From eefa8abaf218f1dad0976fb2ba3b62390365d311 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Tue, 18 Apr 2017 14:45:33 +0100
Subject: [PATCH 1/2] Throw exceptions if something attempts to add a closed
 Tile or Entity to a chunk

---
 src/pocketmine/level/format/Chunk.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/pocketmine/level/format/Chunk.php b/src/pocketmine/level/format/Chunk.php
index 9f47296cf..00db9a89c 100644
--- a/src/pocketmine/level/format/Chunk.php
+++ b/src/pocketmine/level/format/Chunk.php
@@ -568,6 +568,9 @@ class Chunk{
 	 * @param Entity $entity
 	 */
 	public function addEntity(Entity $entity){
+		if($entity->closed){
+			throw new \InvalidArgumentException("Attempted to add a garbage closed Entity to a chunk");
+		}
 		$this->entities[$entity->getId()] = $entity;
 		if(!($entity instanceof Player) and $this->isInit){
 			$this->hasChanged = true;
@@ -588,6 +591,9 @@ class Chunk{
 	 * @param Tile $tile
 	 */
 	public function addTile(Tile $tile){
+		if($tile->closed){
+			throw new \InvalidArgumentException("Attempted to add a garbage closed Tile to a chunk");
+		}
 		$this->tiles[$tile->getId()] = $tile;
 		if(isset($this->tileList[$index = (($tile->x & 0x0f) << 12) | (($tile->z & 0x0f) << 8) | ($tile->y & 0xff)]) and $this->tileList[$index] !== $tile){
 			$this->tileList[$index]->close();

From d2efcee115e9edac8c200a9169edfba656ad2c8c Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Tue, 18 Apr 2017 14:47:42 +0100
Subject: [PATCH 2/2] Fixed tiles and entities being closed when replacing
 chunks, should fix #490

---
 src/pocketmine/level/Level.php | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/pocketmine/level/Level.php b/src/pocketmine/level/Level.php
index 8e480d712..44e27894b 100644
--- a/src/pocketmine/level/Level.php
+++ b/src/pocketmine/level/Level.php
@@ -2228,18 +2228,20 @@ class Level implements ChunkManager, Metadatable{
 			$oldEntities = $oldChunk !== null ? $oldChunk->getEntities() : [];
 			$oldTiles = $oldChunk !== null ? $oldChunk->getTiles() : [];
 
-			$this->provider->setChunk($chunkX, $chunkZ, $chunk);
-			$this->chunks[$index] = $chunk;
-
 			foreach($oldEntities as $entity){
 				$chunk->addEntity($entity);
+				$oldChunk->removeEntity($entity);
 				$entity->chunk = $chunk;
 			}
 
 			foreach($oldTiles as $tile){
 				$chunk->addTile($tile);
+				$oldChunk->removeTile($tile);
 				$tile->chunk = $chunk;
 			}
+
+			$this->provider->setChunk($chunkX, $chunkZ, $chunk);
+			$this->chunks[$index] = $chunk;
 		}
 
 		unset($this->chunkCache[$index]);