Release 3.15.2

this shouldn't ever be triggered, but we want to know if it does.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,11 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Help & support on Discord
+    url: https://discord.gg/bmSAZBG
+    about: We don't accept support requests on the issue tracker. Please try asking on Discord instead.
+  - name: Help & support on forums
+    url: https://forums.pmmp.io
+    about: We don't accept support requests on the issue tracker. Please try asking on forums instead.
+  - name: Documentation
+    url: https://pmmp.rtfd.io
+    about: PocketMine-MP documentation

.github/ISSUE_TEMPLATE/help---support.md

@@ -1,14 +0,0 @@
----
-name: Help & support
-about: We don't accept support requests here. Try the links on the README.
-title: ''
-labels: Support request
-assignees: ''
-
----
-
-We don't accept support requests on the issue tracker. Please try the following links instead:
-
-Documentation: http://pmmp.rtfd.io
-Forums: https://forums.pmmp.io
-Discord: https://discord.gg/bmSAZBG

.github/ISSUE_TEMPLATE/security-dos-vulnerability.md

@@ -1,12 +0,0 @@
----
-name: Security/DoS vulnerability
-about: 'Bug or exploit that can be used to attack servers (hint: don''t report it
-  on a public issue tracker)'
-title: ''
-labels: 'Auto: Spam'
-assignees: ''
-
----
-
-Please DO NOT report security vulnerabilities here.
-Instead, send an email to team@pmmp.io or contact a developer directly, IN PRIVATE.

.gitmodules

@@ -1,12 +1,12 @@
 [submodule "src/pocketmine/lang/locale"]
 	path = src/pocketmine/lang/locale
-	url = https://github.com/pmmp/PocketMine-Language.git
+	url = https://github.com/pmmp/Language.git
 [submodule "tests/preprocessor"]
 	path = build/preprocessor
 	url = https://github.com/pmmp/preprocessor.git
-[submodule "tests/plugins/PocketMine-DevTools"]
-	path = tests/plugins/PocketMine-DevTools
-	url = https://github.com/pmmp/PocketMine-DevTools.git
+[submodule "tests/plugins/DevTools"]
+	path = tests/plugins/DevTools
+	url = https://github.com/pmmp/DevTools.git
 [submodule "build/php"]
 	path = build/php
 	url = https://github.com/pmmp/php-build-scripts.git

.travis.yml

@@ -1,20 +1,5 @@
-language: php
-
-php:
- - 7.3
-
-before_script:
- - phpenv config-rm xdebug.ini
- - echo | pecl install channel://pecl.php.net/yaml-2.1.0
- - git clone https://github.com/pmmp/pthreads.git
- - cd pthreads
- - git checkout 646dac62ae0d48c1ada7b007e15575fb84f7d71d
- - phpize
- - ./configure
- - make
- - make install
- - cd ..
- - echo "extension=pthreads.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
+import:
+ source: ./tests/travis/setup-php.yml
 
 script:
  - composer install --prefer-dist
@@ -29,4 +14,8 @@ cache:
   - $HOME/.composer/cache/vcs
 
 notifications:
- email: false
+ email:
+  recipients:
+   - team@pmmp.io
+  on_success: change
+  on_failure: always

CONTRIBUTING.md

@@ -116,7 +116,7 @@ class ExampleClass{
 <!-- TODO: RFC and voting on the forums instead -->
 ### RFC and Voting
 * These are big Pull Requests or contributions that change important behavior.
-* RFCs will be tagged with the *PR: RFC* label
+* RFCs will be tagged with the *Type: Request For Comments* label
 * A vote will be held once the RFC is ready. All users can vote commenting on the Pull Request
 * Comments MUST use "Yes" or "No" on the FIRST sentence to signify the vote, except when they don't want it to be counted.
 * If your comment is a voting comment, specify the reason of your vote or it won't be counted.

README.md

@@ -3,7 +3,7 @@
 	<b>A highly customisable, open source server software for Minecraft: Bedrock Edition written in PHP</b>
 </p>
 
-[![Build Status](https://travis-ci.org/pmmp/PocketMine-MP.svg?branch=master)](https://travis-ci.org/pmmp/PocketMine-MP)
+[![Build Status](https://travis-ci.com/pmmp/PocketMine-MP.svg?branch=master)](https://travis-ci.com/pmmp/PocketMine-MP)
 
 ## Getting started
 - [Documentation](http://pmmp.readthedocs.org/)
@@ -19,7 +19,7 @@
 ## For developers
  * [Building and running from source](BUILDING.md)
  * [Latest API documentation](https://jenkins.pmmp.io/job/PocketMine-MP-doc/doxygen/) - Doxygen documentation generated from development
- * [DevTools](https://github.com/pmmp/PocketMine-DevTools/) - Development tools plugin for creating plugins
+ * [DevTools](https://github.com/pmmp/DevTools/) - Development tools plugin for creating plugins
  * [ExamplePlugin](https://github.com/pmmp/ExamplePlugin/) - Example plugin demonstrating some basic API features
  * [Contributing Guidelines](CONTRIBUTING.md)
 

SECURITY.md

@@ -0,0 +1,33 @@
+# Security Policy
+
+## Supported Versions
+The following release lines are currently receiving active security updates and bug fixes:
+
+| Version  | Supported          |
+| -------- | ------------------ |
+| 3.15.x   | :white_check_mark: |
+| < 3.15.0 | :x:                |
+
+## Reporting a Vulnerability
+
+**DO NOT report vulnerabilities on the GitHub issue tracker.**
+GitHub is public and anyone can see the issues you post on the issue tracker, including people who would exploit vulnerabilities for their own gain.
+
+**WARNING: You may put live servers at risk by reporting a vulnerability on the GitHub issue tracker.**
+
+**Contact us** by sending an email to [**team@pmmp.io**](mailto:team@pmmp.io?subject=Security%20Vulnerability%20in%20PocketMine-MP). Include the following information:
+
+- Version of PocketMine-MP
+- Detailed description of the vulnerability (e.g. how to exploit it, what the effects are)
+
+Please note that we can't guarantee a reply to every email.
+
+## FAQ
+### Do you offer a bug bounty?
+No.
+
+### How soon can I expect a fix for a vulnerability I've reported?
+This depends on the nature of the problem. We can't provide any general ETA (nor would it be wise to provide one).
+In general, it depends on when developers have time to look into the problem, how complex the problem is to fix, and how many users it impacts.
+
+When a fix for a severe vulnerability is pushed, a patch release for the target version will usually be released within 24 hours so that users can update.

build/server-phar.php

@@ -49,7 +49,7 @@ require dirname(__DIR__) . '/vendor/autoload.php';
  *
  * @return string[]
  */
-function preg_quote_array(array $strings, string $delim = null) : array{
+function preg_quote_array(array $strings, string $delim) : array{
 	return array_map(function(string $str) use ($delim) : string{ return preg_quote($str, $delim); }, $strings);
 }
 

changelogs/3.12.md

@@ -50,4 +50,9 @@ Plugin developers should **only** update their required API to this version if y
 - Fixed absorption hearts not being consumed.
 
 # 3.12.5
-- Fixed broken attack cooldowns.
+- Fixed broken attack cooldowns.
+
+# 3.12.6
+- Fixed entities not getting movement updates after teleports.
+- Fixed slow flight in spectator mode when starting from the ground and after teleportation.
+- Errors communicating with the crash archive on automatic crash submission are now logged.

changelogs/3.13.md

@@ -109,3 +109,23 @@ AsyncTask thread-local storage has been improved, making it simpler and easier t
   - `Utils::recursiveUnlink()`
   - `Terminal::write()`
   - `Terminal::writeLine()`
+
+# 3.13.1
+- Fixed issues with `server.lock` not being unlocked on some platforms. Now, the server explicitly releases it before exiting.
+- `/timings` now sends a usage message when using an unknown subcommand. Previously, it would just give no output.
+- `/whitelist` now sends a usage message when using an unknown subcommand. Previously, it would just give no output.
+- The output from `/timings` is now broadcasted on the `pocketmine.broadcast.admin` broadcast channel for auditability, similarly to other operator commands.
+- Fixed `ShapedRecipe` deprecation warning on PHP 7.4.
+- Fixed some potential crashes with Bedrock worlds when chunk data is corrupted or missing.
+- Fixed a bug in region handling that caused region loaders to overestimate the amount of space used in the file. This resulted in an up to 4 MB growth of the file size every time the region was reloaded after writing a chunk.
+- Region handlers now try to reuse free space in region files before putting the chunk at the end of the file. Previously, space was only reused if the new version of the chunk was <= the size of the old. This fixes endless growth of region files.
+- Regions now never directly overwrite old copies of chunks when saving; instead they try to find an alternative location (preferring unused space within the file first). This avoids chunk corruption on power failure (the old copy of the chunk won't be damaged, so a rollback might occur instead), and as happy side effect, causes oversized regions to gradually shrink towards their most packed state over time, saving disk space.
+- Regions now have a hard size cap at 64 GB. This is because the header pointers will overflow beyond 64 GB (besides, a normal region shouldn't be this big anyway).
+- Fixed a crash that could occur when reading a too-short region header.
+- `VerifyLoginTask` now only copies JWTs to verify instead of the entire login packet. This reduces the amount of data copied between threads, improving performance.
+- Added a fast-fail check to `VerifyLoginTask` by checking the JWT header's `x5u` against the expected public key.
+- `Skin->validate()` now throws `InvalidSkinException` instead of `\InvalidArgumentException`.
+- A debug message is now logged when a player is kicked for having an invalid skin, giving a brief line of detail why.
+- Fixed players not being kicked for having an invalid `resourcePatch`.
+- Fixed block meta value of cake being preserved when using pick-block.
+- Fixed explosions not fully destroying multi-block objects like beds and doors.

changelogs/3.14.md

@@ -0,0 +1,40 @@
+**For Minecraft: Bedrock Edition 1.16.0**
+
+### Note about API versions
+Plugins which don't touch the protocol and compatible with any previous 3.x.y version will also run on these releases and do not need API bumps.
+Plugin developers should **only** update their required API to this version if you need the changes in this build.
+
+**WARNING: If your plugin uses the protocol, you're not shielded by API change constraints.** You should consider using the `mcpe-protocol` directive in `plugin.yml` as a constraint if you do.
+
+# 3.14.0
+- Added support for Minecraft: Bedrock Edition 1.16.0.
+- Removed compatibility with 1.14.60.
+
+## Known issues (please don't open issues for these)
+- Walls don't connect to each other
+- Pumpkin and melon stems may not connect to their corresponding pumpkin/melon
+- New blocks, items & mobs aren't implemented
+- Nether doesn't exist
+
+# 3.14.1
+- All skins are now trusted, bypassing the client-side trusted skin setting. Note that this means that NSFW skin filtering will **not** apply.
+- Fixed projectile motion being altered by ladders.
+- Fixed client-sided crashes when pressing E repeatedly very quickly on a high-latency connection.
+- `/plugins`, `/whitelist list`, `/banlist` and `/list` now show output in alphabetical order.
+- Some `pocketmine\event` APIs which accept arrays now have more robust type checking, fixing type errors caused by plugin input occurring in core code.
+- `Attribute::getAttributeByName()` is now aware of the `minecraft:lava_movement` attribute.
+
+# 3.14.2
+- Exception stack traces are now logged as CRITICAL. It's hoped that users will recognize that they are just as important as the error message and not leave them out when asking for help with errors on Discord.
+- `TaskScheduler` no longer accepts tasks that already have a handler. This fixes undefined behaviour which occurs when scheduling the same task instance twice, but it does break plugins such as **MyPlot** which unintentionally used this buggy behaviour.
+- Players will now correctly receive the needed number of spawn chunks if they are teleported between `PlayerLoginEvent` and `PlayerJoinEvent`. This fixes a bug that could occur when teleporting players in delayed tasks between login and join.
+- `PlayerRespawnEvent->setRespawnPosition()` now throws an exception if the provided `Position` has an invalid world associated with it (null or unloaded).
+- Fixed a crash that occurred when stats reporting was enabled.
+
+# 3.14.3
+- Fixed deprecation error when running `/whitelist list` on PHP 7.4.
+- Fixed podzol breaking animation being incorrect (incorrect hardness).
+- `Entity::getSaveId()` now reports the class name in the message thrown for unregistered entities.
+- Fixed `CraftingManager->validate()` producing different results when called multiple times for the same transaction.
+- Fixed various issues with batch-crafting items using the recipe book and shift-clicking.
+- `tests/plugins/PocketMine-DevTools` submodule has been renamed to `tests/plugins/DevTools`.

changelogs/3.15.md

@@ -0,0 +1,34 @@
+**For Minecraft: Bedrock Edition 1.16.20**
+
+### Note about API versions
+Plugins which don't touch the protocol and compatible with any previous 3.x.y version will also run on these releases and do not need API bumps.
+Plugin developers should **only** update their required API to this version if you need the changes in this build.
+
+**WARNING: If your plugin uses the protocol, you're not shielded by API change constraints.** You should consider using the `mcpe-protocol` directive in `plugin.yml` as a constraint if you do.
+
+# 3.15.0
+- Added support for Minecraft: Bedrock Edition 1.16.20.
+- Removed compatibility with 1.16.0.
+
+## Known issues (please don't open issues for these)
+- Walls don't connect to each other
+- Pumpkin and melon stems may not connect to their corresponding pumpkin/melon
+- New blocks, items & mobs aren't implemented
+- Nether doesn't exist
+
+# 3.15.1
+- Fixed various PHP 7.4 compatibility issues in Composer dependencies (primarily callback-validator).
+- Fixed LevelDB worlds with corrupted `level.dat` crashing the server instead of failing gracefully.
+- Fixed error spam when using strings for layers in flatworld presets (`e.g. bedrock,3xdirt,grass`).
+- Fixed blocks not getting updated properly on explosions.
+- Fixed `BlockGrowEvent` not being called when sugarcane grows.
+- Potato crops now drop poisonous potatoes when harvested.
+- Fixed the wrong number of potatoes being dropped when harvesting potato crops.
+- Players no longer get pullbacks when sprinting on slabs, stairs and various other blocks when `player.anti-cheat.allow-movement-cheats` is set to `false`. (This bug has been around for over 5 years, so many of you will be used to its existence.)
+- Fixed entity collision box calculation not taking clip distance into account.
+- Entities now step up the correct height of the target block, instead of jumping into the air 0.6 blocks and falling back down.
+
+# 3.15.2
+- Fixed issues with preloading `SubChunk`.
+- `/gc` and automatic garbage collection will now release unused heap blocks back to the OS. Previously, the PHP process might hold onto these blocks indefinitely even when not used, causing elevated real memory usage.
+- Added some documentation to `FurnaceBurnEvent`.

composer.json

@@ -33,15 +33,15 @@
       "pocketmine/classloader": "^0.1.0",
       "pocketmine/log": "^0.2.0",
       "pocketmine/log-pthreads": "^0.1.0",
-      "pocketmine/callback-validator": "^1.0.1",
+      "pocketmine/callback-validator": "^1.0.2",
       "adhocore/json-comment": "^0.1.0",
       "ocramius/package-versions": "^1.5"
    },
    "require-dev": {
-      "phpstan/phpstan": "^0.12.25",
+      "phpstan/phpstan": "0.12.48",
       "phpstan/phpstan-phpunit": "^0.12.6",
       "phpstan/phpstan-strict-rules": "^0.12.2",
-      "phpunit/phpunit": "^8.5"
+      "phpunit/phpunit": "^9.2"
    },
    "autoload": {
       "psr-4": {
@@ -57,5 +57,10 @@
       "psr-4": {
          "pocketmine\\": "tests/phpunit/"
       }
+   },
+   "config": {
+      "platform": {
+         "php": "7.3.0"
+      }
    }
 }

doxygen/index.md

@@ -5,6 +5,6 @@ This site contains auto-generated API documentation for PocketMine-MP (and depen
 This site can be accessed via https://apidoc.pmmp.io.
 
