Submitted by: @helebor

Is it a trivial change to enable conversion of an integer type column that is populated from a generator from a trigger to IDENTITY type?
Example
------------
create generator id_gen_idtest;
create table idtest (id integer not null, data varchar(10);
commit;
set term ^;
create trigger get_id_idtest for idtest
active before insert as
begin
if (http://new.id is null) then http://new.id = next value for id_gen;
end ^
set term ;^
commit;
insert into idtest (data) values ('first');
insert into idtest (data) values ('second');
insert into idtest (data) values ('third');
insert into idtest (data) values ('fourth');
commit;

Make this possible without the need to remove dependencies:

alter table idtest
alter column id type integer generated by default as IDENTITY (start with 5);
-- not forgetting to
drop trigger get_id_idtest;
commit;