rem: MYSQL *s = MYSQL_HANDLE_UNBOX(obj); mysql_close(s);
add: if (!SCM_FALSEP(Scm_ForeignPointerAttrGet(SCM_FOREIGN_POINTER(obj), sym_closed, SCM_FALSE))) { MYSQL *s = MYSQL_HANDLE_UNBOX(obj); mysql_close(s); }
context: static void mysql_cleanup(ScmObj obj){    MYSQL *s = MYSQL_HANDLE_UNBOX(obj);    mysql_close(s);}