Mark correctly initial slot snapshots with MVCC type when built

When building an initial slot snapshot, snapshots are marked with
historic MVCC snapshots as type with the marker field being set in
SnapBuildBuildSnapshot() but not overriden in SnapBuildExportSnapshot().
Existing callers of SnapBuildBuildSnapshot() do not care about the type
of snapshot used, but extensions calling it actually may, as reported.

Author: Antonin Houska
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/23215.1527665193@localhost
Backpatch-through: 9.4

diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index 546e0e7b16fa94441ed8862f5a1c5624c73974bb..cdc117763cb07e7428891a2038471a71ac183e41 100644 (file)
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -633,6 +633,8 @@ SnapBuildExportSnapshot(SnapBuild *builder)
                TransactionIdAdvance(xid);
        }
 
+       /* adjust remaining snapshot fields as needed */
+       snap->satisfies = HeapTupleSatisfiesMVCC;
        snap->xcnt = newxcnt;
        snap->xip = newxip;