From 08df0807717579f5858f08423d0e821cc43cc08a Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Tue, 31 Dec 2019 21:43:02 -0500
Subject: [PATCH] Try to diagnose memory leak

---
 .../netty/MinecraftCipherDecoder.java         |  1 -
 .../netty/MinecraftVarintFrameDecoder.java    | 32 +++++--------------
 2 files changed, 8 insertions(+), 25 deletions(-)

diff --git a/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCipherDecoder.java b/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCipherDecoder.java
index ad02191e7..3eca73b4b 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCipherDecoder.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCipherDecoder.java
@@ -22,7 +22,6 @@ public class MinecraftCipherDecoder extends MessageToMessageDecoder<ByteBuf> {
     try {
       cipher.process(compatible);
       out.add(compatible);
-      in.skipBytes(in.readableBytes());
     } catch (Exception e) {
       compatible.release(); // compatible will never be used if we throw an exception
       throw e;
diff --git a/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java b/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java
index b003fc48c..c8fec71a9 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftVarintFrameDecoder.java
@@ -4,38 +4,22 @@ import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
-import io.netty.handler.codec.CorruptedFrameException;
 import java.util.List;
 
 public class MinecraftVarintFrameDecoder extends ByteToMessageDecoder {
 
   @Override
   protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
-    read_lens: while (in.isReadable()) {
-      int origReaderIndex = in.readerIndex();
-      for (int i = 0; i < 3; i++) {
-        if (!in.isReadable()) {
-          in.readerIndex(origReaderIndex);
-          return;
-        }
+    while (in.isReadable()) {
+      int ri = in.readerIndex();
+      int packetLength = ProtocolUtils.readVarInt(in);
 
-        byte read = in.readByte();
-        if (read >= 0) {
-          // Make sure reader index of length buffer is returned to the beginning
-          in.readerIndex(origReaderIndex);
-          int packetLength = ProtocolUtils.readVarInt(in);
-
-          if (in.readableBytes() >= packetLength) {
-            out.add(in.readRetainedSlice(packetLength));
-            continue read_lens;
-          } else {
-            in.readerIndex(origReaderIndex);
-            return;
-          }
-        }
+      if (in.readableBytes() >= packetLength) {
+        out.add(in.readBytes(packetLength));
+      } else {
+        in.readerIndex(ri);
+        break;
       }
-
-      throw new CorruptedFrameException("VarInt too big");
     }
   }
 }