craftbukkit/nms-patches/net/minecraft/world/entity/EntityExperienceOrb.patch

--- a/net/minecraft/world/entity/EntityExperienceOrb.java
+++ b/net/minecraft/world/entity/EntityExperienceOrb.java
@@ -25,6 +25,14 @@
 import net.minecraft.world.phys.AxisAlignedBB;
 import net.minecraft.world.phys.Vec3D;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.event.entity.EntityRemoveEvent;
+import org.bukkit.event.entity.EntityTargetLivingEntityEvent;
+import org.bukkit.event.entity.EntityTargetEvent;
+import org.bukkit.event.player.PlayerExpCooldownChangeEvent;
+// CraftBukkit end
+
 public class EntityExperienceOrb extends Entity {
 
     private static final int LIFETIME = 6000;
@@ -68,6 +76,7 @@
     @Override
     public void tick() {
         super.tick();
+        EntityHuman prevTarget = this.followingPlayer;// CraftBukkit - store old target
         this.xo = this.getX();
         this.yo = this.getY();
         this.zo = this.getZ();
@@ -93,7 +102,22 @@
             this.followingPlayer = null;
         }
 
-        if (this.followingPlayer != null) {
+        // CraftBukkit start
+        boolean cancelled = false;
+        if (this.followingPlayer != prevTarget) {
+            EntityTargetLivingEntityEvent event = CraftEventFactory.callEntityTargetLivingEvent(this, followingPlayer, (followingPlayer != null) ? EntityTargetEvent.TargetReason.CLOSEST_PLAYER : EntityTargetEvent.TargetReason.FORGOT_TARGET);
+            EntityLiving target = (event.getTarget() == null) ? null : ((org.bukkit.craftbukkit.entity.CraftLivingEntity) event.getTarget()).getHandle();
+            cancelled = event.isCancelled();
+
+            if (cancelled) {
+                followingPlayer = prevTarget;
+            } else {
+                followingPlayer = (target instanceof EntityHuman) ? (EntityHuman) target : null;
+            }
+        }
+
+        if (this.followingPlayer != null && !cancelled) {
+            // CraftBukkit end
             Vec3D vec3d = new Vec3D(this.followingPlayer.getX() - this.getX(), this.followingPlayer.getY() + (double) this.followingPlayer.getEyeHeight() / 2.0D - this.getY(), this.followingPlayer.getZ() - this.getZ());
             double d0 = vec3d.lengthSqr();
 
@@ -119,7 +143,7 @@
 
         ++this.age;
         if (this.age >= 6000) {
-            this.discard();
+            this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
         }
 
     }
@@ -188,7 +212,7 @@
     private void merge(EntityExperienceOrb entityexperienceorb) {
         this.count += entityexperienceorb.count;
         this.age = Math.min(this.age, entityexperienceorb.age);
-        entityexperienceorb.discard();
+        entityexperienceorb.discard(EntityRemoveEvent.Cause.MERGE); // CraftBukkit - add Bukkit remove cause
     }
 
     private void setUnderwaterMovement() {
@@ -213,7 +237,7 @@
             this.markHurt();
             this.health = (int) ((float) this.health - f);
             if (this.health <= 0) {
-                this.discard();
+                this.discard(EntityRemoveEvent.Cause.DEATH); // CraftBukkit - add Bukkit remove cause
             }
 
             return true;
@@ -240,17 +264,17 @@
     public void playerTouch(EntityHuman entityhuman) {
         if (entityhuman instanceof EntityPlayer entityplayer) {
             if (entityhuman.takeXpDelay == 0) {
-                entityhuman.takeXpDelay = 2;
+                entityhuman.takeXpDelay = CraftEventFactory.callPlayerXpCooldownEvent(entityhuman, 2, PlayerExpCooldownChangeEvent.ChangeReason.PICKUP_ORB).getNewCooldown(); // CraftBukkit - entityhuman.takeXpDelay = 2;
                 entityhuman.take(this, 1);
                 int i = this.repairPlayerItems(entityplayer, this.value);
 
                 if (i > 0) {
-                    entityhuman.giveExperiencePoints(i);
+                    entityhuman.giveExperiencePoints(CraftEventFactory.callPlayerExpChangeEvent(entityhuman, i).getAmount()); // CraftBukkit - this.value -> event.getAmount()
                 }
 
                 --this.count;
                 if (this.count == 0) {
-                    this.discard();
+                    this.discard(EntityRemoveEvent.Cause.PICKUP); // CraftBukkit - add Bukkit remove cause
                 }
             }
 
@@ -264,12 +288,20 @@
             ItemStack itemstack = ((EnchantedItemInUse) optional.get()).itemStack();
             int j = EnchantmentManager.modifyDurabilityToRepairFromXp(entityplayer.serverLevel(), itemstack, i);
             int k = Math.min(j, itemstack.getDamageValue());
+            // CraftBukkit start
+            org.bukkit.event.player.PlayerItemMendEvent event = CraftEventFactory.callPlayerItemMendEvent(entityplayer, this, itemstack, optional.get().inSlot(), k);
+            k = event.getRepairAmount();
+            if (event.isCancelled()) {
+                return i;
+            }
+            // CraftBukkit end
 
             itemstack.setDamageValue(itemstack.getDamageValue() - k);
             if (k > 0) {
                 int l = i - k * i / j;
 
                 if (l > 0) {
+                    this.value = l; // CraftBukkit - update exp value of orb for PlayerItemMendEvent calls
                     return this.repairPlayerItems(entityplayer, l);
                 }
             }
@@ -289,6 +321,24 @@
     }
 
     public static int getExperienceValue(int i) {
+        // CraftBukkit start
+        if (i > 162670129) return i - 100000;
+        if (i > 81335063) return 81335063;
+        if (i > 40667527) return 40667527;
+        if (i > 20333759) return 20333759;
+        if (i > 10166857) return 10166857;
+        if (i > 5083423) return 5083423;
+        if (i > 2541701) return 2541701;
+        if (i > 1270849) return 1270849;
+        if (i > 635413) return 635413;
+        if (i > 317701) return 317701;
+        if (i > 158849) return 158849;
+        if (i > 79423) return 79423;
+        if (i > 39709) return 39709;
+        if (i > 19853) return 19853;
+        if (i > 9923) return 9923;
+        if (i > 4957) return 4957;
+        // CraftBukkit end
         return i >= 2477 ? 2477 : (i >= 1237 ? 1237 : (i >= 617 ? 617 : (i >= 307 ? 307 : (i >= 149 ? 149 : (i >= 73 ? 73 : (i >= 37 ? 37 : (i >= 17 ? 17 : (i >= 7 ? 7 : (i >= 3 ? 3 : 1)))))))));
     }