Bump version

Add config wrapper to update config

README.md

@@ -1,4 +1,4 @@
-# ViaVersion 0.5.9
+# ViaVersion 0.6.2
 [![Build Status](https://travis-ci.org/MylesIsCool/ViaVersion.svg?branch=master)](https://travis-ci.org/MylesIsCool/ViaVersion)
 **Allows the connection of 1.9 clients to 1.8**
 
@@ -40,6 +40,8 @@ Contributors:
 
 **fillefilip8**
 
+**lenis0012**
+
 
 
 Releases / Dev Builds:
@@ -55,6 +57,9 @@ You can find unofficial dev builds here:
 
 **fillefilip8's Build Server:** http://build.fillecraft.com:8080/job/ViaVersion
 
+**sgdc3's Build Server:** http://ci.xephi.fr/job/ViaVersion/
+**sgdc3's Maven:** http://ci.xephi.fr/plugin/repository/everything/
+
 License:
 --------
 

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>us.myles</groupId>
     <artifactId>viaversion</artifactId>
-    <version>0.6.0-SNAPSHOT</version>
+    <version>0.6.4-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>ViaVersion</name>

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

@@ -12,6 +12,9 @@ import us.myles.ViaVersion.packets.State;
 @Getter
 @Setter
 public class ConnectionInfo {
+    private static final long IDLE_PACKET_DELAY = 50L; // Update every 50ms (20tps)
+    private static final long IDLE_PACKET_LIMIT = 20; // Max 20 ticks behind
+
     private final SocketChannel channel;
     private Object lastPacket;
     private java.util.UUID UUID;
@@ -22,6 +25,7 @@ public class ConnectionInfo {
     private int entityID;
     private boolean active = true;
     private String username;
+    private long nextIdlePacket = 0L;
 
     public ConnectionInfo(SocketChannel socketChannel) {
         this.channel = socketChannel;
@@ -33,6 +37,7 @@ public class ConnectionInfo {
 
     public void setActive(boolean active) {
         this.active = active;
+        this.nextIdlePacket = System.currentTimeMillis() + IDLE_PACKET_DELAY; // Update every 50 ticks
     }
 
     public void sendRawPacket(final ByteBuf packet, boolean currentThread) {
@@ -56,4 +61,10 @@ public class ConnectionInfo {
     public void closeWindow() {
         this.openWindow = null;
     }
+
+    public void incrementIdlePacket() {
+        // Notify of next update
+        // Allow a maximum lag spike of 1 second (20 ticks/updates)
+        this.nextIdlePacket = Math.max(nextIdlePacket + IDLE_PACKET_DELAY, System.currentTimeMillis() - IDLE_PACKET_DELAY * IDLE_PACKET_LIMIT);
+    }
 }

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

@@ -0,0 +1,42 @@
+package us.myles.ViaVersion;
+
+import org.bukkit.scheduler.BukkitRunnable;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.util.Map;
+import java.util.UUID;
+
+public class ViaIdleThread extends BukkitRunnable {
+    private final Map<UUID, ConnectionInfo> portedPlayers;
+    private final Class<?> idlePacketClass;
+
+    public ViaIdleThread(Map<UUID, ConnectionInfo> portedPlayers) {
+        this.portedPlayers = portedPlayers;
+        try {
+            this.idlePacketClass = ReflectionUtil.nms("PacketPlayInFlying");
+        } catch(ClassNotFoundException e) {
+            throw new RuntimeException("Couldn't find player idle packet, help!", e);
+        }
+    }
+
+    @Override
+    public void run() {
+        for(ConnectionInfo info : portedPlayers.values()) {
+            long nextIdleUpdate = info.getNextIdlePacket();
+            if(nextIdleUpdate <= System.currentTimeMillis()) {
+                try {
+                    Object packet = idlePacketClass.newInstance();
+                    info.getChannel().pipeline().fireChannelRead(packet);
+                } catch(InstantiationException | IllegalAccessException e) {
+                    System.out.println("Failed to create idle packet.");
+                    if(ViaVersion.getInstance().isDebug()) {
+                        e.printStackTrace();
+                    }
+                } finally {
+                    info.incrementIdlePacket();
+                }
+            }
+        }
+    }
+}

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

@@ -24,9 +24,12 @@ 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.Configuration;
 import us.myles.ViaVersion.util.ListWrapper;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
+import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.List;
@@ -36,6 +39,7 @@ import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
 
 public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
 
@@ -64,7 +68,7 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
     @Override
     public void onEnable() {
         ViaVersion.setInstance(this);
-        saveDefaultConfig();
+        generateConfig();
         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.");
@@ -73,6 +77,8 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
 
         getLogger().info("ViaVersion " + getDescription().getVersion() + " is now enabled, injecting. (Allows 1.8 to be accessed via 1.9)");
         injectPacketHandler();
+        if (getConfig().getBoolean("simulate-pt", true))
+            new ViaIdleThread(portedPlayers).runTaskTimerAsynchronously(this, 1L, 1L); // Updates player's idle status
 
         if (getConfig().getBoolean("checkforupdates"))
             UpdateUtil.sendUpdateMessage(this);
@@ -91,6 +97,28 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         getCommand("viaversion").setExecutor(new ViaVersionCommand(this));
     }
 
