From 0000000000000000000000000000000000000000 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/world/entity/player/Player.java b/src/main/java/net/minecraft/world/entity/player/Player.java
index f92a5fc15b05b247dd62ccfdf690c2ef2b702b65..457cafaa39907e85e1d1e9028f0eb75a90f3eb8e 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -2232,18 +2232,29 @@ public abstract class Player extends LivingEntity {
         return ImmutableList.of(Pose.STANDING, Pose.CROUCHING, Pose.SWIMMING);
     }
 
+    // Paper start
+    protected boolean tryReadyArrow(ItemStack bow, ItemStack itemstack) {
+        return !(this instanceof ServerPlayer) ||
+                new com.destroystokyo.paper.event.player.PlayerReadyArrowEvent(
+                    ((ServerPlayer) this).getBukkitEntity(),
+                    org.bukkit.craftbukkit.inventory.CraftItemStack.asCraftMirror(bow),
+                    org.bukkit.craftbukkit.inventory.CraftItemStack.asCraftMirror(itemstack)
+                ).callEvent();
+        // Paper end
+    }
+
     @Override
     public ItemStack getProjectile(ItemStack stack) {
         if (!(stack.getItem() instanceof ProjectileWeaponItem)) {
             return ItemStack.EMPTY;
         } else {
-            Predicate<ItemStack> predicate = ((ProjectileWeaponItem) stack.getItem()).getSupportedHeldProjectiles();
+            Predicate<ItemStack> predicate = ((ProjectileWeaponItem) stack.getItem()).getSupportedHeldProjectiles().and(item -> tryReadyArrow(stack, item)); // Paper
             ItemStack itemstack1 = ProjectileWeaponItem.getHeldProjectile(this, predicate);
 
             if (!itemstack1.isEmpty()) {
                 return itemstack1;
             } else {
-                predicate = ((ProjectileWeaponItem) stack.getItem()).getAllSupportedProjectiles();
+                predicate = ((ProjectileWeaponItem) stack.getItem()).getAllSupportedProjectiles().and(item -> tryReadyArrow(stack, item)); // Paper
 
                 for (int i = 0; i < this.inventory.getContainerSize(); ++i) {
                     ItemStack itemstack2 = this.inventory.getItem(i);