diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 000000000..993b80367
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,8 @@
+version: 2
+updates:
+- package-ecosystem: composer
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "10:00"
+  open-pull-requests-limit: 10
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 3d0f57287..7e4837157 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         image: [ubuntu-20.04]
-        php: [7.4.16]
+        php: [7.4.18]
 
     steps:
       - uses: actions/checkout@v2 #needed for build.sh
@@ -37,7 +37,7 @@ jobs:
       fail-fast: false
       matrix:
         image: [ubuntu-20.04]
-        php: [7.4.16]
+        php: [7.4.18]
 
     steps:
       - uses: actions/checkout@v2
@@ -87,7 +87,7 @@ jobs:
       fail-fast: false
       matrix:
         image: [ubuntu-20.04]
-        php: [7.4.16]
+        php: [7.4.18]
 
     steps:
       - uses: actions/checkout@v2
@@ -139,7 +139,7 @@ jobs:
       fail-fast: false
       matrix:
         image: [ubuntu-20.04]
-        php: [7.4.16]
+        php: [7.4.18]
 
     steps:
       - uses: actions/checkout@v2
@@ -191,7 +191,7 @@ jobs:
       fail-fast: false
       matrix:
         image: [ubuntu-20.04]
-        php: [7.4.16]
+        php: [7.4.18]
 
     steps:
       - uses: actions/checkout@v2
@@ -280,4 +280,4 @@ jobs:
           tools: php-cs-fixer
 
       - name: Run PHP-CS-Fixer
-        run: php-cs-fixer fix --dry-run --diff --diff-format=udiff
+        run: php-cs-fixer fix --dry-run --diff
diff --git a/.github/workflows/update-php-versions.php b/.github/workflows/update-php-versions.php
new file mode 100644
index 000000000..8b24812c8
--- /dev/null
+++ b/.github/workflows/update-php-versions.php
@@ -0,0 +1,51 @@
+<?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);
+
+const VERSIONS = [
+	"7.3",
+	"7.4",
+	"8.0"
+];
+
+$workflowFile = file_get_contents(__DIR__ . '/main.yml');
+$newWorkflowFile = $workflowFile;
+foreach(VERSIONS as $v){
+	$releaseInfo = file_get_contents("https://secure.php.net/releases?json&version=$v");
+	if($releaseInfo === false){
+		throw new \RuntimeException("Failed to contact php.net API");
+	}
+	$data = json_decode($releaseInfo, true);
+	if(!is_array($data) || !isset($data["version"]) || !is_string($data["version"]) || preg_match('/^\d+\.\d+\.\d+(-[A-Za-z\d]+)?$/', $data["version"]) === 0){
+		throw new \RuntimeException("Invalid data returned by API");
+	}
+	$updated = preg_replace("/$v\.\d+/", $data["version"], $newWorkflowFile);
+	if($updated !== $newWorkflowFile){
+		echo "Updated $v revision to " . $data["version"] . "\n";
+	}
+	$newWorkflowFile = $updated;
+}
+
+if($workflowFile !== $newWorkflowFile){
+	echo "Writing modified workflow file\n";
+	file_put_contents(__DIR__ . '/main.yml', $newWorkflowFile);
+}
diff --git a/.gitignore b/.gitignore
index 56671bfe2..ece01a7ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -50,3 +50,4 @@ Documentation/*
 
 # php-cs-fixer
 /.php_cs.cache
+/.php-cs-fixer.cache
diff --git a/.php_cs b/.php-cs-fixer.php
similarity index 97%
rename from .php_cs
rename to .php-cs-fixer.php
index 48c5278b0..d2ea8dfa2 100644
--- a/.php_cs
+++ b/.php-cs-fixer.php
@@ -9,7 +9,7 @@ $finder = PhpCsFixer\Finder::create()
 	->notContains('#ifndef COMPILE') //preprocessor will break if these are changed
 	->notName('PocketMine.php');
 