+    public void generateConfig() {
+        File file = new File(getDataFolder(), "config.yml");
+        if(file.exists()) {
+            // Update config options
+            Configuration oldConfig = new Configuration(file);
+            oldConfig.reload(false); // Load current options from config
+            file.delete(); // Delete old config
+            saveDefaultConfig(); // Generate new config
+            Configuration newConfig = new Configuration(file);
+            newConfig.reload(true); // Load default options
+            for(String key : oldConfig.getKeys(false)) {
+                // Set option in new config if exists
+                if(newConfig.contains(key)) {
+                    newConfig.set(key, oldConfig.get(key));
+                }
+            }
+            newConfig.save();
+        } else {
+            saveDefaultConfig();
+        }
+    }
+
     public void injectPacketHandler() {
         try {
             Class<?> serverClazz = ReflectionUtil.nms("MinecraftServer");
@@ -116,23 +144,28 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
             if (connection != null) {
                 for (Field field : connection.getClass().getDeclaredFields()) {
                     field.setAccessible(true);
-                    Object value = field.get(connection);
+                    final Object value = field.get(connection);
                     if (value instanceof List) {
                         // Inject the list
-                        field.set(connection, new ListWrapper((List) value) {
+                        List wrapper = new ListWrapper((List) value) {
                             @Override
-                            public void handleAdd(Object o) {
-                                if (o instanceof ChannelFuture) {
-                                    inject((ChannelFuture) o);
+                            public synchronized void handleAdd(Object o) {
+                                synchronized (this) {
+                                    if (o instanceof ChannelFuture) {
+                                        inject((ChannelFuture) o);
+                                    }
                                 }
                             }
-                        });
+                        };
+                        field.set(connection, wrapper);
                         // Iterate through current list
-                        for (Object o : (List) value) {
-                            if (o instanceof ChannelFuture) {
-                                inject((ChannelFuture) o);
-                            } else {
-                                break; // not the right list.
+                        synchronized (wrapper) {
+                            for (Object o : (List) value) {
+                                if (o instanceof ChannelFuture) {
+                                    inject((ChannelFuture) o);
+                                } else {
+                                    break; // not the right list.
+                                }
                             }
                         }
                     }
@@ -208,11 +241,6 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         this.debug = value;
     }
 
-    @Override
-    public boolean isSyncedChunks() {
-        return getConfig().getBoolean("sync-chunks", true);
-    }
-
     public boolean isPreventCollision() {
         return getConfig().getBoolean("prevent-collision", true);
     }
@@ -221,6 +249,26 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         return getConfig().getBoolean("suppress-metadata-errors", false);
     }
 
+    public boolean isShieldBlocking() {
+        return getConfig().getBoolean("shield-blocking", true);
+    }
+
+    public boolean isHologramPatch() {
+        return getConfig().getBoolean("hologram-patch", false);
+    }
+
+    public boolean isBossbarPatch() {
+        return getConfig().getBoolean("bossbar-patch", true);
+    }
+
+    public boolean isBossbarAntiflicker() {
+        return getConfig().getBoolean("bossbar-anti-flicker", false);
+    }
+
+    public double getHologramYOffset() {
+        return getConfig().getDouble("hologram-y", -1D);
+    }
+
     public boolean isAutoTeam() {
         // Collision has to be enabled first
         if (!isPreventCollision()) return false;

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

@@ -77,11 +77,4 @@ public interface ViaVersionAPI {
      * @return true if debug is enabled
      */
     boolean isDebug();
-
-    /**
-     * Obtains if syncing chunks is on
-     *
-     * @return true if it is
-     */
-    boolean isSyncedChunks();
 }

