Properly handle reloads on Spigot.

The code is getting uglier and uglier ...

ProtocolLib/src/main/java/com/comphenix/protocol/injector/PacketFilterManager.java

@@ -22,6 +22,7 @@ import java.lang.reflect.Method;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -272,14 +273,9 @@ public final class PacketFilterManager implements ProtocolManager, ListenerInvok
 			delayed.setAsynchronousManager(asyncManager);
 			asyncManager.setManager(delayed);
 
-			Futures.addCallback(BukkitFutures.nextEvent(library, WorldInitEvent.class), new FutureCallback<WorldInitEvent>() {
+			final Callable<Object> registerSpigot = new Callable<Object>() {
 				@Override
-				public void onSuccess(WorldInitEvent event) {
+				public Object call() throws Exception {
-					// Nevermind
-					if (delayed.isClosed())
-						return;
-					
-					try {
 					// Now we are probably able to check for Netty
 					InjectedServerConnection inspector = new InjectedServerConnection(reporter, null, server, null);
 					Object connection = inspector.getServerConnection();
@@ -291,9 +287,24 @@ public final class PacketFilterManager implements ProtocolManager, ListenerInvok
 					delayed.setDelegate(new PacketFilterManager(
 						classLoader, server, library, asyncManager, mcVersion, unhookTask, reporter, useNetty)
 					);
+					
 					// Reference this manager directly
 					asyncManager.setManager(delayed.getDelegate());
+					return null;
+				}
+			};
 
+			// If the server hasn't loaded yet - wait
+			if (server.getWorlds().size() == 0) {
+				Futures.addCallback(BukkitFutures.nextEvent(library, WorldInitEvent.class), new FutureCallback<WorldInitEvent>() {
+					@Override
+					public void onSuccess(WorldInitEvent event) {
+						// Nevermind
+						if (delayed.isClosed())
+							return;
+						
+						try {
+							registerSpigot.call();
 						} catch (Exception e) {
 							onFailure(e);
 						}
@@ -305,6 +316,15 @@ public final class PacketFilterManager implements ProtocolManager, ListenerInvok
 					}
 				});
 				
+			} else {
+				// Do it now
+				try {
+					registerSpigot.call();
+				} catch (Exception e) {
+					e.printStackTrace();
+				}
+			}
+			
 			// Let plugins use this version instead
 			return delayed;
 		} else {