From 8bba43fbcd5555066af8c96d92bc5d528590b0bb 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 39b90fb4c..c0816b9f8 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1153,7 +1153,7 @@ public abstract class World implements IBlockAccess {
                 for (Entity e : entities) {
                     if (e instanceof EntityExperienceOrb) {
                         EntityExperienceOrb loopItem = (EntityExperienceOrb) e;
-                        if (!loopItem.dead && !(maxValue > 0 && loopItem.value >= maxValue)) { // Paper
+                        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()) { // Paper
                             xp.value += loopItem.value;
                             // Paper start
                             if (!mergeUnconditionally && xp.value > maxValue) {
-- 
2.18.0