Improved NFD path finding algorithm to apply on each path section

Each path section of the given full path will be checked in each of the
NFC/NFD form.

Author: Vincent Petry

lib/private/Files/Storage/Wrapper/Encoding.php

@@ -64,42 +64,70 @@ private function isAscii($str) {
 	}
 
 	/**
-	 * Checks whether the given path exists in NFC or NFD form and returns
-	 * the correct form. If no existing path found, returns the pass as
-	 * it was given.
+	 * Checks whether the given path exists in NFC or NFD form after checking
+	 * each form for each path section and returns the correct form.
+	 * If no existing path found, returns the path as it was given.
+	 *
+	 * @param string $fullPath path to check
+	 *
+	 * @return string original or converted path, or null if none of the forms was found
+	 */
+	private function findPathToUse($fullPath) {
+		$sections = explode('/', $fullPath);
+		$path = '';
+		foreach ($sections as $section) {
+			$path .= $section;
+			$convertedPath = $this->findPathToUseLastSection($path);
+			if ($convertedPath === null) {
+				// no point in continuing if the section was not found, use original path
+				return $fullPath;
+			}
+			$path = $convertedPath . '/';
+		}
+		return rtrim($path, '/');
+	}
+
+	/**
+	 * Checks whether the last path section of the given path exists in NFC or NFD form
+	 * and returns the correct form. If no existing path found, returns null.
 	 *
-	 * @param string $path path to check
+	 * @param string $fullPath path to check
 	 *
-	 * @return string original or converted path
+	 * @return string|null original or converted path, or null if none of the forms was found
 	 */
-	private function findPathToUse($path) {
-		if ($path === '' || $this->isAscii($path)) {
-			return $path;
-		}
-		$cachedPath = $this->namesCache[$path];
+	private function findPathToUseLastSection($fullPath) {
+		$cachedPath = $this->namesCache[$fullPath];
 		if ($cachedPath !== null) {
 			return $cachedPath;
 		}
 
-		$result = $this->storage->file_exists($path);
+		$sections = explode('/', $fullPath);
+		$lastSection = array_pop($sections);
+		$basePath = ltrim(implode('/', $sections) . '/', '/');
+
+		if ($lastSection === '' || $this->isAscii($lastSection)) {
+			return $fullPath;
+		}
+
+		$result = $this->storage->file_exists($fullPath);
 		if ($result) {
-			$this->namesCache[$path] = $path;
-			return $path;
+			$this->namesCache[$fullPath] = $fullPath;
+			return $fullPath;
 		}
 		// swap encoding
-		if (\Normalizer::isNormalized($path, \Normalizer::FORM_C)) {
-			$otherFormPath = \Normalizer::normalize($path, \Normalizer::FORM_D);
+		if (\Normalizer::isNormalized($lastSection, \Normalizer::FORM_C)) {
+			$otherFormPath = \Normalizer::normalize($lastSection, \Normalizer::FORM_D);
 		} else {
-			$otherFormPath = \Normalizer::normalize($path, \Normalizer::FORM_C);
+			$otherFormPath = \Normalizer::normalize($lastSection, \Normalizer::FORM_C);
 		}
-		if ($this->storage->file_exists($otherFormPath)) {
-			$this->namesCache[$path] = $otherFormPath;
-			return $otherFormPath;
+		if ($this->storage->file_exists($basePath . $otherFormPath)) {
+			$this->namesCache[$fullPath] = $basePath . $otherFormPath;
+			return $basePath . $otherFormPath;
 		}
 
 		// return original path, file did not exist at all
-		$this->namesCache->set[$path] = self::NOT_FOUND;
-		return $path;
+		$this->namesCache->set[$fullPath] = self::NOT_FOUND;
+		return null;
 	}
 
 	/**

tests/lib/files/storage/wrapper/encoding.php

@@ -111,4 +111,24 @@ public function testNfcHigherPriority() {
 		$this->sourceStorage->file_put_contents(self::NFD_NAME, 'nfd');
 		$this->assertEquals('nfc', $this->instance->file_get_contents(self::NFC_NAME));
 	}
+
+	public function encodedDirectoriesProvider() {
+		return [
+			[self::NFD_NAME, self::NFC_NAME],
+			[self::NFD_NAME . '/' . self::NFD_NAME, self::NFC_NAME . '/' . self::NFC_NAME],
+			[self::NFD_NAME . '/' . self::NFC_NAME . '/' .self::NFD_NAME, self::NFC_NAME . '/' . self::NFC_NAME . '/' . self::NFC_NAME],
+		];
+	}
+
+	/**
+	 * @dataProvider encodedDirectoriesProvider
+	 */
+	public function testOperationInsideDirectory($sourceDir, $accessDir) {
+		$this->sourceStorage->mkdir($sourceDir);
+		$this->instance->file_put_contents($accessDir . '/test.txt', 'bar');
+		$this->assertEquals('bar', $this->instance->file_get_contents($accessDir . '/test.txt'));
+
+		$this->sourceStorage->file_put_contents($sourceDir . '/' . self::NFD_NAME, 'foo');
+		$this->assertEquals('foo', $this->instance->file_get_contents($accessDir . '/' . self::NFC_NAME));
+	}
 }