From 26d79436d7cdb0a56bebbc30fda2463dc7279832 Mon Sep 17 00:00:00 2001
From: fullwall <fullwall25@gmail.com>
Date: Wed, 10 Jul 2013 17:35:20 +0800
Subject: [PATCH] Work around traits removing themselves or adding traits
 during onSpawn iteration

---
 src/main/java/net/citizensnpcs/npc/CitizensNPC.java | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/main/java/net/citizensnpcs/npc/CitizensNPC.java b/src/main/java/net/citizensnpcs/npc/CitizensNPC.java
index 9eb7cf77d..e40ef9f62 100644
--- a/src/main/java/net/citizensnpcs/npc/CitizensNPC.java
+++ b/src/main/java/net/citizensnpcs/npc/CitizensNPC.java
@@ -1,5 +1,6 @@
 package net.citizensnpcs.npc;
 
+import java.util.Collection;
 import java.util.Set;
 
 import javax.annotation.Nullable;
@@ -211,7 +212,9 @@ public class CitizensNPC extends AbstractNPC {
 
         navigator.onSpawn();
         // Modify NPC using traits after the entity has been created
-        for (Trait trait : traits.values()) {
+        Collection<Trait> onSpawn = traits.values();
+        // work around traits modifying the map during this iteration.
+        for (Trait trait : onSpawn.toArray(new Trait[onSpawn.size()])) {
             try {
                 trait.onSpawn();
             } catch (Throwable ex) {