From d9cc2b9aa6ff6b68198dc8948be78ef1ca309e1b Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 19 Dec 2017 22:57:26 -0500
Subject: [PATCH] ExperienceOrbMergeEvent

Fired when the server is about to merge 2 experience orbs
Plugins can cancel this if they want to ensure experience orbs do not lose important
metadata such as spawn reason, or conditionally move data from source to target.

diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 7cd07112a3..852977cab3 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1015,7 +1015,7 @@ public abstract class World implements GeneratorAccess, IIBlockAccess, AutoClose
                     if (e instanceof EntityExperienceOrb) {
                         EntityExperienceOrb loopItem = (EntityExperienceOrb) e;
                         // Paper start
-                        if (!loopItem.dead && !(maxValue > 0 && loopItem.value >= maxValue)) {
+                        if (!loopItem.dead && !(maxValue > 0 && loopItem.value >= maxValue) && new com.destroystokyo.paper.event.entity.ExperienceOrbMergeEvent((org.bukkit.entity.ExperienceOrb) entity.getBukkitEntity(), (org.bukkit.entity.ExperienceOrb) loopItem.getBukkitEntity()).callEvent()) {
                             long newTotal = (long)xp.value + (long)loopItem.value;
                             if ((int) newTotal < 0) continue; // Overflow
                             if (maxValue > 0 && newTotal > (long)maxValue) {
-- 
2.18.0