src/main/java/buttondevteam/discordplugin/listeners/MCChatListener.java

@@ -134,11 +134,11 @@ public class MCChatListener implements Listener, IListener<MessageReceivedEvent>
 				val sender = new DiscordConnectedPlayer(user, channel, mcp.getUUID());
 				ConnectedSenders.put(user.getStringID(), sender);
 				if (p == null)// Player is offline - If the player is online, that takes precedence
-					Bukkit.getPluginManager().callEvent(new PlayerJoinEvent(sender, ""));
+					MCListener.callEventExcluding(new PlayerJoinEvent(sender, ""), "ProtocolLib");
 			} else {
 				val sender = ConnectedSenders.remove(user.getStringID());
 				if (p == null)// Player is offline - If the player is online, that takes precedence
-					Bukkit.getPluginManager().callEvent(new PlayerQuitEvent(sender, ""));
+					MCListener.callEventExcluding(new PlayerQuitEvent(sender, ""), "ProtocolLib");
 			}
 		}
 		return start //

src/main/java/buttondevteam/discordplugin/listeners/MCListener.java

@@ -1,14 +1,22 @@
 package buttondevteam.discordplugin.listeners;
 
+import java.util.Arrays;
+import java.util.logging.Level;
+
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
+import org.bukkit.event.Event;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
+import org.bukkit.event.HandlerList;
 import org.bukkit.event.Listener;
 import org.bukkit.event.entity.PlayerDeathEvent;
 import org.bukkit.event.player.PlayerJoinEvent;
 import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.event.server.ServerCommandEvent;
+import org.bukkit.plugin.AuthorNagException;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.RegisteredListener;
 
 import com.earth2me.essentials.CommandSource;
 
@@ -41,7 +49,7 @@ public class MCListener implements Listener {
 					new DiscordPlayerSender(user, DiscordPlugin.chatchannel, p));
 			MCChatListener.ConnectedSenders.values().stream()
 					.filter(s -> s.getUniqueId().equals(e.getPlayer().getUniqueId())).findAny()
-					.ifPresent(dcp -> Bukkit.getPluginManager().callEvent(new PlayerQuitEvent(dcp, "")));
+					.ifPresent(dcp -> callEventExcluding(new PlayerQuitEvent(dcp, ""), "ProtocolLib"));
 		}
 		if (ConnectCommand.WaitingToConnect.containsKey(e.GetPlayer().PlayerName().get())) {
 			IUser user = DiscordPlugin.dc
@@ -62,7 +70,7 @@ public class MCListener implements Listener {
 				.removeIf(entry -> entry.getValue().getUniqueId().equals(e.getPlayer().getUniqueId()));
 		MCChatListener.ConnectedSenders.values().stream()
 				.filter(s -> s.getUniqueId().equals(e.getPlayer().getUniqueId())).findAny()
-				.ifPresent(dcp -> Bukkit.getPluginManager().callEvent(new PlayerJoinEvent(dcp, "")));
+				.ifPresent(dcp -> callEventExcluding(new PlayerJoinEvent(dcp, ""), "ProtocolLib"));
 		MCChatListener.sendSystemMessageToChat(e.GetPlayer().PlayerName().get() + " left the game");
 	}
 
@@ -121,4 +129,62 @@ public class MCListener implements Listener {
 					ex);
 		}
 	}
+
+	/**
+	 * Calls an event with the given details.
+	 * <p>
+	 * This method only synchronizes when the event is not asynchronous.
+	 *
+	 * @param event
+	 *            Event details
+	 * @param plugins
+	 *            The plugins to exclude. Not case sensitive.
+	 */
+	public static void callEventExcluding(Event event, String... plugins) { // Copied from Spigot-API and modified a bit
+		if (event.isAsynchronous()) {
+			if (Thread.holdsLock(Bukkit.getPluginManager())) {
+				throw new IllegalStateException(
+						event.getEventName() + " cannot be triggered asynchronously from inside synchronized code.");
+			}
+			if (Bukkit.getServer().isPrimaryThread()) {
+				throw new IllegalStateException(
+						event.getEventName() + " cannot be triggered asynchronously from primary server thread.");
+			}
+			fireEventExcluding(event, plugins);
+		} else {
+			synchronized (Bukkit.getPluginManager()) {
+				fireEventExcluding(event, plugins);
+			}
+		}
+	}
+
+	private static void fireEventExcluding(Event event, String... plugins) {
+		HandlerList handlers = event.getHandlers(); // Code taken from SimplePluginManager in Spigot-API
+		RegisteredListener[] listeners = handlers.getRegisteredListeners();
+		val server = Bukkit.getServer();
+
+		for (RegisteredListener registration : listeners) {
+			if (!registration.getPlugin().isEnabled()
+					|| Arrays.stream(plugins).anyMatch(p -> p.equalsIgnoreCase(registration.getPlugin().getName())))
+				continue; // Modified to exclude plugins
+
+			try {
+				registration.callEvent(event);
+			} catch (AuthorNagException ex) {
+				Plugin plugin = registration.getPlugin();
+
+				if (plugin.isNaggable()) {
+					plugin.setNaggable(false);
+
+					server.getLogger().log(Level.SEVERE,
+							String.format("Nag author(s): '%s' of '%s' about the following: %s",
+									plugin.getDescription().getAuthors(), plugin.getDescription().getFullName(),
+									ex.getMessage()));
+				}
+			} catch (Throwable ex) {
+				server.getLogger().log(Level.SEVERE, "Could not pass event " + event.getEventName() + " to "
+						+ registration.getPlugin().getDescription().getFullName(), ex);
+			}
+		}
+	}
 }