Server crash caused by CHECK on child

-- Hi Kevin, and everyone!
-- 
-- I don't think that I only found a minor bug compared to
-- the other you wrote in your last letter: the backend crash
-- is caused by the same CHECK constraint in the child table.
-- 
-- However, for you without time to analyzing Kevin's huge
-- scheme, here is the very simplified, crash-causing script.
-- 
------------------------------------

drop table child;
drop table ancestor;

create table ancestor ( node_id int4, a int4
);

create table child ( b int4 NOT NULL DEFAULT 0 , c int4 not null default 3, CHECK ( child.b = 0 OR child.b = 1 )
) inherits (ancestor);

insert into ancestor values (3,4);
insert into child (node_id, a, b) values (5,6,1);

update ancestor set a=8 where node_id=5;

---------------------------------
-- 
-- I am hunting it, but I have to learn all what this query-executing
-- about, so probably it takes uncomparable longer for me than for
-- a developer.
-- 
-- Regards,
-- Baldvin
--