From e67acc61108ac7a18c19e8cec280c96112f05082 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 18 Jun 2018 01:12:53 -0400
Subject: [PATCH] PlayerReadyArrowEvent

Called when a player is firing a bow and the server is choosing an arrow to use.
Plugins can skip selection of certain arrows and control which is used.

diff --git a/src/main/java/net/minecraft/server/EntityHuman.java b/src/main/java/net/minecraft/server/EntityHuman.java
index 58d2a28a4..f5dac5082 100644
--- a/src/main/java/net/minecraft/server/EntityHuman.java
+++ b/src/main/java/net/minecraft/server/EntityHuman.java
@@ -2032,6 +2032,17 @@ public abstract class EntityHuman extends EntityLiving {
         return (EntitySize) EntityHuman.b.getOrDefault(entitypose, EntityHuman.bs);
     }
 
+    // Paper start
+    protected boolean tryReadyArrow(ItemStack bow, ItemStack itemstack) {
+        return !(this instanceof EntityPlayer) ||
+                new com.destroystokyo.paper.event.player.PlayerReadyArrowEvent(
+                    ((EntityPlayer) this).getBukkitEntity(),
+                    org.bukkit.craftbukkit.inventory.CraftItemStack.asCraftMirror(bow),
+                    org.bukkit.craftbukkit.inventory.CraftItemStack.asCraftMirror(itemstack)
+                ).callEvent();
+        // Paper end
+    }
+
     @Override
     public ItemStack f(ItemStack itemstack) {
         if (!(itemstack.getItem() instanceof ItemProjectileWeapon)) {
@@ -2048,7 +2059,7 @@ public abstract class EntityHuman extends EntityLiving {
                 for (int i = 0; i < this.inventory.getSize(); ++i) {
                     ItemStack itemstack2 = this.inventory.getItem(i);
 
-                    if (predicate.test(itemstack2)) {
+                    if (predicate.test(itemstack2) && tryReadyArrow(itemstack, itemstack2)) { // Paper
                         return itemstack2;
                     }
                 }
-- 
2.21.0