (IOException e1) {
+                this.getLogger().info("Unabled to write config.yml!");
+                e1.printStackTrace();
+            }
+        }
+        if (config.getBoolean("checkforupdates")) {
+            Bukkit.getPluginManager().registerEvents(new UpdateListener(this), this);
+            UpdateUtil.sendUpdateMessage(this);
+        }
+
         Bukkit.getPluginManager().registerEvents(new Listener() {
             @EventHandler
             public void onPlayerQuit(PlayerQuitEvent e) {
-                setPorted(e.getPlayer().getUniqueId(), false);
+                removePortedClient(e.getPlayer().getUniqueId());
             }
         }, this);
-        getCommand("viaversion").setExecutor(new ViaVersionCommand());
+
+        Bukkit.getPluginManager().registerEvents(new ArmorListener(this), this);
+        Bukkit.getPluginManager().registerEvents(new CommandBlockListener(this), this);
+
+        getCommand("viaversion").setExecutor(new ViaVersionCommand(this));
     }
 
     public void injectPacketHandler() throws Exception {
@@ -88,7 +120,7 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
 
     @Override
     public boolean isPorted(Player player) {
-        return portedPlayers.contains(player.getUniqueId());
+        return portedPlayers.containsKey(player.getUniqueId());
     }
 
     @Override
@@ -96,17 +128,46 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         return getDescription().getVersion();
     }
 
-    public void setPorted(UUID id, boolean value) {
-        if (value) {
-            portedPlayers.add(id);
-        } else {
-            portedPlayers.remove(id);
-        }
+    public void sendRawPacket(Player player, ByteBuf packet) throws IllegalArgumentException {
+        if (!isPorted(player)) throw new IllegalArgumentException("This player is not on 1.9");
+        ConnectionInfo ci = portedPlayers.get(player.getUniqueId());
+        ci.sendRawPacket(packet);
+    }
+
+    @Override
+    public boolean isDebug() {
+        return this.debug;
+    }
+
+    public void setDebug(boolean value) {
+        this.debug = value;
+    }
+
+    public void addPortedClient(ConnectionInfo info) {
+        portedPlayers.put(info.getUUID(), info);
+    }
+
+    public void removePortedClient(UUID clientID) {
+        portedPlayers.remove(clientID);
+    }
+
+    private FileConfiguration getFileConfiguration() {
+        if (!this.getDataFolder().exists())
+            this.getDataFolder().mkdirs();
+        this.configFile = new File(this.getDataFolder(), "config.yml");
+        if (!this.configFile.exists())
+            try {
+                this.configFile.createNewFile();
+            } catch (IOException e) {
+                this.getLogger().info("Unable to create config.yml!");
+                e.printStackTrace();
+            }
+        return YamlConfiguration.loadConfiguration(this.configFile);
     }
 
     public static ItemStack getHandItem(final ConnectionInfo info) {
         try {
-            return Bukkit.getScheduler().callSyncMethod(getPlugin(ViaVersionPlugin.class), new Callable<ItemStack>() {
+            return Bukkit.getScheduler().callSyncMethod(Bukkit.getPluginManager().getPlugin("ViaVersion"), new Callable<ItemStack>() {
                 @Override
                 public ItemStack call() throws Exception {
                     if (info.getPlayer() != null) {
@@ -121,4 +182,4 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
             return null;
         }
     }
-}
+}

src/main/java/us/myles/ViaVersion/api/ViaVersionAPI.java

@@ -1,13 +1,33 @@
 package us.myles.ViaVersion.api;
 
+import io.netty.buffer.ByteBuf;
 import org.bukkit.entity.Player;
 
 public interface ViaVersionAPI {
     /**
      * Is player using 1.9?
      * @param player
-     * @return
+     * @return True if the client is on 1.9
      */
     boolean isPorted(Player player);
+
+    /**
+     * Get the version of the plugin
+     * @return Plugin version
+     */
     String getVersion();
+
+    /**
+     * Send a raw packet to the player (Use new IDs)
+     * @param player The player to send packet
+     * @param packet The packet, you need a VarInt ID then the packet contents.
+     * @throws IllegalArgumentException If not on 1.9 throws IllegalArg
+     */
+    void sendRawPacket(Player player, ByteBuf packet) throws IllegalArgumentException;
+
+    /**
+     * Obtain if global debug is enabled
+     * @return true if debug is enabled
+     */
+    boolean isDebug();
 }

