"node rejoin": ensure --dry-run is honoured

Addresses GitHub #383.

HISTORY

@@ -1,4 +1,7 @@
-4.0.3   2018-02-
+4.0.4   2018-??-??
+        repmgr: ensure "node rejoin" honours "--dry-run" option; GitHub #383 (Ian)
+
+4.0.3   2018-02-15
         repmgr: improve switchover handling when "pg_ctl" used to control the
           server and logging output is not explicitly redirected (Ian)
         repmgr: improve switchover log messages and exit code when old primary could

repmgr-action-node.c

@@ -1814,7 +1814,7 @@ do_node_rejoin(void)
 	 * Forcibly rewind node if requested (this is mainly for use when this
 	 * action is being executed by "repmgr standby switchover")
 	 */
-	if (runtime_options.force_rewind == true)
+	if (runtime_options.force_rewind == true && runtime_options.dry_run == false)
 	{
 		int			ret;
 		PQExpBufferData		filebuf;
@@ -1949,6 +1949,12 @@ do_node_rejoin(void)
 		}
 	}
 
+	if (runtime_options.dry_run == true)
+	{
+		log_info(_("prerequisites for executing NODE REJOIN are met"));
+		exit(SUCCESS);
+	}
+
 	initPQExpBuffer(&follow_output);
 
 	success = do_standby_follow_internal(upstream_conn,