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

@@ -0,0 +1,53 @@
+package us.myles.ViaVersion.handlers;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToMessageEncoder;
+import us.myles.ViaVersion.ConnectionInfo;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.List;
+
+public class ViaChunkHandler extends MessageToMessageEncoder {
+    private final ConnectionInfo info;
+
+    public ViaChunkHandler(ConnectionInfo info) {
+        this.info = info;
+    }
+
+    @Override
+    protected void encode(ChannelHandlerContext ctx, Object o, List list) throws Exception {
+        // Split chunk bulk packet up in to single chunk packets before it reached the encoder.
+        // This will prevent issues with several plugins and other protocol handlers due to the chunk being sent twice.
+        // It also sends the chunk in the right order possible resolving some issues with added chunk/block/entity data.
+        if (!(o instanceof ByteBuf)) {
+            info.setLastPacket(o);
+            /* This transformer is more for fixing issues which we find hard at packet level :) */
+            if(o.getClass().getName().endsWith("PacketPlayOutMapChunkBulk") && info.isActive()) {
+                final int[] locX = ReflectionUtil.get(o, "a", int[].class);
+                final int[] locZ = ReflectionUtil.get(o, "b", int[].class);
+                final Object world = ReflectionUtil.get(o, "world", ReflectionUtil.nms("World"));
+                Class<?> mapChunk = ReflectionUtil.nms("PacketPlayOutMapChunk");
+                final Constructor constructor = mapChunk.getDeclaredConstructor(ReflectionUtil.nms("Chunk"), boolean.class, int.class);
+                for(int i = 0; i < locX.length; i++) {
+                    int x = locX[i];
+                    int z = locZ[i];
+                    // world invoke function
+                    try {
+                        Object chunk = ReflectionUtil.nms("World").getDeclaredMethod("getChunkAt", int.class, int.class).invoke(world, x, z);
+                        Object packet = constructor.newInstance(chunk, true, 65535);
+                        list.add(packet);
+                    } catch(InstantiationException | InvocationTargetException | ClassNotFoundException | IllegalAccessException | NoSuchMethodException e) {
+                        e.printStackTrace();
+                    }
+                }
+
+                return;
+            }
+        }
+
+        list.add(o);
+    }
+}

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

@@ -28,38 +28,6 @@ public class ViaEncodeHandler extends MessageToByteEncoder {
     protected void encode(final ChannelHandlerContext ctx, Object o, final ByteBuf bytebuf) throws Exception {
         // handle the packet type
         if (!(o instanceof ByteBuf)) {
-            info.setLastPacket(o);
-            /* This transformer is more for fixing issues which we find hard at packet level :) */
-            if (o.getClass().getName().endsWith("PacketPlayOutMapChunkBulk") && info.isActive()) {
-                final int[] locX = ReflectionUtil.get(o, "a", int[].class);
-                final int[] locZ = ReflectionUtil.get(o, "b", int[].class);
-
-                final Object world = ReflectionUtil.get(o, "world", ReflectionUtil.nms("World"));
-                Class<?> mapChunk = ReflectionUtil.nms("PacketPlayOutMapChunk");
-                final Constructor constructor = mapChunk.getDeclaredConstructor(ReflectionUtil.nms("Chunk"), boolean.class, int.class);
-                Runnable chunks = new Runnable() {
-
-                    @Override
-                    public void run() {
-
-                        for (int i = 0; i < locX.length; i++) {
-                            int x = locX[i];
-                            int z = locZ[i];
-                            // world invoke function
-                            try {
-                                Object chunk = ReflectionUtil.nms("World").getDeclaredMethod("getChunkAt", int.class, int.class).invoke(world, x, z);
-                                Object packet = constructor.newInstance(chunk, true, 65535);
-                                ctx.pipeline().writeAndFlush(packet);
-                            } catch (InstantiationException | InvocationTargetException | ClassNotFoundException | IllegalAccessException | NoSuchMethodException e) {
-                                e.printStackTrace();
-                            }
-                        }
-                    }
-                };
-                chunks.run();
-                bytebuf.clear();
-                throw new CancelException();
-            }
             // call minecraft encoder
             PacketUtil.callEncode(this.minecraftEncoder, ctx, o, bytebuf);
         }

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

@@ -32,8 +32,10 @@ public class ViaVersionInitializer extends ChannelInitializer<SocketChannel> {
         // Add our transformers
         ViaEncodeHandler encoder = new ViaEncodeHandler(info, (MessageToByteEncoder) socketChannel.pipeline().get("encoder"));
         ViaDecodeHandler decoder = new ViaDecodeHandler(info, (ByteToMessageDecoder) socketChannel.pipeline().get("decoder"));
+        ViaChunkHandler chunkHandler = new ViaChunkHandler(info);
 
         socketChannel.pipeline().replace("encoder", "encoder", encoder);
         socketChannel.pipeline().replace("decoder", "decoder", decoder);
+        socketChannel.pipeline().addAfter("packet_handler", "viaversion_chunk_handler", chunkHandler);
     }
 }

