Re: Server crash in pg_replication_slot_advance function

On Fri, Feb 16, 2018 at 1:44 PM, tushar <tushar(dot)ahuja(at)enterprisedb(dot)com> wrote:
> Hi,
[....]
> postgres=# SELECT end_lsn FROM
> pg_replication_slot_advance('regression_slot1', '0/2000071');
> server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> !>
>

I am able to reproduce this on the latest master head, the problem is in the
following hunk of pg_replication_slot_advance() where oldest LSN value
is accessed after releasing replication slot:

476 if (moveto < startlsn)
477 {
478 ReplicationSlotRelease();
479 ereport(ERROR,
480 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
481 errmsg("cannot move slot to %X/%X, minimum is %X/%X",
482 (uint32) (moveto >> 32), (uint32) moveto,
483 (uint32)
(MyReplicationSlot->data.confirmed_flush >> 32),
484 (uint32)
(MyReplicationSlot->data.confirmed_flush))));
485 }
486

Regards,
Amul