Bring over hwloc r4102 and r4104 for some upstream patches.

This commit was SVN r25707.

The following SVN revision numbers were found above:
  r4102 --> open-mpi/ompi@8961ca568d

The following SVN revisions from the original message are invalid or
inconsistent and therefore were not cross-referenced:
  r4104

opal/mca/hwloc/hwloc131/hwloc/src/topology.c

@@ -1,7 +1,7 @@
 /*
  * Copyright © 2009 CNRS
  * Copyright © 2009-2011 INRIA.  All rights reserved.
- * Copyright © 2009-2010 Université Bordeaux 1
+ * Copyright © 2009-2012 Université Bordeaux 1
  * Copyright © 2009-2011 Cisco Systems, Inc.  All rights reserved.
  * See COPYING in top-level directory.
  */
@@ -1713,7 +1713,10 @@ hwloc_connect_levels(hwloc_topology_t topology)
     /* New level.  */
     taken_objs = malloc((n_taken_objs + 1) * sizeof(taken_objs[0]));
     /* New list of pending objects.  */
-    new_objs = malloc((n_objs - n_taken_objs + n_new_objs) * sizeof(new_objs[0]));
+    if (n_objs - n_taken_objs + n_new_objs)
+      new_objs = malloc((n_objs - n_taken_objs + n_new_objs) * sizeof(new_objs[0]));
+    else
+      new_objs = NULL;
 
     n_new_objs = hwloc_level_take_objects(top_obj,
 					  objs, n_objs,
@@ -1765,7 +1768,8 @@ hwloc_connect_levels(hwloc_topology_t topology)
   }
 
   /* It's empty now.  */
-  free(objs);
+  if (objs)
+    free(objs);
 
   topology->bridge_nbobjects = hwloc_build_level_from_list(topology->first_bridge, &topology->bridge_level);
   topology->pcidev_nbobjects = hwloc_build_level_from_list(topology->first_pcidev, &topology->pcidev_level);