inherited primary key misbehavior

Hi,

It seems that ATExecDetachPartition misses to mark a child's primary key
constraint entry (if any) as local (conislocal=true, coninhcount=0), which
causes this:

create table p (a int primary key) partition by list (a);
create table p2 partition of p for values in (2);
alter table p detach partition p2;
alter table p2 drop constraint p2_pkey ;
ERROR:  cannot drop inherited constraint "p2_pkey" of relation "p2"

select conname, conislocal, coninhcount from pg_constraint where conrelid
= 'p2'::regclass;
 conname │ conislocal │ coninhcount
─────────┼────────────┼─────────────
 p2_pkey │ f          │           1
(1 row)

How about the attached patch?

Thanks,
Amit