mqtt_start_receive_schedule will loop forever if read_len < 0;

[shenfumin]

in the function mqtt_start_receive_schedule, if read_len < 0, it will loop forever and not jump out the loop.
while (1) {

    read_len = ClientRead(client->mqtt_state.in_buffer, CONFIG_MQTT_BUFFER_SIZE_BYTE);
    mqtt_info("Read len %d", read_len);
    if (read_len == 0)
        break;
    .......

}
how to fix it?
i had tried the following change
if (read_len <= 0)
break;
it could work normally. but i am not sure. anyboady found this issue or have some idea?