Improved exception handling.

api/src/main/java/com/github/retrooper/packetevents/manager/InternalPacketListener.java

@@ -127,7 +127,9 @@ public class InternalPacketListener extends PacketListenerAbstract {
             WrapperHandshakingClientHandshake handshake = new WrapperHandshakingClientHandshake(event);
             ConnectionState nextState = handshake.getNextConnectionState();
             ClientVersion clientVersion = handshake.getClientVersion();
-
+            if (clientVersion == ClientVersion.UNKNOWN) {
+                return;
+            }
             //Update client version for this event call(and user)
             user.setClientVersion(clientVersion);
             PacketEvents.getAPI().getLogManager().debug("Processed " + address.getHostString() + ":" + address.getPort() + "'s client version. Client Version: " + clientVersion.getReleaseName());

api/src/main/java/com/github/retrooper/packetevents/protocol/ConnectionState.java

@@ -26,6 +26,9 @@ public enum ConnectionState {
     HANDSHAKING, STATUS, LOGIN, PLAY;
 
     public static ConnectionState getById(int id) {
+        if (id >= values().length || id < 0) {
+            return null;
+        }
         return values()[id];
     }
 }

spigot/src/main/java/io/github/retrooper/packetevents/injector/connection/ServerChannelHandler.java

@@ -32,23 +32,29 @@ public class ServerChannelHandler extends ChannelInboundHandlerAdapter {
     public static boolean CHECKED_NETTY_VERSION;
     public static PEVersion NETTY_VERSION;
     public static final PEVersion MODERN_NETTY_VERSION = new PEVersion(4, 1, 24);
+
+    private static PEVersion resolveNettyVersion() {
+        Map<String, Version> nettyArtifacts = Version.identify();
+        Version version = nettyArtifacts.getOrDefault("netty-common", nettyArtifacts.get("netty-all"));
+        if (version != null) {
+            String stringVersion = version.artifactVersion();
+            //Let us remove the ".Final" from the version by just removing any words (non numbers or dots)
+            stringVersion = stringVersion.replaceAll("[^\\d.]", "");
+            if (stringVersion.endsWith(".")) {
+                //Remove "." at the end.
+                stringVersion = stringVersion.substring(0, stringVersion.length() - 1);
+            }
+            return new PEVersion(stringVersion);
+        }
+        return null;
+    }
+
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
         Channel channel = (Channel) msg;
         //Resolve netty version only once.
         if (NETTY_VERSION == null && !CHECKED_NETTY_VERSION) {
-            Map<String, Version> nettyArtifacts = Version.identify();
-            Version version = nettyArtifacts.getOrDefault("netty-common", nettyArtifacts.get("netty-all"));
-            if (version != null) {
-                String stringVersion = version.artifactVersion();
-                //Let us remove the ".Final" from the version by just removing any words (non numbers or dots)
-                stringVersion = stringVersion.replaceAll("[^\\d.]", "");
-                if (stringVersion.endsWith(".")) {
-                    //Remove "." at the end.
-                    stringVersion = stringVersion.substring(0, stringVersion.length() - 1);
-                }
-                NETTY_VERSION = new PEVersion(stringVersion);
-            }
+            NETTY_VERSION = resolveNettyVersion();
             CHECKED_NETTY_VERSION = true;
         }
 

spigot/src/main/java/io/github/retrooper/packetevents/injector/handlers/PacketEventsDecoder.java

@@ -64,7 +64,12 @@ public class PacketEventsDecoder extends ByteToMessageDecoder {
         try {
             boolean doRecompression =
                     handleCompression(ctx, outputBuffer);
-            PacketEventsImplHelper.handleServerBoundPacket(ctx.channel(), user, player, outputBuffer, true);
+            try {
+                PacketEventsImplHelper.handleServerBoundPacket(ctx.channel(), user, player, outputBuffer, true);
+            }
+            catch (Exception ex) {
+                throw new PacketProcessException("Failed to process incoming packet", ex);
+            }
             if (outputBuffer.isReadable()) {
                 if (doRecompression) {
                     ByteBuf temp = ctx.alloc().buffer();
@@ -114,6 +119,7 @@ public class PacketEventsDecoder extends ByteToMessageDecoder {
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         super.exceptionCaught(ctx, cause);
         //Check if the minecraft server will already print our exception for us.
+        //Don't print errors during handshake
         if (ExceptionUtil.isException(cause, PacketProcessException.class) && !SpigotReflectionUtil.isMinecraftServerInstanceDebugging()
                 && (user == null || user.getConnectionState() != ConnectionState.HANDSHAKING)) {
             cause.printStackTrace();

spigot/src/main/java/io/github/retrooper/packetevents/injector/handlers/PacketEventsEncoder.java

@@ -27,7 +27,6 @@ import com.github.retrooper.packetevents.util.PacketEventsImplHelper;
 import io.github.retrooper.packetevents.util.SpigotReflectionUtil;
 import io.github.retrooper.packetevents.util.viaversion.CustomPipelineUtil;
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
@@ -64,9 +63,14 @@ public class PacketEventsEncoder extends MessageToByteEncoder<Object> {
             if (!in.isReadable()) return;
             out.writeBytes(in);
         }
-        PacketSendEvent sendEvent = PacketEventsImplHelper.handleClientBoundPacket(ctx.channel(), user, player, out, true, false);
-        if (sendEvent.hasPostTasks()) {
-            queuedPostTasks.addAll(sendEvent.getPostTasks());
+        try {
+            PacketSendEvent sendEvent = PacketEventsImplHelper.handleClientBoundPacket(ctx.channel(), user, player, out, true, false);
+            if (sendEvent.hasPostTasks()) {
+                queuedPostTasks.addAll(sendEvent.getPostTasks());
+            }
+        }
+        catch (Exception ex) {
+            throw new PacketProcessException("Failed to process outgoing packet", ex);
         }
     }
 
@@ -121,6 +125,7 @@ public class PacketEventsEncoder extends MessageToByteEncoder<Object> {
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         super.exceptionCaught(ctx, cause);
         //Check if the minecraft server will already print our exception for us.
+        //Don't print errors during handshake
         if (ExceptionUtil.isException(cause, PacketProcessException.class) && !SpigotReflectionUtil.isMinecraftServerInstanceDebugging()
                 && (user == null || user.getConnectionState() != ConnectionState.HANDSHAKING)) {
             cause.printStackTrace();