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

@@ -91,6 +91,8 @@ public enum MetaIndex {
     WITHER_TARGET2(Wither.class, 18, Type.Int, 12, NewType.VarInt),
     WITHER_TARGET3(Wither.class, 19, Type.Int, 13, NewType.VarInt),
     WITHER_INVULN_TIME(Wither.class, 20, Type.Int, 14, NewType.VarInt),
+    WITHER_PROPERTIES(Wither.class, 10, Type.Byte, NewType.Byte),
+    WITHER_UNKNOWN(Wither.class, 11, Type.Byte, NewType.Discontinued),
     // wither skull
     WITHERSKULL_INVULN(WitherSkull.class, 10, Type.Byte, 5, NewType.Boolean),
     // guardian
@@ -123,7 +125,13 @@ public enum MetaIndex {
     ITEMFRAME_ITEM(ItemFrame.class, 8, Type.Slot, 5, NewType.Slot),
     ITEMFRAME_ROTATION(ItemFrame.class, 9, Type.Byte, 6, NewType.VarInt),
     // ender crystal
-    ENDERCRYSTAL_HEALTH(EnderCrystal.class, 8, Type.Int, NewType.Discontinued),;
+    ENDERCRYSTAL_HEALTH(EnderCrystal.class, 8, Type.Int, NewType.Discontinued),
+    // Ender dragon boss bar issues
+    ENDERDRAGON_UNKNOWN(EnderDragon.class, 5, Type.Byte, NewType.Discontinued),
+    ENDERDRAGON_NAME(EnderDragon.class, 10, Type.String, NewType.Discontinued),
+    // Normal Ender dragon
+    ENDERDRAGON_FLAG(EnderDragon.class, 15, Type.Byte, NewType.Discontinued),
+    ENDERDRAGON_PHASE(EnderDragon.class, 11, Type.Byte, NewType.VarInt);
 
     private Class<?> clazz;
     private int newIndex;

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

@@ -207,7 +207,7 @@ public class MetadataRewriter {
         private MetaIndex index;
         private Object value;
 
-        private Entry(MetaIndex index, Object value, int id) {
+        public Entry(MetaIndex index, Object value, int id) {
             this.index = index;
             this.value = value;
             this.oldID = id;

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

@@ -16,6 +16,7 @@ import us.myles.ViaVersion.util.PacketUtil;
 import java.io.IOException;
 
 public class IncomingTransformer {
+    private final ViaVersionPlugin plugin = (ViaVersionPlugin) ViaVersion.getInstance();
     private final ConnectionInfo info;
     private boolean startedBlocking = false;
 
@@ -34,7 +35,7 @@ public class IncomingTransformer {
         if (packet.getPacketID() != -1) {
             packetID = packet.getPacketID();
         }
-        if (ViaVersion.getInstance().isDebug()) {
+        if (plugin.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());
             }
@@ -42,6 +43,11 @@ public class IncomingTransformer {
         if (packet == PacketType.PLAY_TP_CONFIRM || packet == PacketType.PLAY_VEHICLE_MOVE_REQUEST) { //TODO handle client-sided horse riding
             throw new CancelException();
         }
+        // Handle movement increment
+        // Update idle status (player, position, look, positionandlook)
+        if(packet == PacketType.PLAY_PLAYER || packet == PacketType.PLAY_PLAYER_POSITION_REQUEST || packet == PacketType.PLAY_PLAYER_LOOK_REQUEST || packet == PacketType.PLAY_PLAYER_POSITION_LOOK_REQUEST) {
+            info.incrementIdlePacket();
+        }
         PacketUtil.writeVarInt(packetID, output);
         if (packet == PacketType.HANDSHAKE) {
             int protVer = PacketUtil.readVarInt(input);
@@ -267,7 +273,7 @@ public class IncomingTransformer {
             output.writeByte(face);
             PacketUtil.readVarInt(input);
 
-            ItemStack inHand = ViaVersionPlugin.getHandItem(info);
+            ItemStack inHand = plugin.getHandItem(info);
             try {
                 ItemSlotRewriter.ItemStack item = ItemSlotRewriter.ItemStack.fromBukkit(inHand);
                 ItemSlotRewriter.fixIdsFrom1_9To1_8(item);
@@ -291,8 +297,8 @@ public class IncomingTransformer {
             output.writeLong(-1L);
             output.writeByte(255);
             // write item in hand
-            ItemStack inHand = ViaVersionPlugin.getHandItem(info);
-            if (inHand != null) {
+            ItemStack inHand = plugin.getHandItem(info);
+            if (inHand != null && plugin.isShieldBlocking()) {
                 if (inHand.getType().name().endsWith("SWORD")) {
                     // blocking?
                     if (hand == 0) {

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

@@ -15,7 +15,12 @@ import us.myles.ViaVersion.CancelException;
 import us.myles.ViaVersion.ConnectionInfo;
 import us.myles.ViaVersion.ViaVersionPlugin;
 import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.api.boss.BossBar;
+import us.myles.ViaVersion.api.boss.BossColor;
+import us.myles.ViaVersion.api.boss.BossStyle;
+import us.myles.ViaVersion.metadata.MetaIndex;
 import us.myles.ViaVersion.metadata.MetadataRewriter;
+import us.myles.ViaVersion.metadata.MetadataRewriter.Entry;
 import us.myles.ViaVersion.packets.PacketType;
 import us.myles.ViaVersion.packets.State;
 import us.myles.ViaVersion.slot.ItemSlotRewriter;
@@ -39,6 +44,8 @@ public class OutgoingTransformer {
     private final Map<Integer, EntityType> clientEntityTypes = new HashMap<>();
     private final Map<Integer, Integer> vehicleMap = new HashMap<>();
     private final Set<Integer> validBlocking = new HashSet<>();
+    private final Set<Integer> knownHolograms = new HashSet<>();
+    private final Map<Integer, BossBar> bossBarMap = new HashMap<>();
     private boolean autoTeam = false;
 