src/main/java/us/myles/ViaVersion/armor/ArmorListener.java

@@ -0,0 +1,106 @@
+package us.myles.ViaVersion.armor;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.HumanEntity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.Action;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.inventory.CraftingInventory;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.packets.PacketType;
+
+import java.util.UUID;
+
+import static us.myles.ViaVersion.util.PacketUtil.*;
+
+public class ArmorListener implements Listener {
+
+    private final ViaVersionPlugin plugin;
+
+    private static UUID armorAttribute = UUID.fromString("2AD3F246-FEE1-4E67-B886-69FD380BB150");
+
+    public ArmorListener(ViaVersionPlugin plugin) {
+        this.plugin = plugin;
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onInventoryClick(InventoryClickEvent e) {
+        HumanEntity human = e.getWhoClicked();
+        if (human instanceof Player && e.getInventory() instanceof CraftingInventory) {
+            final Player player = (Player) human;
+            if (ViaVersion.getInstance().isPorted(player)) {
+                if (e.getCurrentItem() != null) {
+                    if (ArmorType.isArmor(e.getCurrentItem().getType())) {
+                        sendDelayedArmorUpdate(player);
+                        return;
+                    }
+                }
+                if (e.getRawSlot() >= 5 && e.getRawSlot() <= 8) {
+                    sendDelayedArmorUpdate(player);
+                    return;
+                }
+            }
+        }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onInteract(PlayerInteractEvent e) {
+        if (e.getItem() != null) {
+            if (e.getAction() == Action.RIGHT_CLICK_AIR || e.getAction() == Action.RIGHT_CLICK_BLOCK) {
+                if (ArmorType.isArmor(e.getMaterial())) {
+                    final Player player = e.getPlayer();
+                    // Due to odd bugs it's 3 ticks later
+                    Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
+                        @Override
+                        public void run() {
+                            if (ViaVersion.getInstance().isPorted(player)) {
+                                sendArmorUpdate(player);
+                            }
+                        }
+                    }, 3L);
+                }
+            }
+        }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onJoin(PlayerJoinEvent e) {
+        sendDelayedArmorUpdate(e.getPlayer());
+    }
+
+    public void sendDelayedArmorUpdate(final Player player) {
+        Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
+            @Override
+            public void run() {
+                if (ViaVersion.getInstance().isPorted(player)) {
+                    sendArmorUpdate(player);
+                }
+            }
+        });
+    }
+
+    public static void sendArmorUpdate(Player player) {
+        int armor = ArmorType.calculateArmorPoints(player.getInventory().getArmorContents());
+
+        ByteBuf buf = Unpooled.buffer();
+        writeVarInt(PacketType.PLAY_ENTITY_PROPERTIES.getNewPacketID(), buf);
+        writeVarInt(player.getEntityId(), buf);
+        buf.writeInt(1); // only 1 property
+        writeString("generic.armor", buf);
+        buf.writeDouble(0); //default 0 armor
+        writeVarInt(1, buf); // 1 modifier
+        writeUUID(armorAttribute, buf); // armor modifier uuid
+        buf.writeDouble((double) armor); // the modifier value
+        buf.writeByte(0); // the modifier operation, 0 is add number
+
+        ViaVersion.getInstance().sendRawPacket(player, buf);
+    }
+}

src/main/java/us/myles/ViaVersion/armor/ArmorType.java

@@ -0,0 +1,91 @@
+package us.myles.ViaVersion.armor;
+
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+
+public enum ArmorType {
+
+    LEATHER_HELMET(1, 298, Material.LEATHER_HELMET),
+    LEATHER_CHESTPLATE(3, 299, Material.LEATHER_CHESTPLATE),
+    LEATHER_LEGGINGS(2, 300, Material.LEATHER_LEGGINGS),
+    LEATHER_BOOTS(1, 301, Material.LEATHER_BOOTS),
+    CHAINMAIL_HELMET(2, 302, Material.CHAINMAIL_HELMET),
+    CHAINMAIL_CHESTPLATE(5, 303, Material.CHAINMAIL_CHESTPLATE),
+    CHAINMAIL_LEGGINGS(4, 304, Material.CHAINMAIL_LEGGINGS),
+    CHAINMAIL_BOOTS(1, 305, Material.CHAINMAIL_BOOTS),
+    IRON_HELMET(2, 306, Material.IRON_HELMET),
+    IRON_CHESTPLATE(6, 307, Material.IRON_CHESTPLATE),
+    IRON_LEGGINGS(5, 308, Material.IRON_LEGGINGS),
+    IRON_BOOTS(2, 309, Material.IRON_BOOTS),
+    DIAMOND_HELMET(3, 310, Material.DIAMOND_HELMET),
+    DIAMOND_CHESTPLATE(8, 311, Material.DIAMOND_CHESTPLATE),
+    DIAMOND_LEGGINGS(6, 312, Material.DIAMOND_LEGGINGS),
+    DIAMOND_BOOTS(3, 313, Material.DIAMOND_BOOTS),
+    GOLD_HELMET(2, 314, Material.GOLD_HELMET),
+    GOLD_CHESTPLATE(5, 315, Material.GOLD_CHESTPLATE),
+    GOLD_LEGGINGS(3, 316, Material.GOLD_LEGGINGS),
+    GOLD_BOOTS(1, 317, Material.GOLD_BOOTS),
+    NONE(0, 0, Material.AIR);
+
+    private int armorpoints;
+    private int id;
+    private Material type;
+
+    ArmorType(int armor, int id, Material type) {
+        this.armorpoints = armor;
+        this.id = id;
+        this.type = type;
+    }
+
+    public int getArmorPoints() {
+        return this.armorpoints;
+    }
+
+    public int getId() {
+        return this.id;
+    }
+
+    public Material getType() {
+        return this.type;
+    }
+
+    public static ArmorType findByType(Material type) {
+        for(ArmorType a : ArmorType.values())
+            if(a.getType() == type)
+                return a;
+        return ArmorType.NONE;
+    }
+
+    public static int calculateArmorPoints(ItemStack[] armor) {
+        int total = 0;
+        for(int i = 0; i < armor.length; i++) {
+            if(armor[i] != null)
+                total += findByType(armor[i].getType()).getArmorPoints();
+        }
+        return total;
+    }
+
+    public static ArmorType findById(int id) {
+        for(ArmorType a : ArmorType.values())
+            if(a.getId() == id)
+                return a;
+        return ArmorType.NONE;
+    }
+
+    public static boolean isArmor(Material material){
+        for(ArmorType a : ArmorType.values())
+            if(a.getType() == material)
+                return true;
+        return false;
+    }
+
+    public static int calculateArmorPoints(int[] armor) {
+        int total = 0;
+        for(int i = 0; i < armor.length; i++) {
+            if(armor[i] != -1)
+                total += findById(armor[i]).getArmorPoints();
+        }
+        return total;
+    }
+
+}

src/main/java/us/myles/ViaVersion/commands/ViaVersionCommand.java

@@ -5,6 +5,7 @@ import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
+import us.myles.ViaVersion.ViaVersionPlugin;
 import us.myles.ViaVersion.api.ViaVersion;
 
 import java.util.ArrayList;
@@ -14,6 +15,11 @@ import java.util.List;
  * Created by fillefilip8 on 2016-03-03.
  */
 public class ViaVersionCommand implements CommandExecutor {
+    private final ViaVersionPlugin plugin;
+
+    public ViaVersionCommand(ViaVersionPlugin plugin) {
+        this.plugin = plugin;
+    }
 