 ### Additional developer resources
- - [DevTools](https://github.com/pmmp/PocketMine-DevTools/) - Development tools plugin for creating plugins
+ - [DevTools](https://github.com/pmmp/DevTools/) - Development tools plugin for creating plugins
  - [ExamplePlugin](https://github.com/pmmp/ExamplePlugin/) - Example plugin demonstrating some basic API features
  - [DeveloperDocs](https://github.com/pmmp/DeveloperDocs/) - Reference, guides and specifications for the PocketMine-MP API

phpstan.neon.dist

@@ -1,5 +1,6 @@
 includes:
 	- tests/phpstan/configs/actual-problems.neon
+	- tests/phpstan/configs/check-explicit-mixed-baseline.neon
 	- tests/phpstan/configs/com-dotnet-magic.neon
 	- tests/phpstan/configs/custom-leveldb.neon
 	- tests/phpstan/configs/gc-hacks.neon
@@ -16,8 +17,12 @@ includes:
 
 parameters:
 	level: 8
-	autoload_files:
+	checkExplicitMixed: true
+	bootstrapFiles:
 		- tests/phpstan/bootstrap.php
+	scanDirectories:
+	    - tests/plugins/TesterPlugin
+	scanFiles:
 		- src/pocketmine/PocketMine.php
 		- build/make-release.php
 		- build/server-phar.php
@@ -26,12 +31,14 @@ parameters:
 		- build/make-release.php
 		- build/server-phar.php
 		- tests/phpunit
+		- tests/plugins/TesterPlugin
 	dynamicConstantNames:
 		- pocketmine\IS_DEVELOPMENT_BUILD
 		- pocketmine\DEBUG
 	stubFiles:
 		- tests/phpstan/stubs/pthreads.stub
 		- tests/phpstan/stubs/chunkutils.stub
+		- tests/phpstan/stubs/leveldb.stub
 	reportUnmatchedIgnoredErrors: false #no other way to silence platform-specific non-warnings
 	staticReflectionClassNamePatterns:
 		- "#^COM$#"

src/pocketmine/MemoryManager.php

@@ -40,6 +40,7 @@ use function fwrite;
 use function gc_collect_cycles;
 use function gc_disable;
 use function gc_enable;
+use function gc_mem_caches;
 use function get_class;
 use function get_declared_classes;
 use function implode;
@@ -50,6 +51,7 @@ use function is_object;
 use function is_resource;
 use function is_string;
 use function json_encode;
+use function mb_strtoupper;
 use function min;
 use function mkdir;
 use function preg_match;
@@ -58,7 +60,6 @@ use function round;
 use function spl_object_hash;
 use function sprintf;
 use function strlen;
-use function strtoupper;
 use function substr;
 use const JSON_PRETTY_PRINT;
 use const JSON_UNESCAPED_SLASHES;
@@ -127,7 +128,7 @@ class MemoryManager{
 			if($m <= 0){
 				$defaultMemory = 0;
 			}else{
-				switch(strtoupper($matches[2])){
+				switch(mb_strtoupper($matches[2])){
 					case "K":
 						$defaultMemory = $m / 1024;
 						break;
@@ -273,6 +274,7 @@ class MemoryManager{
 		}
 
 		$cycles = gc_collect_cycles();
+		gc_mem_caches();
 
 		Timings::$garbageCollectorTimer->stopTiming();
 

src/pocketmine/Player.php

@@ -33,6 +33,7 @@ use pocketmine\entity\Effect;
 use pocketmine\entity\EffectInstance;
 use pocketmine\entity\Entity;
 use pocketmine\entity\Human;
+use pocketmine\entity\InvalidSkinException;
 use pocketmine\entity\object\ItemEntity;
 use pocketmine\entity\projectile\Arrow;
 use pocketmine\entity\Skin;
@@ -112,6 +113,7 @@ use pocketmine\network\mcpe\protocol\BlockPickRequestPacket;
 use pocketmine\network\mcpe\protocol\BookEditPacket;
 use pocketmine\network\mcpe\protocol\ChunkRadiusUpdatedPacket;
 use pocketmine\network\mcpe\protocol\ContainerClosePacket;
+use pocketmine\network\mcpe\protocol\ContainerOpenPacket;
 use pocketmine\network\mcpe\protocol\DataPacket;
 use pocketmine\network\mcpe\protocol\DisconnectPacket;
 use pocketmine\network\mcpe\protocol\InteractPacket;
@@ -147,6 +149,8 @@ use pocketmine\network\mcpe\protocol\types\CommandParameter;
 use pocketmine\network\mcpe\protocol\types\ContainerIds;
 use pocketmine\network\mcpe\protocol\types\DimensionIds;
 use pocketmine\network\mcpe\protocol\types\GameMode;
+use pocketmine\network\mcpe\protocol\types\inventory\UIInventorySlotOffset;
+use pocketmine\network\mcpe\protocol\types\NetworkInventoryAction;
 use pocketmine\network\mcpe\protocol\types\PersonaPieceTintColor;
 use pocketmine\network\mcpe\protocol\types\PersonaSkinPiece;
 use pocketmine\network\mcpe\protocol\types\PlayerPermissions;
@@ -154,6 +158,8 @@ use pocketmine\network\mcpe\protocol\types\SkinAdapterSingleton;
 use pocketmine\network\mcpe\protocol\types\SkinAnimation;
 use pocketmine\network\mcpe\protocol\types\SkinData;
 use pocketmine\network\mcpe\protocol\types\SkinImage;
+use pocketmine\network\mcpe\protocol\types\SpawnSettings;
+use pocketmine\network\mcpe\protocol\types\WindowTypes;
 use pocketmine\network\mcpe\protocol\UpdateAttributesPacket;
 use pocketmine\network\mcpe\protocol\UpdateBlockPacket;
 use pocketmine\network\mcpe\VerifyLoginTask;
@@ -171,7 +177,9 @@ use pocketmine\timings\Timings;
 use pocketmine\utils\TextFormat;
 use pocketmine\utils\UUID;
 use function abs;
+use function array_key_exists;
 use function array_merge;
+use function array_values;
 use function assert;
 use function base64_decode;
 use function ceil;
@@ -222,6 +230,14 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 
 	private const RESOURCE_PACK_CHUNK_SIZE = 128 * 1024; //128KB
 
+	//TODO: HACK!
+	//these IDs are used for 1.16 to restore 1.14ish crafting & inventory behaviour; since they don't seem to have any
+	//effect on the behaviour of inventory transactions I don't currently plan to integrate these into the main system.
+	private const RESERVED_WINDOW_ID_RANGE_START = ContainerIds::LAST - 10;
+	private const RESERVED_WINDOW_ID_RANGE_END = ContainerIds::LAST;
+	public const HARDCODED_CRAFTING_GRID_WINDOW_ID = self::RESERVED_WINDOW_ID_RANGE_START + 1;
+	public const HARDCODED_INVENTORY_WINDOW_ID = self::RESERVED_WINDOW_ID_RANGE_START + 2;
+
 	/**
 	 * Validates the given username.
 	 */
@@ -301,6 +317,15 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	/** @var CraftingTransaction|null */
 	protected $craftingTransaction = null;
 
+	/**
+	 * TODO: HACK! This tracks GUIs for inventories that the server considers "always open" so that the client can't
+	 * open them twice. (1.16 hack)
+	 * @var true[]
+	 * @phpstan-var array<int, true>
+	 * @internal
+	 */
+	public $openHardcodedWindows = [];
+
 	/** @var int */
 	protected $messageCounter = 2;
 	/** @var bool */
@@ -742,7 +767,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 				}
 				$data->aliases = new CommandEnum();
 				$data->aliases->enumName = ucfirst($command->getName()) . "Aliases";
-				$data->aliases->enumValues = $aliases;
+				$data->aliases->enumValues = array_values($aliases);
 			}
 
 			$pk->commandData[$command->getName()] = $data;
@@ -1227,11 +1252,12 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 		}
 		$this->spawnPosition = new Position($pos->x, $pos->y, $pos->z, $level);
 		$pk = new SetSpawnPositionPacket();
-		$pk->x = $this->spawnPosition->getFloorX();
-		$pk->y = $this->spawnPosition->getFloorY();
-		$pk->z = $this->spawnPosition->getFloorZ();
+		$pk->x = $pk->x2 = $this->spawnPosition->getFloorX();
+		$pk->y = $pk->y2 = $this->spawnPosition->getFloorY();
+		$pk->z = $pk->z2 = $this->spawnPosition->getFloorZ();
+		$pk->dimension = DimensionIds::OVERWORLD;
 		$pk->spawnType = SetSpawnPositionPacket::TYPE_PLAYER_SPAWN;
-		$pk->spawnForced = false;
+
 		$this->dataPacket($pk);
 	}
 
@@ -1575,10 +1601,15 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			$dy = $newPos->y - $this->y;
 			$dz = $newPos->z - $this->z;
 
+			//the client likes to clip into blocks like stairs, but we do full server-side prediction of that without
+			//help from the client's position changes, so we deduct the expected clip height from the moved distance.
+			$expectedClipDistance = $this->ySize * (1 - self::STEP_CLIP_MULTIPLIER);
+			$dy -= $expectedClipDistance;
 			$this->move($dx, $dy, $dz);
 
 			$diff = $this->distanceSquared($newPos);
 
+			//TODO: Explore lowering this threshold now that stairs work properly.
 			if($this->isSurvival() and $diff > 0.0625){
 				$ev = new PlayerIllegalMoveEvent($this, $newPos, new Vector3($this->lastX, $this->lastY, $this->lastZ));
 				$ev->setCancelled($this->allowMovementCheats);
@@ -1588,7 +1619,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 				if(!$ev->isCancelled()){
 					$revert = true;
 					$this->server->getLogger()->debug($this->getServer()->getLanguage()->translateString("pocketmine.player.invalidMove", [$this->getName()]));
-					$this->server->getLogger()->debug("Old position: " . $this->asVector3() . ", new position: " . $newPos);
+					$this->server->getLogger()->debug("Old position: " . $this->asVector3() . ", new position: " . $newPos . ", expected clip distance: $expectedClipDistance");
 				}
 			}
 
@@ -1872,7 +1903,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			}
 
 			//This pocketmine disconnect message will only be seen by the console (PlayStatusPacket causes the messages to be shown for the client)
-			$this->close("", $this->server->getLanguage()->translateString("pocketmine.disconnect.incompatibleProtocol", [$packet->protocol ?? "unknown"]), false);
+			$this->close("", $this->server->getLanguage()->translateString("pocketmine.disconnect.incompatibleProtocol", [$packet->protocol]), false);
 
 			return true;
 		}
@@ -1956,9 +1987,11 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			true
 		);
 
-		$skin = SkinAdapterSingleton::get()->fromSkinData($skinData);
-
-		if(!$skin->isValid()){
+		try{
+			$skin = SkinAdapterSingleton::get()->fromSkinData($skinData);
+			$skin->validate();
+		}catch(InvalidSkinException $e){
+			$this->server->getLogger()->debug("$this->username: Invalid skin: " . $e->getMessage());
 			$this->close("", "disconnectionScreen.invalidSkin");
 
 			return true;
@@ -2197,7 +2230,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 		$pk->pitch = $this->pitch;
 		$pk->yaw = $this->yaw;
 		$pk->seed = -1;
-		$pk->dimension = DimensionIds::OVERWORLD; //TODO: implement this properly
+		$pk->spawnSettings = new SpawnSettings(SpawnSettings::BIOME_TYPE_DEFAULT, "", DimensionIds::OVERWORLD); //TODO: implement this properly
 		$pk->worldGamemode = Player::getClientFriendlyGamemode($this->server->getGamemode());
 		$pk->difficulty = $this->level->getDifficulty();
 		$pk->spawnX = $spawnPosition->getFloorX();
@@ -2364,7 +2397,22 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 
 		/** @var InventoryAction[] $actions */
 		$actions = [];
+		$isCraftingPart = false;
 		foreach($packet->actions as $networkInventoryAction){
+			if(
+				$networkInventoryAction->sourceType === NetworkInventoryAction::SOURCE_TODO and (
+					$networkInventoryAction->windowId === NetworkInventoryAction::SOURCE_TYPE_CRAFTING_RESULT or
+					$networkInventoryAction->windowId === NetworkInventoryAction::SOURCE_TYPE_CRAFTING_USE_INGREDIENT
+				) or (
+					$this->craftingTransaction !== null &&
+					!$networkInventoryAction->oldItem->equalsExact($networkInventoryAction->newItem) &&
+					$networkInventoryAction->sourceType === NetworkInventoryAction::SOURCE_CONTAINER &&
+					$networkInventoryAction->windowId === ContainerIds::UI &&
+					$networkInventoryAction->inventorySlot === UIInventorySlotOffset::CREATED_ITEM_OUTPUT
+				)
+			){
+				$isCraftingPart = true;
+			}
 			try{
 				$action = $networkInventoryAction->createInventoryAction($this);
 				if($action !== null){
@@ -2377,7 +2425,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			}
 		}
 
-		if($packet->isCraftingPart){
+		if($isCraftingPart){
 			if($this->craftingTransaction === null){
 				$this->craftingTransaction = new CraftingTransaction($this, $actions);
 			}else{
@@ -2386,23 +2434,23 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 				}
 			}
 
-			if($packet->isFinalCraftingPart){
-				//we get the actions for this in several packets, so we need to wait until we have all the pieces before
-				//trying to execute it
-
-				$ret = true;
-				try{
-					$this->craftingTransaction->execute();
-				}catch(TransactionValidationException $e){
-					$this->server->getLogger()->debug("Failed to execute crafting transaction for " . $this->getName() . ": " . $e->getMessage());
-					$ret = false;
-				}
-
-				$this->craftingTransaction = null;
-				return $ret;
+			try{
+				$this->craftingTransaction->validate();
+			}catch(TransactionValidationException $e){
+				//transaction is incomplete - crafting transaction comes in lots of little bits, so we have to collect
+				//all of the parts before we can execute it
+				return true;
 			}
 
-			return true;
+			try{
+				$this->craftingTransaction->execute();
+				return true;
+			}catch(TransactionValidationException $e){
+				$this->server->getLogger()->debug("Failed to execute crafting transaction for " . $this->getName() . ": " . $e->getMessage());
+				return false;
+			}finally{
+				$this->craftingTransaction = null;
+			}
 		}elseif($this->craftingTransaction !== null){
 			$this->server->getLogger()->debug("Got unexpected normal inventory action with incomplete crafting transaction from " . $this->getName() . ", refusing to execute crafting");
 			$this->craftingTransaction = null;
@@ -2764,8 +2812,23 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			case InteractPacket::ACTION_LEAVE_VEHICLE:
 			case InteractPacket::ACTION_MOUSEOVER:
 				break; //TODO: handle these
+			case InteractPacket::ACTION_OPEN_INVENTORY:
+				if($target === $this && !array_key_exists($windowId = self::HARDCODED_INVENTORY_WINDOW_ID, $this->openHardcodedWindows)){
+					//TODO: HACK! this restores 1.14ish behaviour, but this should be able to be listened to and
+					//controlled by plugins. However, the player is always a subscriber to their own inventory so it
+					//doesn't integrate well with the regular container system right now.
+					$this->openHardcodedWindows[$windowId] = true;
+					$pk = new ContainerOpenPacket();
+					$pk->windowId = $windowId;
+					$pk->type = WindowTypes::INVENTORY;
+					$pk->x = $pk->y = $pk->z = 0;
+					$pk->entityUniqueId = $this->getId();
+					$this->sendDataPacket($pk);
+					break;
+				}
+				return false;
 			default:
-				$this->server->getLogger()->debug("Unhandled/unknown interaction type " . $packet->action . "received from " . $this->getName());
+				$this->server->getLogger()->debug("Unhandled/unknown interaction type " . $packet->action . " received from " . $this->getName());
 
 				return false;
 		}
@@ -2823,7 +2886,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 				$target = $this->level->getBlock($pos);
 
