Prevent the PlayerQuitEvent from being fired twice. FIXES Ticket-2.

ProtocolLib/dependency-reduced-pom.xml

@@ -4,7 +4,7 @@
   <groupId>com.comphenix.protocol</groupId>
   <artifactId>ProtocolLib</artifactId>
   <name>ProtocolLib</name>
-  <version>1.4.2</version>
+  <version>1.4.3-SNAPSHOT</version>
   <description>Provides read/write access to the Minecraft protocol.</description>
   <url>http://dev.bukkit.org/server-mods/protocollib/</url>
   <developers>

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

@@ -606,6 +606,7 @@ public final class PacketFilterManager implements ProtocolManager, ListenerInvok
 				
 				@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
 			    public void onPlayerQuit(PlayerQuitEvent event) {
+					playerInjection.handleDisconnect(event.getPlayer());
 					playerInjection.uninjectPlayer(event.getPlayer());
 			    }
 				
@@ -689,10 +690,14 @@ public final class PacketFilterManager implements ProtocolManager, ListenerInvok
 						Object event = args[0];
 						
 						// Check for the correct event
-						if (event instanceof PlayerJoinEvent)
-							playerInjection.injectPlayer(((PlayerJoinEvent) event).getPlayer());
-						else if (event instanceof PlayerQuitEvent)
-							playerInjection.uninjectPlayer(((PlayerQuitEvent) event).getPlayer());
+						if (event instanceof PlayerJoinEvent) {
+							Player player = ((PlayerJoinEvent) event).getPlayer();
+							playerInjection.injectPlayer(player);
+						} else if (event instanceof PlayerQuitEvent) {
+							Player player = ((PlayerQuitEvent) event).getPlayer();
+							playerInjection.handleDisconnect(player);
+							playerInjection.uninjectPlayer(player);
+						}
 					}
 					return null;
 				}

ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkFieldInjector.java

@@ -191,6 +191,11 @@ class NetworkFieldInjector extends PlayerInjector {
 		overridenLists.clear();
 	}
 
+	@Override
+	public void handleDisconnect() {
+		// No need to do anything
+	}
+	
 	@Override
 	public boolean canInject(GamePhase phase) {
 		// All phases should work

ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkObjectInjector.java

@@ -159,6 +159,11 @@ class NetworkObjectInjector extends PlayerInjector {
 		}
 	}
 
+	@Override
+	public void handleDisconnect() {
+		// No need to do anything
+	}
+	
 	@Override
 	public boolean canInject(GamePhase phase) {
 		// Works for all phases

ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkServerInjector.java

@@ -17,8 +17,10 @@
 
 package com.comphenix.protocol.injector.player;
 
+import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import net.minecraft.server.Packet;
@@ -50,6 +52,7 @@ import com.comphenix.protocol.reflect.instances.ExistingGenerator;
  */
 public class NetworkServerInjector extends PlayerInjector {
 
+	private static Field disconnectField;
 	private static Method sendPacketMethod;
 	private InjectedServerConnection serverInjection;
 	
@@ -59,6 +62,9 @@ public class NetworkServerInjector extends PlayerInjector {
 	// Used to create proxy objects
 	private ClassLoader classLoader;
 	
+	// Whether or not the player has disconnected
+	private boolean hasDisconnected;
+	
 	public NetworkServerInjector(
 			ClassLoader classLoader, Logger logger, Player player, 
 			ListenerInvoker invoker, IntegerSet sendingFilters, 
@@ -250,11 +256,42 @@ public class NetworkServerInjector extends PlayerInjector {
 			} catch (IllegalAccessException e) {
 				e.printStackTrace();
 			}
+			
+			// Prevent the PlayerQuitEvent from being sent twice
+			if (hasDisconnected) {
+				setDisconnect(serverHandlerRef.getValue(), true);
+			}
 		}
 
