From 77626c4238dae8611bbf3510536071167c36f981 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eren=20Ba=C5=9Fak?= <aamederen@gmail.com>
Date: Mon, 14 Aug 2017 13:18:53 +0300
Subject: [PATCH] Fix NULL nodeClusterString crush on pg_worker_list.conf
 migrations

---
 src/backend/distributed/utils/node_metadata.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/backend/distributed/utils/node_metadata.c b/src/backend/distributed/utils/node_metadata.c
index cf7190d46..8c2ecc2ce 100644
--- a/src/backend/distributed/utils/node_metadata.c
+++ b/src/backend/distributed/utils/node_metadata.c
@@ -1424,7 +1424,17 @@ TupleToWorkerNode(TupleDesc tupleDescriptor, HeapTuple heapTuple)
 	{
 		Name nodeClusterName = DatumGetName(nodeCluster);
 		char *nodeClusterString = NameStr(*nodeClusterName);
-		strlcpy(workerNode->nodeCluster, nodeClusterString, NAMEDATALEN);
+
+		/*
+		 * nodeClusterString can be null if nodecluster column is not present.
+		 * In the case of extension creation/upgrade, master_initialize_node_metadata
+		 * function is called before the nodecluster column is added to pg_dist_node
+		 * table.
+		 */
+		if (nodeClusterString != NULL)
+		{
+			strlcpy(workerNode->nodeCluster, nodeClusterString, NAMEDATALEN);
+		}
 	}
 
 	return workerNode;