     public OutgoingTransformer(ConnectionInfo info) {
@@ -216,13 +223,15 @@ public class OutgoingTransformer {
             return;
         }
         if (packet == PacketType.PLAY_ENTITY_TELEPORT) {
-            // Port this so that it relative moves :P
             int id = PacketUtil.readVarInt(input);
             PacketUtil.writeVarInt(id, output);
 
             int x = input.readInt();
             output.writeDouble(x / 32D);
             int y = input.readInt();
+            if(plugin.isHologramPatch() & knownHolograms.contains(id)){
+                y = (int) ((y) + (plugin.getHologramYOffset() * 32D));
+            }
             output.writeDouble(y / 32D);
             int z = input.readInt();
             output.writeDouble(z / 32D);
@@ -243,6 +252,9 @@ public class OutgoingTransformer {
             int x = input.readByte();
             output.writeShort(x * 128);
             int y = input.readByte();
+            if(plugin.isHologramPatch() & knownHolograms.contains(id)){
+                y = (int) ((y) + plugin.getHologramYOffset());
+            }
             output.writeShort(y * 128);
             int z = input.readByte();
             output.writeShort(z * 128);
@@ -263,12 +275,16 @@ public class OutgoingTransformer {
             short x = (short) (input.readByte());
             output.writeShort(x * 128);
             short y = (short) (input.readByte());
+            if(plugin.isHologramPatch() & knownHolograms.contains(id)){
+                y = (short) (y - 1);
+            }
             output.writeShort(y * 128);
             short z = (short) (input.readByte());
             output.writeShort(z * 128);
 
             boolean onGround = input.readBoolean();
             output.writeBoolean(onGround);
+
             return;
 
         }
@@ -372,7 +388,14 @@ public class OutgoingTransformer {
             int[] toDestroy = PacketUtil.readVarInts(count, input);
             for (int entityID : toDestroy) {
                 clientEntityTypes.remove(entityID);
+                knownHolograms.remove(entityID);
                 PacketUtil.writeVarInt(entityID, output);
+
+                // Remvoe boss bar
+                BossBar bar = bossBarMap.remove(entityID);
+                if(bar != null) {
+                    bar.hide();
+                }
             }
             return;
         }
@@ -821,6 +844,32 @@ public class OutgoingTransformer {
         for (MetadataRewriter.Entry entry : list) {
             handleMetadata(entityID, entry, type);
         }
+        // Fix: wither (crash fix)
+        if(type == EntityType.WITHER) {
+            // Remove custom value if already exist
+            Iterator<Entry> it = list.iterator();
+            while(it.hasNext()) {
+                Entry e = it.next();
+                if(e.getOldID() == 10) {
+                    it.remove();
+                }
+            }
+
+            list.add(new Entry(MetaIndex.WITHER_PROPERTIES, (byte) 0, 10));
+        }
+        // Fix: Dragon (crash fix)
+        if(type == EntityType.ENDER_DRAGON) {
+            // Remove custom value if already exist
+            Iterator<Entry> it = list.iterator();
+            while(it.hasNext()) {
+                Entry e = it.next();
+                if(e.getOldID() == 11) {
+                    it.remove();
+                }
+            }
+
+            list.add(new Entry(MetaIndex.ENDERDRAGON_PHASE, (byte) 0, 11));
+        }
         MetadataRewriter.writeMetadata1_9(type, list, output);
     }
 
