Fixed a number of simple bugs discovered by FindBugs.

ProtocolLib/src/com/comphenix/protocol/events/ListeningWhitelist.java

@@ -62,7 +62,7 @@ public class ListeningWhitelist {
 	 * @return TRUE if there are any packets, FALSE otherwise.
 	 */
 	public boolean isEnabled() {
-		return whitelist != null || whitelist.size() > 0;
+		return whitelist != null && whitelist.size() > 0;
 	}
 	
 	/**

ProtocolLib/src/com/comphenix/protocol/injector/MinecraftRegistry.java

@@ -88,8 +88,8 @@ class MinecraftRegistry {
 		Map<Integer, Class> lookup = forceVanilla ? previousValues : overwrittenPackets;
 		
 		// Optimized lookup
-		if (lookup.containsKey(packetToID)) {
-			return lookup.get(packetToID);
+		if (lookup.containsKey(packetID)) {
+			return lookup.get(packetID);
 		}
 
 		// Will most likely not be used

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

@@ -48,7 +48,7 @@ class NetworkFieldInjector extends PlayerInjector {
 	}
 	
 	@Override
-	protected void initialize() throws IllegalAccessException {
+	protected synchronized void initialize() throws IllegalAccessException {
 		super.initialize();
 	
 		// Get the sync field as well

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

@@ -522,12 +522,12 @@ public final class PacketFilterManager implements ProtocolManager {
 		if (!hasClosed && player != null) {
 			
 			PlayerInjector injector = playerInjection.get(player);
-			DataInputStream input = injector.getInputStream(true);
 			
 			if (injector != null) {
+				DataInputStream input = injector.getInputStream(true);
 				injector.cleanupAll();
 				
-				playerInjection.remove(injector);
+				playerInjection.remove(player);
 				connectionLookup.remove(input);
 			}
 		}	

ProtocolLib/src/com/comphenix/protocol/reflect/StructureModifier.java

@@ -63,8 +63,20 @@ public class StructureModifier<TField> {
 		initialize(targetType, Object.class, fields, defaults, null, new HashMap<Class, StructureModifier>());
 	}
 	
-	private StructureModifier() {
-		// Consumers of this method should call "initialize"
+	/**
+	 * Consumers of this method should call "initialize".
+	 */
+	protected StructureModifier() {
+		
+	}
+	
+	/**
+	 * Initialize using the same field types.
+	 * @param other - information to set.
+	 */
+	protected void initialize(StructureModifier<TField> other) {
+		initialize(other.targetType, other.fieldType, other.data, 
+				   other.defaultFields, other.converter, other.subtypeCache);
 	}
 	
 	/**
@@ -358,7 +370,7 @@ public class StructureModifier<TField> {
 	public List<Field> getFields() {
 		return ImmutableList.copyOf(data);
 	}
-	
+
 	/**
 	 * Retrieve every value stored in the fields of the current type.
 	 * @return Every field value.
@@ -367,8 +379,9 @@ public class StructureModifier<TField> {
 	public List<TField> getValues() throws FieldAccessException {
 		List<TField> values = new ArrayList<TField>();
 		
-		for (int i = 0; i < size(); i++)
+		for (int i = 0; i < size(); i++) {
 			values.add(read(i));
+		}
 		
 		return values;
 	}