Possible dereference null return (src/backend/replication/logical/reorderbuffer.c)

Hi,

Per Coverity.

If xid is a subtransaction, the setup of base snapshot on the top-level
transaction,
can be not optional, otherwise a Dereference null return value
(NULL_RETURNS) can be raised.

Patch suggestion to fix this.

diff --git a/src/backend/replication/logical/reorderbuffer.c
b/src/backend/replication/logical/reorderbuffer.c
index 5a62ab8bbc..3c6a81f716 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -2993,8 +2993,8 @@ ReorderBufferSetBaseSnapshot(ReorderBuffer *rb,
TransactionId xid,
*/
txn = ReorderBufferTXNByXid(rb, xid, true, &is_new, lsn, true);
if (rbtxn_is_known_subxact(txn))
- txn = ReorderBufferTXNByXid(rb, txn->toplevel_xid, false,
- NULL, InvalidXLogRecPtr, false);
+ txn = ReorderBufferTXNByXid(rb, txn->toplevel_xid, true,
+ NULL, InvalidXLogRecPtr, true);
Assert(txn->base_snapshot == NULL);

txn->base_snapshot = snap;

regards,
Ranier Vilela