strong memory leak in plpgsql from handled rollback and lazy cast

Hi

When I tested some hypothesis I wrote buggy code. It was surprise how fast
I lost all free memory

do $$
begin
for i in 1..3000000
loop
begin
-- do some error
if i then end if;
exception when others then
-- do nothing
end;
end loop;
end;
$$;

problem is somewhere in implicit casting inside IF statement. When I use
explicit casting -

IF i::boolean THEN

then there is not memory leak.

Regards

Pavel