@@ -830,17 +879,70 @@ public class OutgoingTransformer {
             if (entry.getOldID() == 0) {
                 // Byte
                 byte data = (byte) entry.getValue();
-
-                if ((data & 0x10) == 0x10) {
-                    if (validBlocking.contains(entityID)) {
-                        ItemSlotRewriter.ItemStack shield = new ItemSlotRewriter.ItemStack();
-                        shield.id = 442;
-                        shield.amount = 1;
-                        shield.data = 0;
-                        sendSecondHandItem(entityID, shield);
+                if (entityID != info.getEntityID() && plugin.isShieldBlocking()) {
+                    if ((data & 0x10) == 0x10) {
+                        if (validBlocking.contains(entityID)) {
+                            ItemSlotRewriter.ItemStack shield = new ItemSlotRewriter.ItemStack();
+                            shield.id = 442;
+                            shield.amount = 1;
+                            shield.data = 0;
+                            sendSecondHandItem(entityID, shield);
+                        }
+                    } else {
+                        sendSecondHandItem(entityID, null);
+                    }
+                }
+            }
+        }
+        if(type == EntityType.ARMOR_STAND && plugin.isHologramPatch()){
+            if(entry.getOldID() == 0){
+                byte data = (byte) entry.getValue();
+                if((data & 0x20) == 0x20){
+                    if(!knownHolograms.contains(entityID)) {
+                        knownHolograms.add(entityID);
+                        // Send movement
+                        ByteBuf buf = info.getChannel().alloc().buffer();
+                        PacketUtil.writeVarInt(PacketType.PLAY_ENTITY_RELATIVE_MOVE.getNewPacketID(), buf);
+                        PacketUtil.writeVarInt(entityID, buf);
+                        buf.writeShort(0);
+                        buf.writeShort((short) (128D * (plugin.getHologramYOffset() * 32D)));
+                        buf.writeShort(0);
+                        buf.writeBoolean(true);
+                        info.sendRawPacket(buf, false);
+                    }
+                }
+            }
+        }
+
+        // Boss bar
+        if(plugin.isBossbarPatch()) {
+            if (type == EntityType.ENDER_DRAGON || type == EntityType.WITHER) {
+                if (entry.getOldID() == 2) {
+                    BossBar bar = bossBarMap.get(entityID);
+                    String title = (String) entry.getValue();
+                    title = title.isEmpty() ? (type == EntityType.ENDER_DRAGON ? "Ender Dragon" : "Wither") : title;
+                    if (bar == null) {
+                        bar = ViaVersion.getInstance().createBossBar(title, BossColor.PINK, BossStyle.SOLID);
+                        bossBarMap.put(entityID, bar);
+                        bar.addPlayer(info.getPlayer());
+                        bar.show();
+                    } else {
+                        bar.setTitle(title);
+                    }
+                } else if (entry.getOldID() == 6 && !plugin.isBossbarAntiflicker()) { // If anti flicker is enabled, don't update health
+                    BossBar bar = bossBarMap.get(entityID);
+                    // Make health range between 0 and 1
+                    float maxHealth = type == EntityType.ENDER_DRAGON ? 200.0f : 300.0f;
+                    float health = Math.max(0.0f, Math.min(((float) entry.getValue()) / maxHealth, 1.0f));
+                    if (bar == null) {
+                        String title = type == EntityType.ENDER_DRAGON ? "Ender Dragon" : "Wither";
+                        bar = ViaVersion.getInstance().createBossBar(title, health, BossColor.PINK, BossStyle.SOLID);
+                        bossBarMap.put(entityID, bar);
+                        bar.addPlayer(info.getPlayer());
+                        bar.show();
+                    } else {
+                        bar.setHealth(health);
                     }
-                } else {
-                    sendSecondHandItem(entityID, null);
                 }
             }
         }

