Method fix_field_count

sql/sql_select.h:2434–2437

Set pre-allocated field count to real field count This can be used when the real number of fields used fields are less than what was estimated at init */

    are less than what was estimated at init
  */
  void fix_field_count()
  {
    m_alloced_field_count= s->fields;
  }

  void set_all_fields_to_null()
  {