/*      real_escape_string(string)   */
static VALUE real_escape_string(VALUE obj, VALUE str)
{
    MYSQL* m = GetHandler(obj);
    VALUE ret;
    Check_Type(str, T_STRING);
    ret = rb_str_new(0, (RSTRING_LEN(str))*2+1);
    rb_str_set_len(ret, mysql_real_escape_string(m, RSTRING_PTR(ret), RSTRING_PTR(str), RSTRING_LEN(str)));
    return ret;
}