Various bugs in zoo_add_auth in C

3 issues:
In zoo_add_auth: there is a race condition:
2940 // ZOOKEEPER-800 zoo_add_auth should return ZINVALIDSTATE if
2941 // the connection is closed.
2942 if (zoo_state(zh) == 0)

{ 2943 return ZINVALIDSTATE; 2944 }

when we do zookeeper_init, the state is initialized to 0 and above we check if state = 0 then throw exception.
There is a race condition where the doIo thread is slow and has not changed the state to CONNECTING, then you end up returning back ZKINVALIDSTATE.
The problem is we use 0 for CLOSED state and UNINITIALIZED state. in case of uninitialized case it should let it go through.

2nd issue:

Another Bug: in send_auth_info, the check is not correct

while (auth->next != NULL) { //--BUG: in cases where there is only one auth in the list, this will never send that auth, as its next will be NULL
rc = send_info_packet(zh, auth);
auth = auth->next;
}

FIX IS:
do

{ rc = send_info_packet(zh, auth); auth = auth->next; }

while (auth != NULL); //this will make sure that even if there is one auth ,that will get sent.

3rd issue:
2965 add_last_auth(&zh->auth_h, authinfo);
2966 zoo_unlock_auth(zh);
2967
2968 if(zh->state == ZOO_CONNECTED_STATE || zh->state == ZOO_ASSOCIATING_STATE)
2969 return send_last_auth_info(zh);

if it is connected, we only send the last_auth_info, which may be different than the one we added, as we unlocked it before sending it.