TYPO3 Core

As the title says, TCA type "passthrough" has not its default value set, when this value is defined in types/columnsOverrides.
The reason is the DataProvider for the default value is executed before the columnsOverrides provider, so at this point the default value is empty.
Normally this is overridden when fields are rendered in the form with their according default value.
But type passthrough is not rendered and so this does not apply.

Fixes could be either try to change the order of data providers (quick try resulted in Cyclic dependency issue) or render a hidden field with the default value (this could be restricted to NEW records).