doc: update HISTORY and release notes

HISTORY

@@ -27,6 +27,8 @@
           server and logging output is not explicitly redirected (Ian)
         repmgr: improve switchover log messages and exit code when old primary could
           not be shut down cleanly (Ian)
+        repmgr: check demotion candidate can make a replication connection to the
+          promotion candidate before executing a switchover; GitHub #370 (Ian)
         repmgr: add check for sufficient walsenders/replication slots before executing
           a switchover; GitHub #371 (Ian)
         repmgr: add --dry-run mode to "repmgr standby follow"; GitHub #368 (Ian)

dbutils.c

@@ -2738,6 +2738,11 @@ get_node_replication_stats(PGconn *conn, int server_version_num, t_node_info *no
 	PQExpBufferData query;
 	PGresult   *res = NULL;
 
+	if (server_version_num == UNKNOWN_SERVER_VERSION_NUM)
+		server_version_num = get_server_version(conn, NULL);
+
+	Assert(server_version_num != UNKNOWN_SERVER_VERSION_NUM);
+
 	initPQExpBuffer(&query);
 
 	appendPQExpBuffer(&query,

doc/appendix-release-notes.sgml

@@ -166,6 +166,13 @@
             </para>
           </listitem>
 
+         <listitem>
+            <para>
+              add check to verify the demotion candidate can make a replication connection to the
+              promotion candidate before executing a switchover (GitHub #370)
+            </para>
+         </listitem>
+
          <listitem>
             <para>
               add check for sufficient walsenders and replication slots on the promotion candidate  before executing