From cbbed5356c380a5ead3ccc168dc13d08d0953052 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 17 Jun 2017 15:18:30 -0400
Subject: [PATCH] Shoulder Entities Release API


diff --git a/src/main/java/net/minecraft/server/EntityHuman.java b/src/main/java/net/minecraft/server/EntityHuman.java
index 0f00eecead..504c9ad473 100644
--- a/src/main/java/net/minecraft/server/EntityHuman.java
+++ b/src/main/java/net/minecraft/server/EntityHuman.java
@@ -1824,21 +1824,48 @@ public abstract class EntityHuman extends EntityLiving {
         }
         // CraftBukkit end
     }
+    // Paper start
+    public Entity releaseLeftShoulderEntity() {
+        Entity entity = this.spawnEntityFromShoulder0(this.getShoulderEntityLeft());
+        if (entity != null) {
+            this.setShoulderEntityLeft(new NBTTagCompound());
+        }
+        return entity;
+    }
 
-    private boolean spawnEntityFromShoulder(@Nullable NBTTagCompound nbttagcompound) { // CraftBukkit void->boolean
-        if (!this.world.isClientSide && !nbttagcompound.isEmpty()) {
+    public Entity releaseRightShoulderEntity() {
+        Entity entity = this.spawnEntityFromShoulder0(this.getShoulderEntityRight());
+        if (entity != null) {
+            this.setShoulderEntityRight(new NBTTagCompound());
+        }
+        return entity;
+    }
+
+    // Paper - incase any plugins used NMS to call this... old method signature to avoid other diff
+    private boolean spawnEntityFromShoulder(@Nullable NBTTagCompound nbttagcompound) {
+        return spawnEntityFromShoulder0(nbttagcompound) != null;
+    }
+    // Paper - Moved to new method that now returns entity, and properly null checks
+    private Entity spawnEntityFromShoulder0(@Nullable NBTTagCompound nbttagcompound) { // CraftBukkit void->boolean - Paper - return Entity
+        if (!this.world.isClientSide && nbttagcompound != null && !nbttagcompound.isEmpty()) { // Paper - null check
             Entity entity = EntityTypes.a(nbttagcompound, this.world);
+            if (entity == null) { // Paper - null check
+                return null;
+            }
 
             if (entity instanceof EntityTameableAnimal) {
                 ((EntityTameableAnimal) entity).setOwnerUUID(this.uniqueID);
             }
 
             entity.setPosition(this.locX, this.locY + 0.699999988079071D, this.locZ);
-            return this.world.addEntity(entity, CreatureSpawnEvent.SpawnReason.SHOULDER_ENTITY); // CraftBukkit
+            if (this.world.addEntity(entity, CreatureSpawnEvent.SpawnReason.SHOULDER_ENTITY)) { // CraftBukkit
+                return entity;
+            }
         }
 
-        return true; // CraftBukkit
+        return null;
     }
+    // Paper end
 
     public abstract boolean isSpectator();
 
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftHumanEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftHumanEntity.java
index 497783d4f3..99705b1344 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftHumanEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftHumanEntity.java
@@ -460,6 +460,32 @@ public class CraftHumanEntity extends CraftLivingEntity implements HumanEntity {
         getHandle().getCooldownTracker().a(CraftMagicNumbers.getItem(material), ticks);
     }
 
+    // Paper start
+    @Override
+    public org.bukkit.entity.Entity releaseLeftShoulderEntity() {
+        if (!getHandle().getShoulderEntityLeft().isEmpty()) {
+            Entity entity = getHandle().releaseLeftShoulderEntity();
+            if (entity != null) {
+                return entity.getBukkitEntity();
+            }
+        }
+
+        return null;
+    }
+
+    @Override
+    public org.bukkit.entity.Entity releaseRightShoulderEntity() {
+        if (!getHandle().getShoulderEntityRight().isEmpty()) {
+            Entity entity = getHandle().releaseRightShoulderEntity();
+            if (entity != null) {
+                return entity.getBukkitEntity();
+            }
+        }
+
+        return null;
+    }
+    // Paper end
+
     @Override
     public boolean discoverRecipe(NamespacedKey recipe) {
         return discoverRecipes(Arrays.asList(recipe)) != 0;
-- 
2.19.0