 				$ev = new PlayerInteractEvent($this, $this->inventory->getItemInHand(), $target, null, $packet->face, PlayerInteractEvent::LEFT_CLICK_BLOCK);
-				if($this->level->checkSpawnProtection($this, $target)){
+				if($this->isSpectator() || $this->level->checkSpawnProtection($this, $target)){
 					$ev->setCancelled();
 				}
 
@@ -2977,18 +3040,23 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	}
 
 	public function handleContainerClose(ContainerClosePacket $packet) : bool{
-		if(!$this->spawned or $packet->windowId === 0){
+		if(!$this->spawned){
 			return true;
 		}
 
 		$this->doCloseInventory();
 
+		if(array_key_exists($packet->windowId, $this->openHardcodedWindows)){
+			unset($this->openHardcodedWindows[$packet->windowId]);
+			$pk = new ContainerClosePacket();
+			$pk->windowId = $packet->windowId;
+			$this->sendDataPacket($pk);
+			return true;
+		}
 		if(isset($this->windowIndex[$packet->windowId])){
 			(new InventoryCloseEvent($this->windowIndex[$packet->windowId], $this))->call();
 			$this->removeWindow($this->windowIndex[$packet->windowId]);
-			return true;
-		}elseif($packet->windowId === 255){
-			//Closed a fake window
+			//removeWindow handles sending the appropriate
 			return true;
 		}
 
@@ -3514,14 +3582,15 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	 * Sends a Form to the player, or queue to send it if a form is already open.
 	 */
 	public function sendForm(Form $form) : void{
+		$formData = json_encode($form);
+		if($formData === false){
+			throw new \InvalidArgumentException("Failed to encode form JSON: " . json_last_error_msg());
+		}
 		$id = $this->formIdCounter++;
 		$pk = new ModalFormRequestPacket();
 		$pk->formId = $id;
-		$pk->formData = json_encode($form);
-		if($pk->formData === false){
-			throw new \InvalidArgumentException("Failed to encode form JSON: " . json_last_error_msg());
-		}
-		if($this->dataPacket($pk)){
+		$pk->formData = $formData;
+		if($this->dataPacket($pk) !== false){
 			$this->forms[$id] = $form;
 		}
 	}
@@ -3839,10 +3908,12 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 		if($targets !== null){
 			if(in_array($this, $targets, true)){
 				$this->forceMoveSync = $pos->asVector3();
+				$this->ySize = 0;
 			}
 			$this->server->broadcastPacket($targets, $pk);
 		}else{
 			$this->forceMoveSync = $pos->asVector3();
+			$this->ySize = 0;
 			$this->dataPacket($pk);
 		}
 	}
@@ -3862,6 +3933,9 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 
 			$this->resetFallDistance();
 			$this->nextChunkOrderRun = 0;
+			if($this->spawnChunkLoadCount !== -1){
+				$this->spawnChunkLoadCount = 0;
+			}
 			$this->stopSleep();
 
 			//TODO: workaround for player last pos not getting updated
@@ -3957,7 +4031,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 		if($forceId === null){
 			$cnt = $this->windowCnt;
 			do{
-				$cnt = max(ContainerIds::FIRST, ($cnt + 1) % ContainerIds::LAST);
+				$cnt = max(ContainerIds::FIRST, ($cnt + 1) % self::RESERVED_WINDOW_ID_RANGE_START);
 				if($cnt === $this->windowCnt){ //wraparound, no free slots
 					throw new \InvalidStateException("No free window IDs found");
 				}
@@ -3965,7 +4039,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			$this->windowCnt = $cnt;
 		}else{
 			$cnt = $forceId;
-			if(isset($this->windowIndex[$cnt])){
+			if(isset($this->windowIndex[$cnt]) or ($cnt >= self::RESERVED_WINDOW_ID_RANGE_START && $cnt <= self::RESERVED_WINDOW_ID_RANGE_END)){
 				throw new \InvalidArgumentException("Requested force ID $forceId already in use");
 			}
 		}

src/pocketmine/PocketMine.php

@@ -289,6 +289,14 @@ namespace pocketmine {
 
 		echo Terminal::$FORMAT_RESET . PHP_EOL;
 
+		if(!flock(\pocketmine\LOCK_FILE, LOCK_UN)){
+			critical_error("Failed to release the server.lock file.");
+		}
+
+		if(!fclose(\pocketmine\LOCK_FILE)){
+			critical_error("Could not close server.lock resource.");
+		}
+
 		exit($exitCode);
 	}
 

src/pocketmine/Server.php

@@ -693,29 +693,32 @@ class Server{
 		return $result;
 	}
 
+	private function getPlayerDataPath(string $username) : string{
+		return $this->getDataPath() . '/players/' . strtolower($username) . '.dat';
+	}
+
 	/**
 	 * Returns whether the server has stored any saved data for this player.
 	 */
 	public function hasOfflinePlayerData(string $name) : bool{
-		$name = strtolower($name);
-		return file_exists($this->getDataPath() . "players/$name.dat");
+		return file_exists($this->getPlayerDataPath($name));
 	}
 
 	public function getOfflinePlayerData(string $name) : CompoundTag{
 		$name = strtolower($name);
-		$path = $this->getDataPath() . "players/";
+		$path = $this->getPlayerDataPath($name);
 		if($this->shouldSavePlayerData()){
-			if(file_exists($path . "$name.dat")){
+			if(file_exists($path)){
 				try{
 					$nbt = new BigEndianNBTStream();
-					$compound = $nbt->readCompressed(file_get_contents($path . "$name.dat"));
+					$compound = $nbt->readCompressed(file_get_contents($path));
 					if(!($compound instanceof CompoundTag)){
 						throw new \RuntimeException("Invalid data found in \"$name.dat\", expected " . CompoundTag::class . ", got " . (is_object($compound) ? get_class($compound) : gettype($compound)));
 					}
 
 					return $compound;
 				}catch(\Throwable $e){ //zlib decode error / corrupt data
-					rename($path . "$name.dat", $path . "$name.dat.bak");
+					rename($path, $path . '.bak');
 					$this->logger->notice($this->getLanguage()->translateString("pocketmine.data.playerCorrupted", [$name]));
 				}
 			}else{
@@ -776,7 +779,7 @@ class Server{
 		if(!$ev->isCancelled()){
 			$nbt = new BigEndianNBTStream();
 			try{
-				file_put_contents($this->getDataPath() . "players/" . strtolower($name) . ".dat", $nbt->writeCompressed($ev->getSaveData()));
+				file_put_contents($this->getPlayerDataPath($name), $nbt->writeCompressed($ev->getSaveData()));
 			}catch(\Throwable $e){
 				$this->logger->critical($this->getLanguage()->translateString("pocketmine.data.saveError", [$name, $e->getMessage()]));
 				$this->logger->logException($e);

src/pocketmine/Thread.php

@@ -76,11 +76,9 @@ abstract class Thread extends \Thread{
 	}
 
 	/**
-	 * @param int|null $options TODO: pthreads bug
-	 *
 	 * @return bool
 	 */
-	public function start(?int $options = PTHREADS_INHERIT_ALL){
+	public function start(int $options = PTHREADS_INHERIT_ALL){
 		ThreadManager::getInstance()->add($this);
 
 		if($this->getClassLoader() === null){

src/pocketmine/VersionInfo.php

@@ -33,6 +33,6 @@ if(defined('pocketmine\_VERSION_INFO_INCLUDED')){
 const _VERSION_INFO_INCLUDED = true;
 
 const NAME = "PocketMine-MP";
-const BASE_VERSION = "3.13.0";
+const BASE_VERSION = "3.15.2";
 const IS_DEVELOPMENT_BUILD = false;
 const BUILD_NUMBER = 0;

src/pocketmine/Worker.php

@@ -76,11 +76,9 @@ abstract class Worker extends \Worker{
 	}
 
 	/**
-	 * @param int|null $options TODO: pthreads bug
-	 *
 	 * @return bool
 	 */
-	public function start(?int $options = PTHREADS_INHERIT_ALL){
+	public function start(int $options = PTHREADS_INHERIT_ALL){
 		ThreadManager::getInstance()->add($this);
 
 		if($this->getClassLoader() === null){

src/pocketmine/block/Block.php

@@ -36,7 +36,7 @@ use pocketmine\math\RayTraceResult;
 use pocketmine\math\Vector3;
 use pocketmine\metadata\Metadatable;
 use pocketmine\metadata\MetadataValue;
-use pocketmine\network\mcpe\protocol\types\RuntimeBlockMapping;
+use pocketmine\network\mcpe\convert\RuntimeBlockMapping;
 use pocketmine\Player;
 use pocketmine\plugin\Plugin;
 use function array_merge;

src/pocketmine/block/BlockFactory.php

@@ -25,7 +25,7 @@ namespace pocketmine\block;
 
 use pocketmine\item\Item;
 use pocketmine\level\Position;
-use pocketmine\network\mcpe\protocol\types\RuntimeBlockMapping;
+use pocketmine\network\mcpe\convert\RuntimeBlockMapping;
 use function min;
 
 /**

src/pocketmine/block/Cake.php

@@ -109,6 +109,10 @@ class Cake extends Transparent implements FoodSource{
 		return true;
 	}
 
+	public function getVariantBitmask() : int{
+		return 0;
+	}
+
 	/**
 	 * @return Block
 	 */

src/pocketmine/block/CraftingTable.php

@@ -25,7 +25,10 @@ namespace pocketmine\block;
 
 use pocketmine\inventory\CraftingGrid;
 use pocketmine\item\Item;
+use pocketmine\network\mcpe\protocol\ContainerOpenPacket;
+use pocketmine\network\mcpe\protocol\types\WindowTypes;
 use pocketmine\Player;
+use function array_key_exists;
 
 class CraftingTable extends Solid{
 
@@ -50,6 +53,19 @@ class CraftingTable extends Solid{
 	public function onActivate(Item $item, Player $player = null) : bool{
 		if($player instanceof Player){
 			$player->setCraftingGrid(new CraftingGrid($player, CraftingGrid::SIZE_BIG));
+
+			if(!array_key_exists($windowId = Player::HARDCODED_CRAFTING_GRID_WINDOW_ID, $player->openHardcodedWindows)){
+				//TODO: HACK! crafting grid doesn't fit very well into the current PM container system, so this hack allows
+				//it to carry on working approximately the same way as it did in 1.14
+				$pk = new ContainerOpenPacket();
+				$pk->windowId = $windowId;
+				$pk->type = WindowTypes::WORKBENCH;
+				$pk->x = $this->getFloorX();
+				$pk->y = $this->getFloorY();
+				$pk->z = $this->getFloorZ();
+				$player->sendDataPacket($pk);
+				$player->openHardcodedWindows[$windowId] = true;
+			}
 		}
 
 		return true;

src/pocketmine/block/Ladder.php

@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace pocketmine\block;
 
 use pocketmine\entity\Entity;
+use pocketmine\entity\Living;
 use pocketmine\item\Item;
 use pocketmine\math\AxisAlignedBB;
 use pocketmine\math\Vector3;
@@ -58,7 +59,7 @@ class Ladder extends Transparent{
 	}
 
 	public function onEntityCollide(Entity $entity) : void{
-		if($entity->asVector3()->floor()->distanceSquared($this) < 1){ //entity coordinates must be inside block
+		if($entity instanceof Living and $entity->asVector3()->floor()->distanceSquared($this) < 1){ //entity coordinates must be inside block
 			$entity->resetFallDistance();
 			$entity->onGround = true;
 		}

src/pocketmine/block/Podzol.php

@@ -40,6 +40,6 @@ class Podzol extends Solid{
 	}
 
 	public function getHardness() : float{
-		return 2.5;
+		return 0.5;
 	}
 }

src/pocketmine/block/Potato.php

@@ -40,9 +40,13 @@ class Potato extends Crops{
 	}
 
 	public function getDropsForCompatibleTool(Item $item) : array{
-		return [
-			ItemFactory::get(Item::POTATO, 0, $this->getDamage() >= 0x07 ? mt_rand(1, 4) : 1)
+		$result = [
+			ItemFactory::get(Item::POTATO, 0, $this->getDamage() >= 0x07 ? mt_rand(1, 5) : 1)
 		];
+		if($this->getDamage() >= 7 && mt_rand(0, 49) === 0){
+			$result[] = ItemFactory::get(Item::POISONOUS_POTATO);
+		}
+		return $result;
 	}
 
 	public function getPickedItem() : Item{

src/pocketmine/block/Rail.php

@@ -71,6 +71,7 @@ class Rail extends BaseRail{
 	}
 
 	protected function getPossibleConnectionDirectionsOneConstraint(int $constraint) : array{
+		/** @var int[] $horizontal */
 		static $horizontal = [
 			Vector3::SIDE_NORTH,
 			Vector3::SIDE_SOUTH,

src/pocketmine/block/Sugarcane.php

@@ -87,7 +87,12 @@ class Sugarcane extends Flowable{
 				for($y = 1; $y < 3; ++$y){
 					$b = $this->getLevelNonNull()->getBlockAt($this->x, $this->y + $y, $this->z);
 					if($b->getId() === self::AIR){
-						$this->getLevelNonNull()->setBlock($b, BlockFactory::get(Block::SUGARCANE_BLOCK), true);
+						$ev = new BlockGrowEvent($b, BlockFactory::get(Block::SUGARCANE_BLOCK));
+						$ev->call();
+						if($ev->isCancelled()){
+							break;
+						}
+						$this->getLevelNonNull()->setBlock($b, $ev->getNewState(), true);
 						break;
 					}
 				}

src/pocketmine/command/defaults/BanListCommand.php

@@ -30,7 +30,9 @@ use pocketmine\permission\BanEntry;
 use function array_map;
 use function count;
 use function implode;
+use function sort;
 use function strtolower;
+use const SORT_STRING;
 
 class BanListCommand extends VanillaCommand{
 
@@ -62,10 +64,11 @@ class BanListCommand extends VanillaCommand{
 			$args[0] = "players";
 		}
 
-		$list = $list->getEntries();
-		$message = implode(", ", array_map(function(BanEntry $entry) : string{
+		$list = array_map(function(BanEntry $entry) : string{
 			return $entry->getName();
-		}, $list));
+		}, $list->getEntries());
+		sort($list, SORT_STRING);
+		$message = implode(", ", $list);
 
 		if($args[0] === "ips"){
 			$sender->sendMessage(new TranslationContainer("commands.banlist.ips", [count($list)]));

src/pocketmine/command/defaults/ListCommand.php

@@ -30,6 +30,8 @@ use function array_filter;
 use function array_map;
 use function count;
 use function implode;
+use function sort;
+use const SORT_STRING;
 
 class ListCommand extends VanillaCommand{
 
@@ -52,6 +54,7 @@ class ListCommand extends VanillaCommand{
 		}, array_filter($sender->getServer()->getOnlinePlayers(), function(Player $player) use ($sender) : bool{
 			return $player->isOnline() and (!($sender instanceof Player) or $sender->canSee($player));
 		}));
+		sort($playerNames, SORT_STRING);
 
 		$sender->sendMessage(new TranslationContainer("commands.players.list", [count($playerNames), $sender->getServer()->getMaxPlayers()]));
 		$sender->sendMessage(implode(", ", $playerNames));

src/pocketmine/command/defaults/PluginsCommand.php

@@ -30,6 +30,8 @@ use pocketmine\utils\TextFormat;
 use function array_map;
 use function count;
 use function implode;
+use function sort;
+use const SORT_STRING;
 
 class PluginsCommand extends VanillaCommand{
 
@@ -51,6 +53,7 @@ class PluginsCommand extends VanillaCommand{
 		$list = array_map(function(Plugin $plugin) : string{
 			return ($plugin->isEnabled() ? TextFormat::GREEN : TextFormat::RED) . $plugin->getDescription()->getFullName();
 		}, $sender->getServer()->getPluginManager()->getPlugins());
+		sort($list, SORT_STRING);
 
