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 d9f6b0e0b20f4106ffead6b773b5489b71924c61..cf9393dd02565134a1ce428e84a9f26ac2d39a0d 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -382,6 +382,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
     public boolean valid;
     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 6d7ac0c8c171834fa8da94f158258a4774d80ec4..a90317100d32974e481e14476843f66997a2cf3a 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/Projectile.java
@@ -49,14 +49,31 @@ 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 && this.level() instanceof ServerLevel) {
             this.cachedOwner = ((ServerLevel) this.level()).getEntity(this.ownerUUID);
@@ -72,6 +89,7 @@ public abstract class Projectile extends Entity implements TraceableEntity {
                 }
             }
             // Paper end
+            this.refreshProjectileSource(false); // Paper
             return this.cachedOwner;
         } else {
             return null;
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java b/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java
index b3814bd6c6d6aae090fe417696535ed1376d84d5..5e82b2d57833fea1adb342f5c8d25f55491945cb 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/AbstractProjectile.java
@@ -64,6 +64,7 @@ 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;
     }