[stable9.1] Cast share id to string (#25402)

Author: Vincent Petry

apps/dav/lib/Connector/PublicAuth.php

@@ -98,7 +98,7 @@ protected function validateUserPass($username, $password) {
 				if ($this->shareManager->checkPassword($share, $password)) {
 					return true;
 				} else if ($this->session->exists('public_link_authenticated')
-					&& $this->session->get('public_link_authenticated') === $share->getId()) {
+					&& $this->session->get('public_link_authenticated') === (string)$share->getId()) {
 					return true;
 				} else {
 					if (in_array('XMLHttpRequest', explode(',', $this->request->getHeader('X-Requested-With')))) {