 		$sender->sendMessage(new TranslationContainer("pocketmine.command.plugins.success", [count($list), implode(TextFormat::WHITE . ", ", $list)]));
 		return true;

src/pocketmine/command/defaults/StatusCommand.php

@@ -54,9 +54,9 @@ class StatusCommand extends VanillaCommand{
 		$server = $sender->getServer();
 		$sender->sendMessage(TextFormat::GREEN . "---- " . TextFormat::WHITE . "Server status" . TextFormat::GREEN . " ----");
 
-		$time = microtime(true) - \pocketmine\START_TIME;
+		$time = (int) (microtime(true) - \pocketmine\START_TIME);
 
-		$seconds = floor($time % 60);
+		$seconds = $time % 60;
 		$minutes = null;
 		$hours = null;
 		$days = null;

src/pocketmine/command/defaults/TeleportCommand.php

@@ -27,11 +27,11 @@ use pocketmine\command\Command;
 use pocketmine\command\CommandSender;
 use pocketmine\command\utils\InvalidCommandSyntaxException;
 use pocketmine\lang\TranslationContainer;
-use pocketmine\math\Vector3;
+use pocketmine\level\Location;
 use pocketmine\Player;
+use pocketmine\utils\AssumptionFailedError;
 use pocketmine\utils\TextFormat;
-use function array_filter;
-use function array_values;
+use function array_shift;
 use function count;
 use function round;
 
@@ -47,84 +47,83 @@ class TeleportCommand extends VanillaCommand{
 		$this->setPermission("pocketmine.command.teleport");
 	}
 
+	private function findPlayer(CommandSender $sender, string $playerName) : ?Player{
+		$subject = $sender->getServer()->getPlayer($playerName);
+		if($subject === null){
+			$sender->sendMessage(TextFormat::RED . "Can't find player " . $playerName);
+			return null;
+		}
+		return $subject;
+	}
+
 	public function execute(CommandSender $sender, string $commandLabel, array $args){
 		if(!$this->testPermission($sender)){
 			return true;
 		}
 
-		$args = array_values(array_filter($args, function(string $arg) : bool{
-			return $arg !== "";
-		}));
-		if(count($args) < 1 or count($args) > 6){
-			throw new InvalidCommandSyntaxException();
-		}
-
-		$target = null;
-		$origin = $sender;
-
-		if(count($args) === 1 or count($args) === 3){
-			if($sender instanceof Player){
-				$target = $sender;
-			}else{
-				$sender->sendMessage(TextFormat::RED . "Please provide a player!");
-
-				return true;
-			}
-			if(count($args) === 1){
-				$target = $sender->getServer()->getPlayer($args[0]);
-				if($target === null){
-					$sender->sendMessage(TextFormat::RED . "Can't find player " . $args[0]);
-
+		switch(count($args)){
+			case 1: // /tp targetPlayer
+			case 3: // /tp x y z
+			case 5: // /tp x y z yaw pitch - TODO: 5 args could be target x y z yaw :(
+				if(!($sender instanceof Player)){
+					$sender->sendMessage(TextFormat::RED . "Please provide a player!");
 					return true;
 				}
-			}
-		}else{
-			$target = $sender->getServer()->getPlayer($args[0]);
-			if($target === null){
-				$sender->sendMessage(TextFormat::RED . "Can't find player " . $args[0]);
-
-				return true;
-			}
-			if(count($args) === 2){
-				$origin = $target;
-				$target = $sender->getServer()->getPlayer($args[1]);
-				if($target === null){
-					$sender->sendMessage(TextFormat::RED . "Can't find player " . $args[1]);
 
+				$subject = $sender;
+				$targetArgs = $args;
+				break;
+			case 2: // /tp player1 player2
+			case 4: // /tp player1 x y z - TODO: 4 args could be x y z yaw :(
+			case 6: // /tp player1 x y z yaw pitch
+				$subject = $this->findPlayer($sender, $args[0]);
+				if($subject === null){
 					return true;
 				}
-			}
+				$targetArgs = $args;
+				array_shift($targetArgs);
+				break;
+			default:
+				throw new InvalidCommandSyntaxException();
 		}
 
-		if(count($args) < 3){
-			$origin->teleport($target);
-			Command::broadcastCommandMessage($sender, new TranslationContainer("commands.tp.success", [$origin->getName(), $target->getName()]));
+		switch(count($targetArgs)){
+			case 1:
+				$targetPlayer = $this->findPlayer($sender, $targetArgs[0]);
+				if($targetPlayer === null){
+					return true;
+				}
 
-			return true;
-		}elseif($target->isValid()){
-			if(count($args) === 4 or count($args) === 6){
-				$pos = 1;
-			}else{
-				$pos = 0;
-			}
+				$subject->teleport($targetPlayer->getLocation());
+				Command::broadcastCommandMessage($sender, new TranslationContainer("commands.tp.success", [$subject->getName(), $targetPlayer->getName()]));
 
-			$x = $this->getRelativeDouble($target->x, $sender, $args[$pos++]);
-			$y = $this->getRelativeDouble($target->y, $sender, $args[$pos++], 0, 256);
-			$z = $this->getRelativeDouble($target->z, $sender, $args[$pos++]);
-			$yaw = $target->getYaw();
-			$pitch = $target->getPitch();
+				return true;
+			case 3:
+			case 5:
+				$base = $subject->getLocation();
+				if(count($targetArgs) === 5){
+					$yaw = (float) $targetArgs[3];
+					$pitch = (float) $targetArgs[4];
+				}else{
+					$yaw = $base->yaw;
+					$pitch = $base->pitch;
+				}
 
-			if(count($args) === 6 or (count($args) === 5 and $pos === 3)){
-				$yaw = (float) $args[$pos++];
-				$pitch = (float) $args[$pos++];
-			}
+				$x = $this->getRelativeDouble($base->x, $sender, $targetArgs[0]);
+				$y = $this->getRelativeDouble($base->y, $sender, $targetArgs[1], 0, 256);
+				$z = $this->getRelativeDouble($base->z, $sender, $targetArgs[2]);
+				$targetLocation = new Location($x, $y, $z, $yaw, $pitch, $base->getLevelNonNull());
 
-			$target->teleport(new Vector3($x, $y, $z), $yaw, $pitch);
-			Command::broadcastCommandMessage($sender, new TranslationContainer("commands.tp.success.coordinates", [$target->getName(), round($x, 2), round($y, 2), round($z, 2)]));
-
-			return true;
+				$subject->teleport($targetLocation);
+				Command::broadcastCommandMessage($sender, new TranslationContainer("commands.tp.success.coordinates", [
+					$subject->getName(),
+					round($targetLocation->x, 2),
+					round($targetLocation->y, 2),
+					round($targetLocation->z, 2)
+				]));
+				return true;
+			default:
+				throw new AssumptionFailedError("This branch should be unreachable (for now)");
 		}
-
-		throw new InvalidCommandSyntaxException();
 	}
 }

src/pocketmine/command/defaults/TimingsCommand.php

@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace pocketmine\command\defaults;
 
+use pocketmine\command\Command;
 use pocketmine\command\CommandSender;
 use pocketmine\command\utils\InvalidCommandSyntaxException;
 use pocketmine\lang\TranslationContainer;
@@ -72,12 +73,12 @@ class TimingsCommand extends VanillaCommand{
 
 		if($mode === "on"){
 			TimingsHandler::setEnabled();
-			$sender->sendMessage(new TranslationContainer("pocketmine.command.timings.enable"));
+			Command::broadcastCommandMessage($sender, new TranslationContainer("pocketmine.command.timings.enable"));
 
 			return true;
 		}elseif($mode === "off"){
 			TimingsHandler::setEnabled(false);
-			$sender->sendMessage(new TranslationContainer("pocketmine.command.timings.disable"));
+			Command::broadcastCommandMessage($sender, new TranslationContainer("pocketmine.command.timings.disable"));
 			return true;
 		}
 
@@ -91,7 +92,7 @@ class TimingsCommand extends VanillaCommand{
 
 		if($mode === "reset"){
 			TimingsHandler::reload();
-			$sender->sendMessage(new TranslationContainer("pocketmine.command.timings.reset"));
+			Command::broadcastCommandMessage($sender, new TranslationContainer("pocketmine.command.timings.reset"));
 		}elseif($mode === "merged" or $mode === "report" or $paste){
 			$timings = "";
 			if($paste){
@@ -150,6 +151,7 @@ class TimingsCommand extends VanillaCommand{
 					}
 
 					public function onCompletion(Server $server){
+						/** @var CommandSender $sender */
 						$sender = $this->fetchLocal();
 						if($sender instanceof Player and !$sender->isOnline()){ // TODO replace with a more generic API method for checking availability of CommandSender
 							return;
@@ -159,18 +161,21 @@ class TimingsCommand extends VanillaCommand{
 							$server->getLogger()->logException($result);
 							return;
 						}
-						if(isset($result[0]) && is_array($response = json_decode($result[0], true)) && isset($response["id"])){
-							$sender->sendMessage(new TranslationContainer("pocketmine.command.timings.timingsRead",
+						$response = json_decode($result[0], true);
+						if(is_array($response) && isset($response["id"])){
+							Command::broadcastCommandMessage($sender, new TranslationContainer("pocketmine.command.timings.timingsRead",
 								["https://" . $this->host . "/?id=" . $response["id"]]));
 						}else{
-							$sender->sendMessage(new TranslationContainer("pocketmine.command.timings.pasteError"));
+							Command::broadcastCommandMessage($sender, new TranslationContainer("pocketmine.command.timings.pasteError"));
 						}
 					}
 				});
 			}else{
 				fclose($fileTimings);
-				$sender->sendMessage(new TranslationContainer("pocketmine.command.timings.timingsWrite", [$timings]));
+				Command::broadcastCommandMessage($sender, new TranslationContainer("pocketmine.command.timings.timingsWrite", [$timings]));
 			}
+		}else{
+			throw new InvalidCommandSyntaxException();
 		}
 
 		return true;

src/pocketmine/command/defaults/WhitelistCommand.php

@@ -31,7 +31,9 @@ use pocketmine\Player;
 use pocketmine\utils\TextFormat;
 use function count;
 use function implode;
+use function sort;
 use function strtolower;
+use const SORT_STRING;
 
 class WhitelistCommand extends VanillaCommand{
 
@@ -49,10 +51,6 @@ class WhitelistCommand extends VanillaCommand{
 			return true;
 		}
 
-		if(count($args) === 0 or count($args) > 2){
-			throw new InvalidCommandSyntaxException();
-		}
-
 		if(count($args) === 1){
 			if($this->badPerm($sender, strtolower($args[0]))){
 				return false;
@@ -75,7 +73,8 @@ class WhitelistCommand extends VanillaCommand{
 					return true;
 				case "list":
 					$entries = $sender->getServer()->getWhitelisted()->getAll(true);
-					$result = implode($entries, ", ");
+					sort($entries, SORT_STRING);
+					$result = implode(", ", $entries);
 					$count = count($entries);
 
 					$sender->sendMessage(new TranslationContainer("commands.whitelist.list", [$count, $count]));
@@ -112,7 +111,7 @@ class WhitelistCommand extends VanillaCommand{
 			}
 		}
 
-		return true;
+		throw new InvalidCommandSyntaxException();
 	}
 
 	private function badPerm(CommandSender $sender, string $subcommand) : bool{

src/pocketmine/entity/Attribute.php

@@ -45,6 +45,7 @@ class Attribute{
 	public const FALL_DAMAGE = 13;
 	public const HORSE_JUMP_STRENGTH = 14;
 	public const ZOMBIE_SPAWN_REINFORCEMENTS = 15;
+	public const LAVA_MOVEMENT = 16;
 
 	/** @var int */
 	private $id;
@@ -84,6 +85,7 @@ class Attribute{
 		self::addAttribute(self::FALL_DAMAGE, "minecraft:fall_damage", 0.0, 340282346638528859811704183484516925440.0, 1.0);
 		self::addAttribute(self::HORSE_JUMP_STRENGTH, "minecraft:horse.jump_strength", 0.0, 2.0, 0.7);
 		self::addAttribute(self::ZOMBIE_SPAWN_REINFORCEMENTS, "minecraft:zombie.spawn_reinforcements", 0.0, 1.0, 0.0);
+		self::addAttribute(self::LAVA_MOVEMENT, "minecraft:lava_movement", 0.0, 340282346638528859811704183484516925440.0, 0.02);
 	}
 
 	/**

src/pocketmine/entity/Effect.php

@@ -31,7 +31,7 @@ use pocketmine\event\player\PlayerExhaustEvent;
 use pocketmine\utils\Color;
 use function constant;
 use function defined;
-use function strtoupper;
+use function mb_strtoupper;
 
 class Effect{
 	public const SPEED = 1;
@@ -102,7 +102,7 @@ class Effect{
 	}
 
 	public static function getEffectByName(string $name) : ?Effect{
-		$const = self::class . "::" . strtoupper($name);
+		$const = self::class . "::" . mb_strtoupper($name);
 		if(defined($const)){
 			return self::getEffect(constant($const));
 		}

src/pocketmine/entity/Entity.php

@@ -80,6 +80,7 @@ use function count;
 use function current;
 use function deg2rad;
 use function floor;
+use function fmod;
 use function get_class;
 use function in_array;
 use function is_a;
@@ -94,6 +95,7 @@ use const M_PI_2;
 abstract class Entity extends Location implements Metadatable, EntityIds{
 
 	public const MOTION_THRESHOLD = 0.00001;
+	protected const STEP_CLIP_MULTIPLIER = 0.4;
 
 	public const NETWORK_ID = -1;
 
@@ -311,12 +313,15 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 	public const DATA_FLAG_ROARING = 83;
 	public const DATA_FLAG_DELAYED_ATTACKING = 84;
 	public const DATA_FLAG_AVOIDING_MOBS = 85;
-	public const DATA_FLAG_FACING_TARGET_TO_RANGE_ATTACK = 86;
-	public const DATA_FLAG_HIDDEN_WHEN_INVISIBLE = 87; //??????????????????
-	public const DATA_FLAG_IS_IN_UI = 88;
-	public const DATA_FLAG_STALKING = 89;
-	public const DATA_FLAG_EMOTING = 90;
-	public const DATA_FLAG_CELEBRATING = 91;
+	public const DATA_FLAG_AVOIDING_BLOCK = 86;
+	public const DATA_FLAG_FACING_TARGET_TO_RANGE_ATTACK = 87;
+	public const DATA_FLAG_HIDDEN_WHEN_INVISIBLE = 88; //??????????????????
+	public const DATA_FLAG_IS_IN_UI = 89;
+	public const DATA_FLAG_STALKING = 90;
+	public const DATA_FLAG_EMOTING = 91;
+	public const DATA_FLAG_CELEBRATING = 92;
+	public const DATA_FLAG_ADMIRING = 93;
+	public const DATA_FLAG_CELEBRATING_SPECIAL = 94;
 
 	public const DATA_PLAYER_FLAG_SLEEP = 1;
 	public const DATA_PLAYER_FLAG_DEAD = 2; //TODO: CHECK
@@ -704,10 +709,10 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 
 		$this->boundingBox->setBounds(
 			$this->x - $halfWidth,
-			$this->y,
+			$this->y + $this->ySize,
 			$this->z - $halfWidth,
 			$this->x + $halfWidth,
-			$this->y + $this->height,
+			$this->y + $this->height + $this->ySize,
 			$this->z + $halfWidth
 		);
 	}
@@ -865,7 +870,7 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 	 */
 	public function getSaveId() : string{
 		if(!isset(self::$saveNames[static::class])){
-			throw new \InvalidStateException("Entity is not registered");
+			throw new \InvalidStateException("Entity " . static::class . " is not registered");
 		}
 		reset(self::$saveNames[static::class]);
 		return current(self::$saveNames[static::class]);
@@ -1308,7 +1313,7 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 	}
 
 	public function getDirection() : ?int{
-		$rotation = ($this->yaw - 90) % 360;
+		$rotation = fmod($this->yaw - 90, 360);
 		if($rotation < 0){
 			$rotation += 360.0;
 		}
@@ -1535,7 +1540,7 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 		if($this->keepMovement){
 			$this->boundingBox->offset($dx, $dy, $dz);
 		}else{
-			$this->ySize *= 0.4;
+			$this->ySize *= self::STEP_CLIP_MULTIPLIER;
 
