Fix empty packets not being processed and added opcode 121 for 317 revision as a spam packet. it is something to do with resetting entities in a region and is not neded.

src/org/apollo/net/codec/game/GamePacketDecoder.java

@@ -1,6 +1,7 @@
 package org.apollo.net.codec.game;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
 
 import java.io.IOException;
@@ -117,9 +118,12 @@ public final class GamePacketDecoder extends StatefulFrameDecoder<GameDecoderSta
 			switch (type) {
 			case FIXED:
 				length = metaData.getLength();
-				if (length != 0) {
-					setState(GameDecoderState.GAME_PAYLOAD);
-				}
+                if (length == 0) {
+                    setState(GameDecoderState.GAME_OPCODE);
+                    out.add(new GamePacket(opcode, type, Unpooled.EMPTY_BUFFER));
+                } else {
+                    setState(GameDecoderState.GAME_PAYLOAD);
+                }
 				break;
 			case VARIABLE_BYTE:
 				setState(GameDecoderState.GAME_LENGTH);

src/org/apollo/net/release/r317/Release317.java

@@ -138,6 +138,7 @@ public final class Release317 extends Release {
 		register(189, spamEventDecoder);
 		register(210, spamEventDecoder);
 		register(226, spamEventDecoder);
+        register(121, spamEventDecoder);
 
 		register(155, new FirstNpcActionEventDecoder());
 		register(17, new SecondNpcActionEventDecoder());