From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Tue, 30 May 2023 12:59:10 -0700
Subject: [PATCH] Refresh ProjectileSource for projectiles

Makes sure the value returned by Projectile#getShooter in
the API matches the owner UUID specified in the entity nbt.
Previously, after the entity reloaded, Projectile#getShooter
would return null, while the entity still had an owner.

Also fixes setting the shooter/owner to null actually
clearing the owner.

Co-authored-by: Warrior <50800980+Warriorrrr@users.noreply.github.com>

diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 00c88798099c72f8682ac3547da96af6830567b4..96cfc5323cf080540c934c54ac00488e5babcea5 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -384,6 +384,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
     public boolean inWorld = false;
     public boolean generation;
     public int maxAirTicks = this.getDefaultMaxAirSupply(); // CraftBukkit - SPIGOT-6907: re-implement LivingEntity#setMaximumAir()
+    @Nullable // Paper
     public org.bukkit.projectiles.ProjectileSource projectileSource; // For projectiles only
     public boolean lastDamageCancelled; // SPIGOT-5339, SPIGOT-6252, SPIGOT-6777: Keep track if the event was canceled
     public boolean persistentInvisibility = false;
diff --git a/src/main/java/net/minecraft/world/entity/projectile/Projectile.java b/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
index 270dd1db56b187bffaedba9f2b86b3e46dda3152..2f058cec80c6ef7a5a5ca065dc6c9fe353c521de 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
@@ -50,14 +50,31 @@ public abstract class Projectile extends Entity implements TraceableEntity {
             this.ownerUUID = entity.getUUID();
             this.cachedOwner = entity;
         }
-        this.projectileSource = (entity != null && entity.getBukkitEntity() instanceof ProjectileSource) ? (ProjectileSource) entity.getBukkitEntity() : null; // CraftBukkit
-
+        // Paper start - Fix null owners not being handled
+        else {
+            this.ownerUUID = null;
+            this.cachedOwner = null;
+            this.projectileSource = null;
+        }
+        // Paper end
+        this.refreshProjectileSource(false); // Paper
+    }
+    // Paper start
+    public void refreshProjectileSource(boolean fillCache) {
+        if (fillCache) {
+            this.getOwner();
+        }
+        if (this.cachedOwner != null && !this.cachedOwner.isRemoved() && this.projectileSource == null && this.cachedOwner.getBukkitEntity() instanceof ProjectileSource projSource) {
+            this.projectileSource = projSource;
+        }
     }
+    // Paper end
 
     @Nullable
     @Override
     public Entity getOwner() {
         if (this.cachedOwner != null && !this.cachedOwner.isRemoved()) {
+            this.refreshProjectileSource(false); // Paper
             return this.cachedOwner;
         } else {
             if (this.ownerUUID != null) {
@@ -67,6 +84,7 @@ public abstract class Projectile extends Entity implements TraceableEntity {
                     ServerLevel worldserver = (ServerLevel) world;
 
                     this.cachedOwner = worldserver.getEntity(this.ownerUUID);
+                    this.refreshProjectileSource(false); // Paper
                     return this.cachedOwner;
                 }
             }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java b/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java
index 2c376687349825833e6d9a5ca92ce6afb98c36a3..0f7ae4a5c672039828454bf18c770dd99e250212 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java
@@ -60,6 +60,7 @@ public abstract class AbstractProjectile extends CraftEntity implements Projecti
 
     @Override
     public final org.bukkit.projectiles.ProjectileSource getShooter() {
+        this.getHandle().refreshProjectileSource(true); // Paper
         return this.getHandle().projectileSource;
     }