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 SnapBuildInitialSnapshot().
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 f17cbda8a0ccf2ce5d280c939d356e19fbe975bb..9b81874ce19be43e6e7e870c4a3096911448496e 100644 (file)
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -617,6 +617,8 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
        TransactionIdAdvance(xid);
    }
 
+   /* adjust remaining snapshot fields as needed */
+   snap->satisfies = HeapTupleSatisfiesMVCC;
    snap->xcnt = newxcnt;
    snap->xip = newxip;