fixing a minor issue in intercomm_create.

adapting group_incl/excl/range_incl/range_excl to return
MPI_GROUP_EMPTY in case the new group size is zero.
group_union/difference/intersection still to be adapted to handle that scenario.

This commit was SVN r1921.

src/mpi/c/group_excl.c

@@ -50,6 +50,12 @@ int MPI_Group_excl(MPI_Group group, int n, int *ranks,
 
     }  /* end if( MPI_CHECK_ARGS) */
 
+    if ( n == group_pointer->grp_proc_count ) {
+        *new_group = MPI_GROUP_EMPTY;
+        OBJ_RETAIN(MPI_GROUP_EMPTY);
+        return MPI_SUCCESS;
+    }
+
     /*
      * pull out elements
      */

src/mpi/c/group_incl.c

@@ -49,6 +49,12 @@ int MPI_Group_incl(MPI_Group group, int n, int *ranks, MPI_Group *new_group)
     }  /* end if( MPI_CHECK_ARGS) */
 
 
+    if ( 0 == n ) {
+        *new_group = MPI_GROUP_EMPTY;
+        OBJ_RETAIN(MPI_GROUP_EMPTY);
+        return MPI_SUCCESS;
+    }
+
     /* get new group struct */
     new_group_pointer=ompi_group_allocate(n);
     if( NULL == new_group_pointer ) {

src/mpi/c/group_range_excl.c

@@ -136,6 +136,12 @@ int MPI_Group_range_excl(MPI_Group group, int n_triplets, int ranges[][3],
     /* we have counted the procs to exclude from the list */
     new_group_size=group_pointer->grp_proc_count-new_group_size;
 
+    if ( 0 == new_group_size ) {
+        *new_group = MPI_GROUP_EMPTY;
+        OBJ_RETAIN(MPI_GROUP_EMPTY);
+        return MPI_SUCCESS;
+    }
+
     /* allocate a new ompi_group_t structure */
     new_group_pointer=ompi_group_allocate(new_group_size);
     if( NULL == new_group_pointer ) {

src/mpi/c/group_range_incl.c

@@ -134,6 +134,12 @@ int MPI_Group_range_incl(MPI_Group group, int n_triplets, int ranges[][3],
         }
     }
 
+    if ( 0 == new_group_size ) {
+        *new_group = MPI_GROUP_EMPTY;
+        OBJ_RETAIN(MPI_GROUP_EMPTY);
+        return MPI_SUCCESS;
+    }
+
     /* allocate a new ompi_group_t structure */
     new_group_pointer=ompi_group_allocate(new_group_size);
     if( NULL == new_group_pointer ) {

src/mpi/c/intercomm_create.c

@@ -80,12 +80,12 @@ int MPI_Intercomm_create(MPI_Comm local_comm, int local_leader,
         MPI_Request req;
         
         /* local leader exchange group sizes lists */
-        rc =mca_pml.pml_irecv (&rsize, 1, MPI_INT, remote_leader, tag, bridge_comm,
+        rc =mca_pml.pml_irecv (&rsize, 1, MPI_INT, rleader, tag, bridge_comm,
                                &req );
         if ( rc != MPI_SUCCESS ) {
             goto err_exit;
         }
-        rc = mca_pml.pml_send ( &local_size, 1, MPI_INT, remote_leader, tag,
+        rc = mca_pml.pml_send ( &local_size, 1, MPI_INT, rleader, tag,
                                 MCA_PML_BASE_SEND_STANDARD, bridge_comm );
         if ( rc != MPI_SUCCESS ) {
             goto err_exit;
@@ -98,13 +98,13 @@ int MPI_Intercomm_create(MPI_Comm local_comm, int local_leader,
     }
     
     /* bcast size and list of remote processes to all processes in local_comm */
-    rc = local_comm->c_coll.coll_bcast ( &rsize, 1, MPI_INT, local_leader, 
+    rc = local_comm->c_coll.coll_bcast ( &rsize, 1, MPI_INT, lleader, 
                                          local_comm );
     if ( rc != MPI_SUCCESS ) {
         goto err_exit;
     }
 
-    rprocs = ompi_comm_get_rprocs ( local_comm, bridge_comm, local_leader,
+    rprocs = ompi_comm_get_rprocs ( local_comm, bridge_comm, lleader,
                                    remote_leader, tag, rsize );
     if ( NULL == rprocs ) {
         goto err_exit;
@@ -158,7 +158,7 @@ int MPI_Intercomm_create(MPI_Comm local_comm, int local_leader,
     }
     
  err_exit:
-    if ( NULL == rprocs ) {
+    if ( NULL != rprocs ) {
         free ( rprocs );
     }
     if ( OMPI_SUCCESS != rc ) {