zlog_reload can cause a crash by freeing memory used by zlog_spec_write_time. about zlog HOT 3 CLOSED

static int zlog_spec_write_time(zlog_spec_t * a_spec, zlog_thread_t * a_thread, zlog_buf_t * a_buf)
{
        if (!a_thread->event->time_stamp.tv_sec) {
                gettimeofday(&(a_thread->event->time_stamp), NULL);
        }

        /* a_event->time_str is a cache, as strftime is slow.
         * It is modified when this event meets another time specifier, or time slips one second.
         * So it is a weak cache, just work when a event goes through only one time specifier.
         * If there is any better way, please tell me!
         */
        if (
             (a_thread->event->time_stamp.tv_sec != a_thread->event->time_last)
             || (a_spec->time_fmt != a_thread->event->time_fmt_last)
           ) {
                a_thread->event->time_last = a_thread->event->time_stamp.tv_sec;
                a_thread->event->time_fmt_last = a_spec->time_fmt;

                localtime_r(&(a_thread->event->time_stamp.tv_sec),
                            &(a_thread->event->time_local));

                a_thread->event->time_str_len = strftime(a_thread->event->time_str,
                        sizeof(a_thread->event->time_str),
                        a_spec->time_fmt, &(a_thread->event->time_local));
        }
        return zlog_buf_append(a_buf, a_thread->event->time_str, a_thread->event->time_str_len);
}