===================================================================
RCS file: /cvs/mandoc/mdoc_html.c,v
retrieving revision 1.314
retrieving revision 1.315
diff -u -p -r1.314 -r1.315
--- mandoc/mdoc_html.c	2018/10/02 19:44:15	1.314
+++ mandoc/mdoc_html.c	2018/10/04 13:23:04	1.315
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_html.c,v 1.314 2018/10/02 19:44:15 schwarze Exp $ */
+/*	$Id: mdoc_html.c,v 1.315 2018/10/04 13:23:04 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014,2015,2016,2017,2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -541,11 +541,13 @@ mdoc_sh_pre(MDOC_ARGS)
 			    subn = subn->next) {
 				if (subn->tok != MDOC_Ss)
 					continue;
+				id = html_make_id(subn->head, 0);
+				if (id == NULL)
+					continue;
 				if (tsub == NULL)
 					print_otag(h, TAG_UL,
 					    "c", "Bl-compact");
 				tsub = print_otag(h, TAG_LI, "");
-				id = html_make_id(subn->head, 0);
 				print_otag(h, TAG_A, "hR", id);
 				free(id);
 				print_mdoc_nodelist(meta,