From 5a1131d72d718383e53a7c654631dd4cd051fdeb Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <dktapps@pmmp.io>
Date: Wed, 27 Jan 2021 21:08:46 +0000
Subject: [PATCH] Populator: require dependencies explicitly, don't make bad
 assumptions about fields this also leaks ChunkManagers on the worker threads
 because the generator context is long-lived.

---
 src/world/generator/populator/TallGrass.php | 19 ++++++++-----------
 src/world/generator/populator/Tree.php      | 11 ++++-------
 2 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/src/world/generator/populator/TallGrass.php b/src/world/generator/populator/TallGrass.php
index 30a1d8135e..2c2667f8ca 100644
--- a/src/world/generator/populator/TallGrass.php
+++ b/src/world/generator/populator/TallGrass.php
@@ -29,8 +29,6 @@ use pocketmine\utils\Random;
 use pocketmine\world\ChunkManager;
 
 class TallGrass extends Populator{
-	/** @var ChunkManager */
-	private $world;
 	/** @var int */
 	private $randomAmount = 1;
 	/** @var int */
@@ -45,29 +43,28 @@ class TallGrass extends Populator{
 	}
 
 	public function populate(ChunkManager $world, int $chunkX, int $chunkZ, Random $random) : void{
-		$this->world = $world;
 		$amount = $random->nextRange(0, $this->randomAmount) + $this->baseAmount;
 
 		$block = VanillaBlocks::TALL_GRASS();
 		for($i = 0; $i < $amount; ++$i){
 			$x = $random->nextRange($chunkX * 16, $chunkX * 16 + 15);
 			$z = $random->nextRange($chunkZ * 16, $chunkZ * 16 + 15);
-			$y = $this->getHighestWorkableBlock($x, $z);
+			$y = $this->getHighestWorkableBlock($world, $x, $z);
 
-			if($y !== -1 and $this->canTallGrassStay($x, $y, $z)){
-				$this->world->setBlockAt($x, $y, $z, $block);
+			if($y !== -1 and $this->canTallGrassStay($world, $x, $y, $z)){
+				$world->setBlockAt($x, $y, $z, $block);
 			}
 		}
 	}
 
-	private function canTallGrassStay(int $x, int $y, int $z) : bool{
-		$b = $this->world->getBlockAt($x, $y, $z)->getId();
-		return ($b === BlockLegacyIds::AIR or $b === BlockLegacyIds::SNOW_LAYER) and $this->world->getBlockAt($x, $y - 1, $z)->getId() === BlockLegacyIds::GRASS;
+	private function canTallGrassStay(ChunkManager $world, int $x, int $y, int $z) : bool{
+		$b = $world->getBlockAt($x, $y, $z)->getId();
+		return ($b === BlockLegacyIds::AIR or $b === BlockLegacyIds::SNOW_LAYER) and $world->getBlockAt($x, $y - 1, $z)->getId() === BlockLegacyIds::GRASS;
 	}
 
-	private function getHighestWorkableBlock(int $x, int $z) : int{
+	private function getHighestWorkableBlock(ChunkManager $world, int $x, int $z) : int{
 		for($y = 127; $y >= 0; --$y){
-			$b = $this->world->getBlockAt($x, $y, $z)->getId();
+			$b = $world->getBlockAt($x, $y, $z)->getId();
 			if($b !== BlockLegacyIds::AIR and $b !== BlockLegacyIds::LEAVES and $b !== BlockLegacyIds::LEAVES2 and $b !== BlockLegacyIds::SNOW_LAYER){
 				return $y + 1;
 			}
diff --git a/src/world/generator/populator/Tree.php b/src/world/generator/populator/Tree.php
index 8680e0d51f..2e1df68d65 100644
--- a/src/world/generator/populator/Tree.php
+++ b/src/world/generator/populator/Tree.php
@@ -30,8 +30,6 @@ use pocketmine\world\ChunkManager;
 use pocketmine\world\generator\object\Tree as ObjectTree;
 
 class Tree extends Populator{
-	/** @var ChunkManager */
-	private $world;
 	/** @var int */
 	private $randomAmount = 1;
 	/** @var int */
@@ -56,22 +54,21 @@ class Tree extends Populator{
 	}
 
 	public function populate(ChunkManager $world, int $chunkX, int $chunkZ, Random $random) : void{
-		$this->world = $world;
 		$amount = $random->nextRange(0, $this->randomAmount) + $this->baseAmount;
 		for($i = 0; $i < $amount; ++$i){
 			$x = $random->nextRange($chunkX << 4, ($chunkX << 4) + 15);
 			$z = $random->nextRange($chunkZ << 4, ($chunkZ << 4) + 15);
-			$y = $this->getHighestWorkableBlock($x, $z);
+			$y = $this->getHighestWorkableBlock($world, $x, $z);
 			if($y === -1){
 				continue;
 			}
-			ObjectTree::growTree($this->world, $x, $y, $z, $random, $this->type);
+			ObjectTree::growTree($world, $x, $y, $z, $random, $this->type);
 		}
 	}
 
-	private function getHighestWorkableBlock(int $x, int $z) : int{
+	private function getHighestWorkableBlock(ChunkManager $world, int $x, int $z) : int{
 		for($y = 127; $y >= 0; --$y){
-			$b = $this->world->getBlockAt($x, $y, $z)->getId();
+			$b = $world->getBlockAt($x, $y, $z)->getId();
 			if($b === BlockLegacyIds::DIRT or $b === BlockLegacyIds::GRASS){
 				return $y + 1;
 			}elseif($b !== BlockLegacyIds::AIR and $b !== BlockLegacyIds::SNOW_LAYER){