From 71dca408c0030ad76044c6b17367c9fbeac511ec Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 7 Aug 2016 13:15:55 -0400 Subject: Don't propagate a null subtransaction snapshot up to parent transaction. This oversight could cause logical decoding to fail to decode an outer transaction containing changes, if a subtransaction had an XID but no actual changes. Per bug #14279 from Marko Tiikkaja. Patch by Marko based on analysis by Andrew Gierth. Discussion: <20160804191757.1430.39011@wrigleys.postgresql.org> --- src/backend/replication/logical/reorderbuffer.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'src/backend/replication/logical/reorderbuffer.c') diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c index 9b5642a5162..29bbae601c0 100644 --- a/src/backend/replication/logical/reorderbuffer.c +++ b/src/backend/replication/logical/reorderbuffer.c @@ -744,13 +744,14 @@ ReorderBufferCommitChild(ReorderBuffer *rb, TransactionId xid, elog(ERROR, "subxact logged without previous toplevel record"); /* - * Pass the our base snapshot to the parent transaction if it doesn't have + * Pass our base snapshot to the parent transaction if it doesn't have * one, or ours is older. That can happen if there are no changes in the * toplevel transaction but in one of the child transactions. This allows - * the parent to simply use it's base snapshot initially. + * the parent to simply use its base snapshot initially. */ - if (txn->base_snapshot == NULL || - txn->base_snapshot_lsn > subtxn->base_snapshot_lsn) + if (subtxn->base_snapshot != NULL && + (txn->base_snapshot == NULL || + txn->base_snapshot_lsn > subtxn->base_snapshot_lsn)) { txn->base_snapshot = subtxn->base_snapshot; txn->base_snapshot_lsn = subtxn->base_snapshot_lsn; -- cgit v1.2.3