Minor indent cleanup in init_query()

Only use Portals on communicators with more than one rank
Fix computation of number of children when using the hypercube tree

This commit was SVN r29616.

ompi/mca/coll/portals4/coll_portals4.h

@@ -101,7 +101,7 @@ static inline int
 ompi_coll_portals4_get_nchildren(int cube_dim, int hibit, int rank, int size)
 {
     int guess = cube_dim - (hibit + 1);
-    if ((rank | (1 << cube_dim)) >= size) guess--;
+    if ((rank | (1 << (cube_dim - 1))) >= size) guess--;
     if (guess < 0) return 0;
     return guess;
 }

ompi/mca/coll/portals4/coll_portals4_component.c

@@ -434,8 +434,10 @@ portals4_comm_query(struct ompi_communicator_t *comm,
 {
     mca_coll_portals4_module_t *portals4_module;
 
-    /* For now, we don't support intercommunicators */
-    if (OMPI_COMM_IS_INTER(comm)) {
+    /* For now, we don't support intercommunicators and we probably
+       never should handle the single proc case, since there's the
+       self module... */
+    if (OMPI_COMM_IS_INTER(comm) || ompi_comm_size(comm) < 2) {
         return NULL;
     }