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

@@ -0,0 +1,246 @@
+package us.myles.ViaVersion.util;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import org.bukkit.Bukkit;
+import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.configuration.file.YamlConfiguration;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.regex.Pattern;
+
+public class Configuration extends YamlConfiguration {
+    private List<String> mainHeader = Lists.newArrayList();
+    private final Map<String, List<String>> headers = Maps.newConcurrentMap();
+    private final File file;
+    private boolean loadHeaders;
+
+    public Configuration(File file) {
+        this.file = file;
+    }
+
+    /**
+     * Set the main header displayed at top of config.
+     *
+     * @param header header
+     */
+    public void mainHeader(String... header) {
+        mainHeader = Arrays.asList(header);
+    }
+
+    /**
+     * Get main header displayed at top of config.
+     *
+     * @return header
+     */
+    public List<String> mainHeader() {
+        return mainHeader;
+    }
+
+    /**
+     * Set option header.
+     *
+     * @param key of option (or section)
+     * @param header of option (or section)
+     */
+    public void header(String key, String... header) {
+//        String value = Joiner.on('\n').join(header);
+        headers.put(key, Arrays.asList(header));
+    }
+
+    /**
+     * Get header of option
+     *
+     * @param key of option (or section)
+     * @return Header
+     */
+    public List<String> header(String key) {
+        return headers.get(key);
+    }
+
+    public <T> T get(String key, Class<T> type) {
+        return type.cast(get(key));
+    }
+
+    /**
+     * Reload config from file.
+     */
+    public void reload() {
+        reload(headers.isEmpty());
+    }
+
+    /**
+     * Reload config from file.
+     *
+     * @param loadHeaders Whether or not to load headers.
+     */
+    public void reload(boolean loadHeaders) {
+        this.loadHeaders = loadHeaders;
+        try {
+            load(file);
+        } catch(Exception e) {
+            Bukkit.getLogger().log(Level.WARNING, "failed to reload file", e);
+        }
+    }
+
+    @Override
+    public void loadFromString(String contents) throws InvalidConfigurationException {
+        if(!loadHeaders) {
+            super.loadFromString(contents);
+            return;
+        }
+
+        StringBuilder memoryData = new StringBuilder();
+
+        // Parse headers
+        final int indentLength = options().indent();
+        final String pathSeparator = Character.toString(options().pathSeparator());
+        int currentIndents = 0;
+        String key = "";
+        List<String> headers = Lists.newArrayList();
+        for(String line : contents.split("\n")) {
+            if(line.isEmpty()) continue; // Skip empty lines
+            int indent = getSuccessiveCharCount(line, ' ');
+            String subline = indent > 0 ? line.substring(indent) : line;
+            if(subline.startsWith("#")) {
+                if(subline.startsWith("#>")) {
+                    String txt = subline.startsWith("#> ") ? subline.substring(3) : subline.substring(2);
+                    mainHeader.add(txt);
+                    continue; // Main header, handled by bukkit
+                }
+
+                // Add header to list
+                String txt = subline.startsWith("# ") ? subline.substring(2) : subline.substring(1);
+                headers.add(txt);
+                continue;
+            }
+
+            int indents = indent / indentLength;
+            if(indents <= currentIndents) {
+                // Remove last section of key
+                String[] array = key.split(Pattern.quote(pathSeparator));
+                int backspace = currentIndents - indents + 1;
+                key = join(array, options().pathSeparator(), 0, array.length - backspace);
+            }
+
+            // Add new section to key
+            String separator = key.length() > 0 ? pathSeparator : "";
+            String lineKey = line.contains(":") ? line.split(Pattern.quote(":"))[0] : line;
+            key += separator + lineKey.substring(indent);
+
+            currentIndents = indents;
+
+            memoryData.append(line).append('\n');
+            if(!headers.isEmpty()) {
+                this.headers.put(key, headers);
+                headers = Lists.newArrayList();
+            }
+        }
+
+        // Parse remaining text
+        super.loadFromString(memoryData.toString());
+
+        // Clear bukkit header
+        options().header(null);
+    }
+
+    /**
+     * Save config to file
+     */
+    public void save() {
+        if(headers.isEmpty() && mainHeader.isEmpty()) {
+            try {
+                super.save(file);
+            } catch(IOException e) {
+                Bukkit.getLogger().log(Level.WARNING, "Failed to save file", e);
+            }
+            return;
+        }
+
+        // Custom save
+        final int indentLength = options().indent();
+        final String pathSeparator = Character.toString(options().pathSeparator());
+        String content = saveToString();
+        StringBuilder fileData = new StringBuilder(buildHeader());
+        int currentIndents = 0;
+        String key = "";
+        for(String h : mainHeader) {
+            // Append main header to top of file
+            fileData.append("#> ").append(h).append('\n');
+        }
+
+        for(String line : content.split("\n")) {
+            if(line.isEmpty()) continue; // Skip empty lines
+            int indent = getSuccessiveCharCount(line, ' ');
+            int indents = indent / indentLength;
+            String indentText = indent > 0 ? line.substring(0, indent) : "";
+            if(indents <= currentIndents) {
+                // Remove last section of key
+                String[] array = key.split(Pattern.quote(pathSeparator));
+                int backspace = currentIndents - indents + 1;
+                key = join(array, options().pathSeparator(), 0, array.length - backspace);
+            }
+
+            // Add new section to key
+            String separator = key.length() > 0 ? pathSeparator : "";
+            String lineKey = line.contains(":") ? line.split(Pattern.quote(":"))[0] : line;
+            key += separator + lineKey.substring(indent);
+
+            currentIndents = indents;
+
+            List<String> header = headers.get(key);
+            String headerText = header != null ? addHeaderTags(header, indentText) : "";
+            fileData.append(headerText).append(line).append('\n');
+        }
+
+        // Write data to file
+        FileWriter writer = null;
+        try {
+            writer = new FileWriter(file);
+            writer.write(fileData.toString());
+            writer.flush();
+        } catch(IOException e) {
+            Bukkit.getLogger().log(Level.WARNING, "Failed to save file", e);
+        } finally {
+            if(writer != null) {
+                try {
+                    writer.close();
+                } catch(IOException e) {
+                }
+            }
+        }
+    }
+
+    private String addHeaderTags(List<String> header, String indent) {
+        StringBuilder builder = new StringBuilder();
+        for(String line : header) {
+            builder.append(indent).append("# ").append(line).append('\n');
+        }
+        return builder.toString();
+    }
+
+    private String join(String[] array, char joinChar, int start, int length) {
+        String[] copy = new String[length - start];
+        System.arraycopy(array, start, copy, 0, length - start);
+        return Joiner.on(joinChar).join(copy);
+    }
+
+    private int getSuccessiveCharCount(String text, char key) {
+        int count = 0;
+        for(int i = 0; i < text.length(); i++) {
+            if(text.charAt(i) == key) {
+                count += 1;
+            } else {
+                break;
+            }
+        }
+        return count;
+    }
+}

