0.9.7 release

Also remove a TODO.

README.md

@@ -1,15 +1,17 @@
-# ViaVersion 0.9.3
+# ViaVersion 0.9.7
 [![Build Status](https://travis-ci.org/MylesIsCool/ViaVersion.svg?branch=master)](https://travis-ci.org/MylesIsCool/ViaVersion)
 [![Gitter](https://badges.gitter.im/MylesIsCool/ViaVersion.svg)](https://gitter.im/MylesIsCool/ViaVersion)
 
-**Allows the connection of 1.9 clients to 1.8**
-**1.10 clients on 1.8 / 1.9 servers**
+**Allows the connection of higher client versions to lower server versions**
 
-This took 100s hours of work, so if you enjoy this consider looking into contacting me and supporting my projects.
+Allows 1.10, 1.9 on 1.8 server and 1.10 on a 1.9 server.
+
+**User Docs:** https://docs.viaversion.com/display/VIAVERSION/
 
 **Contributor Chat:** https://gitter.im/MylesIsCool/ViaVersion
 
 
+
 Sources:
 --------
 
@@ -21,12 +23,12 @@ Sources:
 
 
 
-Contributors:
+All Time Contributors:
 --------
 
 **Myself** (harhar)
 
-**Matsv/StamBoom**
+**Matsv**
 
 **HugoDaBosss**
 
@@ -40,6 +42,10 @@ Contributors:
 
 **lenis0012**
 
+**fuzzy_bot**
+
+**joserobjr**
+
 
 
 Releases / Dev Builds:

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>us.myles</groupId>
     <artifactId>viaversion</artifactId>
-    <version>0.9.4</version>
+    <version>0.9.7</version>
     <packaging>jar</packaging>
 
     <name>ViaVersion</name>

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

@@ -4,6 +4,7 @@ import us.myles.ViaVersion.api.ViaVersionConfig;
 import us.myles.ViaVersion.util.Configuration;
 
 import java.io.File;
+import java.util.List;
 
 public class ViaConfig implements ViaVersionConfig {
     private final ViaVersionPlugin plugin;
@@ -150,8 +151,33 @@ public class ViaConfig implements ViaVersionConfig {
         return plugin.getConfig().getBoolean("nms-player-ticking", true);
     }
 
+    @Override
+    public boolean isReplacePistons() {
+        return plugin.getConfig().getBoolean("replace-pistons", false);
+    }
+
+    @Override
+    public int getPistonReplacementId() {
+        return plugin.getConfig().getInt("replacement-piston-id", 0);
+    }
+
     public boolean isAutoTeam() {
         // Collision has to be enabled first
         return isPreventCollision() && plugin.getConfig().getBoolean("auto-team", true);
     }
+
+    @Override
+    public boolean isForceJsonTransform() {
+        return plugin.getConfig().getBoolean("force-json-transform", false);
+    }
+
+    @Override
+    public List<Integer> getBlockedProtocols() {
+        return plugin.getConfig().getIntegerList("block-protocols");
+    }
+
+    @Override
+    public String getBlockedDisconnectMsg() {
+        return plugin.getConfig().getString("block-disconnect-msg", "You are using an unsupported Minecraft version!");
+    }
 }

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

@@ -27,6 +27,7 @@ import us.myles.ViaVersion.handlers.ViaVersionInitializer;
 import us.myles.ViaVersion.protocols.base.ProtocolInfo;
 import us.myles.ViaVersion.update.UpdateListener;
 import us.myles.ViaVersion.update.UpdateUtil;
+import us.myles.ViaVersion.util.ConcurrentList;
 import us.myles.ViaVersion.util.ListWrapper;
 import us.myles.ViaVersion.util.ProtocolSupportUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
@@ -53,6 +54,20 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
     @Getter
     private ViaConfig conf;
 
+    public ViaVersionPlugin() {
+        // Check if we're using protocol support too
+        protocolSupport = Bukkit.getPluginManager().getPlugin("ProtocolSupport") != null;
+
+        if (protocolSupport) {
+            getLogger().info("Patching to prevent concurrency issues...");
+            try {
+                patchLists();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
     @Override
     public void onLoad() {
         // Config magic
@@ -87,9 +102,6 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
             compatSpigotBuild = false;
         }
 
-        // Check if we're using protocol support too
-        protocolSupport = Bukkit.getPluginManager().getPlugin("ProtocolSupport") != null;
-
         // Generate classes needed (only works if it's compat or ps)
         ClassGenerator.generate();
         lateBind = !isBinded();
@@ -248,6 +260,27 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         }
     }
 
+
+    public void patchLists() throws Exception {
+        Object connection = getServerConnection();
+        if (connection == null) {
+            getLogger().warning("We failed to find the ServerConnection? :( What server are you running?");
+            return;
+        }
+        for (Field field : connection.getClass().getDeclaredFields()) {
+            field.setAccessible(true);
+            final Object value = field.get(connection);
+            if (value instanceof List) {
+                if (!(value instanceof ConcurrentList)) {
+                    ConcurrentList list = new ConcurrentList();
+                    list.addAll((List) value);
+                    field.set(connection, list);
+                }
+            }
+        }
+    }
+
+
     public boolean isBinded() {
         try {
             Object connection = getServerConnection();
@@ -417,7 +450,10 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
 
     @Override
     public SortedSet<Integer> getSupportedVersions() {
-        return ProtocolRegistry.getSupportedVersions();
+        SortedSet<Integer> outputSet = new TreeSet<>(ProtocolRegistry.getSupportedVersions());
+        outputSet.removeAll(getConf().getBlockedProtocols());
+
+        return outputSet;
     }
 
     @Override

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

@@ -3,6 +3,7 @@ package us.myles.ViaVersion.api;
 import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
 import lombok.Getter;
 import lombok.Setter;
 import us.myles.ViaVersion.api.data.UserConnection;
@@ -223,6 +224,7 @@ public class PacketWrapper {
         }
         if (readableObjects.size() > 0) {
             packetValues.addAll(readableObjects);
+            readableObjects.clear();
         }
 
         int index = 0;
@@ -267,10 +269,59 @@ public class PacketWrapper {
 
     private void writeRemaining(ByteBuf output) {
         if (inputBuffer != null) {
-            output.writeBytes(inputBuffer);
+            output.writeBytes(inputBuffer, inputBuffer.readableBytes());
         }
     }
 
