From 97d541d1463575e707c42fdac223ac4e3d8e9a8d Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Sat, 29 Sep 2018 03:15:49 -0400
Subject: [PATCH] Warn if someone tries to register the plugin instance as a
 listener

---
 .../com/velocitypowered/proxy/plugin/VelocityEventManager.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/proxy/src/main/java/com/velocitypowered/proxy/plugin/VelocityEventManager.java b/proxy/src/main/java/com/velocitypowered/proxy/plugin/VelocityEventManager.java
index b93afb3f..e931576a 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/plugin/VelocityEventManager.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/plugin/VelocityEventManager.java
@@ -58,6 +58,9 @@ public class VelocityEventManager implements EventManager {
         Preconditions.checkNotNull(plugin, "plugin");
         Preconditions.checkNotNull(listener, "listener");
         Preconditions.checkArgument(pluginManager.fromInstance(plugin).isPresent(), "Specified plugin is not loaded");
+        if (plugin == listener && registeredListenersByPlugin.containsEntry(plugin, plugin)) {
+            throw new IllegalArgumentException("Trying to register the plugin main instance. Velocity already takes care of this for you.");
+        }
         registeredListenersByPlugin.put(plugin, listener);
         bus.register(listener);
     }