Fix commandblocks not able to change command on every-tick commandblock update

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

@@ -1,6 +1,7 @@
 package us.myles.ViaVersion.listeners;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufOutputStream;
 import io.netty.buffer.Unpooled;
 import lombok.RequiredArgsConstructor;
 import org.bukkit.block.Block;
@@ -12,12 +13,15 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.block.Action;
 import org.bukkit.event.player.PlayerInteractEvent;
 import org.bukkit.event.player.PlayerJoinEvent;
+import org.spacehq.opennbt.tag.builtin.ByteTag;
+import org.spacehq.opennbt.tag.builtin.CompoundTag;
 import us.myles.ViaVersion.ViaVersionPlugin;
 import us.myles.ViaVersion.packets.PacketType;
 import us.myles.ViaVersion.util.PacketUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
-import java.lang.reflect.InvocationTargetException;
+import java.io.DataOutput;
+import java.io.DataOutputStream;
 import java.lang.reflect.Method;
 
 @RequiredArgsConstructor
@@ -41,22 +45,58 @@ public class CommandBlockListener implements Listener {
         if (e.getAction() == Action.RIGHT_CLICK_BLOCK && plugin.isPorted(e.getPlayer()) && e.getPlayer().isOp()) {
             try {
                 sendCommandBlockPacket(e.getClickedBlock(), e.getPlayer());
-            } catch (NoSuchFieldException | IllegalAccessException | InvocationTargetException | NoSuchMethodException | ClassNotFoundException e1) {
+            } catch (Exception ex) {
-                e1.printStackTrace();
+                ex.printStackTrace();
             }
         }
     }
 
-    private void sendCommandBlockPacket(Block b, Player player) throws NoSuchFieldException, IllegalAccessException, NoSuchMethodException, InvocationTargetException, ClassNotFoundException {
+    private void sendCommandBlockPacket(Block b, Player player) throws Exception {
         if (!(b.getState() instanceof CommandBlock))
             return;
         CommandBlock cmd = (CommandBlock) b.getState();
 
         Object tileEntityCommand = ReflectionUtil.get(cmd, "commandBlock", ReflectionUtil.nms("TileEntityCommand"));
         Object updatePacket = ReflectionUtil.invoke(tileEntityCommand, "getUpdatePacket");
-        Object nmsPlayer = ReflectionUtil.invoke(player, "getHandle");
+        ByteBuf buf = packetToByteBuf(updatePacket);
-        Object playerConnection = ReflectionUtil.get(nmsPlayer, "playerConnection", ReflectionUtil.nms("PlayerConnection"));
+        plugin.sendRawPacket(player, buf);
-        Method sendPacket = playerConnection.getClass().getMethod("sendPacket", ReflectionUtil.nms("Packet"));
+    }
-        sendPacket.invoke(playerConnection, updatePacket); //Let the transformer do the work
+
+    private ByteBuf packetToByteBuf(Object updatePacket) throws Exception {
+        ByteBuf buf = Unpooled.buffer();
+        PacketUtil.writeVarInt(PacketType.PLAY_UPDATE_BLOCK_ENTITY.getNewPacketID(), buf); //Packet ID
+        long[] pos = getPosition(ReflectionUtil.get(updatePacket, "a", ReflectionUtil.nms("BlockPosition")));
+        PacketUtil.writeBlockPosition(buf, pos[0], pos[1], pos[2]); //Block position
+        buf.writeByte(2); //Action id always 2
+        CompoundTag nbt = getNBT(ReflectionUtil.get(updatePacket, "c", ReflectionUtil.nms("NBTTagCompound")));
+        if (nbt == null) {
+            buf.writeByte(0); //If nbt is null. Use 0 as nbt
+            return buf;
+        }
+        nbt.put(new ByteTag("powered", (byte) 0));
+        nbt.put(new ByteTag("auto", (byte) 0));
+        nbt.put(new ByteTag("conditionMet", (byte) 0));
+        PacketUtil.writeNBT(buf, nbt); //NBT tag
+        return buf;
+    }
+
+    private long[] getPosition(Object obj) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
+        return new long[]{
+                (long) ReflectionUtil.getSuper(obj, "a", int.class), //X
+                (long) ReflectionUtil.getSuper(obj, "c", int.class), //Y
+                (long) ReflectionUtil.getSuper(obj, "d", int.class)  //Z
+        };
+    }
+
+    private CompoundTag getNBT(Object obj) throws Exception {
+        ByteBuf buf = Unpooled.buffer();
+        Method m = ReflectionUtil.nms("NBTCompressedStreamTools").getMethod("a", ReflectionUtil.nms("NBTTagCompound"), DataOutput.class);
+        m.invoke(null, obj, new DataOutputStream(new ByteBufOutputStream(buf)));
+        try {
+            return PacketUtil.readNBT(buf);
+        } finally {
+            buf.release();
+        }
     }
 }
+

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

@@ -759,20 +759,7 @@ public class OutgoingTransformer {
                 return;
             }
             if (action == 2) { //Update commandblock
-                try {
+                throw new CancelException(); //Only update if player interact with commandblock (The commandblock window will update every time this packet is sent, this would prevent you from change things that update every tick)
-                    CompoundTag nbt = readNBT(input);
-                    if (nbt == null)
-                        throw new CancelException();
-                    //Thanks http://www.minecraftforum.net/forums/minecraft-discussion/redstone-discussion-and/command-blocks/2488148-1-9-nbt-changes-and-additions#TileAllCommandBlocks
-                    nbt.put(new ByteTag("powered", (byte) 0));
-                    nbt.put(new ByteTag("auto", (byte) 0));
-                    nbt.put(new ByteTag("conditionMet", (byte) 0));
-                    writeNBT(output, nbt);
-                    return;
-                } catch (IOException e) {
-                    e.printStackTrace();
-                    throw new CancelException();
-                }
             }
             output.writeBytes(input, input.readableBytes());
             return;

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

@@ -37,6 +37,12 @@ public class ReflectionUtil {
         return (T) field.get(null);
     }
 
+    public static <T> T getSuper(Object o, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
+        Field field = o.getClass().getSuperclass().getDeclaredField(f);
+        field.setAccessible(true);
+        return (T) field.get(o);
+    }
+
     public static <T> T get(Object instance, Class<?> clazz, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
         Field field = clazz.getDeclaredField(f);
         field.setAccessible(true);