Param Datatype detection wrong, if coalesce used [CORE6299]

Submitted by: Jan Kohlmeyer (colaflasche)

Hi,
i've this statement in 3\.0\.4 and 3\.0\.5\.

In 3\.0\.4 the param datatype is char$4$ in 3\.0\.5 the param datatype is char$0$:

select coalesce$:test, ''$ between '0815' and '4700' from rdb$database

If i remove the coalesce, the datatype is in both char$4$:

select :test between '0815' and '4700' from rdb$database

Regards, Jan