Allow duplication of MPI_LB and MPI_UB. A very usefull feature :)

This commit was SVN r11496.

ompi/datatype/dt_create_dup.c

@@ -42,9 +42,11 @@ int32_t ompi_ddt_duplicate( const ompi_datatype_t* oldType, ompi_datatype_t** ne
        the top level (specifically, MPI_TYPE_DUP). */
     pdt->d_keyhash = NULL;
 
+    /**
+     * Allow duplication of MPI_UB and MPI_LB.
+     */
+    if( 0 != oldType->desc.used ) {
         memcpy( pdt->desc.desc, oldType->desc.desc, sizeof(dt_elem_desc_t) * desc_length );
-    pdt->id  = 0;
-    pdt->args = NULL;
         /* TODO: if the data was commited update the opt_desc field */
         if( 0 != oldType->opt_desc.used ) {
             desc_length = pdt->opt_desc.used + 1;
@@ -56,6 +58,9 @@ int32_t ompi_ddt_duplicate( const ompi_datatype_t* oldType, ompi_datatype_t** ne
             pdt->opt_desc.used = oldType->opt_desc.used;
             memcpy( pdt->opt_desc.desc, oldType->opt_desc.desc, desc_length * sizeof(dt_elem_desc_t) );
         }
+    }
+    pdt->id  = 0;
+    pdt->args = NULL;
     *newType = pdt;
     return OMPI_SUCCESS;
 }