From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 6 Nov 2016 16:29:40 +0000 (-0500)
Subject: Fix silly nil-pointer-dereference bug introduced in commit d5f6f13f8.
X-Git-Tag: REL_10_BETA1~1445
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=5485c99e7f507b2849ac675e9c10f34551f645b6;p=postgresql.git

Fix silly nil-pointer-dereference bug introduced in commit d5f6f13f8.

Don't fetch record->xl_info before we've verified that record isn't
NULL.  Per Coverity.

Michael Paquier
---

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 813f6467fdf..6cec02797a3 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7812,7 +7812,6 @@ ReadCheckpointRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr,
 	}
 
 	record = ReadRecord(xlogreader, RecPtr, LOG, true);
-	info = record->xl_info & ~XLR_INFO_MASK;
 
 	if (record == NULL)
 	{
@@ -7855,6 +7854,7 @@ ReadCheckpointRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr,
 		}
 		return NULL;
 	}
+	info = record->xl_info & ~XLR_INFO_MASK;
 	if (info != XLOG_CHECKPOINT_SHUTDOWN &&
 		info != XLOG_CHECKPOINT_ONLINE)
 	{