Fix a couple of protocol issues

src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java

@@ -24,15 +24,16 @@ public class HandshakeSessionHandler implements MinecraftSessionHandler {
         }
 
         Handshake handshake = (Handshake) packet;
-        connection.setProtocolVersion(handshake.getProtocolVersion());
         switch (handshake.getNextStatus()) {
             case 1:
                 // Status protocol
                 connection.setState(StateRegistry.STATUS);
+                connection.setProtocolVersion(handshake.getProtocolVersion());
                 connection.setSessionHandler(new StatusSessionHandler(connection));
                 break;
             case 2:
                 connection.setState(StateRegistry.LOGIN);
+                connection.setProtocolVersion(handshake.getProtocolVersion());
                 if (!ProtocolConstants.isSupported(handshake.getProtocolVersion())) {
                     connection.closeWith(Disconnect.create(TextComponent.of("Unsupported client")));
                     return;

src/main/java/com/velocitypowered/proxy/connection/client/StatusSessionHandler.java

@@ -11,6 +11,8 @@ import com.velocitypowered.proxy.protocol.packets.StatusResponse;
 import com.velocitypowered.proxy.connection.MinecraftConnection;
 import com.velocitypowered.proxy.data.ServerPing;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
 
 public class StatusSessionHandler implements MinecraftSessionHandler {
     private final MinecraftConnection connection;
@@ -43,4 +45,9 @@ public class StatusSessionHandler implements MinecraftSessionHandler {
         response.setStatus(VelocityServer.GSON.toJson(ping));
         connection.write(response);
     }
+
+    @Override
+    public void handleUnknown(ByteBuf buf) {
+        throw new IllegalStateException("Unknown data " + ByteBufUtil.hexDump(buf));
+    }
 }

src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -45,17 +45,13 @@ public enum StateRegistry {
                     map(0x04, MINECRAFT_1_12_1));
 
             CLIENTBOUND.register(Chat.class, Chat::new,
-                    map(0x0F, MINECRAFT_1_11),
+                    map(0x0F, MINECRAFT_1_11));
-                    map(0x0F, MINECRAFT_1_12));
             CLIENTBOUND.register(Disconnect.class, Disconnect::new,
-                    map(0x1A, MINECRAFT_1_11),
+                    map(0x1A, MINECRAFT_1_11));
-                    map(0x1A, MINECRAFT_1_12));
             CLIENTBOUND.register(KeepAlive.class, KeepAlive::new,
-                    map(0x1F, MINECRAFT_1_11),
+                    map(0x1F, MINECRAFT_1_11));
-                    map(0x1F, MINECRAFT_1_12));
             CLIENTBOUND.register(JoinGame.class, JoinGame::new,
-                    map(0x23, MINECRAFT_1_11),
+                    map(0x23, MINECRAFT_1_11));
-                    map(0x23, MINECRAFT_1_12));
             CLIENTBOUND.register(Respawn.class, Respawn::new,
                     map(0x33, MINECRAFT_1_11),
                     map(0x34, MINECRAFT_1_12),
@@ -87,7 +83,7 @@ public enum StateRegistry {
         private static final IntObjectMap<int[]> LINKED_PROTOCOL_VERSIONS = new IntObjectHashMap<>();
 
         static {
-            LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_11, new int[] { MINECRAFT_1_11_1 });
+            LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_11, new int[] { MINECRAFT_1_11_1, MINECRAFT_1_12 });
             LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_12, new int[] { MINECRAFT_1_12_1 });
             LINKED_PROTOCOL_VERSIONS.put(MINECRAFT_1_12_1, new int[] { MINECRAFT_1_12_2 });
         }