Paper/patches/server/0437-Option-for-maximum-exp-value-when-merging-orbs.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: BillyGalbreath <Blake.Galbreath@GMail.com>
Date: Fri, 10 Nov 2017 23:03:12 -0500
Subject: [PATCH] Option for maximum exp value when merging orbs


diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 4acfd9aa46aed545591a46afe3fa162bf710d5c9..157d19c9e1d86922392a1542109312565abc7561 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -356,6 +356,12 @@ public class PaperWorldConfig {
         log("Creeper lingering effect: " + disableCreeperLingeringEffect);
     }
 
+    public int expMergeMaxValue;
+    private void expMergeMaxValue() {
+        expMergeMaxValue = getInt("experience-merge-max-value", -1);
+        log("Experience Merge Max Value: " + expMergeMaxValue);
+    }
+
     public double squidMaxSpawnHeight;
     private void squidMaxSpawnHeight() {
         squidMaxSpawnHeight = getDouble("squid-spawn-height.maximum", 0.0D);
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index 09c152123d055432266bbb5a1434c21aed64da1f..7b59cfc35968a82c5db78c5107b175d994df3535 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -610,16 +610,30 @@ public class CraftEventFactory {
             net.minecraft.world.entity.ExperienceOrb xp = (net.minecraft.world.entity.ExperienceOrb) entity;
             double radius = world.spigotConfig.expMerge;
             if (radius > 0) {
+                // Paper start - Maximum exp value when merging - Whole section has been tweaked, see comments for specifics
+                final int maxValue = world.paperConfig.expMergeMaxValue;
+                final boolean mergeUnconditionally = world.paperConfig.expMergeMaxValue <= 0;
+                if (mergeUnconditionally || xp.value < maxValue) { // Paper - Skip iteration if unnecessary
+
                 List<Entity> entities = world.getEntities(entity, entity.getBoundingBox().inflate(radius, radius, radius));
                 for (Entity e : entities) {
                     if (e instanceof net.minecraft.world.entity.ExperienceOrb) {
                         net.minecraft.world.entity.ExperienceOrb loopItem = (net.minecraft.world.entity.ExperienceOrb) e;
-                        if (!loopItem.isRemoved()) {
+                        // Paper start
+                        if (!loopItem.isRemoved() && !(maxValue > 0 && loopItem.value >= maxValue)) {
+                            long newTotal = (long)xp.value + (long)loopItem.value;
+                            if ((int) newTotal < 0) continue; // Overflow
+                            if (maxValue > 0 && newTotal > (long)maxValue) {
+                                loopItem.value = (int) (newTotal - maxValue);
+                                xp.value = maxValue;
+                            } else {
                             xp.value += loopItem.value;
                             loopItem.discard();
+                            } // Paper end
                         }
                     }
                 }
+                } // Paper end - End iteration skip check - All tweaking ends here
             }
         // Spigot end
         } else if (!(entity instanceof ServerPlayer)) {