     @Override
     public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
@@ -22,6 +28,7 @@ public class ViaVersionCommand implements CommandExecutor {
                 sender.sendMessage(color("&aViaVersion &c" + ViaVersion.getInstance().getVersion()));
                 sender.sendMessage(color("&6Commands:"));
                 sender.sendMessage(color("&2/viaversion list &7- &6Shows lists of all 1.9 clients and 1.8 clients."));
+                sender.sendMessage(color("&2/viaversion dontbugme &7- &6Toggle checking for updates."));
             } else if (args.length == 1) {
                 if (args[0].equalsIgnoreCase("list")) {
                     List<String> portedPlayers = new ArrayList<String>();
@@ -37,12 +44,23 @@ public class ViaVersionCommand implements CommandExecutor {
                     sender.sendMessage(color("&8[&61.9&8]: &b" + portedPlayers.toString()));
                     sender.sendMessage(color("&8[&61.8&8]: &b" + normalPlayers.toString()));
                 }
+                if (args[0].equalsIgnoreCase("debug")) {
+                    plugin.setDebug(!plugin.isDebug());
+                    sender.sendMessage(color("&6Debug mode is now " + (plugin.isDebug() ? "&aenabled" : "&cdisabled")));
+                }
+                if (args[0].equalsIgnoreCase("dontbugme")) {
+                    boolean newValue = !plugin.getConfig().getBoolean("checkforupdates", true);
+                    plugin.getConfig().set("checkforupdates", newValue);
+                    plugin.saveConfig();
+                    sender.sendMessage(color("&6We will " + (newValue ? "&anotify you about updates." : "&cnot tell you about updates.")));
+                }
             }
 
         }
         return false;
     }
-    public String color(String string){
+
+    public String color(String string) {
         return string.replace("&", "§");
     }
 }

src/main/java/us/myles/ViaVersion/handlers/ViaEncodeHandler.java

@@ -10,7 +10,6 @@ import us.myles.ViaVersion.util.PacketUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
 import java.lang.reflect.Constructor;
-import java.nio.channels.ClosedChannelException;
 
 public class ViaEncodeHandler extends MessageToByteEncoder {
     private final ConnectionInfo info;

src/main/java/us/myles/ViaVersion/listeners/CommandBlockListener.java

@@ -0,0 +1,63 @@
+package us.myles.ViaVersion.listeners;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import org.bukkit.block.Block;
+import org.bukkit.block.CommandBlock;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.Action;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.player.PlayerJoinEvent;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.packets.PacketType;
+import us.myles.ViaVersion.util.PacketUtil;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public class CommandBlockListener implements Listener {
+    private final ViaVersionPlugin plugin;
+
+    public CommandBlockListener(ViaVersionPlugin plugin) {
+        this.plugin = plugin;
+    }
+
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.MONITOR)
+    public void onJoin(final PlayerJoinEvent e) {
+        if (e.getPlayer().isOp() && plugin.isPorted(e.getPlayer())) {
+            ByteBuf buf = Unpooled.buffer();
+            PacketUtil.writeVarInt(PacketType.PLAY_ENTITY_STATUS.getNewPacketID(), buf);
+            buf.writeInt(e.getPlayer().getEntityId());
+            buf.writeByte(26);
+            plugin.sendRawPacket(e.getPlayer(), buf);
+        }
+    }
+
+    @EventHandler(ignoreCancelled = true)
+    public void onInteract(PlayerInteractEvent e) {
+        if (e.getAction() == Action.RIGHT_CLICK_BLOCK && plugin.isPorted(e.getPlayer()) && e.getPlayer().isOp()) {
+            try {
+                sendCommandBlockPacket(e.getClickedBlock(), e.getPlayer());
+            } catch (NoSuchFieldException | IllegalAccessException | InvocationTargetException | NoSuchMethodException | ClassNotFoundException e1) {
+                e1.printStackTrace();
+            }
+        }
+    }
+
+    private void sendCommandBlockPacket(Block b, Player player) throws NoSuchFieldException, IllegalAccessException, NoSuchMethodException, InvocationTargetException, ClassNotFoundException {
+        if (!(b.getState() instanceof CommandBlock))
+            return;
+        CommandBlock cmd = (CommandBlock) b.getState();
+
+        Object tileEntityCommand = ReflectionUtil.get(cmd, "commandBlock", ReflectionUtil.nms("TileEntityCommand"));
+        Object updatePacket = ReflectionUtil.invoke(tileEntityCommand, "getUpdatePacket");
+        Object nmsPlayer = ReflectionUtil.invoke(player, "getHandle");
+        Object playerConnection = ReflectionUtil.get(nmsPlayer, "playerConnection", ReflectionUtil.nms("PlayerConnection"));
+        Method sendPacket = playerConnection.getClass().getMethod("sendPacket", ReflectionUtil.nms("Packet"));
+        sendPacket.invoke(playerConnection, updatePacket); //Let the transformer do the work
+    }
+}

src/main/java/us/myles/ViaVersion/metadata/MetaIndex.java

@@ -1,6 +1,7 @@
 package us.myles.ViaVersion.metadata;
 
 import org.bukkit.entity.*;
+import org.bukkit.entity.minecart.CommandMinecart;
 
 public enum MetaIndex {
 
@@ -105,6 +106,9 @@ public enum MetaIndex {
     MINECART_BLOCK(Minecart.class, 20, Type.Int, 8, NewType.VarInt),
     MINECART_BLOCK_Y(Minecart.class, 21, Type.Int, 9, NewType.VarInt),
     MINECART_SHOWBLOCK(Minecart.class, 22, Type.Byte, 10, NewType.Boolean),
+    // Command minecart (they are still broken)
+    MINECART_COMMANDBLOCK_COMMAND(CommandMinecart.class,23,Type.String,11,NewType.String),
+    MINECART_COMMANDBLOCK_OUTPUT(CommandMinecart.class,24,Type.String,12,NewType.Chat),
     // furnace cart
     FURNACECART_ISPOWERED(org.bukkit.entity.minecart.PoweredMinecart.class, 16, Type.Byte, 11, NewType.Boolean),
     // item drop

