Set the default to null before looking for the current value (simplesamlphp#2455)

Author: monkeyiq

modules/admin/src/Controller/Federation.php

@@ -409,6 +409,7 @@ public function metadataConverter(Request $request): Response
             return $response;
         }
 
+        $xmldata = null;
         if ($xmlfile = $request->files->get('xmlfile')) {
             // Some security-tooling will falsely think that request-data is passed into file_get_contents(),
             // but it's actually a random filename generated by PHP.

modules/multiauth/src/Controller/DiscoController.php

@@ -105,6 +105,7 @@ public function discovery(Request $request): Template|Response
         $urlSource = $request->query->get('source', null);
         $discoSource = $request->query->get('sourceChoice', null);
 
+        $selectedSource = null;
         if ($urlSource !== null) {
             $selectedSource = $urlSource;
         } elseif ($discoSource !== null) {