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

@@ -15,43 +15,43 @@ public abstract class ListWrapper implements List {
     public abstract void handleAdd(Object o);
 
     @Override
-    public int size() {
+    public synchronized int size() {
         return this.list.size();
     }
 
     @Override
-    public boolean isEmpty() {
+    public synchronized boolean isEmpty() {
         return this.list.isEmpty();
     }
 
     @Override
-    public boolean contains(Object o) {
+    public synchronized boolean contains(Object o) {
         return this.list.contains(o);
     }
 
     @Override
-    public Iterator iterator() {
+    public synchronized Iterator iterator() {
         return this.list.iterator();
     }
 
     @Override
-    public Object[] toArray() {
+    public synchronized Object[] toArray() {
         return this.list.toArray();
     }
 
     @Override
-    public boolean add(Object o) {
+    public synchronized boolean add(Object o) {
         handleAdd(o);
         return this.list.add(o);
     }
 
     @Override
-    public boolean remove(Object o) {
+    public synchronized boolean remove(Object o) {
         return this.list.remove(o);
     }
 
     @Override
-    public boolean addAll(Collection c) {
+    public synchronized boolean addAll(Collection c) {
         for (Object o : c) {
             handleAdd(o);
         }
@@ -59,7 +59,7 @@ public abstract class ListWrapper implements List {
     }
 
     @Override
-    public boolean addAll(int index, Collection c) {
+    public synchronized boolean addAll(int index, Collection c) {
         for (Object o : c) {
             handleAdd(o);
         }
@@ -67,72 +67,72 @@ public abstract class ListWrapper implements List {
     }
 
     @Override
-    public void clear() {
+    public synchronized void clear() {
         this.list.clear();
     }
 
     @Override
-    public Object get(int index) {
+    public synchronized Object get(int index) {
         return this.list.get(index);
     }
 
     @Override
-    public Object set(int index, Object element) {
+    public synchronized Object set(int index, Object element) {
         return this.list.set(index, element);
     }
 
     @Override
-    public void add(int index, Object element) {
+    public synchronized void add(int index, Object element) {
         this.list.add(index, element);
     }
 
     @Override
-    public Object remove(int index) {
+    public synchronized Object remove(int index) {
         return this.list.remove(index);
     }
 
     @Override
-    public int indexOf(Object o) {
+    public synchronized int indexOf(Object o) {
         return this.list.indexOf(o);
     }
 
     @Override
-    public int lastIndexOf(Object o) {
+    public synchronized int lastIndexOf(Object o) {
         return this.list.lastIndexOf(o);
     }
 
     @Override
-    public ListIterator listIterator() {
+    public synchronized ListIterator listIterator() {
         return this.list.listIterator();
     }
 
     @Override
-    public ListIterator listIterator(int index) {
-        return this.listIterator(index);
+    public synchronized ListIterator listIterator(int index) {
+        return this.list.listIterator(index);
     }
 
     @Override
-    public List subList(int fromIndex, int toIndex) {
+    public synchronized List subList(int fromIndex, int toIndex) {
         return this.list.subList(fromIndex, toIndex);
     }
 
     @Override
-    public boolean retainAll(Collection c) {
+    public synchronized boolean retainAll(Collection c) {
         return this.list.retainAll(c);
     }
 
     @Override
-    public boolean removeAll(Collection c) {
+    public synchronized boolean removeAll(Collection c) {
         return this.list.removeAll(c);
     }
 
     @Override
-    public boolean containsAll(Collection c) {
+    public synchronized boolean containsAll(Collection c) {
         return this.list.containsAll(c);
     }
 
     @Override
-    public Object[] toArray(Object[] a) {
+    public synchronized Object[] toArray(Object[] a) {
         return this.list.toArray(a);
     }
 }

src/main/resources/config.yml

@@ -1,12 +1,22 @@
 # Should ViaVersion check for updates?
 checkforupdates: true
-# Should we send any bulk chunks, in sync (may be slower but fixes timings)
-# Currently broken due to sign updates, possibly will return
-sync-chunks: true
 # No collide options, these allow you to configure how collision works.
 # Do you want us to prevent collision?
 prevent-collision: true
 # If the above is true, should we automatically team players until you do?
 auto-team: true
 # When enabled if certain metadata can't be read we won't tell you about it
-suppress-metadata-errors: false
+suppress-metadata-errors: false
+# When enabled 1.9 will be able to block by using shields
+shield-blocking: true
+# Should we enable our hologram patch?
+# If they're in the wrong place enable this
+hologram-patch: false
+# This is the offset, should work as default when enabled.
+hologram-y: -1
+# Enable player tick simulation, this fixes eating, drinking, nether portals.
+simulate-pt: true
+# Should we patch boss bars so they work? (Default: true, disable if you're having issues)
+bossbar-patch: true
+# If your boss bar flickers on 1.9, set this to 'true'. It will keep all boss bars on 100% (not recommended)
+bossbar-anti-flicker: false