TYPO3 Core

Function TYPO3\CMS\Backend\Form\Container\InlineControlContainer::renderPossibleRecordsSelectorTypeGroupDB does not check if the mode is 'db' (internal_type='db') and always renders 'allowed' tables as "Allowed file extensions".

// IRRE field
        'relations' => [
            'config' => [
                'type' => 'inline',
                'foreign_table' => 'tx_foo_reference',
                'foreign_selector' => 'uid_local',
                ...
            ],
        ],

// foreign_selector definition in relation table tx_foo_reference
        'uid_local' => [
            'config' => [
                'type' => 'group',
                'internal_type' => 'db',
                'allowed' => 'sys_category,fe_users',
                ...
            ],
        ],

Renders "Allowed file extensions SYS_CATEGORY FE_USERS" below the new inline relation button.

Allowed file extensions should only be rendered for internal_type='file'.