 			/*
 			if($this->isColliding){ //With cobweb?
@@ -1602,7 +1607,7 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 
 			$this->boundingBox->offset(0, 0, $dz);
 
-			if($this->stepHeight > 0 and $fallingFlag and $this->ySize < 0.05 and ($movX != $dx or $movZ != $dz)){
+			if($this->stepHeight > 0 and $fallingFlag and ($movX != $dx or $movZ != $dz)){
 				$cx = $dx;
 				$cy = $dy;
 				$cz = $dz;
@@ -1634,13 +1639,20 @@ abstract class Entity extends Location implements Metadatable, EntityIds{
 
 				$this->boundingBox->offset(0, 0, $dz);
 
+				$reverseDY = -$dy;
+				foreach($list as $bb){
+					$reverseDY = $bb->calculateYOffset($this->boundingBox, $reverseDY);
+				}
+				$dy += $reverseDY;
+				$this->boundingBox->offset(0, $reverseDY, 0);
+
 				if(($cx ** 2 + $cz ** 2) >= ($dx ** 2 + $dz ** 2)){
 					$dx = $cx;
 					$dy = $cy;
 					$dz = $cz;
 					$this->boundingBox->setBB($axisalignedbb1);
 				}else{
-					$this->ySize += 0.5; //FIXME: this should be the height of the block it walked up, not fixed 0.5
+					$this->ySize += $dy;
 				}
 			}
 		}

src/pocketmine/entity/InvalidSkinException.php

@@ -0,0 +1,28 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\entity;
+
+final class InvalidSkinException extends \InvalidArgumentException{
+
+}

src/pocketmine/entity/Living.php

@@ -45,6 +45,7 @@ use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\FloatTag;
 use pocketmine\nbt\tag\IntTag;
 use pocketmine\nbt\tag\ListTag;
+use pocketmine\nbt\tag\ShortTag;
 use pocketmine\network\mcpe\protocol\ActorEventPacket;
 use pocketmine\network\mcpe\protocol\LevelSoundEventPacket;
 use pocketmine\network\mcpe\protocol\MobEffectPacket;
@@ -97,17 +98,15 @@ abstract class Living extends Entity implements Damageable{
 		//TODO: load/save armor inventory contents
 		$this->armorInventory->setEventProcessor(new ArmorInventoryEventProcessor($this));
 
-		$health = $this->getMaxHealth();
-
 		if($this->namedtag->hasTag("HealF", FloatTag::class)){
 			$health = $this->namedtag->getFloat("HealF");
 			$this->namedtag->removeTag("HealF");
-		}elseif($this->namedtag->hasTag("Health")){
-			$healthTag = $this->namedtag->getTag("Health");
-			$health = (float) $healthTag->getValue(); //Older versions of PocketMine-MP incorrectly saved this as a short instead of a float
-			if(!($healthTag instanceof FloatTag)){
-				$this->namedtag->removeTag("Health");
-			}
+		}elseif($this->namedtag->hasTag("Health", ShortTag::class)){
+			//Older versions of PocketMine-MP incorrectly saved this as a short instead of a float
+			$health = $this->namedtag->getShort("Health");
+			$this->namedtag->removeTag("Health");
+		}else{
+			$health = $this->namedtag->getFloat("Health", $this->getMaxHealth());
 		}
 
 		$this->setHealth($health);

src/pocketmine/entity/Skin.php

@@ -62,24 +62,24 @@ class Skin{
 		try{
 			$this->validate();
 			return true;
-		}catch(\InvalidArgumentException $e){
+		}catch(InvalidSkinException $e){
 			return false;
 		}
 	}
 
 	/**
-	 * @throws \InvalidArgumentException
+	 * @throws InvalidSkinException
 	 */
 	public function validate() : void{
 		if($this->skinId === ""){
-			throw new \InvalidArgumentException("Skin ID must not be empty");
+			throw new InvalidSkinException("Skin ID must not be empty");
 		}
 		$len = strlen($this->skinData);
 		if(!in_array($len, self::ACCEPTED_SKIN_SIZES, true)){
-			throw new \InvalidArgumentException("Invalid skin data size $len bytes (allowed sizes: " . implode(", ", self::ACCEPTED_SKIN_SIZES) . ")");
+			throw new InvalidSkinException("Invalid skin data size $len bytes (allowed sizes: " . implode(", ", self::ACCEPTED_SKIN_SIZES) . ")");
 		}
 		if($this->capeData !== "" and strlen($this->capeData) !== 8192){
-			throw new \InvalidArgumentException("Invalid cape data size " . strlen($this->capeData) . " bytes (must be exactly 8192 bytes)");
+			throw new InvalidSkinException("Invalid cape data size " . strlen($this->capeData) . " bytes (must be exactly 8192 bytes)");
 		}
 		//TODO: validate geometry
 	}

src/pocketmine/entity/utils/ExperienceUtils.php

@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace pocketmine\entity\utils;
 
 use pocketmine\math\Math;
+use pocketmine\utils\AssumptionFailedError;
 use function max;
 
 abstract class ExperienceUtils{
@@ -59,6 +60,9 @@ abstract class ExperienceUtils{
 	 * This returns a floating-point number, the decimal part being the progress through the resulting level.
 	 */
 	public static function getLevelFromXp(int $xp) : float{
+		if($xp < 0){
+			throw new \InvalidArgumentException("XP must be at least 0");
+		}
 		if($xp <= self::getXpToReachLevel(16)){
 			$a = 1;
 			$b = 6;
@@ -74,6 +78,9 @@ abstract class ExperienceUtils{
 		}
 
 		$x = Math::solveQuadratic($a, $b, $c - $xp);
+		if(count($x) === 0){
+			throw new AssumptionFailedError("Expected at least 1 solution");
+		}
 
 		return max($x); //we're only interested in the positive solution
 	}

src/pocketmine/event/EventPriority.php

@@ -25,7 +25,7 @@ namespace pocketmine\event;
 
 use function constant;
 use function defined;
-use function strtoupper;
+use function mb_strtoupper;
 
 /**
  * List of event priorities
@@ -79,7 +79,7 @@ abstract class EventPriority{
 	 * @throws \InvalidArgumentException
 	 */
 	public static function fromString(string $name) : int{
-		$name = strtoupper($name);
+		$name = mb_strtoupper($name);
 		$const = self::class . "::" . $name;
 		if($name !== "ALL" and defined($const)){
 			return constant($const);

src/pocketmine/event/block/SignChangeEvent.php

@@ -26,6 +26,7 @@ namespace pocketmine\event\block;
 use pocketmine\block\Block;
 use pocketmine\event\Cancellable;
 use pocketmine\Player;
+use pocketmine\utils\Utils;
 use function count;
 
 /**
@@ -79,6 +80,7 @@ class SignChangeEvent extends BlockEvent implements Cancellable{
 		if(count($lines) !== 4){
 			throw new \InvalidArgumentException("Array size must be 4!");
 		}
+		Utils::validateArrayValueType($lines, function(string $_) : void{});
 		$this->lines = $lines;
 	}
 

src/pocketmine/event/entity/EntityBlockChangeEvent.php

@@ -29,6 +29,7 @@ use pocketmine\event\Cancellable;
 
 /**
  * Called when an Entity, excluding players, changes a block directly
+ * @phpstan-extends EntityEvent<Entity>
  */
 class EntityBlockChangeEvent extends EntityEvent implements Cancellable{
 	/** @var Block */

src/pocketmine/event/entity/EntityCombustEvent.php

@@ -26,6 +26,9 @@ namespace pocketmine\event\entity;
 use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 
+/**
+ * @phpstan-extends EntityEvent<Entity>
+ */
 class EntityCombustEvent extends EntityEvent implements Cancellable{
 	/** @var int */
 	protected $duration;

src/pocketmine/event/entity/EntityDamageEvent.php

@@ -30,6 +30,7 @@ use function max;
 
 /**
  * Called when an entity takes damage.
+ * @phpstan-extends EntityEvent<Entity>
  */
 class EntityDamageEvent extends EntityEvent implements Cancellable{
 	public const MODIFIER_ARMOR = 1;

src/pocketmine/event/entity/EntityDeathEvent.php

@@ -25,7 +25,11 @@ namespace pocketmine\event\entity;
 
 use pocketmine\entity\Living;
 use pocketmine\item\Item;
+use pocketmine\utils\Utils;
 
+/**
+ * @phpstan-extends EntityEvent<Living>
+ */
 class EntityDeathEvent extends EntityEvent{
 	/** @var Item[] */
 	private $drops = [];
@@ -59,6 +63,7 @@ class EntityDeathEvent extends EntityEvent{
 	 * @param Item[] $drops
 	 */
 	public function setDrops(array $drops) : void{
+		Utils::validateArrayValueType($drops, function(Item $_) : void{});
 		$this->drops = $drops;
 	}
 

src/pocketmine/event/entity/EntityDespawnEvent.php

@@ -32,6 +32,7 @@ use pocketmine\entity\Vehicle;
 
 /**
  * Called when a entity is despawned
+ * @phpstan-extends EntityEvent<Entity>
  */
 class EntityDespawnEvent extends EntityEvent{
 	/** @var int */

src/pocketmine/event/entity/EntityEffectEvent.php

@@ -27,6 +27,9 @@ use pocketmine\entity\EffectInstance;
 use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 
+/**
+ * @phpstan-extends EntityEvent<Entity>
+ */
 class EntityEffectEvent extends EntityEvent implements Cancellable{
 	/** @var EffectInstance */
 	private $effect;

src/pocketmine/event/entity/EntityEvent.php

@@ -29,12 +29,19 @@ namespace pocketmine\event\entity;
 use pocketmine\entity\Entity;
 use pocketmine\event\Event;
 
+/**
+ * @phpstan-template TEntity of Entity
+ */
 abstract class EntityEvent extends Event{
-	/** @var Entity */
+	/**
+	 * @var Entity
+	 * @phpstan-var TEntity
+	 */
 	protected $entity;
 
 	/**
 	 * @return Entity
+	 * @phpstan-return TEntity
 	 */
 	public function getEntity(){
 		return $this->entity;

src/pocketmine/event/entity/EntityExplodeEvent.php

@@ -27,9 +27,11 @@ use pocketmine\block\Block;
 use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 use pocketmine\level\Position;
+use pocketmine\utils\Utils;
 
 /**
  * Called when a entity explodes
+ * @phpstan-extends EntityEvent<Entity>
  */
 class EntityExplodeEvent extends EntityEvent implements Cancellable{
 	/** @var Position */
@@ -66,6 +68,7 @@ class EntityExplodeEvent extends EntityEvent implements Cancellable{
 	 * @param Block[] $blocks
 	 */
 	public function setBlockList(array $blocks) : void{
+		Utils::validateArrayValueType($blocks, function(Block $_) : void{});
 		$this->blocks = $blocks;
 	}
 

src/pocketmine/event/entity/EntityInventoryChangeEvent.php

@@ -29,6 +29,7 @@ use pocketmine\item\Item;
 
 /**
  * Called before a slot in an entity's inventory changes.
+ * @phpstan-extends EntityEvent<Entity>
  */
 class EntityInventoryChangeEvent extends EntityEvent implements Cancellable{
 	/** @var Item */

src/pocketmine/event/entity/EntityLevelChangeEvent.php

@@ -27,6 +27,9 @@ use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 use pocketmine\level\Level;
 
+/**
+ * @phpstan-extends EntityEvent<Entity>
+ */
 class EntityLevelChangeEvent extends EntityEvent implements Cancellable{
 	/** @var Level */
 	private $originLevel;

src/pocketmine/event/entity/EntityMotionEvent.php

@@ -27,6 +27,9 @@ use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 use pocketmine\math\Vector3;
 
+/**
+ * @phpstan-extends EntityEvent<Entity>
+ */
 class EntityMotionEvent extends EntityEvent implements Cancellable{
 	/** @var Vector3 */
 	private $mot;

src/pocketmine/event/entity/EntityRegainHealthEvent.php

@@ -26,6 +26,9 @@ namespace pocketmine\event\entity;
 use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 
+/**
+ * @phpstan-extends EntityEvent<Entity>
+ */
 class EntityRegainHealthEvent extends EntityEvent implements Cancellable{
 	public const CAUSE_REGEN = 0;
 	public const CAUSE_EATING = 1;

src/pocketmine/event/entity/EntityShootBowEvent.php

@@ -30,6 +30,9 @@ use pocketmine\event\Cancellable;
 use pocketmine\item\Item;
 use function count;
 
+/**
+ * @phpstan-extends EntityEvent<Living>
+ */
 class EntityShootBowEvent extends EntityEvent implements Cancellable{
 	/** @var Item */
 	private $bow;

src/pocketmine/event/entity/EntitySpawnEvent.php

@@ -33,6 +33,7 @@ use pocketmine\level\Position;
 
 /**
  * Called when a entity is spawned
+ * @phpstan-extends EntityEvent<Entity>
  */
 class EntitySpawnEvent extends EntityEvent{
 	/** @var int */

src/pocketmine/event/entity/EntityTeleportEvent.php

@@ -27,6 +27,9 @@ use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 use pocketmine\level\Position;
 
+/**
+ * @phpstan-extends EntityEvent<Entity>
+ */
 class EntityTeleportEvent extends EntityEvent implements Cancellable{
 	/** @var Position */
 	private $from;

src/pocketmine/event/entity/ExplosionPrimeEvent.php

@@ -28,6 +28,7 @@ use pocketmine\event\Cancellable;
 
 /**
  * Called when a entity decides to explode
+ * @phpstan-extends EntityEvent<Entity>
  */
 class ExplosionPrimeEvent extends EntityEvent implements Cancellable{
 	/** @var float */

src/pocketmine/event/entity/ItemDespawnEvent.php

@@ -26,6 +26,9 @@ namespace pocketmine\event\entity;
 use pocketmine\entity\object\ItemEntity;
 use pocketmine\event\Cancellable;
 
+/**
+ * @phpstan-extends EntityEvent<ItemEntity>
+ */
 class ItemDespawnEvent extends EntityEvent implements Cancellable{
 
 	public function __construct(ItemEntity $item){

src/pocketmine/event/entity/ItemSpawnEvent.php

@@ -25,6 +25,9 @@ namespace pocketmine\event\entity;
 
 use pocketmine\entity\object\ItemEntity;
 
+/**
+ * @phpstan-extends EntityEvent<ItemEntity>
+ */
 class ItemSpawnEvent extends EntityEvent{
 
 	public function __construct(ItemEntity $item){

src/pocketmine/event/entity/ProjectileHitEvent.php

@@ -28,6 +28,7 @@ use pocketmine\math\RayTraceResult;
 
 /**
  * @allowHandle
+ * @phpstan-extends EntityEvent<Projectile>
  */
 abstract class ProjectileHitEvent extends EntityEvent{
 	/** @var RayTraceResult */

src/pocketmine/event/entity/ProjectileLaunchEvent.php

@@ -26,6 +26,9 @@ namespace pocketmine\event\entity;
 use pocketmine\entity\projectile\Projectile;
 use pocketmine\event\Cancellable;
 
+/**
+ * @phpstan-extends EntityEvent<Projectile>
+ */
 class ProjectileLaunchEvent extends EntityEvent implements Cancellable{
 	public function __construct(Projectile $entity){
 		$this->entity = $entity;

src/pocketmine/event/inventory/FurnaceBurnEvent.php

@@ -28,6 +28,9 @@ use pocketmine\event\Cancellable;
 use pocketmine\item\Item;
 use pocketmine\tile\Furnace;
 
+/**
+ * Called when a furnace is about to consume a new fuel item.
+ */
 class FurnaceBurnEvent extends BlockEvent implements Cancellable{
 	/** @var Furnace */
 	private $furnace;
@@ -53,18 +56,31 @@ class FurnaceBurnEvent extends BlockEvent implements Cancellable{
 		return $this->fuel;
 	}
 
