Method session_value_ptr

sql/sys_vars.h:1145–1150

  bool check_update_type(Item_result type)
  { return type != STRING_RESULT; }
  uchar *session_value_ptr(THD *thd, LEX_STRING *base)
  {
    plugin_ref plugin= session_var(thd, plugin_ref);
    return (uchar*)(plugin ? thd->strmake(plugin_name(plugin)->str,
                                          plugin_name(plugin)->length) : 0);
  }
  uchar *global_value_ptr(THD *thd, LEX_STRING *base)
  {
    plugin_ref plugin= global_var(plugin_ref);