TYPO3 Core

When i click on "Edit the whole Template Record" in the backend, i currently get the following error:

Core: Exception handler (WEB): Uncaught TYPO3 Exception: strtoupper() expects parameter 1 to be string, integer given | TypeError thrown in file /app/htdocs/typo3_src/typo3/sysext/backend/Classes/Form/FormDataProvider/EvaluateDisplayConditions.php in line 205. Requested URL

I guess that this happens because of the strict type check:

declare(strict_types=1);

...

$logicalOperator = strtoupper($logicalOperator);
                if (($logicalOperator !== 'AND' && $logicalOperator !== 'OR') || !is_array($groupedDisplayConditions)) {
                    throw new \RuntimeException(
                        'Multiple conditions must have boolean operator "OR" or "AND", "' . $logicalOperator . '" given.',
                        1481380393
                    );
                }
...

I think the value should be casted to string before passing it to strtoupper.