diff -Naur samba-4.8.9/source3/winbindd/winbindd_util.c samba-4.8.9-fix_winbind_empty_domain/source3/winbindd/winbindd_util.c
--- samba-4.8.9/source3/winbindd/winbindd_util.c	2018-12-13 04:08:40.000000000 -0500
+++ samba-4.8.9-fix_winbind_empty_domain/source3/winbindd/winbindd_util.c	2019-02-21 06:30:52.358040157 -0500
@@ -1604,6 +1604,7 @@
 			fstrcpy(namespace, domain);
 		} else {
 			fstrcpy(namespace, lp_netbios_name());
+			return false;
 		}
 	}