src/main/java/us/myles/ViaVersion/metadata/MetadataRewriter.java

@@ -117,7 +117,7 @@ public class MetadataRewriter {
                 }
             } catch (Exception e) {
                 if (type != null) {
-                    System.out.println("An error occurred with entity meta data for " + type);
+                    System.out.println("An error occurred with entity meta data for " + type + " OldID: " + entry.oldID);
                     if (metaIndex != null) {
                         System.out.println("Old ID: " + metaIndex.getIndex() + " New ID: " + metaIndex.getNewIndex());
                         System.out.println("Old Type: " + metaIndex.getOldType() + " New Type: " + metaIndex.getNewType());
@@ -138,23 +138,23 @@ public class MetadataRewriter {
             MetaIndex index = MetaIndex.getIndex(entityType, id);
             switch (type) {
                 case Byte:
-                    entries.add(new Entry(index, buf.readByte()));
+                    entries.add(new Entry(index, buf.readByte(), id));
                     break;
                 case Short:
-                    entries.add(new Entry(index, buf.readShort()));
+                    entries.add(new Entry(index, buf.readShort(), id));
                     break;
                 case Int:
-                    entries.add(new Entry(index, buf.readInt()));
+                    entries.add(new Entry(index, buf.readInt(), id));
                     break;
                 case Float:
-                    entries.add(new Entry(index, buf.readFloat()));
+                    entries.add(new Entry(index, buf.readFloat(), id));
                     break;
                 case String:
-                    entries.add(new Entry(index, PacketUtil.readString(buf)));
+                    entries.add(new Entry(index, PacketUtil.readString(buf), id));
                     break;
                 case Slot: {
                     try {
-                        entries.add(new Entry(index, ItemSlotRewriter.readItemStack(buf)));
+                        entries.add(new Entry(index, ItemSlotRewriter.readItemStack(buf), id));
                     } catch (Exception e) {
                         e.printStackTrace();
                     }
@@ -164,14 +164,14 @@ public class MetadataRewriter {
                     int x = buf.readInt();
                     int y = buf.readInt();
                     int z = buf.readInt();
-                    entries.add(new Entry(index, new Vector(x, y, z)));
+                    entries.add(new Entry(index, new Vector(x, y, z), id));
                     break;
                 }
                 case Rotation: {
                     float x = buf.readFloat();
                     float y = buf.readFloat();
                     float z = buf.readFloat();
-                    entries.add(new Entry(index, new EulerAngle(x, y, z)));
+                    entries.add(new Entry(index, new EulerAngle(x, y, z), id));
                     break;
                 }
                 default:
@@ -184,12 +184,14 @@ public class MetadataRewriter {
 
     public static class Entry {
 
+        private final int oldID;
         private MetaIndex index;
         private Object value;
 
-        private Entry(MetaIndex index, Object value) {
+        private Entry(MetaIndex index, Object value, int id) {
             this.index = index;
             this.value = value;
+            this.oldID = id;
         }
     }
 }

src/main/java/us/myles/ViaVersion/slot/ItemSlotRewriter.java

@@ -1,18 +1,20 @@
 package us.myles.ViaVersion.slot;
 
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
-
+import io.netty.buffer.ByteBuf;
 import org.bukkit.Material;
 import org.spacehq.opennbt.tag.builtin.CompoundTag;
+import org.spacehq.opennbt.tag.builtin.ListTag;
 import org.spacehq.opennbt.tag.builtin.StringTag;
-
-import io.netty.buffer.ByteBuf;
-
+import org.spacehq.opennbt.tag.builtin.Tag;
 import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.transformers.OutgoingTransformer;
 import us.myles.ViaVersion.util.PacketUtil;
 
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
 public class ItemSlotRewriter {
 
     public static void rewrite1_9To1_8(ByteBuf input, ByteBuf output) throws CancelException {
@@ -48,7 +50,35 @@ public class ItemSlotRewriter {
                     CompoundTag entityTag = tag.get("EntityTag");
                     if (entityTag.get("id") instanceof StringTag) {
                         StringTag id = entityTag.get("id");
-                        data = ENTTIY_NAME_TO_ID.get(id.getValue());
+                        if (ENTTIY_NAME_TO_ID.containsKey(id.getValue()))
+                            data = ENTTIY_NAME_TO_ID.get(id.getValue());
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+            if (item.id == Material.POTION.getId()) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                if (tag != null && tag.get("Potion") instanceof StringTag) {
+                    StringTag potion = tag.get("Potion");
+                    String potionName = potion.getValue().replace("minecraft:", "");
+                    if (POTION_NAME_TO_ID.containsKey(potionName)) {
+                        data = POTION_NAME_TO_ID.get(potionName);
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+            if (item.id == 438) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                item.id = (short) Material.POTION.getId();
+                if (tag != null && tag.get("Potion") instanceof StringTag) {
+                    StringTag potion = tag.get("Potion");
+                    String potionName = potion.getValue().replace("minecraft:", "");
+                    if (POTION_NAME_TO_ID.containsKey(potionName)) {
+                        data = POTION_NAME_TO_ID.get(potionName) + 8192;
                     }
                 }
                 item.tag = null;
@@ -65,18 +95,59 @@ public class ItemSlotRewriter {
                     tag = new CompoundTag("tag");
                 }
                 CompoundTag entityTag = new CompoundTag("EntityTag");
-                StringTag id = new StringTag("id", ENTTIY_ID_TO_NAME.get(Integer.valueOf(item.data)));
-                entityTag.put(id);
-                tag.put(entityTag);
+                if (ENTTIY_ID_TO_NAME.containsKey(Integer.valueOf(item.data))) {
+                    StringTag id = new StringTag("id", ENTTIY_ID_TO_NAME.get(Integer.valueOf(item.data)));
+                    entityTag.put(id);
+                    tag.put(entityTag);
+                }
                 item.tag = tag;
                 item.data = 0;
             }
+            if (item.id == Material.POTION.getId()) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                if (item.data >= 16384) {
+                    item.id = 438; // splash id
+                    item.data = (short) (item.data - 8192);
+                }
+                if (POTION_ID_TO_NAME.containsKey(Integer.valueOf(item.data))) {
+                    String name = POTION_ID_TO_NAME.get(Integer.valueOf(item.data));
+                    StringTag potion = new StringTag("Potion", "minecraft:" + name);
+                    tag.put(potion);
+                }
+                item.tag = tag;
+                item.data = 0;
+            }
+            if (item.id == Material.WRITTEN_BOOK.getId()) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                ListTag pages = tag.get("pages");
+                if (pages == null) {
+                    pages = new ListTag("pages", Collections.<Tag>singletonList(new StringTag(OutgoingTransformer.fixJson(""))));
+                    tag.put(pages);
+                    item.tag = tag;
+                    return;
+                }
+
+                for (int i = 0; i < pages.size(); i++) {
+                    if (!(pages.get(i) instanceof StringTag))
+                        continue;
+                    StringTag page = pages.get(i);
+                    page.setValue(OutgoingTransformer.fixJson(page.getValue()));
+                }
+                item.tag = tag;
+            }
         }
     }
 
