fix(s3): prevent "0" path from being treated as root

apps/files_external/lib/Lib/Storage/AmazonS3.php

@@ -32,30 +32,27 @@ class AmazonS3 extends Common {
 
 	private LoggerInterface $logger;
 
-	public function needsPartFile(): bool {
-		return false;
-	}
-
 	/** @var CappedMemoryCache<array|false> */
 	private CappedMemoryCache $objectCache;
-
 	/** @var CappedMemoryCache<bool> */
 	private CappedMemoryCache $directoryCache;
-
 	/** @var CappedMemoryCache<array> */
 	private CappedMemoryCache $filesCache;
 
 	private IMimeTypeDetector $mimeDetector;
-	private ?bool $versioningEnabled = null;
 	private ICache $memCache;
+	private ?bool $versioningEnabled = null;
 
 	public function __construct(array $parameters) {
 		parent::__construct($parameters);
 		$this->parseParams($parameters);
+		// @todo: using `key` here may be problematic with different authentication methods and/or key rotation...
 		$this->id = 'amazon::external::' . md5($this->params['hostname'] . ':' . $this->params['bucket'] . ':' . $this->params['key']);
+
 		$this->objectCache = new CappedMemoryCache();
 		$this->directoryCache = new CappedMemoryCache();
 		$this->filesCache = new CappedMemoryCache();
+
 		$this->mimeDetector = Server::get(IMimeTypeDetector::class);
 		/** @var ICacheFactory $cacheFactory */
 		$cacheFactory = Server::get(ICacheFactory::class);
@@ -66,7 +63,7 @@ public function __construct(array $parameters) {
 	private function normalizePath(string $path): string {
 		$path = trim($path, '/');
 
-		if (!$path) {
+		if ($path === '') {
 			$path = '.';
 		}
 
@@ -742,6 +739,11 @@ public function hasUpdated(string $path, int $time): bool {
 		}
 	}
 
+	public function needsPartFile(): bool {
+		// handled natively by the S3 backend/client integration
+		return false;
+	}
+
 	public function writeStream(string $path, $stream, ?int $size = null): int {
 		if ($size === null) {
 			$size = 0;

lib/private/Files/ObjectStore/ObjectStoreStorage.php

@@ -130,7 +130,7 @@ private function normalizePath(string $path): string {
 		$path = str_replace('//', '/', $path);
 
 		// dirname('/folder') returns '.' but internally (in the cache) we store the root as ''
-		if (!$path || $path === '.') {
+		if ($path === '.') {
 			$path = '';
 		}
 

tests/lib/Files/Storage/Storage.php

@@ -116,6 +116,10 @@ public static function fileNameProvider(): array {
 			['file with space.txt'],
 			['spéciäl fäile'],
 			['test single\'quote.txt'],
+			/*['0'],*/ // disabled until upstream aws-sdk is patched
+			['#'],
+			['%'],
+			['%20'],
 		];
 	}
 
@@ -127,6 +131,10 @@ public static function directoryProvider(): array {
 			['folder with space'],
 			['spéciäl földer'],
 			['test single\'quote'],
+			/*['0'],*/ // disabled until upstream aws-sdk is patched
+			['#'],
+			['%'],
+			['%20'],
 		];
 	}