+    /**
+     * Send this packet to the associated user.
+     * Be careful not to send packets twice.
+     * (Sends it after current)
+     *
+     * @param packetProtocol      - The protocol version of the packet.
+     * @param skipCurrentPipeline - Skip the current pipeline
+     * @throws Exception if it fails to write
+     */
+    public void send(Class<? extends Protocol> packetProtocol, boolean skipCurrentPipeline) throws Exception {
+        if (!isCancelled()) {
+            ByteBuf output = constructPacket(packetProtocol, skipCurrentPipeline);
+            user().sendRawPacket(output);
+        }
+    }
+
+    /**
+     * Let the packet go through the protocol pipes and write it to ByteBuf
+     *
+     * @param packetProtocol      - The protocol version of the packet.
+     * @param skipCurrentPipeline - Skip the current pipeline
+     * @return Packet buffer
+     * @throws Exception if it fails to write
+     */
+    private ByteBuf constructPacket(Class<? extends Protocol> packetProtocol, boolean skipCurrentPipeline) throws Exception {
+        // Apply current pipeline
+        List<Protocol> protocols = new ArrayList<>(user().get(ProtocolInfo.class).getPipeline().pipes());
+        // Other way if outgoing
+        Collections.reverse(protocols);
+        int index = 0;
+        for (int i = 0; i < protocols.size(); i++) {
+            if (protocols.get(i).getClass().equals(packetProtocol)) {
+                index = skipCurrentPipeline ? (i + 1) : (i);
+                break;
+            }
+        }
+
+        // Reset reader before we start
+        resetReader();
+
+        // Apply other protocols
+        apply(Direction.OUTGOING, user().get(ProtocolInfo.class).getState(), index, protocols);
+        // Send
+        ByteBuf output = inputBuffer == null ? Unpooled.buffer() : inputBuffer.alloc().buffer();
+        writeToBuffer(output);
+
+        return output;
+    }
+
     /**
      * Send this packet to the associated user.
      * Be careful not to send packets twice.
@@ -280,25 +331,25 @@ public class PacketWrapper {
      * @throws Exception if it fails to write
      */
     public void send(Class<? extends Protocol> packetProtocol) throws Exception {
+        send(packetProtocol, true);
+    }
+
+    /**
+     * Send this packet to the associated user.
+     * Be careful not to send packets twice.
+     * (Sends it after current)
+     * Also returns the packets ChannelFuture
+     *
+     * @param packetProtocol - The protocol version of the packet.
+     * @return The packets ChannelFuture
+     * @throws Exception if it fails to write
+     */
+    public ChannelFuture sendFuture(Class<? extends Protocol> packetProtocol) throws Exception {
         if (!isCancelled()) {
-            // Apply current pipeline
-            List<Protocol> protocols = new ArrayList<>(user().get(ProtocolInfo.class).getPipeline().pipes());
-            // Other way if outgoing
-            Collections.reverse(protocols);
-            int index = 0;
-            for (int i = 0; i < protocols.size(); i++) {
-                if (protocols.get(i).getClass().equals(packetProtocol)) {
-                    index = i + 1;
-                    break;
-                }
-            }
-            // Apply other protocols
-            apply(Direction.OUTGOING, user().get(ProtocolInfo.class).getState(), index, protocols);
-            // Send
-            ByteBuf output = inputBuffer == null ? Unpooled.buffer() : inputBuffer.alloc().buffer();
-            writeToBuffer(output);
-            user().sendRawPacket(output);
+            ByteBuf output = constructPacket(packetProtocol, true);
+            return user().sendRawPacketFuture(output);
         }
+        return user().getChannel().newFailedFuture(new Exception("Cancelled packet"));
     }
 
     /**
@@ -393,6 +444,10 @@ public class PacketWrapper {
      * Reset the reader, so that it can be read again.
      */
     public void resetReader() {
+        // Move readable objects are packet values
+        this.packetValues.addAll(readableObjects);
+        this.readableObjects.clear();
+        // Move all packet values to the readable for next packet.
         this.readableObjects.addAll(packetValues);
         this.packetValues.clear();
     }

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

@@ -6,6 +6,7 @@ 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.api.command.ViaVersionCommand;
+import us.myles.ViaVersion.api.protocol.ProtocolRegistry;
 
 import java.util.SortedSet;
 import java.util.UUID;
@@ -114,6 +115,8 @@ public interface ViaVersionAPI {
 
     /**
      * Get the supported protocol versions
+     * This method removes any blocked protocol versions.
+     * @see ProtocolRegistry#getSupportedVersions() for full list.
      *
      * @return a list of protocol versions
      */

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

@@ -1,5 +1,7 @@
 package us.myles.ViaVersion.api;
 
+import java.util.List;
+
 public interface ViaVersionConfig {
 
     /**
@@ -172,4 +174,39 @@ public interface ViaVersionConfig {
      * @return if true, enabled
      */
     boolean isNMSPlayerTicking();
+
+    /**
+     * Replace extended pistons on 1.10 chunk loading.
+     *
+     * @return True if to replace them
+     */
+    boolean isReplacePistons();
+
+    /**
+     * Get the id for replacing extended pistons.
+     *
+     * @return The integer id
+     */
+    int getPistonReplacementId();
+
+    /**
+     * Force json transform
+     *
+     * @return True if enabled
+     */
+    boolean isForceJsonTransform();
+
+    /**
+     * Get the blocked protocols
+     *
+     * @return An Integer list
+     */
+    List<Integer> getBlockedProtocols();
+
+    /**
+     * Get the custom disconnect message
+     *
+     * @return Disconnect message
+     */
+    String getBlockedDisconnectMsg();
 }

src/main/java/us/myles/ViaVersion/api/data/StoredObject.java

@@ -1,10 +1,9 @@
 package us.myles.ViaVersion.api.data;
 
-import lombok.AccessLevel;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 
-@Getter(AccessLevel.PROTECTED)
+@Getter
 @AllArgsConstructor
 public class StoredObject {
     private UserConnection user;

src/main/java/us/myles/ViaVersion/api/data/UserConnection.java

@@ -1,6 +1,7 @@
 package us.myles.ViaVersion.api.data;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.socket.SocketChannel;
 import lombok.Data;
@@ -85,6 +86,17 @@ public class UserConnection {
         }
     }
 
+    /**
+     * Send a raw packet to the player with returning the future
+     *
+     * @param packet The raw packet to send
+     * @return ChannelFuture of the packet being sent
+     */
+    public ChannelFuture sendRawPacketFuture(final ByteBuf packet) {
+        final ChannelHandler handler = channel.pipeline().get("encoder");
+        return channel.pipeline().context(handler).writeAndFlush(packet);
+    }
+
     /**
      * Send a raw packet to the player (netty thread)
      *

src/main/java/us/myles/ViaVersion/api/minecraft/chunks/Chunk.java

@@ -1,4 +1,17 @@
 package us.myles.ViaVersion.api.minecraft.chunks;
 
 public interface Chunk {
+    int getX();
+
+    int getZ();
+
+    ChunkSection[] getSections();
+
+    boolean isGroundUp();
+
+    boolean isBiomeData();
+
+    byte[] getBiomeData();
+
+    int getBitmask();
 }

src/main/java/us/myles/ViaVersion/api/minecraft/chunks/ChunkSection.java

@@ -0,0 +1,15 @@
+package us.myles.ViaVersion.api.minecraft.chunks;
+
+import io.netty.buffer.ByteBuf;
+
+public interface ChunkSection {
+    int getBlockId(int x, int y, int z);
+
+    void writeBlocks(ByteBuf output) throws Exception;
+
+    void writeBlockLight(ByteBuf output) throws Exception;
+
+    boolean hasSkyLight();
+
+    void writeSkyLight(ByteBuf output) throws Exception;
+}

src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java

@@ -79,6 +79,11 @@ public class ProtocolRegistry {
         }
     }
 
+    /**
+     * Get the versions compatible with the server.
+     *
+     * @return Read-only set of the versions.
+     */
     public static SortedSet<Integer> getSupportedVersions() {
         return Collections.unmodifiableSortedSet(new TreeSet<>(supportedVersions));
     }

src/main/java/us/myles/ViaVersion/api/type/Type.java

@@ -10,7 +10,6 @@ import us.myles.ViaVersion.api.minecraft.item.Item;
 import us.myles.ViaVersion.api.type.types.*;
 import us.myles.ViaVersion.api.type.types.minecraft.*;
 
-import java.util.List;
 import java.util.UUID;
 
 @Getter

src/main/java/us/myles/ViaVersion/api/type/types/UnsignedByteType.java

@@ -6,7 +6,7 @@ import us.myles.ViaVersion.api.type.TypeConverter;
 
 public class UnsignedByteType extends Type<Short> implements TypeConverter<Short> {
     public UnsignedByteType() {
-        super(Short.class);
+        super("Unsigned Byte", Short.class);
     }
 
     @Override

src/main/java/us/myles/ViaVersion/protocols/base/BaseProtocol.java

@@ -1,5 +1,9 @@
 package us.myles.ViaVersion.protocols.base;
 