     public static ItemStack readItemStack(ByteBuf input) throws IOException {
         short id = input.readShort();
         if (id < 0) {
+
             return null;
         } else {
             ItemStack item = new ItemStack();
@@ -101,10 +172,10 @@ public class ItemSlotRewriter {
 
     public static class ItemStack {
 
-        private short id;
-        private byte amount;
-        private short data;
-        private CompoundTag tag;
+        public short id;
+        public byte amount;
+        public short data;
+        public CompoundTag tag;
 
         public static ItemStack fromBukkit(org.bukkit.inventory.ItemStack stack) {
             ItemStack item = new ItemStack();
@@ -119,73 +190,133 @@ public class ItemSlotRewriter {
     private static Map<String, Integer> ENTTIY_NAME_TO_ID = new HashMap<>();
     private static Map<Integer, String> ENTTIY_ID_TO_NAME = new HashMap<>();
 
+    private static Map<String, Integer> POTION_NAME_TO_ID = new HashMap<>();
+    private static Map<Integer, String> POTION_ID_TO_NAME = new HashMap<>();
+
     static {
-        register(1, "Item");
-        register(2, "XPOrb");
-        register(7, "ThrownEgg");
-        register(8, "LeashKnot");
-        register(9, "Painting");
-        register(10, "Arrow");
-        register(11, "Snowball");
-        register(12, "Fireball");
-        register(13, "SmallFireball");
-        register(14, "ThrownEnderpearl");
-        register(15, "EyeOfEnderSignal");
-        register(16, "ThrownPotion");
-        register(17, "ThrownExpBottle");
-        register(18, "ItemFrame");
-        register(19, "WitherSkull");
-        register(20, "PrimedTnt");
-        register(21, "FallingSand");
-        register(22, "FireworksRocketEntity");
-        register(30, "ArmorStand");
-        register(40, "MinecartCommandBlock");
-        register(41, "Boat");
-        register(42, "MinecartRideable");
-        register(43, "MinecartChest");
-        register(44, "MinecartFurnace");
-        register(45, "MinecartTNT");
-        register(46, "MinecartHopper");
-        register(47, "MinecartSpawner");
-        register(48, "Mob");
-        register(49, "Monster");
-        register(50, "Creeper");
-        register(51, "Skeleton");
-        register(52, "Spider");
-        register(53, "Giant");
-        register(54, "Zombie");
-        register(55, "Slime");
-        register(56, "Ghast");
-        register(57, "PigZombie");
-        register(58, "Enderman");
-        register(59, "CaveSpider");
-        register(60, "Silverfish");
-        register(61, "Blaze");
-        register(62, "LavaSlime");
-        register(63, "EnderDragon");
-        register(64, "WitherBoss");
-        register(65, "Bat");
-        register(66, "Witch");
-        register(67, "Endermite");
-        register(68, "Guardian");
-        register(90, "Pig");
-        register(91, "Sheep");
-        register(92, "Cow");
-        register(93, "Chicken");
-        register(94, "Squid");
-        register(95, "Wolf");
-        register(96, "MushroomCow");
-        register(97, "SnowMan");
-        register(98, "Ozelot");
-        register(99, "VillagerGolem");
-        register(100, "EntityHorse");
-        register(101, "Rabbit");
-        register(120, "Villager");
-        register(200, "EnderCrystal");
+        /* Entities */
+        registerEntity(1, "Item");
+        registerEntity(2, "XPOrb");
+        registerEntity(7, "ThrownEgg");
+        registerEntity(8, "LeashKnot");
+        registerEntity(9, "Painting");
+        registerEntity(10, "Arrow");
+        registerEntity(11, "Snowball");
+        registerEntity(12, "Fireball");
+        registerEntity(13, "SmallFireball");
+        registerEntity(14, "ThrownEnderpearl");
+        registerEntity(15, "EyeOfEnderSignal");
+        registerEntity(16, "ThrownPotion");
+        registerEntity(17, "ThrownExpBottle");
+        registerEntity(18, "ItemFrame");
+        registerEntity(19, "WitherSkull");
+        registerEntity(20, "PrimedTnt");
+        registerEntity(21, "FallingSand");
+        registerEntity(22, "FireworksRocketEntity");
+        registerEntity(30, "ArmorStand");
+        registerEntity(40, "MinecartCommandBlock");
+        registerEntity(41, "Boat");
+        registerEntity(42, "MinecartRideable");
+        registerEntity(43, "MinecartChest");
+        registerEntity(44, "MinecartFurnace");
+        registerEntity(45, "MinecartTNT");
+        registerEntity(46, "MinecartHopper");
+        registerEntity(47, "MinecartSpawner");
+        registerEntity(48, "Mob");
+        registerEntity(49, "Monster");
+        registerEntity(50, "Creeper");
+        registerEntity(51, "Skeleton");
+        registerEntity(52, "Spider");
+        registerEntity(53, "Giant");
+        registerEntity(54, "Zombie");
+        registerEntity(55, "Slime");
+        registerEntity(56, "Ghast");
+        registerEntity(57, "PigZombie");
+        registerEntity(58, "Enderman");
+        registerEntity(59, "CaveSpider");
+        registerEntity(60, "Silverfish");
+        registerEntity(61, "Blaze");
+        registerEntity(62, "LavaSlime");
+        registerEntity(63, "EnderDragon");
+        registerEntity(64, "WitherBoss");
+        registerEntity(65, "Bat");
+        registerEntity(66, "Witch");
+        registerEntity(67, "Endermite");
+        registerEntity(68, "Guardian");
+        registerEntity(90, "Pig");
+        registerEntity(91, "Sheep");
+        registerEntity(92, "Cow");
+        registerEntity(93, "Chicken");
+        registerEntity(94, "Squid");
+        registerEntity(95, "Wolf");
+        registerEntity(96, "MushroomCow");
+        registerEntity(97, "SnowMan");
+        registerEntity(98, "Ozelot");
+        registerEntity(99, "VillagerGolem");
+        registerEntity(100, "EntityHorse");
+        registerEntity(101, "Rabbit");
+        registerEntity(120, "Villager");
+        registerEntity(200, "EnderCrystal");
+
+        /* Potions */
+        registerPotion(0, "water");
+        registerPotion(64, "mundane");
+        registerPotion(32, "thick");
+        registerPotion(16, "awkward");
+
+        registerPotion(8198, "night_vision");
+        registerPotion(8262, "long_night_vision");
+
+        registerPotion(8206, "invisibility");
+        registerPotion(8270, "long_invisibility");
+
+        registerPotion(8203, "leaping");
+        registerPotion(8267, "long_leaping");
+        registerPotion(8235, "strong_leaping");
+
+        registerPotion(8195, "fire_resistance");
+        registerPotion(8259, "long_fire_resistance");
+
+        registerPotion(8194, "swiftness");
+        registerPotion(8258, "long_swiftness");
+        registerPotion(8226, "strong_swiftness");
+
+        registerPotion(8202, "slowness");
+        registerPotion(8266, "long_slowness");
+
+        registerPotion(8205, "water_breathing");
+        registerPotion(8269, "long_water_breathing");
+
+        registerPotion(8197, "healing");
+        registerPotion(8229, "strong_healing");
+
+        registerPotion(8204, "harming");
+        registerPotion(8236, "strong_harming");
+
+        registerPotion(8196, "poison");
+        registerPotion(8260, "long_poison");
+        registerPotion(8228, "strong_poison");
+
+        registerPotion(8193, "regeneration");
+        registerPotion(8257, "long_regeneration");
+        registerPotion(8225, "strong_regeneration");
+
+        registerPotion(8201, "strength");
+        registerPotion(8265, "long_strength");
+        registerPotion(8233, "strong_strength");
+
+        registerPotion(8200, "weakness");
+        registerPotion(8264, "long_weakness");
+
     }
 
