From: Simon Riggs <simon@2ndQuadrant.com>
Date: Sat, 24 Jun 2017 12:03:55 +0000 (+0100)
Subject: Revert 1f30295eab65eddaa88528876ab66e7095f4bb65
X-Git-Tag: REL_10_BETA2~74
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=829f12e2690c0442e156069092b05f1edc78b08a;p=postgresql

Revert 1f30295eab65eddaa88528876ab66e7095f4bb65

Reported-by: Tom Lane
---

diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 6369be78a3..6bf3a94f05 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -2076,6 +2076,14 @@ SerializeSnapshot(Snapshot snapshot, char *start_address)
 	serialized_snapshot.whenTaken = snapshot->whenTaken;
 	serialized_snapshot.lsn = snapshot->lsn;
 
+	/*
+	 * Ignore the SubXID array if it has overflowed, unless the snapshot was
+	 * taken during recovey - in that case, top-level XIDs are in subxip as
+	 * well, and we mustn't lose them.
+	 */
+	if (serialized_snapshot.suboverflowed && !snapshot->takenDuringRecovery)
+		serialized_snapshot.subxcnt = 0;
+
 	/* Copy struct to possibly-unaligned buffer */
 	memcpy(start_address,
 		   &serialized_snapshot, sizeof(SerializedSnapshotData));
@@ -2092,9 +2100,6 @@ 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 (serialized_snapshot.suboverflowed && !snapshot->takenDuringRecovery)
-		serialized_snapshot.subxcnt = 0;
-
 	if (serialized_snapshot.subxcnt > 0)
 	{
 		Size		subxipoff = sizeof(SerializedSnapshotData) +