+import io.netty.channel.ChannelFuture;
+import io.netty.util.concurrent.Future;
+import io.netty.util.concurrent.GenericFutureListener;
+import net.md_5.bungee.api.ChatColor;
 import org.apache.commons.lang.StringUtils;
 import org.bukkit.Bukkit;
 import org.bukkit.event.EventHandler;
@@ -21,6 +25,7 @@ import us.myles.ViaVersion.api.remapper.PacketRemapper;
 import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.packets.Direction;
 import us.myles.ViaVersion.packets.State;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9TO1_8;
 
 import java.util.List;
 import java.util.UUID;
@@ -31,6 +36,8 @@ public class BaseProtocol extends Protocol {
     @Override
     protected void registerPackets() {
         /* Outgoing Packets */
+
+        // Status Response Packet
         registerOutgoing(State.STATUS, 0x00, 0x00, new PacketRemapper() { // Status Response Packet
             @Override
             public void registerMap() {
@@ -43,20 +50,26 @@ public class BaseProtocol extends Protocol {
                         try {
                             JSONObject json = (JSONObject) new JSONParser().parse(originalStatus);
                             JSONObject version = (JSONObject) json.get("version");
-                            if (ViaVersion.getConfig().isSendSupportedVersions())
+                            int protocolVersion = ((Long) version.get("protocol")).intValue();
+
+                            if (ViaVersion.getConfig().isSendSupportedVersions()) //Send supported versions
                                 version.put("supportedVersions", ViaVersion.getInstance().getSupportedVersions());
-                            if (ProtocolRegistry.SERVER_PROTOCOL == -1) {
-                                Long original = (Long) version.get("protocol");
-                                ProtocolRegistry.SERVER_PROTOCOL = original.intValue();
-                            }
+
+                            if (ProtocolRegistry.SERVER_PROTOCOL == -1) // Set the Server protocol if the detection on startup failed
+                                ProtocolRegistry.SERVER_PROTOCOL = protocolVersion;
+
                             List<Pair<Integer, Protocol>> protocols = ProtocolRegistry.getProtocolPath(info.getProtocolVersion(), ProtocolRegistry.SERVER_PROTOCOL);
                             if (protocols != null) {
-                                if ((long) version.get("protocol") != 9999) //Fix serverlistplus
+                                if (protocolVersion != 9999) //Fix ServerListPlus
                                     version.put("protocol", info.getProtocolVersion());
                             } else {
                                 // not compatible :(, *plays very sad violin*
                                 wrapper.user().setActive(false);
                             }
+
+                            if (ViaVersion.getConfig().getBlockedProtocols().contains(info.getProtocolVersion()))
+                                version.put("protocol", -1); // Show blocked versions as outdated
+
                             wrapper.set(Type.STRING, 0, json.toJSONString()); // Update value
                         } catch (ParseException e) {
                             e.printStackTrace();
@@ -88,6 +101,10 @@ public class BaseProtocol extends Protocol {
                         info.setUsername(wrapper.get(Type.STRING, 1));
                         // Add to ported clients
                         ((ViaVersionPlugin) ViaVersion.getInstance()).addPortedClient(wrapper.user());
+
+                        if (info.getPipeline().pipes().size() == 1 && info.getPipeline().pipes().get(0).getClass() == BaseProtocol.class) // Only base protocol
+                            wrapper.user().setActive(false);
+
                         if (ViaVersion.getInstance().isDebug()) {
                             // Print out the route to console
                             ((ViaVersionPlugin) ViaVersion.getInstance()).getLogger().log(Level.INFO, "{0} logged in with protocol {1}, Route: {2}",
@@ -130,11 +147,6 @@ public class BaseProtocol extends Protocol {
                                 pipeline.add(prot.getValue());
                             }
                             wrapper.set(Type.VAR_INT, 0, ProtocolRegistry.SERVER_PROTOCOL);
-                        } else {
-                            if (state == 2) {
-                                // not compatible :(, *plays very sad violin*
-                                wrapper.user().setActive(false);
-                            }
                         }
 
                         // Change state
@@ -151,7 +163,34 @@ public class BaseProtocol extends Protocol {
         registerIncoming(State.STATUS, 0x00, 0x00); // Status Request Packet
         registerIncoming(State.STATUS, 0x01, 0x01); // Status Ping Packet
 
-        registerIncoming(State.LOGIN, 0x00, 0x00); // Login Start Packet
+        // Login Start Packet
+        registerIncoming(State.LOGIN, 0x00, 0x00, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                handler(new PacketHandler() {
+                    @Override
+                    public void handle(final PacketWrapper wrapper) throws Exception {
+                        int protocol = wrapper.user().get(ProtocolInfo.class).getProtocolVersion();
+                        if (ViaVersion.getConfig().getBlockedProtocols().contains(protocol)) {
+                            if (!wrapper.user().getChannel().isOpen()) return;
+
+                            PacketWrapper disconnectPacket = new PacketWrapper(0x00, null, wrapper.user()); // Disconnect Packet
+                            Protocol1_9TO1_8.FIX_JSON.write(disconnectPacket, ChatColor.translateAlternateColorCodes('&', ViaVersion.getConfig().getBlockedDisconnectMsg()));
+                            wrapper.cancel(); // cancel current
+
+                            // Send and close
+                            ChannelFuture future = disconnectPacket.sendFuture(BaseProtocol.class);
+                            future.addListener(new GenericFutureListener<Future<? super Void>>() {
+                                @Override
+                                public void operationComplete(Future<? super Void> future) throws Exception {
+                                    wrapper.user().getChannel().close();
+                                }
+                            });
+                        }
+                    }
+                });
+            }
+        }); // Login Start Packet
         registerIncoming(State.LOGIN, 0x01, 0x01); // Encryption Response Packet
     }
 

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_1_2to1_9_3_4/BlockEntity.java

@@ -26,9 +26,6 @@ public class BlockEntity {
         types.put("UNKNOWN", 7);
         types.put("EndGateway", 8);
         types.put("Sign", 9);
-
-        //I didn't see anything that didn't work about chests
-//        types.put("Chest", -1);
     }
 
     public static void handle(List<CompoundTag> tags, UserConnection connection) {
@@ -45,21 +42,13 @@ public class BlockEntity {
                 if (newId == -1)
                     continue;
 
-
                 int x = (int) tag.get("x").getValue();
                 int y = (int) tag.get("y").getValue();
                 int z = (int) tag.get("z").getValue();
 
                 Position pos = new Position((long) x, (long) y, (long) z);
 
-                if (newId != 9) {
-                    updateBlockEntity(pos, (short) newId, tag, connection);
-                } else {
-                    String[] lines = new String[4];
-                    for (int i = 1; i < 5; i++)
-                        lines[i - 1] = (String) tag.get("Text" + i).getValue();
-                    updateSign(pos, lines, connection);
-                }
+                updateBlockEntity(pos, (short) newId, tag, connection);
             } catch (Exception e) {
                 if (ViaVersion.getInstance().isDebug()) {
                     System.out.println("Block Entity: " + e.getMessage() + ": " + tag);
@@ -73,14 +62,6 @@ public class BlockEntity {
         wrapper.write(Type.POSITION, pos);
         wrapper.write(Type.UNSIGNED_BYTE, id);
         wrapper.write(Type.NBT, tag);
-        wrapper.send(Protocol1_9_1_2TO1_9_3_4.class);
-    }
-
-    private static void updateSign(Position pos, String[] lines, UserConnection connection) throws Exception {
-        PacketWrapper wrapper = new PacketWrapper(0x46, null, connection);
-        wrapper.write(Type.POSITION, pos);
-        for (String s : lines)
-            wrapper.write(Type.STRING, s);
-        wrapper.send(Protocol1_9_1_2TO1_9_3_4.class);
+        wrapper.send(Protocol1_9_1_2TO1_9_3_4.class, false);
     }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_1_2to1_9_3_4/Chunk1_9_3_4.java

@@ -14,7 +14,16 @@ public class Chunk1_9_3_4 implements Chunk {
     private int z;
     private boolean groundUp;
     private int bitmask;
-    private byte[] sections;
+    private ChunkSection1_9_3_4[] sections;
     List<CompoundTag> blockEntities;
 
+    @Override
+    public boolean isBiomeData() {
+        return false;
+    }
+
+    @Override
+    public byte[] getBiomeData() {
+        return new byte[0];
+    }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_1_2to1_9_3_4/Chunk1_9_3_4Type.java

@@ -31,7 +31,7 @@ public class Chunk1_9_3_4Type extends BaseChunkType {
         for (int i = 0; i < blockEntities; i++) {
             nbtData.add(Type.NBT.read(input));
         }
-        return new Chunk1_9_3_4(chunkX, chunkZ, groundUp, primaryBitmask, sections, nbtData);
+        return new Chunk1_9_3_4(chunkX, chunkZ, groundUp, primaryBitmask, new ChunkSection1_9_3_4[] {new ChunkSection1_9_3_4(sections)}, nbtData);
     }
 
