From 8dbe3d081c2a4ea608577b97f3ec64f7efb19ea3 Mon Sep 17 00:00:00 2001
From: Steveice10 <Steveice10@gmail.com>
Date: Sun, 31 May 2020 17:23:22 -0700
Subject: [PATCH] Make sure bad packet data is skipped when errors are
 suppressed.

---
 .../steveice10/packetlib/tcp/TcpPacketCodec.java      | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/github/steveice10/packetlib/tcp/TcpPacketCodec.java b/src/main/java/com/github/steveice10/packetlib/tcp/TcpPacketCodec.java
index 43425c48..0a710016 100644
--- a/src/main/java/com/github/steveice10/packetlib/tcp/TcpPacketCodec.java
+++ b/src/main/java/com/github/steveice10/packetlib/tcp/TcpPacketCodec.java
@@ -23,12 +23,17 @@ public class TcpPacketCodec extends ByteToMessageCodec<Packet> {
 
     @Override
     public void encode(ChannelHandlerContext ctx, Packet packet, ByteBuf buf) throws Exception {
+        int initial = buf.writerIndex();
+
         try {
             NetOutput out = new ByteBufNetOutput(buf);
 
             this.session.getPacketProtocol().getPacketHeader().writePacketId(out, this.session.getPacketProtocol().getOutgoingId(packet));
             packet.write(out);
         } catch(Throwable t) {
+            // Reset writer index to make sure incomplete data is not written out.
+            buf.writerIndex(initial);
+
             PacketErrorEvent e = new PacketErrorEvent(this.session, t);
             this.session.callEvent(e);
             if(!e.shouldSuppress()) {
@@ -39,11 +44,12 @@ public class TcpPacketCodec extends ByteToMessageCodec<Packet> {
 
     @Override
     protected void decode(ChannelHandlerContext ctx, ByteBuf buf, List<Object> out) throws Exception {
+        int initial = buf.readerIndex();
+
         Packet packet;
         try {
             NetInput in = new ByteBufNetInput(buf);
 
-            int initial = buf.readerIndex();
             int id = this.session.getPacketProtocol().getPacketHeader().readPacketId(in);
             if(id == -1) {
                 buf.readerIndex(initial);
@@ -57,6 +63,9 @@ public class TcpPacketCodec extends ByteToMessageCodec<Packet> {
                 throw new IllegalStateException("Packet \"" + packet.getClass().getSimpleName() + "\" not fully read.");
             }
         } catch(Throwable t) {
+            // Advance buffer to end to make sure remaining data in this packet is skipped.
+            buf.readerIndex(buf.readerIndex() + buf.readableBytes());
+
             PacketErrorEvent e = new PacketErrorEvent(this.session, t);
             this.session.callEvent(e);
             if(!e.shouldSuppress()) {