-    private static void register(Integer id, String name) {
+    private static void registerEntity(Integer id, String name) {
         ENTTIY_ID_TO_NAME.put(id, name);
         ENTTIY_NAME_TO_ID.put(name, id);
     }
+
+    private static void registerPotion(Integer id, String name) {
+        POTION_ID_TO_NAME.put(id, name);
+        POTION_NAME_TO_ID.put(name, id);
+    }
 }

src/main/java/us/myles/ViaVersion/sounds/SoundEffect.java

@@ -198,7 +198,7 @@ public enum SoundEffect {
     MOB_ENDERMEN_SCREAM("mob.endermen.scream", "entity.endermen.scream", SoundCategory.HOSTILE),
     MOB_CAT_HITT("mob.cat.hitt", "entity.cat.hurt", SoundCategory.NEUTRAL),
     MOB_MAGMACUBE_SMALL("mob.magmacube.small", "entity.small_magmacube.squish", SoundCategory.HOSTILE),
-    FIRE_IGNITE("fire.ignite", "item.flintandsteel.use", SoundCategory.BLOCK),
+    FIRE_IGNITE("fire.ignite", "item.flintandsteel.use", SoundCategory.BLOCK, true),
     MOB_ENDERDRAGON_HIT("mob.enderdragon.hit", "entity.enderdragon.hurt", SoundCategory.HOSTILE),
     MOB_ZOMBIE_HURT("mob.zombie.hurt", "entity.zombie_villager.hurt", SoundCategory.HOSTILE),
     RANDOM_EXPLODE("random.explode", "block.end_gateway.spawn", SoundCategory.BLOCK),
@@ -260,6 +260,13 @@ public enum SoundEffect {
         this.name = name;
         this.breaksound = name.startsWith("dig.");
     }
+    
+    SoundEffect(String name, String newname, SoundCategory cat, boolean shouldIgnore) {
+        this.cat = cat;
+        this.newname = newname;
+        this.name = name;
+        this.breaksound = name.startsWith("dig.") || shouldIgnore;
+    }
 
     public static SoundEffect getByName(String name) {
         name = name.toLowerCase();

