isAllowedInColumn in B13\Container\Tca\Registry checks disallowed configuration against child $cType instead of $containerCType

[cbammann]

TYPO3 Version: 14.3.4
Container Version: 4.0.2

I have nested containers, e.g. a 1col container that contains a 2col container, and the child container (2col) has the following configuration, to prevent that containers of the same type (2col) can be inserted:

'disallowedContentTypes' => '2col'

The 1col container has no restrictions.
In the backend preview however, after inserting a 2col container into a 1col container (which works without problems), there is a message saying "This element of type "2col" is not allowed in this column.

After debugging, I found that in B13\Container\Tca\Registry the method isAllowedInColumn fetches the content_defender configuration using the variable $cType instead of $containerCType. So it uses the configuration of the child type to check which types are disallowed for the parent container type. The check for the allowed types afterwards uses the correct $containerCType.