Merge pull request #9070 from nextcloud/bugfix/9028/guessing_without_…

…target_is_useles

When formatting a share node an Empty target is invalid

apps/files_sharing/lib/Controller/ShareAPIController.php

@@ -154,7 +154,7 @@ protected function formatShare(\OCP\Share\IShare $share, Node $recipientNode = n
 			if (empty($nodes)) {
 				// fallback to guessing the path
 				$node = $userFolder->get($share->getTarget());
-				if ($node === null) {
+				if ($node === null || $share->getTarget() === '') {
 					throw new NotFoundException();
 				}
 			} else {