src/main/java/us/myles/ViaVersion/transformers/IncomingTransformer.java

@@ -1,16 +1,20 @@
 package us.myles.ViaVersion.transformers;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
 import us.myles.ViaVersion.CancelException;
 import us.myles.ViaVersion.ConnectionInfo;
 import us.myles.ViaVersion.ViaVersionPlugin;
-import us.myles.ViaVersion.slot.ItemSlotRewriter;
+import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.packets.PacketType;
 import us.myles.ViaVersion.packets.State;
+import us.myles.ViaVersion.slot.ItemSlotRewriter;
 import us.myles.ViaVersion.util.PacketUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
+import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 
@@ -32,9 +36,11 @@ public class IncomingTransformer {
         if (packet.getPacketID() != -1) {
             packetID = packet.getPacketID();
         }
-//        if (packet != PacketType.PLAY_PLAYER_POSITION_LOOK_REQUEST && packet != PacketType.PLAY_KEEP_ALIVE_REQUEST && packet != PacketType.PLAY_PLAYER_POSITION_REQUEST && packet != PacketType.PLAY_PLAYER_LOOK_REQUEST) {
-//            System.out.println("Packet Type: " + packet + " New ID: " + packetID + " Original: " + original);
-//        }
+        if (ViaVersion.getInstance().isDebug()) {
+            if (packet != PacketType.PLAY_PLAYER_POSITION_LOOK_REQUEST && packet != PacketType.PLAY_KEEP_ALIVE_REQUEST && packet != PacketType.PLAY_PLAYER_POSITION_REQUEST && packet != PacketType.PLAY_PLAYER_LOOK_REQUEST) {
+                System.out.println("Direction " + packet.getDirection().name() + " Packet Type: " + packet + " New ID: " + packetID + " Original: " + original + " Size: " + input.readableBytes());
+            }
+        }
         if (packet == PacketType.PLAY_TP_CONFIRM || packet == PacketType.PLAY_VEHICLE_MOVE_REQUEST) { //TODO handle client-sided horse riding
             throw new CancelException();
         }
@@ -100,6 +106,7 @@ public class IncomingTransformer {
             byte button = input.readByte();
             short action = input.readShort();
             byte mode = input.readByte();
+            // if the action is on an elytra armour slot
             if (slot == 45 && windowID == 0) {
                 try {
                     Class<?> setSlot = ReflectionUtil.nms("PacketPlayOutSetSlot");
@@ -129,6 +136,9 @@ public class IncomingTransformer {
             ItemSlotRewriter.rewrite1_9To1_8(input, output);
             return;
         }
+        if (packet == PacketType.PLAY_CLOSE_WINDOW_REQUEST) {
+            info.closeWindow();
+        }
         if (packet == PacketType.PLAY_CLIENT_SETTINGS) {
             String locale = PacketUtil.readString(input);
             PacketUtil.writeString(locale, output);
@@ -171,6 +181,44 @@ public class IncomingTransformer {
             }
             return;
         }
+        if (packet == PacketType.PLAY_PLUGIN_MESSAGE_REQUEST) {
+            String name = PacketUtil.readString(input);
+            PacketUtil.writeString(name, output);
+            byte[] b = new byte[input.readableBytes()];
+            input.readBytes(b);
+            // patch books
+            if (name.equals("MC|BSign")) {
+                ByteBuf in = Unpooled.wrappedBuffer(b);
+                try {
+                    ItemSlotRewriter.ItemStack stack = ItemSlotRewriter.readItemStack(in);
+                    stack.id = (short) Material.WRITTEN_BOOK.getId();
+                    // write
+                    ItemSlotRewriter.writeItemStack(stack, output);
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                return;
+            } else if (name.equals("MC|AutoCmd")) {
+                ByteBuf in = Unpooled.wrappedBuffer(b);
+                int x = in.readInt();
+                int y = in.readInt();
+                int z = in.readInt();
+                String command = PacketUtil.readString(in);
+                boolean flag = in.readBoolean();
+
+                output.clear();
+                PacketUtil.writeVarInt(PacketType.PLAY_PLUGIN_MESSAGE_REQUEST.getPacketID(), output);
+                PacketUtil.writeString("MC|AdvCdm", output);
+                output.writeByte(0);
+                output.writeInt(x);
+                output.writeInt(y);
+                output.writeInt(z);
+                PacketUtil.writeString(command, output);
+                output.writeBoolean(flag);
+                return;
+            }
+            output.writeBytes(b);
+        }
         if (packet == PacketType.PLAY_PLAYER_BLOCK_PLACEMENT) {
             Long position = input.readLong();
             output.writeLong(position);
@@ -204,7 +252,7 @@ public class IncomingTransformer {
             // write item in hand
             ItemStack inHand = ViaVersionPlugin.getHandItem(info);
             try {
-                us.myles.ViaVersion.slot.ItemSlotRewriter.ItemStack item = us.myles.ViaVersion.slot.ItemSlotRewriter.ItemStack.fromBukkit(inHand);
+                ItemSlotRewriter.ItemStack item = ItemSlotRewriter.ItemStack.fromBukkit(inHand);
                 ItemSlotRewriter.fixIdsFrom1_9To1_8(item);
                 ItemSlotRewriter.writeItemStack(item, output);
             } catch (Exception e) {

src/main/java/us/myles/ViaVersion/update/UpdateListener.java

@@ -0,0 +1,24 @@
+package us.myles.ViaVersion.update;
+
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.plugin.Plugin;
+
+public class UpdateListener implements Listener {
+	
+	private Plugin plugin;
+	
+	public UpdateListener(Plugin plugin) {
+		this.plugin = plugin;
+	}
+	
+	@EventHandler
+	public void onJoin(PlayerJoinEvent e) {
+		if(e.getPlayer().hasPermission("viaversion.update")
+				&& plugin.getConfig().getBoolean("checkforupdates", true)) {
+			UpdateUtil.sendUpdateMessage(e.getPlayer().getUniqueId(), plugin);
+		}
+	}
+
+}