 		serverInjection.revertServerHandler(serverHandler);
 	}
 	
+	@Override
+	public void handleDisconnect() {
+		hasDisconnected = true;
+	}
+	
+	/**
+	 * Set the disconnected field in a NetServerHandler.
+	 * @param handler - the NetServerHandler.
+	 * @param value - the new value.
+	 */
+	private void setDisconnect(Object handler, boolean value) {
+		// Set it 
+		try {
+			// Load the field
+			if (disconnectField == null) {
+				disconnectField = FuzzyReflection.fromObject(handler).getFieldByName("disconnected.*");
+			}
+			FieldUtils.writeField(disconnectField, handler, value);
+		
+		} catch (IllegalArgumentException e) {
+			logger.log(Level.WARNING, "Unable to find disconnect field. Is ProtocolLib up to date?");
+		} catch (IllegalAccessException e) {
+			logger.log(Level.WARNING, "Unable to update disconnected field. Player quit event may be sent twice.");
+		}
+	}
+	
 	@Override
 	public void checkListener(PacketListener listener) {
 		// We support everything

ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/PlayerInjectionHandler.java

@@ -358,6 +358,18 @@ public class PlayerInjectionHandler {
 		}
 	}
 	
+	/**
+	 * Invoke special routines for handling disconnect before a player is uninjected.
+	 * @param player - player to process.
+	 */
+	public void handleDisconnect(Player player) {
+		PlayerInjector injector = getInjector(player);
+		
+		if (injector != null) {
+			injector.handleDisconnect();
+		}
+	}
+	
 	/**
 	 * Unregisters the given player.
 	 * @param player - player to unregister.

ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/PlayerInjector.java

@@ -452,6 +452,11 @@ abstract class PlayerInjector {
 		clean = true;
 	}
 
+	/**
+	 * Clean up after the player has disconnected.
+	 */
+	public abstract void handleDisconnect();
+	
 	/**
 	 * Override to add custom cleanup behavior.
 	 */

ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/ReplacedArrayList.java

@@ -68,7 +68,7 @@ class ReplacedArrayList<TKey> extends ArrayList<TKey> {
 	}
 	
 	/**
-	 * Invoksed when an element is being removed.
+	 * Invoked when an element is being removed.
 	 * @param removing - the element being removed.
 	 */
 	protected void onRemoved(TKey removing) {
@@ -264,6 +264,15 @@ class ReplacedArrayList<TKey> extends ArrayList<TKey> {
 		addMapping(target, replacement, false);
 	}
 	
+	/**
+	 * Retrieve the old value, if it exists.
+	 * @param target - the key.
+	 * @return The value that was replaced, or NULL.
+	 */
+	public TKey getMapping(TKey target) {
+		return replaceMap.get(target);
+	}
+	
 	/**
 	 * Add a replace rule.
 	 * <p>
@@ -284,8 +293,9 @@ class ReplacedArrayList<TKey> extends ArrayList<TKey> {
 	/**
 	 * Revert the given mapping.
 	 * @param target - the instance we replaced.
+	 * @return The old mapped value, or NULL if nothing was replaced.
 	 */
-	public synchronized void removeMapping(TKey target) {
+	public synchronized TKey removeMapping(TKey target) {
 		// Make sure the mapping exist
 		if (replaceMap.containsKey(target)) {
 			TKey replacement = replaceMap.get(target);
@@ -293,7 +303,25 @@ class ReplacedArrayList<TKey> extends ArrayList<TKey> {
 	
 			// Revert existing elements
 			replaceAll(replacement, target);
+			return replacement;
 		}
+		return null;
+	}
+	
+	/**
+	 * Swap the new replaced value with its old value.
+	 * @param target - the instance we replaced.
+	 * @param The old mapped value, or NULL if nothing was swapped.
+	 */
+	public synchronized TKey swapMapping(TKey target) {
+		// Make sure the mapping exist
+		TKey replacement = removeMapping(target);
+		
+		// Add the reverse
+		if (replacement != null) {
+			replaceMap.put(replacement, target);
+		}
+		return replacement;
 	}
 	
 	/**