     @Override
@@ -46,8 +46,8 @@ public class Chunk1_9_3_4Type extends BaseChunkType {
         buffer.writeBoolean(chunk.isGroundUp());
         Type.VAR_INT.write(buffer, chunk.getBitmask());
 
-        Type.VAR_INT.write(buffer, chunk.getSections().length);
-        buffer.writeBytes(chunk.getSections());
+        Type.VAR_INT.write(buffer, chunk.getSections()[0].getData().length);
+        buffer.writeBytes(chunk.getSections()[0].getData());
 
         // no block entities as it's earlier
     }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_1_2to1_9_3_4/ChunkSection1_9_3_4.java

@@ -0,0 +1,41 @@
+package us.myles.ViaVersion.protocols.protocol1_9_1_2to1_9_3_4;
+
+import io.netty.buffer.ByteBuf;
+import us.myles.ViaVersion.api.minecraft.chunks.ChunkSection;
+
+public class ChunkSection1_9_3_4 implements ChunkSection {
+    private final byte[] data;
+
+    public ChunkSection1_9_3_4(byte[] data) {
+        this.data = data;
+    }
+
+    public byte[] getData() {
+        return data;
+    }
+
+    @Override
+    public int getBlockId(int x, int y, int z) {
+        throw new UnsupportedOperationException("Invalid chunk type!");
+    }
+
+    @Override
+    public void writeBlocks(ByteBuf output) throws Exception {
+        throw new UnsupportedOperationException("Invalid chunk type!");
+    }
+
+    @Override
+    public void writeBlockLight(ByteBuf output) throws Exception {
+        throw new UnsupportedOperationException("Invalid chunk type!");
+    }
+
+    @Override
+    public boolean hasSkyLight() {
+        throw new UnsupportedOperationException("Invalid chunk type!");
+    }
+
+    @Override
+    public void writeSkyLight(ByteBuf output) throws Exception {
+        throw new UnsupportedOperationException("Invalid chunk type!");
+    }
+}

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/Chunk1_9_1_2Type.java

@@ -2,22 +2,32 @@ package us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import org.bukkit.World;
 import org.spacehq.opennbt.tag.builtin.CompoundTag;
+import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.minecraft.chunks.Chunk;
+import us.myles.ViaVersion.api.minecraft.chunks.ChunkSection;
+import us.myles.ViaVersion.api.type.PartialType;
 import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.api.type.types.minecraft.BaseChunkType;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.chunks.ChunkSection1_9to1_8;
+import us.myles.ViaVersion.protocols.base.ProtocolInfo;
+import us.myles.ViaVersion.protocols.protocol1_10to1_9_3.Protocol1_10To1_9_3_4;
+import us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2.storage.ClientWorld;
 
 import java.util.ArrayList;
 import java.util.BitSet;
 
-public class Chunk1_9_1_2Type extends BaseChunkType {
-    public Chunk1_9_1_2Type() {
-        super("1.9.1/2 Chunk");
+public class Chunk1_9_1_2Type extends PartialType<Chunk, ClientWorld> {
+
+    public Chunk1_9_1_2Type(ClientWorld clientWorld) {
+        super(clientWorld, Chunk.class);
     }
 
     @Override
-    public Chunk read(ByteBuf input) throws Exception {
+    public Chunk read(ByteBuf input, ClientWorld world) throws Exception {
+        boolean replacePistons = world.getUser().get(ProtocolInfo.class).getPipeline().contains(Protocol1_10To1_9_3_4.class) && ViaVersion.getConfig().isReplacePistons();
+        int replacementId = ViaVersion.getConfig().getPistonReplacementId();
+
         int chunkX = input.readInt();
         int chunkZ = input.readInt();
 
@@ -39,29 +49,29 @@ public class Chunk1_9_1_2Type extends BaseChunkType {
             if (!usedSections.get(i)) continue; // Section not set
             ChunkSection1_9_1_2 section = new ChunkSection1_9_1_2();
             sections[i] = section;
-            // WIP.
-//            section.readBlocks(input);
-//            section.readBlockLight(input);
-//            section.readSkyLight(input);
-            /*
-                    BlockStorage blocks = new BlockStorage(in);
-                    NibbleArray3d blocklight = new NibbleArray3d(in, 2048); (1024 bytes)
-                    NibbleArray3d skylight = hasSkylight ? new NibbleArray3d(in, 2048) : null; (1024 bytes)
-                    chunks[index] = new Chunk(blocks, blocklight, skylight);
-             */
+            section.readBlocks(input);
+            section.readBlockLight(input);
+            if (world.getEnvironment() == World.Environment.NORMAL) {
+                section.readSkyLight(input);
+            }
+            if (replacePistons) {
+                if (section.getPalette().contains(36)) {
+                    section.getPalette().set(section.getPalette().indexOf(36), replacementId);
+                }
+            }
         }
+
         byte[] biomeData = groundUp ? new byte[256] : null;
-        if (groundUp)
+        if (groundUp) {
             input.readBytes(biomeData);
+        }
 
         return new Chunk1_9_1_2(chunkX, chunkZ, groundUp, primaryBitmask, sections, biomeData, new ArrayList<CompoundTag>());
     }
 
     @Override
-    public void write(ByteBuf output, Chunk input) throws Exception {
-        if (!(input instanceof Chunk1_9_1_2))
-            throw new Exception("Tried to send the wrong chunk type from 1.9.3-4 chunk: " + input.getClass());
-        Chunk1_9_1_2 chunk = (Chunk1_9_1_2) input;
+    public void write(ByteBuf output, ClientWorld world, Chunk input) throws Exception {
+        Chunk chunk = input;
 
         output.writeInt(chunk.getX());
         output.writeInt(chunk.getZ());
@@ -71,7 +81,7 @@ public class Chunk1_9_1_2Type extends BaseChunkType {
 
         ByteBuf buf = Unpooled.buffer();
         for (int i = 0; i < 16; i++) {
-            ChunkSection1_9_1_2 section = chunk.getSections()[i];
+            ChunkSection section = chunk.getSections()[i];
             if (section == null) continue; // Section not set
             section.writeBlocks(buf);
             section.writeBlockLight(buf);
@@ -89,7 +99,10 @@ public class Chunk1_9_1_2Type extends BaseChunkType {
         if (chunk.isBiomeData()) {
             output.writeBytes(chunk.getBiomeData());
         }
+    }
 
-//        Type.NBT_ARRAY.write(output, tags.toArray(new CompoundTag[0])); Written by the handler
+    @Override
+    public Class<? extends Type> getBaseClass() {
+        return BaseChunkType.class;
     }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/ChunkSection1_9_1_2.java

@@ -3,12 +3,14 @@ package us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2;
 import com.google.common.collect.Lists;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import lombok.Getter;
+import us.myles.ViaVersion.api.minecraft.chunks.ChunkSection;
 import us.myles.ViaVersion.api.minecraft.chunks.NibbleArray;
 import us.myles.ViaVersion.api.type.Type;
 
 import java.util.List;
 
-public class ChunkSection1_9_1_2 {
+public class ChunkSection1_9_1_2 implements ChunkSection {
     /**
      * Size (dimensions) of blocks in a chunks section.
      */
@@ -20,7 +22,7 @@ public class ChunkSection1_9_1_2 {
     /**
      * Length of the block data array.
      */
-
+    @Getter
     private final List<Integer> palette = Lists.newArrayList();
     private final int[] blocks;
     private final NibbleArray blockLight;
@@ -45,9 +47,9 @@ public class ChunkSection1_9_1_2 {
         setBlock(index(x, y, z), type, data);
     }
 
-    public int getBlockId(int x, int y, int z){
+    public int getBlockId(int x, int y, int z) {
         int index = blocks[index(x, y, z)];
-        return palette.indexOf(index) >> 4;
+        return palette.get(index) >> 4;
     }
 
