Backport 1.20.1

Author: tonimatasdev

forge/src/main/java/dev/tonimatas/packetfixer/mixins/Varint21FrameDecoderMixin.java

@@ -1,15 +1,31 @@
 package dev.tonimatas.packetfixer.mixins;
 
-import dev.tonimatas.packetfixer.util.Config;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
 import net.minecraft.network.NettyVarint21FrameDecoder;
+import net.minecraft.network.PacketBuffer;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Constant;
+import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.ModifyConstant;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
-@Mixin(NettyVarint21FrameDecoder.class)
+import java.util.List;
+
+@Mixin(value = NettyVarint21FrameDecoder.class, priority = 1001)
 public abstract class Varint21FrameDecoderMixin {
+    @Unique
+    private int packetFixer$varInt21Size = 10;
+
+    @Inject(method = "decode", at = @At("HEAD"))
+    private void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list, CallbackInfo ci) {
+        packetFixer$varInt21Size = PacketBuffer.getVarIntSize(byteBuf.readableBytes()) + 2;
+    }
+
     @ModifyConstant(method = "decode", constant = @Constant(intValue = 3))
-    private int newSize(int value) {
-        return Config.getVarInt21Size();
+    private int newSize(int constant) {
+        return packetFixer$varInt21Size;
     }
-}
+}