+	/**
+	 * Returns the number of ticks that the furnace will be powered for.
+	 */
 	public function getBurnTime() : int{
 		return $this->burnTime;
 	}
 
+	/**
+	 * Sets the number of ticks that the given fuel will power the furnace for.
+	 */
 	public function setBurnTime(int $burnTime) : void{
 		$this->burnTime = $burnTime;
 	}
 
+	/**
+	 * Returns whether the fuel item will be consumed.
+	 */
 	public function isBurning() : bool{
 		return $this->burning;
 	}
 
+	/**
+	 * Sets whether the fuel will be consumed. If false, the furnace will smelt as if it consumed fuel, but no fuel
+	 * will be deducted.
+	 */
 	public function setBurning(bool $burning) : void{
 		$this->burning = $burning;
 	}

src/pocketmine/event/player/PlayerChatEvent.php

@@ -28,6 +28,7 @@ use pocketmine\event\Cancellable;
 use pocketmine\permission\PermissionManager;
 use pocketmine\Player;
 use pocketmine\Server;
+use pocketmine\utils\Utils;
 use function spl_object_id;
 
 /**
@@ -97,6 +98,7 @@ class PlayerChatEvent extends PlayerEvent implements Cancellable{
 	 * @param CommandSender[] $recipients
 	 */
 	public function setRecipients(array $recipients) : void{
+		Utils::validateArrayValueType($recipients, function(CommandSender $_) : void{});
 		$this->recipients = $recipients;
 	}
 }

src/pocketmine/event/player/PlayerExhaustEvent.php

@@ -27,6 +27,9 @@ use pocketmine\entity\Human;
 use pocketmine\event\Cancellable;
 use pocketmine\event\entity\EntityEvent;
 
+/**
+ * @phpstan-extends EntityEvent<Human>
+ */
 class PlayerExhaustEvent extends EntityEvent implements Cancellable{
 	public const CAUSE_ATTACK = 1;
 	public const CAUSE_DAMAGE = 2;

src/pocketmine/event/player/PlayerExperienceChangeEvent.php

@@ -29,6 +29,7 @@ use pocketmine\event\entity\EntityEvent;
 
 /**
  * Called when a player gains or loses XP levels and/or progress.
+ * @phpstan-extends EntityEvent<Human>
  */
 class PlayerExperienceChangeEvent extends EntityEvent implements Cancellable{
 	/** @var Human */

src/pocketmine/event/player/PlayerRespawnEvent.php

@@ -43,6 +43,9 @@ class PlayerRespawnEvent extends PlayerEvent{
 	}
 
 	public function setRespawnPosition(Position $position) : void{
+		if(!$position->isValid()){
+			throw new \InvalidArgumentException("Spawn position must reference a valid and loaded World");
+		}
 		$this->position = $position;
 	}
 }

src/pocketmine/event/server/QueryRegenerateEvent.php

@@ -27,6 +27,7 @@ use pocketmine\Player;
 use pocketmine\plugin\Plugin;
 use pocketmine\Server;
 use pocketmine\utils\Binary;
+use pocketmine\utils\Utils;
 use function chr;
 use function count;
 use function str_replace;
@@ -76,7 +77,7 @@ class QueryRegenerateEvent extends ServerEvent{
 
 	public function __construct(Server $server){
 		$this->serverName = $server->getMotd();
-		$this->listPlugins = $server->getProperty("settings.query-plugins", true);
+		$this->listPlugins = (bool) $server->getProperty("settings.query-plugins", true);
 		$this->plugins = $server->getPluginManager()->getPlugins();
 		$this->players = [];
 		foreach($server->getOnlinePlayers() as $player){
@@ -145,6 +146,7 @@ class QueryRegenerateEvent extends ServerEvent{
 	 * @param Plugin[] $plugins
 	 */
 	public function setPlugins(array $plugins) : void{
+		Utils::validateArrayValueType($plugins, function(Plugin $_) : void{});
 		$this->plugins = $plugins;
 		$this->destroyCache();
 	}
@@ -160,6 +162,7 @@ class QueryRegenerateEvent extends ServerEvent{
 	 * @param Player[] $players
 	 */
 	public function setPlayerList(array $players) : void{
+		Utils::validateArrayValueType($players, function(Player $_) : void{});
 		$this->players = $players;
 		$this->destroyCache();
 	}

src/pocketmine/inventory/ArmorInventory.php

@@ -28,7 +28,9 @@ use pocketmine\item\Item;
 use pocketmine\network\mcpe\protocol\InventoryContentPacket;
 use pocketmine\network\mcpe\protocol\InventorySlotPacket;
 use pocketmine\network\mcpe\protocol\MobArmorEquipmentPacket;
+use pocketmine\network\mcpe\protocol\types\inventory\ItemStackWrapper;
 use pocketmine\Player;
+use function array_map;
 use function array_merge;
 
 class ArmorInventory extends BaseInventory{
@@ -109,7 +111,7 @@ class ArmorInventory extends BaseInventory{
 				$pk2 = new InventorySlotPacket();
 				$pk2->windowId = $player->getWindowId($this);
 				$pk2->inventorySlot = $index;
-				$pk2->item = $this->getItem($index);
+				$pk2->item = ItemStackWrapper::legacy($this->getItem($index));
 				$player->dataPacket($pk2);
 			}else{
 				$player->dataPacket($pk);
@@ -134,7 +136,7 @@ class ArmorInventory extends BaseInventory{
 			if($player === $this->getHolder()){
 				$pk2 = new InventoryContentPacket();
 				$pk2->windowId = $player->getWindowId($this);
-				$pk2->items = $this->getContents(true);
+				$pk2->items = array_map([ItemStackWrapper::class, 'legacy'], $this->getContents(true));
 				$player->dataPacket($pk2);
 			}else{
 				$player->dataPacket($pk);

src/pocketmine/inventory/BaseInventory.php

@@ -31,7 +31,9 @@ use pocketmine\math\Vector3;
 use pocketmine\network\mcpe\protocol\InventoryContentPacket;
 use pocketmine\network\mcpe\protocol\InventorySlotPacket;
 use pocketmine\network\mcpe\protocol\types\ContainerIds;
+use pocketmine\network\mcpe\protocol\types\inventory\ItemStackWrapper;
 use pocketmine\Player;
+use function array_map;
 use function array_slice;
 use function count;
 use function max;
@@ -53,7 +55,7 @@ abstract class BaseInventory implements Inventory{
 	protected $slots;
 	/** @var Player[] */
 	protected $viewers = [];
-	/** @var InventoryEventProcessor */
+	/** @var InventoryEventProcessor|null */
 	protected $eventProcessor;
 
 	/**
@@ -433,7 +435,7 @@ abstract class BaseInventory implements Inventory{
 		}
 
 		$pk = new InventoryContentPacket();
-		$pk->items = $this->getContents(true);
+		$pk->items = array_map([ItemStackWrapper::class, 'legacy'], $this->getContents(true));
 
 		foreach($target as $player){
 			if(($id = $player->getWindowId($this)) === ContainerIds::NONE){
@@ -455,7 +457,7 @@ abstract class BaseInventory implements Inventory{
 
 		$pk = new InventorySlotPacket();
 		$pk->inventorySlot = $index;
-		$pk->item = $this->getItem($index);
+		$pk->item = ItemStackWrapper::legacy($this->getItem($index));
 
 		foreach($target as $player){
 			if(($id = $player->getWindowId($this)) === ContainerIds::NONE){

src/pocketmine/inventory/CraftingManager.php

@@ -28,8 +28,10 @@ use pocketmine\network\mcpe\protocol\BatchPacket;
 use pocketmine\network\mcpe\protocol\CraftingDataPacket;
 use pocketmine\Server;
 use pocketmine\timings\Timings;
+use pocketmine\utils\AssumptionFailedError;
 use function array_map;
 use function file_get_contents;
+use function is_array;
 use function json_decode;
 use function json_encode;
 use function usort;
@@ -52,41 +54,39 @@ class CraftingManager{
 
 	public function init() : void{
 		$recipes = json_decode(file_get_contents(\pocketmine\RESOURCE_PATH . "vanilla" . DIRECTORY_SEPARATOR . "recipes.json"), true);
+		if(!is_array($recipes)){
+			throw new AssumptionFailedError("recipes.json root should contain a map of recipe types");
+		}
 
 		$itemDeserializerFunc = \Closure::fromCallable([Item::class, 'jsonDeserialize']);
-		foreach($recipes as $recipe){
-			switch($recipe["type"]){
-				case "shapeless":
-					if($recipe["block"] !== "crafting_table"){ //TODO: filter others out for now to avoid breaking economics
-						break;
-					}
-					$this->registerShapelessRecipe(new ShapelessRecipe(
-						array_map($itemDeserializerFunc, $recipe["input"]),
-						array_map($itemDeserializerFunc, $recipe["output"])
-					));
-					break;
-				case "shaped":
-					if($recipe["block"] !== "crafting_table"){ //TODO: filter others out for now to avoid breaking economics
-						break;
-					}
-					$this->registerShapedRecipe(new ShapedRecipe(
-						$recipe["shape"],
-						array_map($itemDeserializerFunc, $recipe["input"]),
-						array_map($itemDeserializerFunc, $recipe["output"])
-					));
-					break;
-				case "smelting":
-					if($recipe["block"] !== "furnace"){ //TODO: filter others out for now to avoid breaking economics
-						break;
-					}
-					$this->registerFurnaceRecipe(new FurnaceRecipe(
-						Item::jsonDeserialize($recipe["output"]),
-						Item::jsonDeserialize($recipe["input"]))
-					);
-					break;
-				default:
-					break;
+
+		foreach($recipes["shapeless"] as $recipe){
+			if($recipe["block"] !== "crafting_table"){ //TODO: filter others out for now to avoid breaking economics
+				continue;
 			}
+			$this->registerShapelessRecipe(new ShapelessRecipe(
+				array_map($itemDeserializerFunc, $recipe["input"]),
+				array_map($itemDeserializerFunc, $recipe["output"])
+			));
+		}
+		foreach($recipes["shaped"] as $recipe){
+			if($recipe["block"] !== "crafting_table"){ //TODO: filter others out for now to avoid breaking economics
+				continue;
+			}
+			$this->registerShapedRecipe(new ShapedRecipe(
+				$recipe["shape"],
+				array_map($itemDeserializerFunc, $recipe["input"]),
+				array_map($itemDeserializerFunc, $recipe["output"])
+			));
+		}
+		foreach($recipes["smelting"] as $recipe){
+			if($recipe["block"] !== "furnace"){ //TODO: filter others out for now to avoid breaking economics
+				continue;
+			}
+			$this->registerFurnaceRecipe(new FurnaceRecipe(
+				Item::jsonDeserialize($recipe["output"]),
+				Item::jsonDeserialize($recipe["input"]))
+			);
 		}
 
 		$this->buildCraftingDataCache();

src/pocketmine/inventory/PlayerInventory.php

@@ -26,10 +26,12 @@ namespace pocketmine\inventory;
 use pocketmine\entity\Human;
 use pocketmine\event\player\PlayerItemHeldEvent;
 use pocketmine\item\Item;
-use pocketmine\network\mcpe\protocol\InventoryContentPacket;
+use pocketmine\network\mcpe\protocol\CreativeContentPacket;
 use pocketmine\network\mcpe\protocol\MobEquipmentPacket;
 use pocketmine\network\mcpe\protocol\types\ContainerIds;
+use pocketmine\network\mcpe\protocol\types\inventory\CreativeContentEntry;
 use pocketmine\Player;
+use function array_map;
 use function in_array;
 use function is_array;
 
@@ -196,16 +198,11 @@ class PlayerInventory extends BaseInventory{
 		if(!($holder instanceof Player)){
 			throw new \LogicException("Cannot send creative inventory contents to non-player inventory holder");
 		}
-		$pk = new InventoryContentPacket();
-		$pk->windowId = ContainerIds::CREATIVE;
 
-		if(!$holder->isSpectator()){ //fill it for all gamemodes except spectator
-			foreach(Item::getCreativeItems() as $i => $item){
-				$pk->items[$i] = clone $item;
-			}
-		}
-
-		$holder->dataPacket($pk);
+		$nextEntryId = 1;
+		$holder->sendDataPacket(CreativeContentPacket::create(array_map(function(Item $item) use (&$nextEntryId) : CreativeContentEntry{
+			return new CreativeContentEntry($nextEntryId++, clone $item);
+		}, $holder->isSpectator() ? [] : Item::getCreativeItems()))); //fill it for all gamemodes except spectator
 	}
 
 	/**

src/pocketmine/inventory/ShapedRecipe.php

@@ -164,7 +164,7 @@ class ShapedRecipe implements CraftingRecipe{
 	}
 
 	public function getIngredient(int $x, int $y) : Item{
-		$exists = $this->ingredientList[$this->shape[$y]{$x}] ?? null;
+		$exists = $this->ingredientList[$this->shape[$y][$x]] ?? null;
 		return $exists !== null ? clone $exists : ItemFactory::get(Item::AIR, 0, 0);
 	}
 

src/pocketmine/inventory/transaction/CraftingTransaction.php

@@ -27,7 +27,7 @@ use pocketmine\event\inventory\CraftItemEvent;
 use pocketmine\inventory\CraftingRecipe;
 use pocketmine\item\Item;
 use pocketmine\network\mcpe\protocol\ContainerClosePacket;
-use pocketmine\network\mcpe\protocol\types\ContainerIds;
+use pocketmine\Player;
 use function array_pop;
 use function count;
 use function intdiv;
@@ -165,7 +165,7 @@ class CraftingTransaction extends InventoryTransaction{
 		 * transaction goes wrong.
 		 */
 		$pk = new ContainerClosePacket();
-		$pk->windowId = ContainerIds::NONE;
+		$pk->windowId = Player::HARDCODED_CRAFTING_GRID_WINDOW_ID;
 		$this->source->dataPacket($pk);
 	}
 

src/pocketmine/inventory/transaction/InventoryTransaction.php

@@ -136,6 +136,8 @@ class InventoryTransaction{
 	 * @throws TransactionValidationException
 	 */
 	protected function matchItems(array &$needItems, array &$haveItems) : void{
+		$needItems = [];
+		$haveItems = [];
 		foreach($this->actions as $key => $action){
 			if(!$action->getTargetItem()->isNull()){
 				$needItems[] = $action->getTargetItem();

src/pocketmine/item/ChorusFruit.php

@@ -27,7 +27,6 @@ use pocketmine\block\Liquid;
 use pocketmine\entity\Living;
 use pocketmine\level\sound\EndermanTeleportSound;
 use pocketmine\math\Vector3;
-use function assert;
 use function min;
 use function mt_rand;
 

src/pocketmine/item/Item.php

@@ -42,6 +42,7 @@ use pocketmine\nbt\tag\NamedTag;
 use pocketmine\nbt\tag\ShortTag;
 use pocketmine\nbt\tag\StringTag;
 use pocketmine\Player;
+use pocketmine\utils\AssumptionFailedError;
 use pocketmine\utils\Binary;
 use function array_map;
 use function base64_decode;
@@ -475,7 +476,12 @@ class Item implements ItemIds, \JsonSerializable{
 	public function getLore() : array{
 		$display = $this->getNamedTagEntry(self::TAG_DISPLAY);
 		if($display instanceof CompoundTag and ($lore = $display->getListTag(self::TAG_DISPLAY_LORE)) !== null){
-			return $lore->getAllValues();
+			return array_map(function(NamedTag $line) : string{
+				if(!($line instanceof StringTag)){
+					throw new AssumptionFailedError("Nobody bothered to handle this error case and we can't fix it until PM4, oops ... #blameshoghi");
+				}
+				return $line->getValue();
+			}, $lore->getValue());
 		}
 
 		return [];

src/pocketmine/item/ItemFactory.php

@@ -34,8 +34,8 @@ use function gettype;
 use function is_numeric;
 use function is_object;
 use function is_string;
+use function mb_strtoupper;
 use function str_replace;
-use function strtoupper;
 use function trim;
 