     /**
@@ -88,7 +90,101 @@ public class ChunkSection1_9_1_2 {
     }
 
     private int index(int x, int y, int z) {
-        return z << 8 | y << 4 | x;
+        return y << 8 | z << 4 | x;
+    }
+
+    /**
+     * Read blocks from input stream.
+     * This reads all the block related data:
+     * <ul>
+     * <li>Block length/palette type</li>
+     * <li>Palette</li>
+     * <li>Block hashes/palette reference</li>
+     * </ul>
+     *
+     * @param input The buffer to read from.
+     * @throws Exception
+     */
+    public void readBlocks(ByteBuf input) throws Exception {
+        palette.clear();
+
+        // Reaad bits per block
+        int bitsPerBlock = input.readUnsignedByte();
+        long maxEntryValue = (1L << bitsPerBlock) - 1;
+
+        if (bitsPerBlock == 0) {
+            bitsPerBlock = 13;
+        }
+        if (bitsPerBlock < 4) {
+            bitsPerBlock = 4;
+        }
+        if (bitsPerBlock > 8) {
+            bitsPerBlock = 13;
+        }
+        int paletteLength = Type.VAR_INT.read(input);
+        // Read palette
+        for (int i = 0; i < paletteLength; i++) {
+            if (bitsPerBlock != 13) {
+                palette.add(Type.VAR_INT.read(input));
+            } else {
+                Type.VAR_INT.read(input);
+            }
+        }
+
+        // Read blocks
+        Long[] blockData = Type.LONG_ARRAY.read(input);
+        if (blockData.length > 0) {
+            for (int i = 0; i < blocks.length; i++) {
+                int bitIndex = i * bitsPerBlock;
+                int startIndex = bitIndex / 64;
+                int endIndex = ((i + 1) * bitsPerBlock - 1) / 64;
+                int startBitSubIndex = bitIndex % 64;
+                int val;
+                if (startIndex == endIndex) {
+                    val = (int) (blockData[startIndex] >>> startBitSubIndex & maxEntryValue);
+                } else {
+                    int endBitSubIndex = 64 - startBitSubIndex;
+                    val = (int) ((blockData[startIndex] >>> startBitSubIndex | blockData[endIndex] << endBitSubIndex) & maxEntryValue);
+                }
+
+                if (bitsPerBlock == 13) {
+                    int type = val >> 4;
+                    int data = val & 0xF;
+
+                    setBlock(i, type, data);
+                } else {
+                    blocks[i] = val;
+                }
+            }
+        }
+    }
+
+    /**
+     * Read block light from buffer.
+     *
+     * @param input The buffer to read from
+     */
+    public void readBlockLight(ByteBuf input) {
+        byte[] handle = new byte[LIGHT_LENGTH];
+        input.readBytes(handle);
+        blockLight.setHandle(handle);
+    }
+
+    /**
+     * Read sky light from buffer.
+     * Note: Only sent in overworld!
+     *
+     * @param input The buffer to read from
+     */
+    public void readSkyLight(ByteBuf input) {
+        byte[] handle = new byte[LIGHT_LENGTH];
+        input.readBytes(handle);
+        if (skyLight != null) {
+            skyLight.setHandle(handle);
+            return;
+        }
+
+        this.skyLight = new NibbleArray(handle);
     }
 
     /**

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/FakeTileEntity.java

@@ -27,7 +27,7 @@ public class FakeTileEntity {
         register(Arrays.asList(Material.SIGN_POST, Material.WALL_SIGN), "Sign");
         register(Material.MOB_SPAWNER, "MobSpawner");
         register(Material.NOTE_BLOCK, "Music");
-        register(Material.PISTON_BASE, "Piston");
+        register(Arrays.asList(Material.PISTON_BASE, Material.PISTON_EXTENSION, Material.PISTON_STICKY_BASE, Material.PISTON_MOVING_PIECE), "Piston");
         register(Arrays.asList(Material.BREWING_STAND, Material.CAULDRON), "Cauldron");
         register(Material.ENCHANTMENT_TABLE, "EnchantTable");
         register(Arrays.asList(Material.ENDER_PORTAL, Material.ENDER_PORTAL_FRAME), "Airportal");
@@ -38,7 +38,7 @@ public class FakeTileEntity {
         register(Arrays.asList(Material.REDSTONE_COMPARATOR, Material.REDSTONE_COMPARATOR_OFF, Material.REDSTONE_COMPARATOR_ON), "Comparator");
         register(Material.FLOWER_POT, "FlowerPot");
         register(Arrays.asList(Material.STANDING_BANNER, Material.WALL_BANNER, Material.BANNER), "Banner");
-        register(209, "EndGateway"); // todo test
+        register(209, "EndGateway");
         register(Material.COMMAND.getId(), "Control");
     }
 

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/Protocol1_9_3TO1_9_1_2.java

@@ -6,15 +6,14 @@ import org.spacehq.opennbt.tag.builtin.StringTag;
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.minecraft.Position;
+import us.myles.ViaVersion.api.minecraft.chunks.Chunk;
+import us.myles.ViaVersion.api.minecraft.chunks.ChunkSection;
 import us.myles.ViaVersion.api.protocol.Protocol;
 import us.myles.ViaVersion.api.remapper.PacketHandler;
 import us.myles.ViaVersion.api.remapper.PacketRemapper;
 import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.packets.State;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.chunks.Chunk1_9to1_8;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.chunks.ChunkSection1_9to1_8;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.ClientChunks;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.types.ChunkType;
+import us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2.storage.ClientWorld;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -74,35 +73,65 @@ public class Protocol1_9_3TO1_9_1_2 extends Protocol {
                 handler(new PacketHandler() {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
-                        ClientChunks clientChunks = wrapper.user().get(ClientChunks.class);
+                        ClientWorld clientWorld = wrapper.user().get(ClientWorld.class);
 
-                        ChunkType type = new ChunkType(clientChunks);
-                        if (wrapper.isReadable(type, 0)) {
-                            Chunk1_9to1_8 chunk = (Chunk1_9to1_8) wrapper.read(type);
+                        Chunk1_9_1_2Type type = new Chunk1_9_1_2Type(clientWorld);
+                        Chunk chunk = wrapper.passthrough(type);
 
-                            List<CompoundTag> tags = new ArrayList<>();
-                            for (int i = 0; i < chunk.getSections().length; i++) {
-                                ChunkSection1_9to1_8 section = chunk.getSections()[i];
-                                if (section == null)
-                                    continue;
+                        List<CompoundTag> tags = new ArrayList<>();
+                        for (int i = 0; i < chunk.getSections().length; i++) {
+                            ChunkSection section = chunk.getSections()[i];
+                            if (section == null)
+                                continue;
 
-                                for (int x = 0; x < 16; x++)
-                                    for (int y = 0; y < 16; y++)
-                                        for (int z = 0; z < 16; z++) {
-                                            int block = section.getBlockId(x, y, z);
-                                            if (FakeTileEntity.hasBlock(block)) {
-                                                // NOT SURE WHY Y AND Z WORK THIS WAY, TODO: WORK OUT WHY THIS IS OR FIX W/E BROKE IT
-                                                tags.add(FakeTileEntity.getFromBlock(x + (chunk.getX() << 4), z + (i << 4), y + (chunk.getZ() << 4), block));
-                                            }
+                            for (int x = 0; x < 16; x++) {
+                                for (int y = 0; y < 16; y++) {
+                                    for (int z = 0; z < 16; z++) {
+                                        int block = section.getBlockId(x, y, z);
+                                        if (FakeTileEntity.hasBlock(block)) {
+                                            tags.add(FakeTileEntity.getFromBlock(x + (chunk.getX() << 4), y + (i << 4), z + (chunk.getZ() << 4), block));
                                         }
+                                    }
+                                }
                             }
-
-                            wrapper.write(type, chunk);
-                            wrapper.write(Type.NBT_ARRAY, tags.toArray(new CompoundTag[0]));
-                        } else {
-                            wrapper.passthroughAll();
-                            wrapper.write(Type.VAR_INT, 0);
                         }
+
+                        wrapper.write(Type.NBT_ARRAY, tags.toArray(new CompoundTag[0]));
+                    }
+                });
+            }
+        });
+
+        // Join (save dimension id)
+        registerOutgoing(State.PLAY, 0x23, 0x23, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.INT); // 0 - Entity ID
+                map(Type.UNSIGNED_BYTE); // 1 - Gamemode
+                map(Type.INT); // 2 - Dimension
+
+                handler(new PacketHandler() {
+                    @Override
+                    public void handle(PacketWrapper wrapper) throws Exception {
+                        ClientWorld clientChunks = wrapper.user().get(ClientWorld.class);
+                        int dimensionId = wrapper.get(Type.INT, 1);
+                        clientChunks.setEnvironment(dimensionId);
+                    }
+                });
+            }
+        });
+
+        // Respawn (save dimension id)
+        registerOutgoing(State.PLAY, 0x33, 0x33, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.INT); // 0 - Dimension ID
+                handler(new PacketHandler() {
+                    @Override
+                    public void handle(PacketWrapper wrapper) throws Exception {
+                        ClientWorld clientWorld = wrapper.user().get(ClientWorld.class);
+                        int dimensionId = wrapper.get(Type.INT, 0);
+                        clientWorld.setEnvironment(dimensionId);
                     }
                 });
             }
@@ -110,7 +139,7 @@ public class Protocol1_9_3TO1_9_1_2 extends Protocol {
     }
 
