split out some path manipulation logic

Signed-off-by: Robin Appelman <robin@icewind.nl>

lib/composer/composer/autoload_classmap.php

@@ -1209,6 +1209,7 @@ return array(
     'OC\\Files\\Type\\Detection' => $baseDir . '/lib/private/Files/Type/Detection.php',
     'OC\\Files\\Type\\Loader' => $baseDir . '/lib/private/Files/Type/Loader.php',
     'OC\\Files\\Type\\TemplateManager' => $baseDir . '/lib/private/Files/Type/TemplateManager.php',
+    'OC\\Files\\Utils\\PathHelper' => $baseDir . '/lib/private/Files/Utils/PathHelper.php',
     'OC\\Files\\Utils\\Scanner' => $baseDir . '/lib/private/Files/Utils/Scanner.php',
     'OC\\Files\\View' => $baseDir . '/lib/private/Files/View.php',
     'OC\\ForbiddenException' => $baseDir . '/lib/private/ForbiddenException.php',

lib/composer/composer/autoload_static.php

@@ -1238,6 +1238,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Files\\Type\\Detection' => __DIR__ . '/../../..' . '/lib/private/Files/Type/Detection.php',
         'OC\\Files\\Type\\Loader' => __DIR__ . '/../../..' . '/lib/private/Files/Type/Loader.php',
         'OC\\Files\\Type\\TemplateManager' => __DIR__ . '/../../..' . '/lib/private/Files/Type/TemplateManager.php',
+        'OC\\Files\\Utils\\PathHelper' => __DIR__ . '/../../..' . '/lib/private/Files/Utils/PathHelper.php',
         'OC\\Files\\Utils\\Scanner' => __DIR__ . '/../../..' . '/lib/private/Files/Utils/Scanner.php',
         'OC\\Files\\View' => __DIR__ . '/../../..' . '/lib/private/Files/View.php',
         'OC\\ForbiddenException' => __DIR__ . '/../../..' . '/lib/private/ForbiddenException.php',

lib/private/Files/Node/Folder.php

@@ -36,6 +36,7 @@ use OC\Files\Cache\Wrapper\CacheJail;
 use OC\Files\Search\SearchComparison;
 use OC\Files\Search\SearchOrder;
 use OC\Files\Search\SearchQuery;
+use OC\Files\Utils\PathHelper;
 use OCP\Files\Cache\ICacheEntry;
 use OCP\Files\FileInfo;
 use OCP\Files\Mount\IMountPoint;
@@ -76,17 +77,7 @@ class Folder extends Node implements \OCP\Files\Folder {
 	 * @return string|null
 	 */
 	public function getRelativePath($path) {
-		if ($this->path === '' or $this->path === '/') {
-			return $this->normalizePath($path);
-		}
-		if ($path === $this->path) {
-			return '/';
-		} elseif (strpos($path, $this->path . '/') !== 0) {
-			return null;
-		} else {
-			$path = substr($path, strlen($this->path));
-			return $this->normalizePath($path);
-		}
+		return PathHelper::getRelativePath($this->getPath(), $path);
 	}
 
 	/**

lib/private/Files/Node/Node.php

@@ -31,6 +31,7 @@ namespace OC\Files\Node;
 
 use OC\Files\Filesystem;
 use OC\Files\Mount\MoveableMount;
+use OC\Files\Utils\PathHelper;
 use OCP\Files\FileInfo;
 use OCP\Files\InvalidPathException;
 use OCP\Files\NotFoundException;
@@ -298,23 +299,7 @@ class Node implements \OCP\Files\Node {
 	 * @return string
 	 */
 	protected function normalizePath($path) {
-		if ($path === '' or $path === '/') {
-			return '/';
-		}
-		//no windows style slashes
-		$path = str_replace('\\', '/', $path);
-		//add leading slash
-		if ($path[0] !== '/') {
-			$path = '/' . $path;
-		}
-		//remove duplicate slashes
-		while (strpos($path, '//') !== false) {
-			$path = str_replace('//', '/', $path);
-		}
-		//remove trailing slash
-		$path = rtrim($path, '/');
-
-		return $path;
+		return PathHelper::normalizePath($path);
 	}
 
 	/**

lib/private/Files/Node/Root.php

@@ -33,8 +33,10 @@
 namespace OC\Files\Node;
 
 use OC\Cache\CappedMemoryCache;
+use OC\Files\FileInfo;
 use OC\Files\Mount\Manager;
 use OC\Files\Mount\MountPoint;
+use OC\Files\Utils\PathHelper;
 use OC\Files\View;
 use OC\Hooks\PublicEmitter;
 use OC\User\NoUserException;

lib/private/Files/Utils/PathHelper.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Files\Utils;
+
+class PathHelper {
+	/**
+	 * Make a path relative to a root path, or return null if the path is outside the root
+	 *
+	 * @param string $root
+	 * @param string $path
+	 * @return ?string
+	 */
+	public static function getRelativePath(string $root, string $path) {
+		if ($root === '' or $root === '/') {
+			return self::normalizePath($path);
+		}
+		if ($path === $root) {
+			return '/';
+		} elseif (strpos($path, $root . '/') !== 0) {
+			return null;
+		} else {
+			$path = substr($path, strlen($root));
+			return self::normalizePath($path);
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @return string
+	 */
+	public static function normalizePath(string $path): string {
+		if ($path === '' or $path === '/') {
+			return '/';
+		}
+		//no windows style slashes
+		$path = str_replace('\\', '/', $path);
+		//add leading slash
+		if ($path[0] !== '/') {
+			$path = '/' . $path;
+		}
+		//remove duplicate slashes
+		while (strpos($path, '//') !== false) {
+			$path = str_replace('//', '/', $path);
+		}
+		//remove trailing slash
+		$path = rtrim($path, '/');
+
+		return $path;
+	}
+}