Fix regex for allowed characters in user ID

was incorrectly banning # symbols
solves issues regarding SSO with Microsoft 365 accounts

Signed-off-by: kale1d0code <[email protected]>

Author: kale1d0code

lib/private/User/Manager.php

@@ -694,8 +694,8 @@ public function validateUserId(string $uid, bool $checkDataDirectory = false): v
 		$l = Server::get(IFactory::class)->get('lib');
 
 		// Check the ID for bad characters
-		// Allowed are: "a-z", "A-Z", "0-9", spaces and "_.@-'"
-		if (preg_match('/[^a-zA-Z0-9 _.@\-\']/', $uid)) {
+		// Allowed are: "a-z", "A-Z", "0-9", spaces and "_.@-'#"
+		if (preg_match(‘/[^a-zA-Z0-9 _.@\-'#]/’, $uid)) {
 			throw new \InvalidArgumentException($l->t('Only the following characters are allowed in an Login:'
 				. ' "a-z", "A-Z", "0-9", spaces and "_.@-\'"'));
 		}