     @Override
-    public void init(UserConnection userConnection) {
-
+    public void init(UserConnection user) {
+        user.put(new ClientWorld(user));
     }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/storage/ClientWorld.java

@@ -0,0 +1,32 @@
+package us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2.storage;
+
+import lombok.Getter;
+import org.bukkit.World;
+import us.myles.ViaVersion.api.data.StoredObject;
+import us.myles.ViaVersion.api.data.UserConnection;
+
+@Getter
+public class ClientWorld extends StoredObject {
+    private World.Environment environment;
+
+    public ClientWorld(UserConnection user) {
+        super(user);
+    }
+
+    public void setEnvironment(int environmentId) {
+        this.environment = getEnvFromId(environmentId);
+    }
+
+    private World.Environment getEnvFromId(int id) {
+        switch(id) {
+            case -1:
+                return World.Environment.NETHER;
+            case 0:
+                return World.Environment.NORMAL;
+            case 1:
+                return World.Environment.THE_END;
+            default:
+                throw new IllegalArgumentException("Invalid environment id:" + id);
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/ItemRewriter.java

@@ -213,11 +213,9 @@ public class ItemRewriter {
                     item.setId((short) 438); // splash id
                     item.setData((short) (item.getData() - 8192));
                 }
-                if (POTION_ID_TO_NAME.containsKey((int) item.getData())) {
-                    String name = POTION_ID_TO_NAME.get((int) item.getData());
-                    StringTag potion = new StringTag("Potion", "minecraft:" + name);
-                    tag.put(potion);
-                }
+                String name = potionNameFromDamage(item.getData());
+                StringTag potion = new StringTag("Potion", "minecraft:" + name);
+                tag.put(potion);
                 item.setTag(tag);
                 item.setData((short) 0);
             }
@@ -245,10 +243,113 @@ public class ItemRewriter {
         }
     }
 
+    public static String potionNameFromDamage(short damage) {
+        String cached = POTION_ID_TO_NAME.get((int) damage);
+        if (cached != null) {
+            return cached;
+        }
+        if (damage == 0) {
+            return "water";
+        }
+
+        int effect = damage & 0xF;
+        int name = damage & 0x3F;
+        boolean enhanced = (damage & 0x20) > 0;
+        boolean extended = (damage & 0x40) > 0;
+
+        boolean canEnhance = true;
+        boolean canExtend = true;
+
+        String id;
+        switch (effect) {
+            case 1:
+                id = "regeneration";
+                break;
+            case 2:
+                id = "swiftness";
+                break;
+            case 3:
+                id = "fire_resistance";
+                canEnhance = false;
+                break;
+            case 4:
+                id = "poison";
+                break;
+            case 5:
+                id = "healing";
+                canExtend = false;
+                break;
+            case 6:
+                id = "night_vision";
+                canEnhance = false;
+                break;
+
+            case 8:
+                id = "weakness";
+                canEnhance = false;
+                break;
+            case 9:
+                id = "strength";
+                break;
+            case 10:
+                id = "slowness";
+                canEnhance = false;
+                break;
+            case 11:
+                id = "leaping";
+                break;
+            case 12:
+                id = "harming";
+                canExtend = false;
+                break;
+            case 13:
+                id = "water_breathing";
+                canEnhance = false;
+                break;
+            case 14:
+                id = "invisibility";
+                canEnhance = false;
+                break;
+
+
+            default:
+                canEnhance = false;
+                canExtend = false;
+                switch (name) {
+                    case 0:
+                        id = "mundane";
+                        break;
+                    case 16:
+                        id = "awkward";
+                        break;
+                    case 32:
+                        id = "thick";
+                        break;
+                    default:
+                        id = "empty";
+                }
+        }
+
+        if (effect > 0) {
+            if (canEnhance && enhanced) {
+                id = "strong_" + id;
+            } else if (canExtend && extended) {
+                id = "long_" + id;
+            }
+        }
+
+        return id;
+    }
+
     public static int getNewEffectID(int oldID) {
         if (oldID >= 16384) {
             oldID -= 8192;
         }
+        if (POTION_INDEX.containsKey(oldID)) {
+            return POTION_INDEX.get(oldID);
+        }
+
+        oldID = POTION_NAME_TO_ID.get(potionNameFromDamage((short) oldID));
         return POTION_INDEX.containsKey(oldID) ? POTION_INDEX.get(oldID) : 0;
     }
 

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/Protocol1_9TO1_8.java

@@ -41,9 +41,7 @@ public class Protocol1_9TO1_8 extends Protocol {
             line = "{\"text\":\"\"}";
         } else {
             if ((!line.startsWith("\"") || !line.endsWith("\"")) && (!line.startsWith("{") || !line.endsWith("}"))) {
-                JsonObject jsonObject = new JsonObject();
-                jsonObject.addProperty("text", line);
-                return gson.toJson(jsonObject);
+                return constructJson(line);
             }
             if (line.startsWith("\"") && line.endsWith("\"")) {
                 line = "{\"text\":" + line + "}";
@@ -52,12 +50,22 @@ public class Protocol1_9TO1_8 extends Protocol {
         try {
             gson.fromJson(line, JsonObject.class);
         } catch (Exception e) {
-            System.out.println("Invalid JSON String: \"" + line + "\" Please report this issue to the ViaVersion Github: " + e.getMessage());
-            return "{\"text\":\"\"}";
+            if (ViaVersion.getConfig().isForceJsonTransform()) {
+                return constructJson(line);
+            } else {
+                System.out.println("Invalid JSON String: \"" + line + "\" Please report this issue to the ViaVersion Github: " + e.getMessage());
+                return "{\"text\":\"\"}";
+            }
         }
         return line;
     }
 
+    private static String constructJson(String text) {
+        JsonObject jsonObject = new JsonObject();
+        jsonObject.addProperty("text", text);
+        return gson.toJson(jsonObject);
+    }
+
     public static Item getHandItem(final UserConnection info) {
         if (HandItemCache.CACHE) {
             return HandItemCache.getHandItem(info.get(ProtocolInfo.class).getUuid());

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/chunks/Chunk1_9to1_8.java

@@ -36,4 +36,14 @@ public class Chunk1_9to1_8 implements Chunk {
     public boolean hasBiomeData() {
         return biomeData != null && groundUp;
     }
+
+    @Override
+    public boolean isBiomeData() {
+        return biomeData != null;
+    }
+
+    @Override
+    public int getBitmask() {
+        return primaryBitmask;
+    }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/chunks/ChunkSection1_9to1_8.java

@@ -3,12 +3,13 @@ package us.myles.ViaVersion.protocols.protocol1_9to1_8.chunks;
 import com.google.common.collect.Lists;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import us.myles.ViaVersion.api.minecraft.chunks.ChunkSection;
 import us.myles.ViaVersion.api.minecraft.chunks.NibbleArray;
 import us.myles.ViaVersion.api.type.Type;
 
 import java.util.List;
 
