[BUGFIX] Handle undefined tt_content_defValues in NewContentElementController

Resolves: #98306
Releases: 11.5
Change-Id: I7a5ec64e330a6a779abb5ed95eb6c70acb221785
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75670


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>

typo3/sysext/backend/Classes/Controller/ContentElement/NewContentElementController.php

@@ -370,7 +370,7 @@ class NewContentElementController
         $itemConf['title'] = $this->getLanguageService()->sL($itemConf['title']);
         $itemConf['description'] = $this->getLanguageService()->sL($itemConf['description']);
         $itemConf['saveAndClose'] = (bool)($itemConf['saveAndClose'] ?? false);
-        $itemConf['tt_content_defValues'] = $itemConf['tt_content_defValues.'];
+        $itemConf['tt_content_defValues'] = $itemConf['tt_content_defValues.'] ?? [];
         unset($itemConf['tt_content_defValues.']);
         return $itemConf;
     }