iffy handling 2-03-YYY

[cpb]

Code in question is bufr_dataset.c:1778,

      case TYPE_CHNG_REF_VAL_OP :
         ival = bufr_value_get_int32( bd->value );
         if (isdebug)
            {
            sprintf( errmsg, _("INT: %llu "), (unsigned long long)ival );
            bufr_print_debug( errmsg );
            }
         if (ival < 0)
            {
            ival = bufr_negative_ivalue( ival, bd->encoding.nbits );

ival is uint64_t, which makes the "if (ival < 0)" test a NOP. Not entirely sure what was intended here so I added a FIXME comment and left it alone.

[vanh souvanlasy (vanh-souvanlasy)]

The return value could be negative and for this case, the returned value is not just -1 for missing
the ival should be int32_t and then the converted final value should be cast to uint64_t for output.