-public class ChunkSection1_9to1_8 {
+public class ChunkSection1_9to1_8 implements ChunkSection {
     /**
      * Size (dimensions) of blocks in a chunks section.
      */
@@ -88,7 +89,7 @@ public class ChunkSection1_9to1_8 {
     }
 
     private int index(int x, int y, int z) {
-        return z << 8 | y << 4 | x;
+        return y << 8 | z << 4 | x;
     }
 
     /**

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/ClientChunks.java

@@ -3,7 +3,10 @@ package us.myles.ViaVersion.protocols.protocol1_9to1_8.storage;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import lombok.Getter;
+import lombok.Setter;
 import org.bukkit.Bukkit;
+import org.bukkit.World;
+import org.bukkit.WorldType;
 import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.data.StoredObject;
 import us.myles.ViaVersion.api.data.UserConnection;
@@ -26,8 +29,10 @@ public class ClientChunks extends StoredObject {
         try {
             mapChunkBulkRef = new ReflectionUtil.ClassReflection(ReflectionUtil.nms("PacketPlayOutMapChunkBulk"));
             mapChunkRef = new ReflectionUtil.ClassReflection(ReflectionUtil.nms("PacketPlayOutMapChunk"));
-            obfuscateRef = Class.forName("org.spigotmc.AntiXray").getMethod("obfuscate", int.class, int.class, int.class, byte[].class, ReflectionUtil.nms("World"));
-            worldRef = ReflectionUtil.nms("World");
+            if (ViaVersion.getInstance().isSpigot()) {
+                obfuscateRef = Class.forName("org.spigotmc.AntiXray").getMethod("obfuscate", int.class, int.class, int.class, byte[].class, ReflectionUtil.nms("World"));
+                worldRef = ReflectionUtil.nms("World");
+            }
         } catch (Exception e) {
             Bukkit.getLogger().log(Level.WARNING, "Failed to initialise chunks reflection", e);
         }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/types/ChunkType.java

@@ -3,10 +3,13 @@ package us.myles.ViaVersion.protocols.protocol1_9to1_8.types;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.bukkit.Bukkit;
+import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.minecraft.chunks.Chunk;
 import us.myles.ViaVersion.api.type.PartialType;
 import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.api.type.types.minecraft.BaseChunkType;
+import us.myles.ViaVersion.protocols.base.ProtocolInfo;
+import us.myles.ViaVersion.protocols.protocol1_10to1_9_3.Protocol1_10To1_9_3_4;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.chunks.Chunk1_9to1_8;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.chunks.ChunkSection1_9to1_8;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.ClientChunks;
@@ -46,6 +49,9 @@ public class ChunkType extends PartialType<Chunk, ClientChunks> {
 
     @Override
     public Chunk read(ByteBuf input, ClientChunks param) throws Exception {
+        boolean replacePistons = param.getUser().get(ProtocolInfo.class).getPipeline().contains(Protocol1_10To1_9_3_4.class) && ViaVersion.getConfig().isReplacePistons();
+        int replacementId = ViaVersion.getConfig().getPistonReplacementId();
+
         int chunkX = input.readInt();
         int chunkZ = input.readInt();
         long chunkHash = toLong(chunkX, chunkZ);
@@ -93,7 +99,8 @@ public class ChunkType extends PartialType<Chunk, ClientChunks> {
                 int mask = blockBuf.get();
                 int type = mask >> 4;
                 int data = mask & 0xF;
-
+                if (replacePistons && type == 36)
+                    type = replacementId;
                 section.setBlock(j, type, data);
             }
         }

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

@@ -0,0 +1,268 @@
+package us.myles.ViaVersion.util;
+
+import lombok.SneakyThrows;
+
+import java.lang.reflect.Field;
+import java.util.*;
+
+/**
+ * Created by wea_ondara licensed under MIT
+ * Same license as in LICENSE
+ *
+ * Taken from:
+ * https://github.com/weaondara/BungeePerms/blob/master/src/main/java/net/alpenblock/bungeeperms/util/ConcurrentList.java
+ * @param <E> List Type
+ */
+public class ConcurrentList<E> extends ArrayList<E> {
+
+    private final Object lock = new Object();
+
+    @Override
+    public boolean add(E e) {
+        synchronized (lock) {
+            return super.add(e);
+        }
+    }
+
+    @Override
+    public void add(int index, E element) {
+        synchronized (lock) {
+            super.add(index, element);
+        }
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends E> c) {
+        synchronized (lock) {
+            return super.addAll(c);
+        }
+    }
+
+    @Override
+    public boolean addAll(int index, Collection<? extends E> c) {
+        synchronized (lock) {
+            return super.addAll(index, c);
+        }
+    }
+
+    @Override
+    public void clear() {
+        synchronized (lock) {
+            super.clear();
+        }
+    }
+
+    @Override
+    @SneakyThrows
+    public Object clone() {
+        synchronized (lock) {
+            ConcurrentList<E> clist = (ConcurrentList<E>) super.clone();
+            clist.modCount = 0;
+            Field f = ArrayList.class.getDeclaredField("elementData");
+            f.setAccessible(true);
+            f.set(clist, Arrays.copyOf((Object[]) f.get(this), this.size()));
+
+            return clist;
+        }
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        synchronized (lock) {
+            return super.contains(o);
+        }
+    }
+
+    @Override
+    public void ensureCapacity(int minCapacity) {
+        synchronized (lock) {
+            super.ensureCapacity(minCapacity);
+        }
+    }
+
+    @Override
+    public E get(int index) {
+        synchronized (lock) {
+            return super.get(index);
+        }
+    }
+
+    @Override
+    public int indexOf(Object o) {
+        synchronized (lock) {
+            return super.indexOf(o);
+        }
+    }
+
+    @Override
+    public int lastIndexOf(Object o) {
+        synchronized (lock) {
+            return super.lastIndexOf(o);
+        }
+    }
+
+    @Override
+    public E remove(int index) {
+        synchronized (lock) {
+            return super.remove(index);
+        }
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        synchronized (lock) {
+            return super.remove(o);
+        }
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> c) {
+        synchronized (lock) {
+            return super.removeAll(c);
+        }
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+        synchronized (lock) {
+            return super.retainAll(c);
+        }
+    }
+
+    @Override
+    public E set(int index, E element) {
+        synchronized (lock) {
+            return super.set(index, element);
+        }
+    }
+
+    @Override
+    public List<E> subList(int fromIndex, int toIndex) {
+        synchronized (lock) {
+            return super.subList(fromIndex, toIndex);
+        }
+    }
+
+    @Override
+    public Object[] toArray() {
+        synchronized (lock) {
+            return super.toArray();
+        }
+    }
+
+    @Override
+    public <T> T[] toArray(T[] a) {
+        synchronized (lock) {
+            return super.toArray(a);
+        }
+    }
+
+    @Override
+    public void trimToSize() {
+        synchronized (lock) {
+            super.trimToSize();
+        }
+    }
+
+    @Override
+    public ListIterator<E> listIterator() {
+        return new ListItr(0);
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+        return new Itr();
+    }
+
+    private class Itr implements Iterator<E> {
+
+        protected int cursor;
+        protected int lastRet;
+        final ConcurrentList l;
+
+        public Itr() {
+            cursor = 0;
+            lastRet = -1;
+            l = (ConcurrentList) ConcurrentList.this.clone();
+        }
+
+        @Override
+        public boolean hasNext() {
+            return cursor < l.size();
+        }
+
+        @Override
+        public E next() {
+            int i = cursor;
+            if (i >= l.size()) {
+                throw new NoSuchElementException();
+            }
+            cursor = i + 1;
+            return (E) l.get(lastRet = i);
+        }
+
+        @Override
+        public void remove() {
+            if (lastRet < 0) {
+                throw new IllegalStateException();
+            }
+
+            l.remove(lastRet);
+            ConcurrentList.this.remove(lastRet);
+            cursor = lastRet;
+            lastRet = -1;
+        }
+    }
+
+    public class ListItr extends Itr implements ListIterator<E> {
+
+        ListItr(int index) {
+            super();
+            cursor = index;
+        }
+
+        @Override
+        public boolean hasPrevious() {
+            return cursor > 0;
+        }
+
+        @Override
+        public int nextIndex() {
+            return cursor;
+        }
+
+        @Override
+        public int previousIndex() {
+            return cursor - 1;
+        }
+
+        @Override
+        public E previous() {
+            int i = cursor - 1;
+            if (i < 0) {
+                throw new NoSuchElementException();
+            }
+            cursor = i;
+            return (E) l.get(lastRet = i);
+        }
+
+        @Override
+        public void set(E e) {
+            if (lastRet < 0) {
+                throw new IllegalStateException();
+            }
+
+            l.set(lastRet, e);
+            ConcurrentList.this.set(lastRet, e);
+        }
+
+        @Override
+        public void add(E e) {
+            int i = cursor;
+            l.add(i, e);
+            ConcurrentList.this.add(i, e);
+            cursor = i + 1;
+            lastRet = -1;
+        }
+    }
+}

