fix: Use getRelativePath method to check if node is inside folder

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

[skip ci]

lib/private/Share20/Manager.php

@@ -1215,7 +1215,8 @@ protected function promoteReshares(IShare $share): void {
 							/* Ignore share of non-existing node */
 							continue;
 						}
-						if (str_starts_with($path, $node->getPath() . '/') || ($path === $node->getPath())) {
+						if ($node->getRelativePath($path) !== null) {
+							/* If relative path is not null it means the shared node is the same or in a subfolder */
 							$reshareRecords[] = $share;
 						}
 					}

tests/lib/Share20/ManagerTest.php

@@ -23,6 +23,7 @@
 
 use DateTimeZone;
 use OC\Files\Mount\MoveableMount;
+use OC\Files\Utils\PathHelper;
 use OC\KnownUser\KnownUserService;
 use OC\Share20\DefaultShareProvider;
 use OC\Share20\Exception;
@@ -213,6 +214,14 @@ private function createManagerMock() {
 			]);
 	}
 
+	private function createFolderMock(string $folderPath): MockObject&Folder {
+		$folder = $this->createMock(Folder::class);
+		$folder->method('getPath')->willReturn($folderPath);
+		$folder->method('getRelativePath')->willReturnCallback(
+			fn (string $path): ?string => PathHelper::getRelativePath($folderPath, $path)
+		);
+		return $folder;
+	}
 
 	public function testDeleteNoShareId() {
 		$this->expectException(\InvalidArgumentException::class);