Fix SerializeSnapshot not to overrun the allocated space.

Rushabh Lathia

diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 63e908d0a000aad77101e1ba849b055d5c997749..b88e01200419b114309f01ab7dd8ab4e5c9cc3b3 100644 (file)
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -1515,7 +1515,7 @@ SerializeSnapshot(Snapshot snapshot, char *start_address)
     * snapshot taken during recovery; all the top-level XIDs are in subxip as
     * well in that case, so we mustn't lose them.
     */
-   if (snapshot->subxcnt > 0)
+   if (serialized_snapshot->subxcnt > 0)
    {
        Size        subxipoff = sizeof(SerializedSnapshotData) +
        snapshot->xcnt * sizeof(TransactionId);