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

@@ -1,11 +1,9 @@
 package us.myles.ViaVersion.util;
 
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.List;
-import java.util.ListIterator;
+import java.util.*;
 
 public abstract class ListWrapper implements List {
+    public final Object lock = new Object();
     private final List list;
 
     public ListWrapper(List inputList) {
@@ -20,123 +18,169 @@ public abstract class ListWrapper implements List {
 
     @Override
     public synchronized int size() {
-        return this.list.size();
+        synchronized (lock) {
+            return this.list.size();
+        }
     }
 
     @Override
     public synchronized boolean isEmpty() {
-        return this.list.isEmpty();
+        synchronized (lock) {
+            return this.list.isEmpty();
+        }
     }
 
     @Override
     public synchronized boolean contains(Object o) {
-        return this.list.contains(o);
+        synchronized (lock) {
+            return this.list.contains(o);
+        }
     }
 
     @Override
     public synchronized Iterator iterator() {
-        return this.list.iterator();
+        synchronized (lock) {
+            return listIterator();
+        }
     }
 
     @Override
     public synchronized Object[] toArray() {
-        return this.list.toArray();
+        synchronized (lock) {
+            return this.list.toArray();
+        }
     }
 
     @Override
     public synchronized boolean add(Object o) {
-        handleAdd(o);
-        return this.list.add(o);
+        synchronized (lock) {
+            handleAdd(o);
+            return this.list.add(o);
+        }
     }
 
     @Override
     public synchronized boolean remove(Object o) {
-        return this.list.remove(o);
+        synchronized (lock) {
+            return this.list.remove(o);
+        }
     }
 
     @Override
     public synchronized boolean addAll(Collection c) {
-        for (Object o : c) {
-            handleAdd(o);
+        synchronized (lock) {
+            for (Object o : c) {
+                handleAdd(o);
+            }
+            return this.list.addAll(c);
         }
-        return this.list.addAll(c);
     }
 
     @Override
     public synchronized boolean addAll(int index, Collection c) {
-        for (Object o : c) {
-            handleAdd(o);
+        synchronized (lock) {
+            for (Object o : c) {
+                handleAdd(o);
+            }
+            return this.list.addAll(index, c);
         }
-        return this.list.addAll(index, c);
     }
 
     @Override
     public synchronized void clear() {
-        this.list.clear();
+        synchronized (lock) {
+            this.list.clear();
+        }
     }
 
     @Override
     public synchronized Object get(int index) {
-        return this.list.get(index);
+        synchronized (lock) {
+            return this.list.get(index);
+        }
     }
 
     @Override
     public synchronized Object set(int index, Object element) {
-        return this.list.set(index, element);
+        synchronized (lock) {
+            return this.list.set(index, element);
+        }
     }
 
     @Override
     public synchronized void add(int index, Object element) {
-        this.list.add(index, element);
+        synchronized (lock) {
+            this.list.add(index, element);
+        }
     }
 
     @Override
     public synchronized Object remove(int index) {
-        return this.list.remove(index);
+        synchronized (lock) {
+            return this.list.remove(index);
+        }
     }
 
     @Override
     public synchronized int indexOf(Object o) {
-        return this.list.indexOf(o);
+        synchronized (lock) {
+            return this.list.indexOf(o);
+        }
     }
 
     @Override
     public synchronized int lastIndexOf(Object o) {
-        return this.list.lastIndexOf(o);
+        synchronized (lock) {
+            return this.list.lastIndexOf(o);
+        }
     }
 
     @Override
     public synchronized ListIterator listIterator() {
-        return this.list.listIterator();
+        synchronized (lock) {
+            return this.list.listIterator();
+        }
     }
 
     @Override
     public synchronized ListIterator listIterator(int index) {
-        return this.list.listIterator(index);
+        synchronized (lock) {
+            return this.list.listIterator(index);
+        }
     }
 
     @Override
     public synchronized List subList(int fromIndex, int toIndex) {
-        return this.list.subList(fromIndex, toIndex);
+        synchronized (lock) {
+            return this.list.subList(fromIndex, toIndex);
+        }
     }
 
     @Override
     public synchronized boolean retainAll(Collection c) {
-        return this.list.retainAll(c);
+        synchronized (lock) {
+            return this.list.retainAll(c);
+        }
     }
 
     @Override
     public synchronized boolean removeAll(Collection c) {
-        return this.list.removeAll(c);
+        synchronized (lock) {
+            return this.list.removeAll(c);
+        }
     }
 
     @Override
     public synchronized boolean containsAll(Collection c) {
-        return this.list.containsAll(c);
+        synchronized (lock) {
+            return this.list.containsAll(c);
+        }
     }
 
     @Override
     public synchronized Object[] toArray(Object[] a) {
-        return this.list.toArray(a);
+        synchronized (lock) {
+            return this.list.toArray(a);
+        }
     }
 }

src/main/resources/config.yml

@@ -12,28 +12,34 @@
 checkforupdates: true
 # Send the supported versions with the Status (Ping) response packet
 send-supported-versions: false
+# Block specific Minecraft protocols that ViaVersion allows
+# List of all Minecraft protocol versions: http://wiki.vg/Protocol_version_numbers
+block-protocols: []
+# Change the blocked disconnect message
+block-disconnect-msg: "You are using an unsupported Minecraft version!"
 #
 #----------------------------------------------------------#
 #                  GLOBAL PACKET LIMITER                    #
 #----------------------------------------------------------#
 #
-# Anti-Cheat, Packets Per Second (PPS) limiter
+#
+# Packets Per Second (PPS) limiter (Use -1 on max-pps and tracking-period to disable)
 # Clients by default send around 20-90 packets per second.
-
+#
 # What is the maximum per second a client can send (Use %pps to display their pps)
 # Use -1 to disable.
 max-pps: 600
 max-pps-kick-msg: "You are sending too many packets!"
-
+#
 # We can also kick them if over a period they send over a threshold a certain amount of times.
-
+#
 # Period to track (in seconds)
 # Use -1 to disable.
 tracking-period: 6
 # How many packets per second counts as a warning
 tracking-warning-pps: 120
 # How many warnings over the interval can we have
-# This can never be higher than "tracking-interval"
+# This can never be higher than "tracking-period"
 tracking-max-warnings: 4
 tracking-max-kick-msg: "You are sending too many packets, :("
 #
@@ -70,4 +76,10 @@ use-new-deathmessages: false
 # Should we cache our items, this will prevent server from being lagged out, however the cost is a constant task caching items
 item-cache: true
 # Patch the Anti xray to work on 1.9 & 1.10 (If your server is 1.8) This can cost more performance, so disable it if you don't use it.
-anti-xray-patch: true
+anti-xray-patch: true
+# Should we replace extended pistons to fix 1.10.1 (Only on chunk load)
+replace-pistons: false
+# What id should we replace with, default is air. (careful of players getting stuck standing on them)
+replacement-piston-id: 0
+# Force the string -> json transform
+force-json-transform: false