-return PhpCsFixer\Config::create()
+return (new PhpCsFixer\Config)
 	->setRiskyAllowed(true)
 	->setRules([
 		'align_multiline_comment' => [
diff --git a/composer.json b/composer.json
index ee45b2a7f..096638c97 100644
--- a/composer.json
+++ b/composer.json
@@ -50,7 +50,7 @@
       "respect/validation": "^2.0"
    },
    "require-dev": {
-      "phpstan/phpstan": "0.12.84",
+      "phpstan/phpstan": "0.12.85",
       "phpstan/phpstan-phpunit": "^0.12.6",
       "phpstan/phpstan-strict-rules": "^0.12.2",
       "phpunit/phpunit": "^9.2"
diff --git a/composer.lock b/composer.lock
index 018752547..83adc0a69 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "74d082e62d264fb0579bf4da87ab6eaf",
+    "content-hash": "6bd8f2ec899a5899fb8196fbd0fff82f",
     "packages": [
         {
             "name": "adhocore/json-comment",
@@ -1793,16 +1793,16 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "0.12.84",
+            "version": "0.12.85",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "9c43f15da8798c8f30a4b099e6a94530a558cfd5"
+                "reference": "20e6333c0067875ad7697cd8acdf245c6ef69d03"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/9c43f15da8798c8f30a4b099e6a94530a558cfd5",
-                "reference": "9c43f15da8798c8f30a4b099e6a94530a558cfd5",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/20e6333c0067875ad7697cd8acdf245c6ef69d03",
+                "reference": "20e6333c0067875ad7697cd8acdf245c6ef69d03",
                 "shasum": ""
             },
             "require": {
@@ -1833,7 +1833,7 @@
             "description": "PHPStan - PHP Static Analysis Tool",
             "support": {
                 "issues": "https://github.com/phpstan/phpstan/issues",
-                "source": "https://github.com/phpstan/phpstan/tree/0.12.84"
+                "source": "https://github.com/phpstan/phpstan/tree/0.12.85"
             },
             "funding": [
                 {
@@ -1849,7 +1849,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2021-04-19T17:10:54+00:00"
+            "time": "2021-04-27T14:13:16+00:00"
         },
         {
             "name": "phpstan/phpstan-phpunit",
diff --git a/src/block/BaseSign.php b/src/block/BaseSign.php
index 1709e4a8a..3e047c2bd 100644
--- a/src/block/BaseSign.php
+++ b/src/block/BaseSign.php
@@ -26,9 +26,12 @@ namespace pocketmine\block;
 use pocketmine\block\tile\Sign as TileSign;
 use pocketmine\block\utils\SignText;
 use pocketmine\event\block\SignChangeEvent;
+use pocketmine\item\Item;
 use pocketmine\math\AxisAlignedBB;
+use pocketmine\math\Vector3;
 use pocketmine\player\Player;
 use pocketmine\utils\TextFormat;
+use pocketmine\world\BlockTransaction;
 use function array_map;
 use function assert;
 use function strlen;
@@ -39,6 +42,9 @@ abstract class BaseSign extends Transparent{
 	/** @var SignText */
 	protected $text;
 
+	/** @var int|null */
+	protected $editorEntityRuntimeId = null;
+
 	public function __construct(BlockIdentifier $idInfo, string $name, ?BlockBreakInfo $breakInfo = null){
 		parent::__construct($idInfo, $name, $breakInfo ?? new BlockBreakInfo(1.0, BlockToolType::AXE));
 		$this->text = new SignText();
@@ -49,6 +55,7 @@ abstract class BaseSign extends Transparent{
 		$tile = $this->pos->getWorld()->getTile($this->pos);
 		if($tile instanceof TileSign){
 			$this->text = $tile->getText();
+			$this->editorEntityRuntimeId = $tile->getEditorEntityRuntimeId();
 		}
 	}
 
