Store the mainHand and change it on serverChange for Bungee, fixes #536

bungee/src/main/java/us/myles/ViaVersion/bungee/handlers/BungeeServerHandler.java

@@ -47,7 +47,7 @@ public class BungeeServerHandler implements Listener {
 
     // Set the handshake version every time someone connects to any server
     @EventHandler
-    public void onServerConnect(ServerConnectEvent e) throws NoSuchFieldException, IllegalAccessException {
+    public void onServerConnect(ServerConnectEvent e) {
         UserConnection user = Via.getManager().getConnection(e.getPlayer().getUniqueId());
         if (!user.has(BungeeStorage.class)) {
             user.put(new BungeeStorage(user, e.getPlayer()));
@@ -61,7 +61,7 @@ public class BungeeServerHandler implements Listener {
             Object pendingConnection = getPendingConnection.invoke(e.getPlayer());
             Object handshake = getHandshake.invoke(pendingConnection);
             setProtocol.invoke(handshake, protocols == null ? user.get(ProtocolInfo.class).getProtocolVersion() : protocolId);
-        } catch (InvocationTargetException e1) {
+        } catch (InvocationTargetException | IllegalAccessException e1) {
             e1.printStackTrace();
         }
     }

bungee/src/main/java/us/myles/ViaVersion/bungee/listeners/MainHandPatch.java

@@ -0,0 +1,43 @@
+package us.myles.ViaVersion.bungee.listeners;
+
+import net.md_5.bungee.api.event.ServerConnectEvent;
+import net.md_5.bungee.api.plugin.Listener;
+import net.md_5.bungee.event.EventHandler;
+import us.myles.ViaVersion.api.Via;
+import us.myles.ViaVersion.api.data.UserConnection;
+import us.myles.ViaVersion.protocols.base.ProtocolInfo;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9TO1_8;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.EntityTracker;
+
+import java.lang.reflect.Method;
+
+/*
+    This solves the wrong mainhand issue when you join with BungeeCord on a 1.8 server, and switch to a 1.9 or higher.
+ */
+public class MainHandPatch implements Listener {
+    private static Method getSettings = null;
+    private static Method setMainHand = null;
+
+    static {
+        try {
+            getSettings = Class.forName("net.md_5.bungee.UserConnection").getDeclaredMethod("getSettings");
+            setMainHand = Class.forName("net.md_5.bungee.protocol.packet.ClientSettings").getDeclaredMethod("setMainHand", int.class);
+        } catch (NoSuchMethodException | ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @EventHandler
+    public void onServerConnect(ServerConnectEvent event) {
+        UserConnection user = Via.getManager().getConnection(event.getPlayer().getUniqueId());
+
+        try {
+            if (user.get(ProtocolInfo.class).getPipeline().contains(Protocol1_9TO1_8.class)) {
+                Object settings = getSettings.invoke(event.getPlayer());
+                setMainHand.invoke(settings, user.get(EntityTracker.class).getMainHand());
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+}

bungee/src/main/java/us/myles/ViaVersion/bungee/platform/BungeeViaLoader.java

@@ -6,6 +6,7 @@ import us.myles.ViaVersion.BungeePlugin;
 import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.api.platform.ViaPlatformLoader;
 import us.myles.ViaVersion.bungee.handlers.BungeeServerHandler;
+import us.myles.ViaVersion.bungee.listeners.MainHandPatch;
 import us.myles.ViaVersion.bungee.listeners.UpdateListener;
 import us.myles.ViaVersion.bungee.providers.BungeeEntityIdProvider;
 import us.myles.ViaVersion.bungee.providers.BungeeMovementTransmitter;
@@ -27,6 +28,7 @@ public class BungeeViaLoader implements ViaPlatformLoader {
         ProxyServer.getInstance().getPluginManager().registerListener(plugin, plugin);
         ProxyServer.getInstance().getPluginManager().registerListener(plugin, new UpdateListener());
         ProxyServer.getInstance().getPluginManager().registerListener(plugin, new BungeeServerHandler());
+        ProxyServer.getInstance().getPluginManager().registerListener(plugin, new MainHandPatch());
 
         // Providers
         Via.getManager().getProviders().use(MovementTransmitterProvider.class, new BungeeMovementTransmitter());

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/PlayerPackets.java

@@ -433,7 +433,16 @@ public class PlayerPackets {
                 map(Type.VAR_INT, Type.BYTE); // 2 - Chat Mode
                 map(Type.BOOLEAN); // 3 - If Chat Colours on
                 map(Type.UNSIGNED_BYTE); // 4 - Skin Parts
-                map(Type.VAR_INT, Type.NOTHING); // 5 - Main Hand
+
+                handler(new PacketHandler() {
+                    @Override
+                    public void handle(PacketWrapper wrapper) throws Exception {
+                        int hand = wrapper.read(Type.VAR_INT);
+
+                        EntityTracker tracker = wrapper.user().get(EntityTracker.class);
+                        tracker.setMainHand(hand);
+                    }
+                });
             }
         });
 

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/EntityTracker.java

@@ -51,6 +51,8 @@ public class EntityTracker extends StoredObject {
     private boolean teamExists = false;
     @Setter
     private GameMode gameMode;
+    @Setter
+    private int mainHand;
 
     public EntityTracker(UserConnection user) {
         super(user);