 /**
@@ -375,8 +375,8 @@ class ItemFactory{
 
 		if(is_numeric($b[0])){
 			$item = self::get((int) $b[0], $meta);
-		}elseif(defined(ItemIds::class . "::" . strtoupper($b[0]))){
-			$item = self::get(constant(ItemIds::class . "::" . strtoupper($b[0])), $meta);
+		}elseif(defined(ItemIds::class . "::" . mb_strtoupper($b[0]))){
+			$item = self::get(constant(ItemIds::class . "::" . mb_strtoupper($b[0])), $meta);
 		}else{
 			throw new \InvalidArgumentException("Unable to resolve \"" . $str . "\" to a valid item");
 		}

src/pocketmine/item/enchantment/Enchantment.php

@@ -26,7 +26,7 @@ namespace pocketmine\item\enchantment;
 use pocketmine\event\entity\EntityDamageEvent;
 use function constant;
 use function defined;
-use function strtoupper;
+use function mb_strtoupper;
 
 /**
  * Manages enchantment type data.
@@ -69,6 +69,7 @@ class Enchantment{
 	public const MULTISHOT = 33;
 	public const PIERCING = 34;
 	public const QUICK_CHARGE = 35;
+	public const SOUL_SPEED = 36;
 
 	public const RARITY_COMMON = 10;
 	public const RARITY_UNCOMMON = 5;
@@ -161,7 +162,7 @@ class Enchantment{
 	}
 
 	public static function getEnchantmentByName(string $name) : ?Enchantment{
-		$const = Enchantment::class . "::" . strtoupper($name);
+		$const = Enchantment::class . "::" . mb_strtoupper($name);
 		if(defined($const)){
 			return self::getEnchantment(constant($const));
 		}

src/pocketmine/lang/BaseLang.php

@@ -131,7 +131,7 @@ class BaseLang{
 		$baseText = $this->parseTranslation(($onlyPrefix === null or strpos($str, $onlyPrefix) === 0) ? $baseText : $str, $onlyPrefix);
 
 		foreach($params as $i => $p){
-			$baseText = str_replace("{%$i}", $this->parseTranslation((string) $p), $baseText, $onlyPrefix);
+			$baseText = str_replace("{%$i}", $this->parseTranslation((string) $p), $baseText);
 		}
 
 		return $baseText;

src/pocketmine/level/Explosion.php

@@ -132,8 +132,11 @@ class Explosion{
 							if($blockId !== 0){
 								$blastForce -= (BlockFactory::$blastResistance[$blockId] / 5 + 0.3) * $this->stepLen;
 								if($blastForce > 0){
-									if(!isset($this->affectedBlocks[$index = Level::blockHash($vBlock->x, $vBlock->y, $vBlock->z)])){
-										$this->affectedBlocks[$index] = BlockFactory::get($blockId, $this->subChunkHandler->currentSubChunk->getBlockData($vBlock->x & 0x0f, $vBlock->y & 0x0f, $vBlock->z & 0x0f), $vBlock);
+									if(!isset($this->affectedBlocks[Level::blockHash($vBlock->x, $vBlock->y, $vBlock->z)])){
+										$_block = BlockFactory::get($blockId, $this->subChunkHandler->currentSubChunk->getBlockData($vBlock->x & 0x0f, $vBlock->y & 0x0f, $vBlock->z & 0x0f), $vBlock);
+										foreach($_block->getAffectedBlocks() as $_affectedBlock){
+											$this->affectedBlocks[Level::blockHash($_affectedBlock->x, $_affectedBlock->y, $_affectedBlock->z)] = $_affectedBlock;
+										}
 									}
 								}
 							}
@@ -229,7 +232,9 @@ class Explosion{
 
 				$t->close();
 			}
+		}
 
+		foreach($this->affectedBlocks as $block){
 			$pos = new Vector3($block->x, $block->y, $block->z);
 
 			for($side = 0; $side <= 5; $side++){

src/pocketmine/level/Level.php

@@ -72,6 +72,7 @@ use pocketmine\metadata\Metadatable;
 use pocketmine\metadata\MetadataValue;
 use pocketmine\nbt\tag\ListTag;
 use pocketmine\nbt\tag\StringTag;
+use pocketmine\network\mcpe\convert\RuntimeBlockMapping;
 use pocketmine\network\mcpe\protocol\AddActorPacket;
 use pocketmine\network\mcpe\protocol\BatchPacket;
 use pocketmine\network\mcpe\protocol\DataPacket;
@@ -79,7 +80,6 @@ use pocketmine\network\mcpe\protocol\LevelEventPacket;
 use pocketmine\network\mcpe\protocol\LevelSoundEventPacket;
 use pocketmine\network\mcpe\protocol\SetDifficultyPacket;
 use pocketmine\network\mcpe\protocol\SetTimePacket;
-use pocketmine\network\mcpe\protocol\types\RuntimeBlockMapping;
 use pocketmine\network\mcpe\protocol\UpdateBlockPacket;
 use pocketmine\Player;
 use pocketmine\plugin\Plugin;
@@ -216,12 +216,18 @@ class Level implements ChunkManager, Metadatable{
 	/** @var Vector3[][] */
 	private $changedBlocks = [];
 
-	/** @var ReversePriorityQueue */
+	/**
+	 * @var ReversePriorityQueue
+	 * @phpstan-var ReversePriorityQueue<int, Vector3>
+	 */
 	private $scheduledBlockUpdateQueue;
 	/** @var int[] */
 	private $scheduledBlockUpdateQueueIndex = [];
 
-	/** @var \SplQueue */
+	/**
+	 * @var \SplQueue
+	 * @phpstan-var \SplQueue<int>
+	 */
 	private $neighbourBlockUpdateQueue;
 
 	/** @var Player[][] */

src/pocketmine/level/Position.php

@@ -24,8 +24,8 @@ declare(strict_types=1);
 namespace pocketmine\level;
 
 use pocketmine\math\Vector3;
-use pocketmine\utils\MainLogger;
 use pocketmine\utils\AssumptionFailedError;
+use pocketmine\utils\MainLogger;
 use function assert;
 
 class Position extends Vector3{

src/pocketmine/level/format/Chunk.php

@@ -30,6 +30,7 @@ use pocketmine\block\BlockFactory;
 use pocketmine\entity\Entity;
 use pocketmine\level\Level;
 use pocketmine\nbt\tag\CompoundTag;
+use pocketmine\nbt\tag\IntTag;
 use pocketmine\nbt\tag\StringTag;
 use pocketmine\Player;
 use pocketmine\tile\Spawnable;
@@ -109,6 +110,7 @@ class Chunk{
 	 * @param CompoundTag[]       $entities
 	 * @param CompoundTag[]       $tiles
 	 * @param int[]               $heightMap
+	 * @phpstan-param list<int> $heightMap
 	 */
 	public function __construct(int $chunkX, int $chunkZ, array $subChunks = [], array $entities = [], array $tiles = [], string $biomeIds = "", array $heightMap = []){
 		$this->x = $chunkX;
@@ -690,13 +692,14 @@ class Chunk{
 
 			$level->timings->syncChunkLoadEntitiesTimer->startTiming();
 			foreach($this->NBTentities as $nbt){
-				if(!$nbt->hasTag("id")){ //allow mixed types (because of leveldb)
+				$idTag = $nbt->getTag("id");
+				if(!($idTag instanceof IntTag) && !($idTag instanceof StringTag)){ //allow mixed types (because of leveldb)
 					$changed = true;
 					continue;
 				}
 
 				try{
-					$entity = Entity::createEntity($nbt->getTag("id")->getValue(), $level, $nbt);
+					$entity = Entity::createEntity($idTag->getValue(), $level, $nbt);
 					if(!($entity instanceof Entity)){
 						$changed = true;
 						continue;

src/pocketmine/level/format/SubChunk.php

@@ -38,6 +38,8 @@ if(!defined(__NAMESPACE__ . '\ZERO_NIBBLE_ARRAY')){
 }
 
 class SubChunk implements SubChunkInterface{
+	private const ZERO_NIBBLE_ARRAY = ZERO_NIBBLE_ARRAY;
+
 	/** @var string */
 	protected $ids;
 	/** @var string */
@@ -68,7 +70,7 @@ class SubChunk implements SubChunkInterface{
 			substr_count($this->ids, "\x00") === 4096 and
 			(!$checkLight or (
 				substr_count($this->skyLight, "\xff") === 2048 and
-				$this->blockLight === ZERO_NIBBLE_ARRAY
+				$this->blockLight === self::ZERO_NIBBLE_ARRAY
 			))
 		);
 	}
@@ -230,14 +232,14 @@ class SubChunk implements SubChunkInterface{
 		 * reference to the const instead of duplicating the whole string. The string will only be duplicated when
 		 * modified, which is perfect for this purpose.
 		 */
-		if($this->data === ZERO_NIBBLE_ARRAY){
-			$this->data = ZERO_NIBBLE_ARRAY;
+		if($this->data === self::ZERO_NIBBLE_ARRAY){
+			$this->data = self::ZERO_NIBBLE_ARRAY;
 		}
-		if($this->skyLight === ZERO_NIBBLE_ARRAY){
-			$this->skyLight = ZERO_NIBBLE_ARRAY;
+		if($this->skyLight === self::ZERO_NIBBLE_ARRAY){
+			$this->skyLight = self::ZERO_NIBBLE_ARRAY;
 		}
-		if($this->blockLight === ZERO_NIBBLE_ARRAY){
-			$this->blockLight = ZERO_NIBBLE_ARRAY;
+		if($this->blockLight === self::ZERO_NIBBLE_ARRAY){
+			$this->blockLight = self::ZERO_NIBBLE_ARRAY;
 		}
 	}
 }

src/pocketmine/level/format/io/ChunkUtils.php

@@ -98,6 +98,7 @@ if(!extension_loaded('pocketmine_chunkutils')){
 		 * Converts pre-MCPE-1.0 biome color array to biome ID array.
 		 *
 		 * @param int[] $array of biome color values
+		 * @phpstan-param list<int> $array
 		 */
 		public static function convertBiomeColors(array $array) : string{
 			$result = str_repeat("\x00", 256);

src/pocketmine/level/format/io/leveldb/LevelDB.php

@@ -131,7 +131,11 @@ class LevelDB extends BaseLevelProvider{
 			throw new LevelException("Truncated level.dat");
 		}
 		$nbt = new LittleEndianNBTStream();
-		$levelData = $nbt->read(substr($rawLevelData, 8));
+		try{
+			$levelData = $nbt->read(substr($rawLevelData, 8));
+		}catch(\UnexpectedValueException $e){
+			throw new LevelException("Invalid level.dat (" . $e->getMessage() . ")", 0, $e);
+		}
 		if($levelData instanceof CompoundTag){
 			$this->levelData = $levelData;
 		}else{
@@ -301,7 +305,8 @@ class LevelDB extends BaseLevelProvider{
 	protected function readChunk(int $chunkX, int $chunkZ) : ?Chunk{
 		$index = LevelDB::chunkIndex($chunkX, $chunkZ);
 
-		if(!$this->chunkExists($chunkX, $chunkZ)){
+		$chunkVersionRaw = $this->db->get($index . self::TAG_VERSION);
+		if($chunkVersionRaw === false){
 			return null;
 		}
 
@@ -316,7 +321,7 @@ class LevelDB extends BaseLevelProvider{
 		/** @var bool $lightPopulated */
 		$lightPopulated = true;
 
-		$chunkVersion = ord($this->db->get($index . self::TAG_VERSION));
+		$chunkVersion = ord($chunkVersionRaw);
 		$hasBeenUpgraded = $chunkVersion < self::CURRENT_LEVEL_CHUNK_VERSION;
 
 		$binaryStream = new BinaryStream();
@@ -368,7 +373,11 @@ class LevelDB extends BaseLevelProvider{
 				}
 				break;
 			case 2: // < MCPE 1.0
-				$binaryStream->setBuffer($this->db->get($index . self::TAG_LEGACY_TERRAIN));
+				$legacyTerrain = $this->db->get($index . self::TAG_LEGACY_TERRAIN);
+				if($legacyTerrain === false){
+					throw new CorruptedChunkException("Expected to find a LEGACY_TERRAIN key for this chunk version, but none found");
+				}
+				$binaryStream->setBuffer($legacyTerrain);
 				$fullIds = $binaryStream->get(32768);
 				$fullData = $binaryStream->get(16384);
 				$fullSkyLight = $binaryStream->get(16384);

src/pocketmine/level/format/io/region/RegionGarbageMap.php

@@ -0,0 +1,157 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\level\format\io\region;
+
+use pocketmine\utils\AssumptionFailedError;
+use function end;
+use function ksort;
+use function time;
+use const SORT_NUMERIC;
+
+final class RegionGarbageMap{
+
+	/** @var RegionLocationTableEntry[] */
+	private $entries = [];
+	/** @var bool */
+	private $clean = false;
+
+	/**
+	 * @param RegionLocationTableEntry[] $entries
+	 */
+	public function __construct(array $entries){
+		foreach($entries as $entry){
+			$this->entries[$entry->getFirstSector()] = $entry;
+		}
+	}
+
+	/**
+	 * @param RegionLocationTableEntry[]|null[] $locationTable
+	 */
+	public static function buildFromLocationTable(array $locationTable) : self{
+		/** @var RegionLocationTableEntry[] $usedMap */
+		$usedMap = [];
+		foreach($locationTable as $entry){
+			if($entry === null){
+				continue;
+			}
+			if(isset($usedMap[$entry->getFirstSector()])){
+				throw new AssumptionFailedError("Overlapping entries detected");
+			}
+			$usedMap[$entry->getFirstSector()] = $entry;
+		}
+
+		ksort($usedMap, SORT_NUMERIC);
+
+		/** @var RegionLocationTableEntry[] $garbageMap */
+		$garbageMap = [];
+
+		/** @var RegionLocationTableEntry|null $prevEntry */
+		$prevEntry = null;
+		foreach($usedMap as $firstSector => $entry){
+			$prevEndPlusOne = ($prevEntry !== null ? $prevEntry->getLastSector() + 1 : RegionLoader::FIRST_SECTOR);
+			$currentStart = $entry->getFirstSector();
+			if($prevEndPlusOne < $currentStart){
+				//found a gap in the table
+				$garbageMap[$prevEndPlusOne] = new RegionLocationTableEntry($prevEndPlusOne, $currentStart - $prevEndPlusOne, 0);
+			}elseif($prevEndPlusOne > $currentStart){
+				//current entry starts inside the previous. This would be a bug since RegionLoader should prevent this
+				throw new AssumptionFailedError("Overlapping entries detected");
+			}
+			$prevEntry = $entry;
+		}
+
+		return new self($garbageMap);
+	}
+
+	/**
+	 * @return RegionLocationTableEntry[]
+	 * @phpstan-return array<int, RegionLocationTableEntry>
+	 */
+	public function getArray() : array{
+		if(!$this->clean){
+			ksort($this->entries, SORT_NUMERIC);
+
+			/** @var int|null $prevIndex */
+			$prevIndex = null;
+			foreach($this->entries as $k => $entry){
+				if($prevIndex !== null and $this->entries[$prevIndex]->getLastSector() + 1 === $entry->getFirstSector()){
+					//this SHOULD overwrite the previous index and not appear at the end
+					$this->entries[$prevIndex] = new RegionLocationTableEntry(
+						$this->entries[$prevIndex]->getFirstSector(),
+						$this->entries[$prevIndex]->getSectorCount() + $entry->getSectorCount(),
+						0
+					);
+					unset($this->entries[$k]);
+				}else{
+					$prevIndex = $k;
+				}
+			}
+			$this->clean = true;
+		}
+		return $this->entries;
+	}
+
+	public function add(RegionLocationTableEntry $entry) : void{
+		if(isset($this->entries[$k = $entry->getFirstSector()])){
+			throw new \InvalidArgumentException("Overlapping entry starting at " . $k);
+		}
+		$this->entries[$k] = $entry;
+		$this->clean = false;
+	}
+
+	public function remove(RegionLocationTableEntry $entry) : void{
+		if(isset($this->entries[$k = $entry->getFirstSector()])){
+			//removal doesn't affect ordering and shouldn't affect fragmentation
+			unset($this->entries[$k]);
+		}
+	}
+
+	public function end() : ?RegionLocationTableEntry{
+		$array = $this->getArray();
+		$end = end($array);
+		return $end !== false ? $end : null;
+	}
+
+	public function allocate(int $newSize) : ?RegionLocationTableEntry{
+		foreach($this->getArray() as $start => $candidate){
+			$candidateSize = $candidate->getSectorCount();
+			if($candidateSize < $newSize){
+				continue;
+			}
+
+			$newLocation = new RegionLocationTableEntry($candidate->getFirstSector(), $newSize, time());
+			$this->remove($candidate);
+
+			if($candidateSize > $newSize){ //we're not using the whole area, just take part of it
+				$newGarbageStart = $candidate->getFirstSector() + $newSize;
+				$newGarbageSize = $candidateSize - $newSize;
+				$this->add(new RegionLocationTableEntry($newGarbageStart, $newGarbageSize, 0));
+			}
+			return $newLocation;
+
+		}
+
+		return null;
+	}
+}

src/pocketmine/level/format/io/region/RegionLoader.php

@@ -28,6 +28,7 @@ use pocketmine\level\format\io\exception\CorruptedChunkException;
 use pocketmine\utils\AssumptionFailedError;
 use pocketmine\utils\Binary;
 use pocketmine\utils\MainLogger;
+use function assert;
 use function ceil;
 use function chr;
 use function fclose;
@@ -40,10 +41,12 @@ use function fseek;
 use function ftruncate;
 use function fwrite;
 use function is_resource;
+use function ksort;
 use function max;
 use function ord;
 use function pack;
 use function str_pad;
+use function str_repeat;
 use function stream_set_read_buffer;
 use function stream_set_write_buffer;
 use function strlen;
@@ -51,6 +54,7 @@ use function substr;
 use function time;
 use function touch;
 use function unpack;
+use const SORT_NUMERIC;
 use const STR_PAD_RIGHT;
 
 class RegionLoader{
@@ -61,7 +65,7 @@ class RegionLoader{
 	public const MAX_SECTOR_LENGTH = 255 << 12; //255 sectors (~0.996 MiB)
 	public const REGION_HEADER_LENGTH = 8192; //4096 location table + 4096 timestamps
 