@@ -57,6 +64,7 @@ abstract class BaseSign extends Transparent{
 		$tile = $this->pos->getWorld()->getTile($this->pos);
 		assert($tile instanceof TileSign);
 		$tile->setText($this->text);
+		$tile->setEditorEntityRuntimeId($this->editorEntityRuntimeId);
 	}
 
 	public function isSolid() : bool{
@@ -78,6 +86,13 @@ abstract class BaseSign extends Transparent{
 		}
 	}
 
+	public function place(BlockTransaction $tx, Item $item, Block $blockReplace, Block $blockClicked, int $face, Vector3 $clickVector, ?Player $player = null) : bool{
+		if($player !== null){
+			$this->editorEntityRuntimeId = $player->getId();
+		}
+		return parent::place($tx, $item, $blockReplace, $blockClicked, $face, $clickVector, $player);
+	}
+
 	/**
 	 * Returns an object containing information about the sign text.
 	 */
@@ -108,6 +123,9 @@ abstract class BaseSign extends Transparent{
 		$ev = new SignChangeEvent($this, $author, new SignText(array_map(function(string $line) : string{
 			return TextFormat::clean($line, false);
 		}, $text->getLines())));
+		if($this->editorEntityRuntimeId === null || $this->editorEntityRuntimeId !== $author->getId()){
+			$ev->cancel();
+		}
 		$ev->call();
 		if(!$ev->isCancelled()){
 			$this->setText($ev->getNewText());
diff --git a/src/block/tile/Sign.php b/src/block/tile/Sign.php
index 8701d4a0b..38cad085f 100644
--- a/src/block/tile/Sign.php
+++ b/src/block/tile/Sign.php
@@ -53,6 +53,9 @@ class Sign extends Spawnable{
 	/** @var SignText */
 	protected $text;
 
+	/** @var int|null */
+	protected $editorEntityRuntimeId = null;
+
 	public function __construct(World $world, Vector3 $pos){
 		$this->text = new SignText();
 		parent::__construct($world, $pos);
@@ -90,6 +93,22 @@ class Sign extends Spawnable{
 		$this->text = $text;
 	}
 
+	/**
+	 * Returns the entity runtime ID of the player who placed this sign. Only the player whose entity ID matches this
+	 * one may edit the sign text.
+	 * This is needed because as of 1.16.220, there is still no reliable way to detect when the MCPE client closed the
+	 * sign edit GUI, so we have no way to know when the text is finalized. This limits editing of the text to only the
+	 * player who placed it, and only while that player is online.
+	 * We can say for sure that the sign is finalized if either of the following occurs:
+	 * - The player quits (after rejoin, the player's entity runtimeID will be different).
+	 * - The chunk is unloaded (on next load, the entity runtimeID will be null, because it's not saved).
+	 */
+	public function getEditorEntityRuntimeId() : ?int{ return $this->editorEntityRuntimeId; }
+
+	public function setEditorEntityRuntimeId(?int $editorEntityRuntimeId) : void{
+		$this->editorEntityRuntimeId = $editorEntityRuntimeId;
+	}
+
 	protected function addAdditionalSpawnData(CompoundTag $nbt) : void{
 		$nbt->setString(self::TAG_TEXT_BLOB, implode("\n", $this->text->getLines()));
 	}
diff --git a/src/network/mcpe/protocol/types/inventory/UseItemOnEntityTransactionData.php b/src/network/mcpe/protocol/types/inventory/UseItemOnEntityTransactionData.php
index 9b9de7c1e..857df5e60 100644
--- a/src/network/mcpe/protocol/types/inventory/UseItemOnEntityTransactionData.php
+++ b/src/network/mcpe/protocol/types/inventory/UseItemOnEntityTransactionData.php
@@ -30,6 +30,7 @@ use pocketmine\network\mcpe\protocol\serializer\PacketSerializer;
 class UseItemOnEntityTransactionData extends TransactionData{
 	public const ACTION_INTERACT = 0;
 	public const ACTION_ATTACK = 1;
+	public const ACTION_ITEM_INTERACT = 2;
 
 	/** @var int */
 	private $entityRuntimeId;