src/main/java/us/myles/ViaVersion/update/UpdateUtil.java

@@ -0,0 +1,108 @@
+package us.myles.ViaVersion.update;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+import us.myles.ViaVersion.api.ViaVersion;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.UUID;
+
+public class UpdateUtil {
+
+    private final static String URL = "https://api.spiget.org/v1/resources/";
+    private final static int PLUGIN = 19254;
+
+    public final static String PREFIX = ChatColor.GREEN + "" + ChatColor.BOLD + "[ViaVersion] " + ChatColor.GREEN;
+
+    public static void sendUpdateMessage(final UUID uuid, final Plugin plugin) {
+        new BukkitRunnable() {
+
+            @Override
+            public void run() {
+                final String message = getUpdateMessage(false);
+                if (message != null) {
+                    new BukkitRunnable() {
+
+                        @Override
+                        public void run() {
+                            Player p = Bukkit.getPlayer(uuid);
+                            if (p != null) {
+                                p.sendMessage(PREFIX + message);
+                            }
+                        }
+                    }.runTask(plugin);
+                }
+            }
+        }.runTaskAsynchronously(plugin);
+    }
+
+    public static void sendUpdateMessage(final Plugin plugin) {
+        new BukkitRunnable() {
+
+            @Override
+            public void run() {
+                final String message = getUpdateMessage(true);
+                if (message != null) {
+                    new BukkitRunnable() {
+
+                        @Override
+                        public void run() {
+                            plugin.getLogger().warning(message);
+                        }
+                    }.runTask(plugin);
+                }
+            }
+        }.runTaskAsynchronously(plugin);
+    }
+
+    private static String getUpdateMessage(boolean console) {
+        if (ViaVersion.getInstance().getVersion().equals("${project.version}")) {
+            return "You are using a debug/custom version, consider updating.";
+        }
+
+        Version current = new Version(ViaVersion.getInstance().getVersion());
+        Version newest = new Version(getNewestVersion());
+        if (current.compareTo(newest) < 0)
+            return "There is a newer version available: " + newest.toString();
+        else if (console) {
+            return "You are running a newer version than is released!";
+        }
+        return null;
+    }
+
+    private static String getNewestVersion() {
+        String result = "";
+        try {
+            URL url = new URL(URL + PLUGIN + "?" + System.currentTimeMillis());
+            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+            connection.setUseCaches(true);
+            connection.addRequestProperty("User-Agent", "Mozilla/4.76");
+            connection.setDoOutput(true);
+            BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
+            String input;
+            String content = "";
+            while ((input = br.readLine()) != null) {
+                content = content + input;
+            }
+            br.close();
+            JsonParser parser = new JsonParser();
+            JsonObject statistics = (JsonObject) parser.parse(content);
+            result = statistics.get("version").getAsString();
+        } catch (MalformedURLException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return result;
+    }
+}

src/main/java/us/myles/ViaVersion/update/Version.java

@@ -0,0 +1,65 @@
+package us.myles.ViaVersion.update;
+
+import org.apache.commons.lang.StringUtils;
+
+public class Version implements Comparable<Version> {
+    private int[] parts;
+
+    public Version(String value) {
+        if (value == null)
+            throw new IllegalArgumentException("Version can not be null");
+
+        if (value.matches("^[0-9]+(\\.[0-9]+)*$") == false)
+            throw new IllegalArgumentException("Invalid version format");
+
+        String[] split = value.split("\\.");
+        parts = new int[split.length];
+
+        for (int i = 0; i < split.length; i += 1)
+            parts[i] = Integer.parseInt(split[i]);
+    }
+
+    @Override
+    public String toString() {
+        String[] split = new String[parts.length];
+
+        for (int i = 0; i < parts.length; i += 1)
+            split[i] = String.valueOf(parts[i]);
+
+        return StringUtils.join(split, ".");
+    }
+
+    public static int compare(Version verA, Version verB) {
+        if (verA == verB) return 0;
+        if (verA == null) return -1;
+        if (verB == null) return 1;
+
+        int max = Math.max(verA.parts.length, verB.parts.length);
+
+        for (int i = 0; i < max; i += 1) {
+            int partA = i < verA.parts.length ? verA.parts[i] : 0;
+            int partB = i < verB.parts.length ? verB.parts[i] : 0;
+            if (partA < partB) return -1;
+            if (partA > partB) return 1;
+        }
+
+        return 0;
+    }
+
+    @Override
+    public int compareTo(Version that) {
+        return compare(this, that);
+    }
+
+    public static boolean equals(Version verA, Version verB) {
+        if (verA == verB) return true;
+        if (verA == null) return false;
+        if (verB == null) return false;
+        return compare(verA, verB) == 0;
+    }
+
+    @Override
+    public boolean equals(Object that) {
+        return that instanceof Version && equals(this, (Version) that);
+    }
+}

src/main/java/us/myles/ViaVersion/util/PacketUtil.java

@@ -8,6 +8,8 @@ import io.netty.buffer.ByteBufOutputStream;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.MessageToByteEncoder;
+import org.spacehq.opennbt.NBTIO;
+import org.spacehq.opennbt.tag.builtin.CompoundTag;
 import us.myles.ViaVersion.chunks.MagicBitSet;
 import us.myles.ViaVersion.chunks.PacketChunk;
 import us.myles.ViaVersion.chunks.PacketChunkData;
@@ -26,9 +28,6 @@ import java.util.BitSet;
 import java.util.List;
 import java.util.UUID;
 
-import org.spacehq.opennbt.NBTIO;
-import org.spacehq.opennbt.tag.builtin.CompoundTag;
-
 public class PacketUtil {
     private static Method DECODE_METHOD;
     private static Method ENCODE_METHOD;
@@ -406,7 +405,8 @@ public class PacketUtil {
     public static boolean containsCause(Throwable t, Class<? extends Throwable> c) {
         while (t != null) {
             t = t.getCause();
-            if (c.isAssignableFrom(t.getClass())) return true;
+            if (t != null)
+                if (c.isAssignableFrom(t.getClass())) return true;
         }
         return false;
     }

src/main/resources/plugin.yml

@@ -1,7 +1,7 @@
 name: ViaVersion
 main: us.myles.ViaVersion.ViaVersionPlugin
 author: _MylesC
-version: ${version}
+version: ${project.version}
 load: startup
 loadbefore: [ProtocolLib, ProxyPipe]
 commands: