tests/groups: check failing insert

Signed-off-by: Brice Goglin <[email protected]>

Author: bgoglin

tests/hwloc/hwloc_groups.c

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2011-2021 Inria.  All rights reserved.
+ * Copyright © 2011-2023 Inria.  All rights reserved.
  * See COPYING in top-level directory.
  */
 
@@ -31,6 +31,11 @@ int main(void)
   hwloc_topology_load(topology);
   root = hwloc_get_root_obj(topology);
   assert(hwloc_topology_get_depth(topology) == 3);
+  /* insert without sets, fails */
+  group = hwloc_topology_alloc_group_object(topology);
+  assert(group);
+  res = hwloc_topology_insert_group_object(topology, group);
+  assert(res == NULL);
   /* insert a group identical to root, will be merged */
   group = hwloc_topology_alloc_group_object(topology);
   assert(group);