Fixed misuse of kill() and close() when deleting entities (#1490)

src/pocketmine/Player.php

@@ -1445,7 +1445,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 				$this->server->broadcastPacket($entity->getViewers(), $pk);
 
 				$this->inventory->addItem(clone $item);
-				$entity->kill();
+				$entity->flagForDespawn();
 			}elseif($entity instanceof DroppedItem){
 				if($entity->getPickupDelay() <= 0){
 					$item = $entity->getItem();
@@ -1475,7 +1475,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 						$this->server->broadcastPacket($entity->getViewers(), $pk);
 
 						$this->inventory->addItem(clone $item);
-						$entity->kill();
+						$entity->flagForDespawn();
 					}
 				}
 			}

src/pocketmine/entity/Entity.php

@@ -471,6 +471,8 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 
 	/** @var bool */
 	protected $closed = false;
+	/** @var bool */
+	private $needsDespawn = false;
 
 	/** @var TimingsHandler */
 	protected $timings;
@@ -1280,15 +1282,20 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 
 		$this->lastUpdate = $currentTick;
 
+		if($this->needsDespawn){
+			$this->close();
+			return false;
+		}
+
 		if(!$this->isAlive()){
 			$this->deadTicks += $tickDiff;
 			if($this->deadTicks >= $this->maxDeadTicks){
 				$this->despawnFromAll();
 				if(!$this->isPlayer){
-					$this->close();
+					$this->flagForDespawn();
 				}
 			}
-			return $this->deadTicks < $this->maxDeadTicks;
+			return true;
 		}
 
 
@@ -1930,6 +1937,13 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 		}
 	}
 
+	/**
+	 * Flags the entity to be removed from the world on the next tick.
+	 */
+	public function flagForDespawn() : void{
+		$this->needsDespawn = true;
+	}
+
 	/**
 	 * Returns whether the entity has been "closed".
 	 * @return bool

src/pocketmine/entity/FallingSand.php

@@ -104,7 +104,7 @@ class FallingSand extends Entity{
 			}
 
 			if($this->onGround or $blockTarget !== null){
-				$this->kill();
+				$this->flagForDespawn();
 
 				$block = $this->level->getBlock($pos);
 				if($block->getId() > 0 and $block->isTransparent() and !$block->canBeReplaced()){

src/pocketmine/entity/Item.php

@@ -118,7 +118,7 @@ class Item extends Entity{
 				if($ev->isCancelled()){
 					$this->age = 0;
 				}else{
-					$this->kill();
+					$this->flagForDespawn();
 					$hasUpdate = true;
 				}
 			}

src/pocketmine/entity/PrimedTNT.php

@@ -91,7 +91,7 @@ class PrimedTNT extends Entity implements Explosive{
 			$this->fuse -= $tickDiff;
 
 			if($this->fuse <= 0){
-				$this->kill();
+				$this->flagForDespawn();
 				$this->explode();
 			}
 		}

src/pocketmine/entity/projectile/Arrow.php

@@ -72,7 +72,7 @@ class Arrow extends Projectile{
 		}
 
 		if($this->age > 1200){
-			$this->close();
+			$this->flagForDespawn();
 			$hasUpdate = true;
 		}
 

src/pocketmine/entity/projectile/Projectile.php

@@ -102,7 +102,7 @@ abstract class Projectile extends Entity{
 			}
 		}
 
-		$this->close();
+		$this->flagForDespawn();
 	}
 
 	public function saveNBT(){

src/pocketmine/entity/projectile/Throwable.php

@@ -40,7 +40,7 @@ abstract class Throwable extends Projectile{
 
 		if($this->age > 1200 or $this->isCollided){
 			//TODO: hit particles
-			$this->kill();
+			$this->flagForDespawn();
 			$hasUpdate = true;
 		}
 

src/pocketmine/item/Bow.php

@@ -75,7 +75,7 @@ class Bow extends Tool{
 			$entity = $ev->getProjectile(); //This might have been changed by plugins
 
 			if($ev->isCancelled()){
-				$entity->kill();
+				$entity->flagForDespawn();
 				$player->getInventory()->sendContents($player);
 			}else{
 				$entity->setMotion($entity->getMotion()->multiply($ev->getForce()));
@@ -87,7 +87,7 @@ class Bow extends Tool{
 				if($entity instanceof Projectile){
 					$player->getServer()->getPluginManager()->callEvent($projectileEv = new ProjectileLaunchEvent($entity));
 					if($projectileEv->isCancelled()){
-						$ev->getProjectile()->kill();
+						$ev->getProjectile()->flagForDespawn();
 					}else{
 						$ev->getProjectile()->spawnToAll();
 						$player->level->addSound(new LaunchSound($player), $player->getViewers());

src/pocketmine/item/ProjectileItem.php

@@ -49,7 +49,7 @@ abstract class ProjectileItem extends Item{
 		if($projectile instanceof Projectile){
 			$player->getServer()->getPluginManager()->callEvent($projectileEv = new ProjectileLaunchEvent($projectile));
 			if($projectileEv->isCancelled()){
-				$projectile->kill();
+				$projectile->flagForDespawn();
 			}else{
 				$projectile->spawnToAll();
 				$player->getLevel()->addSound(new LaunchSound($player), $player->getViewers());