From 66d9b64b2f327cefc3d0659e64daee01e8ed4620 Mon Sep 17 00:00:00 2001
From: Matthias Schmidt <gravatronics@live.com>
Date: Sun, 18 Aug 2019 12:40:35 +0200
Subject: [PATCH] Check if main directories are writable during Core updates

See #2847
---
 .../install/files/lib/system/WCF.class.php    | 74 +++++++++++++++++++
 .../PackageInstallationDispatcher.class.php   |  5 +-
 2 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/wcfsetup/install/files/lib/system/WCF.class.php b/wcfsetup/install/files/lib/system/WCF.class.php
index 4faf6054dc..8248040996 100644
--- a/wcfsetup/install/files/lib/system/WCF.class.php
+++ b/wcfsetup/install/files/lib/system/WCF.class.php
@@ -34,6 +34,7 @@ use wcf\system\style\StyleHandler;
 use wcf\system\template\EmailTemplateEngine;
 use wcf\system\template\TemplateEngine;
 use wcf\system\user\storage\UserStorageHandler;
+use wcf\util\DirectoryUtil;
 use wcf\util\FileUtil;
 use wcf\util\HeaderUtil;
 use wcf\util\StringUtil;
@@ -1129,4 +1130,77 @@ class WCF {
 			self::getTPL()->assign('executeCronjobs', CronjobScheduler::getInstance()->getNextExec() < TIME_NOW && defined('OFFLINE') && !OFFLINE);
 		}
 	}
+	
+	/**
+	 * Checks recursively that the most important system files of `com.woltlab.wcf` are writable.
+	 * 
+	 * @throws	\RuntimeException	if any relevant file or directory is not writable
+	 */
+	public static function checkWritability() {
+		$nonWritablePaths = [];
+		
+		$nonRecursiveDirectories = [
+			'',
+			'acp/',
+			'tmp/'
+		];
+		foreach ($nonRecursiveDirectories as $directory) {
+			$path = WCF_DIR . $directory;
+			if ($path === 'tmp/' && !is_dir($path)) {
+				continue;
+			}
+			
+			if (!is_writable($path)) {
+				$nonWritablePaths[] = $path;
+				continue;
+			}
+			
+			DirectoryUtil::getInstance($path, false)->executeCallback(function($file, \SplFileInfo $fileInfo) use ($path, &$nonWritablePaths) {
+				if ($fileInfo instanceof \DirectoryIterator) {
+					if (!is_writable($fileInfo->getPath())) {
+						$nonWritablePaths[] = $fileInfo->getPath();
+					}
+				}
+				else if (!is_writable($fileInfo->getRealPath())) {
+					$nonWritablePaths[] = $fileInfo->getRealPath();
+				}
+			});
+		}
+		
+		$recursiveDirectories = [
+			'acp/js/',
+			'acp/style/',
+			'acp/templates/',
+			'acp/uninstall/',
+			'js/',
+			'lib/',
+			'log/',
+			'style/',
+			'templates/'
+		];
+		foreach ($recursiveDirectories as $directory) {
+			$path = WCF_DIR . $directory;
+			
+			if (!is_writable($path)) {
+				$nonWritablePaths[] = $path;
+				continue;
+			}
+			
+			DirectoryUtil::getInstance($path)->executeCallback(function($file, \SplFileInfo $fileInfo) use ($path, &$nonWritablePaths) {
+				if ($fileInfo instanceof \DirectoryIterator) {
+					if (!is_writable($fileInfo->getPath())) {
+						$nonWritablePaths[] = $fileInfo->getPath();
+					}
+				}
+				else if (!is_writable($fileInfo->getRealPath())) {
+					$nonWritablePaths[] = $fileInfo->getRealPath();
+				}
+			});
+		}
+		
+		if (!empty($nonWritablePaths)) {
+			$maxPaths = 10;
+			throw new \RuntimeException('The following paths are not writable: ' . implode(',' ,array_slice($nonWritablePaths, 0, $maxPaths)) . (count($nonWritablePaths) > $maxPaths ? ',' . StringUtil::HELLIP : ''));
+		}
+	}
 }
diff --git a/wcfsetup/install/files/lib/system/package/PackageInstallationDispatcher.class.php b/wcfsetup/install/files/lib/system/package/PackageInstallationDispatcher.class.php
index 8ea75049bb..551219baae 100644
--- a/wcfsetup/install/files/lib/system/package/PackageInstallationDispatcher.class.php
+++ b/wcfsetup/install/files/lib/system/package/PackageInstallationDispatcher.class.php
@@ -396,6 +396,10 @@ class PackageInstallationDispatcher {
 	protected function installPackage(array $nodeData) {
 		$installationStep = new PackageInstallationStep();
 		
+		if ($this->getAction() === 'update' && $this->getPackageName() === 'com.woltlab.wcf') {
+			WCF::checkWritability();
+		}
+		
 		// check requirements
 		if (!empty($nodeData['requirements'])) {
 			foreach ($nodeData['requirements'] as $package => $requirementData) {
@@ -1176,7 +1180,6 @@ class PackageInstallationDispatcher {
 					];
 				}
 			}
-				
 		}
 		
 		return $errors;
-- 
2.20.1