-	private const FIRST_SECTOR = 2; //location table occupies 0 and 1
+	public const FIRST_SECTOR = 2; //location table occupies 0 and 1
 
 	/** @var int */
 	public static $COMPRESSION_LEVEL = 7;
@@ -76,8 +80,10 @@ class RegionLoader{
 	protected $filePointer;
 	/** @var int */
 	protected $nextSector = self::FIRST_SECTOR;
-	/** @var RegionLocationTableEntry[] */
+	/** @var RegionLocationTableEntry[]|null[] */
 	protected $locationTable = [];
+	/** @var RegionGarbageMap */
+	protected $garbageTable;
 	/** @var int */
 	public $lastUsed = 0;
 
@@ -85,6 +91,7 @@ class RegionLoader{
 		$this->x = $regionX;
 		$this->z = $regionZ;
 		$this->filePath = $filePath;
+		$this->garbageTable = new RegionGarbageMap([]);
 	}
 
 	/**
@@ -121,7 +128,7 @@ class RegionLoader{
 	}
 
 	protected function isChunkGenerated(int $index) : bool{
-		return !$this->locationTable[$index]->isNull();
+		return $this->locationTable[$index] !== null;
 	}
 
 	/**
@@ -133,7 +140,7 @@ class RegionLoader{
 
 		$this->lastUsed = time();
 
-		if(!$this->isChunkGenerated($index)){
+		if($this->locationTable[$index] === null){
 			return null;
 		}
 
@@ -194,19 +201,50 @@ class RegionLoader{
 
 		$newSize = (int) ceil(($length + 4) / 4096);
 		$index = self::getChunkOffset($x, $z);
-		$offset = $this->locationTable[$index]->getFirstSector();
 
-		if($this->locationTable[$index]->getSectorCount() < $newSize){
-			$offset = $this->nextSector;
+		/*
+		 * look for an unused area big enough to hold this data
+		 * this is corruption-resistant (it leaves the old data intact if a failure occurs when writing new data), and
+		 * also allows the file to become more compact across consecutive writes without introducing a dedicated garbage
+		 * collection mechanism.
+		 */
+		$newLocation = $this->garbageTable->allocate($newSize);
+
+		/* if no gaps big enough were found, append to the end of the file instead */
+		if($newLocation === null){
+			$newLocation = new RegionLocationTableEntry($this->nextSector, $newSize, time());
+			$this->bumpNextFreeSector($newLocation);
 		}
 
-		$this->locationTable[$index] = new RegionLocationTableEntry($offset, $newSize, time());
-		$this->bumpNextFreeSector($this->locationTable[$index]);
-
-		fseek($this->filePointer, $offset << 12);
+		/* write the chunk data into the chosen location */
+		fseek($this->filePointer, $newLocation->getFirstSector() << 12);
 		fwrite($this->filePointer, str_pad(Binary::writeInt($length) . chr(self::COMPRESSION_ZLIB) . $chunkData, $newSize << 12, "\x00", STR_PAD_RIGHT));
 
+		/*
+		 * update the file header - we do this after writing the main data, so that if a failure occurs while writing,
+		 * the header will still point to the old (intact) copy of the chunk, instead of a potentially broken new
+		 * version of the file (e.g. partially written).
+		*/
+		$oldLocation = $this->locationTable[$index];
+		$this->locationTable[$index] = $newLocation;
 		$this->writeLocationIndex($index);
+
+		if($oldLocation !== null){
+			/* release the area containing the old copy to the garbage pool */
+			$this->garbageTable->add($oldLocation);
+
+			$endGarbage = $this->garbageTable->end();
+			$nextSector = $this->nextSector;
+			for(; $endGarbage !== null and $endGarbage->getLastSector() + 1 === $nextSector; $endGarbage = $this->garbageTable->end()){
+				$nextSector = $endGarbage->getFirstSector();
+				$this->garbageTable->remove($endGarbage);
+			}
+
+			if($nextSector !== $this->nextSector){
+				$this->nextSector = $nextSector;
+				ftruncate($this->filePointer, $this->nextSector << 12);
+			}
+		}
 	}
 
 	/**
@@ -215,7 +253,7 @@ class RegionLoader{
 	 */
 	public function removeChunk(int $x, int $z){
 		$index = self::getChunkOffset($x, $z);
-		$this->locationTable[$index] = new RegionLocationTableEntry(0, 0, 0);
+		$this->locationTable[$index] = null;
 		$this->writeLocationIndex($index);
 	}
 
@@ -261,27 +299,33 @@ class RegionLoader{
 		fseek($this->filePointer, 0);
 
 		$headerRaw = fread($this->filePointer, self::REGION_HEADER_LENGTH);
-		if(($len = strlen($headerRaw)) !== self::REGION_HEADER_LENGTH){
-			throw new CorruptedRegionException("Invalid region file header, expected " . self::REGION_HEADER_LENGTH . " bytes, got " . $len . " bytes");
+		if($headerRaw === false or strlen($headerRaw) !== self::REGION_HEADER_LENGTH){
+			throw new CorruptedRegionException("Corrupted region header (unexpected end of file)");
 		}
 
+		/** @var int[] $data */
 		$data = unpack("N*", $headerRaw);
 
 		for($i = 0; $i < 1024; ++$i){
 			$index = $data[$i + 1];
 			$offset = $index >> 8;
+			$sectorCount = $index & 0xff;
 			$timestamp = $data[$i + 1025];
 
-			if($offset === 0){
-				$this->locationTable[$i] = new RegionLocationTableEntry(0, 0, 0);
+			if($offset === 0 or $sectorCount === 0){
+				$this->locationTable[$i] = null;
+			}elseif($offset >= self::FIRST_SECTOR){
+				$this->bumpNextFreeSector($this->locationTable[$i] = new RegionLocationTableEntry($offset, $sectorCount, $timestamp));
 			}else{
-				$this->locationTable[$i] = new RegionLocationTableEntry($offset, $index & 0xff, $timestamp);
-				$this->bumpNextFreeSector($this->locationTable[$i]);
+				self::getChunkCoords($i, $chunkXX, $chunkZZ);
+				throw new CorruptedRegionException("Invalid region header entry for x=$chunkXX z=$chunkZZ, offset overlaps with header");
 			}
 		}
 
 		$this->checkLocationTableValidity();
 
+		$this->garbageTable = RegionGarbageMap::buildFromLocationTable($this->locationTable);
+
 		fseek($this->filePointer, 0);
 	}
 
@@ -294,7 +338,7 @@ class RegionLoader{
 
 		for($i = 0; $i < 1024; ++$i){
 			$entry = $this->locationTable[$i];
-			if($entry->isNull()){
+			if($entry === null){
 				continue;
 			}
 
@@ -314,16 +358,34 @@ class RegionLoader{
 			}
 			$usedOffsets[$offset] = $i;
 		}
+		ksort($usedOffsets, SORT_NUMERIC);
+		$prevLocationIndex = null;
+		foreach($usedOffsets as $startOffset => $locationTableIndex){
+			if($this->locationTable[$locationTableIndex] === null){
+				continue;
+			}
+			if($prevLocationIndex !== null){
+				assert($this->locationTable[$prevLocationIndex] !== null);
+				if($this->locationTable[$locationTableIndex]->overlaps($this->locationTable[$prevLocationIndex])){
+					self::getChunkCoords($locationTableIndex, $chunkXX, $chunkZZ);
+					self::getChunkCoords($prevLocationIndex, $prevChunkXX, $prevChunkZZ);
+					throw new CorruptedRegionException("Overlapping chunks detected in region header (chunk1: x=$chunkXX,z=$chunkZZ, chunk2: x=$prevChunkXX,z=$prevChunkZZ)");
+				}
+			}
+			$prevLocationIndex = $locationTableIndex;
+		}
 	}
 
 	private function writeLocationTable() : void{
 		$write = [];
 
 		for($i = 0; $i < 1024; ++$i){
-			$write[] = (($this->locationTable[$i]->getFirstSector() << 8) | $this->locationTable[$i]->getSectorCount());
+			$entry = $this->locationTable[$i];
+			$write[] = $entry !== null ? (($entry->getFirstSector() << 8) | $entry->getSectorCount()) : 0;
 		}
 		for($i = 0; $i < 1024; ++$i){
-			$write[] = $this->locationTable[$i]->getTimestamp();
+			$entry = $this->locationTable[$i];
+			$write[] = $entry !== null ? $entry->getTimestamp() : 0;
 		}
 		fseek($this->filePointer, 0);
 		fwrite($this->filePointer, pack("N*", ...$write), 4096 * 2);
@@ -335,10 +397,11 @@ class RegionLoader{
 	 * @return void
 	 */
 	protected function writeLocationIndex($index){
+		$entry = $this->locationTable[$index];
 		fseek($this->filePointer, $index << 2);
-		fwrite($this->filePointer, Binary::writeInt(($this->locationTable[$index]->getFirstSector() << 8) | $this->locationTable[$index]->getSectorCount()), 4);
+		fwrite($this->filePointer, Binary::writeInt($entry !== null ? ($entry->getFirstSector() << 8) | $entry->getSectorCount() : 0), 4);
 		fseek($this->filePointer, 4096 + ($index << 2));
-		fwrite($this->filePointer, Binary::writeInt($this->locationTable[$index]->getTimestamp()), 4);
+		fwrite($this->filePointer, Binary::writeInt($entry !== null ? $entry->getTimestamp() : 0), 4);
 	}
 
 	/**
@@ -348,12 +411,48 @@ class RegionLoader{
 		fseek($this->filePointer, 0);
 		ftruncate($this->filePointer, 8192); // this fills the file with the null byte
 		for($i = 0; $i < 1024; ++$i){
-			$this->locationTable[$i] = new RegionLocationTableEntry(0, 0, 0);
+			$this->locationTable[$i] = null;
 		}
 	}
 
 	private function bumpNextFreeSector(RegionLocationTableEntry $entry) : void{
-		$this->nextSector = max($this->nextSector, $entry->getLastSector()) + 1;
+		$this->nextSector = max($this->nextSector, $entry->getLastSector() + 1);
+	}
+
+	public function generateSectorMap(string $usedChar, string $freeChar) : string{
+		$result = str_repeat($freeChar, $this->nextSector);
+		for($i = 0; $i < self::FIRST_SECTOR; ++$i){
+			$result[$i] = $usedChar;
+		}
+		foreach($this->locationTable as $locationTableEntry){
+			if($locationTableEntry === null){
+				continue;
+			}
+			foreach($locationTableEntry->getUsedSectors() as $sectorIndex){
+				if($sectorIndex >= strlen($result)){
+					throw new AssumptionFailedError("This should never happen...");
+				}
+				if($result[$sectorIndex] === $usedChar){
+					throw new AssumptionFailedError("Overlap detected");
+				}
+				$result[$sectorIndex] = $usedChar;
+			}
+		}
+		return $result;
+	}
+
+	/**
+	 * Returns a float between 0 and 1 indicating what fraction of the file is currently unused space.
+	 */
+	public function getProportionUnusedSpace() : float{
+		$size = $this->nextSector;
+		$used = self::FIRST_SECTOR; //header is always allocated
+		foreach($this->locationTable as $entry){
+			if($entry !== null){
+				$used += $entry->getSectorCount();
+			}
+		}
+		return 1 - ($used / $size);
 	}
 
 	public function getX() : int{

src/pocketmine/level/format/io/region/RegionLocationTableEntry.php

@@ -38,12 +38,12 @@ class RegionLocationTableEntry{
 	 * @throws \InvalidArgumentException
 	 */
 	public function __construct(int $firstSector, int $sectorCount, int $timestamp){
-		if($firstSector < 0){
+		if($firstSector < 0 or $firstSector >= 2 ** 24){
 			throw new \InvalidArgumentException("Start sector must be positive, got $firstSector");
 		}
 		$this->firstSector = $firstSector;
-		if($sectorCount < 0 or $sectorCount > 255){
-			throw new \InvalidArgumentException("Sector count must be in range 0...255, got $sectorCount");
+		if($sectorCount < 1){
+			throw new \InvalidArgumentException("Sector count must be positive, got $sectorCount");
 		}
 		$this->sectorCount = $sectorCount;
 		$this->timestamp = $timestamp;
@@ -73,7 +73,16 @@ class RegionLocationTableEntry{
 		return $this->timestamp;
 	}
 
-	public function isNull() : bool{
-		return $this->firstSector === 0 or $this->sectorCount === 0;
+	public function overlaps(RegionLocationTableEntry $other) : bool{
+		$overlapCheck = static function(RegionLocationTableEntry $entry1, RegionLocationTableEntry $entry2) : bool{
+			$entry1Last = $entry1->getLastSector();
+			$entry2Last = $entry2->getLastSector();
+
+			return (
+				($entry2->firstSector >= $entry1->firstSector and $entry2->firstSector <= $entry1Last) or
+				($entry2Last >= $entry1->firstSector and $entry2Last <= $entry1Last)
+			);
+		};
+		return $overlapCheck($this, $other) or $overlapCheck($other, $this);
 	}
 }

src/pocketmine/level/generator/GeneratorRegisterTask.php

@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace pocketmine\level\generator;
 
 use pocketmine\block\BlockFactory;
+use pocketmine\item\ItemFactory;
 use pocketmine\level\biome\Biome;
 use pocketmine\level\Level;
 use pocketmine\level\SimpleChunkManager;
@@ -59,6 +60,7 @@ class GeneratorRegisterTask extends AsyncTask{
 
 	public function onRun(){
 		BlockFactory::init();
+		ItemFactory::init();
 		Biome::init();
 		$manager = new SimpleChunkManager($this->seed, $this->worldHeight);
 		$this->saveToThreadStore("generation.level{$this->levelId}.manager", $manager);