Update the definition of the Fortran MPI_DATATYPE_NULL.

This commit was SVN r2752.

include/mpif.h.in

@@ -128,7 +128,7 @@
 
        parameter (MPI_GROUP_NULL=0)
        parameter (MPI_COMM_NULL=2)
-       parameter (MPI_DATATYPE_NULL=-1)
+       parameter (MPI_DATATYPE_NULL=0)
        parameter (MPI_REQUEST_NULL=-1)
        parameter (MPI_OP_NULL=-1)
        parameter (MPI_ERRHANDLER_NULL=-1)

src/datatype/dt_module.c

@@ -268,8 +268,11 @@ int ompi_ddt_init( void )
     for( i = 0; i < DT_MAX_PREDEFINED; i++ )
         local_sizes[i] = basicDatatypes[i].size;
 
+    /* The order of the data registration should be the same as the one
+     * in the mpif.h file. Any modification here should be reflected there !!!
+     */ 
     /* Start to populate the f2c index translation table */
-    ompi_pointer_array_add( ompi_datatype_f_to_c_table, NULL );  /* why not ? */
+    ompi_pointer_array_add( ompi_datatype_f_to_c_table, ompi_mpi_datatype_null );
     ompi_pointer_array_add( ompi_datatype_f_to_c_table, ompi_mpi_byte );
     ompi_pointer_array_add( ompi_datatype_f_to_c_table, ompi_mpi_packed );
     ompi_pointer_array_add( ompi_datatype_f_to_c_table, ompi_mpi_ub );