Merge pull request #883 from nextcloud/backport/875/stable22

[stable22] strtolower on mail address

Author: ArtificialOwl

lib/Service/FederatedUserService.php

@@ -689,6 +689,10 @@ public function getFederatedUser(string $federatedId, int $type = Member::TYPE_S
 	 * @return FederatedUser
 	 */
 	public function generateFederatedUser(string $federatedId, int $type = 0): FederatedUser {
+		if ($type === Member::TYPE_MAIL) {
+			$federatedId = strtolower($federatedId);
+		}
+
 		try {
 			return $this->getFederatedUser($federatedId, $type);
 		} catch (Exception $e) {