node-zookeeper: Node crashes if timeout (rc: -7) is thrown during init()

Describe the bug If timeout is reached (rc: -7) during the first init() call, I receive the error below and app crashes with code: 139.

Assertion failed: loop->watchers[w->fd] == w

I am sure that app doesn’t use Zookeeper instance until there is a ‘connect’ event (which is never received).

To Reproduce

1. Initialize Zookeeper via .init() or .connect() with a timeout set to a tiny value. E.g. 5ms. (This will produce the same effect as on our server, where timeout is set to 10000ms.)
2. See error.

Error Log

2021-01-11 16:58:46,945:14539:ZOO_INFO@log_env@1102: Client environment:zookeeper.version=zookeeper C client 3.5.8
2021-01-11 16:58:46,945:14539:ZOO_INFO@log_env@1106: Client environment:host.name=project
2021-01-11 16:58:46,945:14539:ZOO_INFO@log_env@1113: Client environment:os.name=Linux
2021-01-11 16:58:46,945:14539:ZOO_INFO@log_env@1114: Client environment:os.arch=4.19.121-linuxkit
2021-01-11 16:58:46,946:14539:ZOO_INFO@log_env@1115: Client environment:os.version=#1 SMP Tue Dec 1 17:50:32 UTC 2020
2021-01-11 16:58:46,946:14539:ZOO_INFO@log_env@1123: Client environment:user.name=(null)
2021-01-11 16:58:46,946:14539:ZOO_INFO@log_env@1131: Client environment:user.home=/home/node
2021-01-11 16:58:46,946:14539:ZOO_INFO@log_env@1143: Client environment:user.dir=/srv
2021-01-11 16:58:46,946:14539:ZOO_INFO@zookeeper_init_internal@1177: Initiating client connection, host=zookeeper:2181 sessionTimeout=5 watcher=0x7f988ef61490 sessionId=0 sessionPasswd=<null> context=0x5623b4960d20 flags=0
2021-01-11 16:58:46,947:14539:ZOO_DEBUG@get_next_server_in_reconfig@1330: [OLD] count=0 capacity=0 next=0 hasnext=0
2021-01-11 16:58:46,947:14539:ZOO_DEBUG@get_next_server_in_reconfig@1333: [NEW] count=1 capacity=16 next=0 hasnext=1
2021-01-11 16:58:46,947:14539:ZOO_DEBUG@get_next_server_in_reconfig@1344: Using next from NEW=172.18.0.2:2181
2021-01-11 16:58:46,947:14539:ZOO_DEBUG@zookeeper_connect@2232: [zk] connect()
Interest in (fd=19, read=true, write=true, timeout=1)
2021-01-11 16:58:46,957:14539:ZOO_WARN@zookeeper_interest@2284: Exceeded deadline by 9ms
zk_timer_cb fired
ping timer went off
2021-01-11 16:58:46,957:14539:ZOO_ERROR@handle_socket_error_msg@2386: Socket [172.18.0.2:2181] zk retcode=-7, errno=110(Operation timed out): connection to 172.18.0.2:2181 timed out (exceeded timeout by 7ms)
2021-01-11 16:58:46,958:14539:ZOO_DEBUG@cleanup@1785: Previous connection=[172.18.0.2:2181] delay=0
yield:zookeeper_interest returned error: -7 - operation timeout
zk_timer_cb fired
ping timer went off
2021-01-11 16:58:46,959:14539:ZOO_WARN@zookeeper_interest@2284: Exceeded deadline by 11ms
2021-01-11 16:58:46,960:14539:ZOO_DEBUG@get_next_server_in_reconfig@1330: [OLD] count=0 capacity=0 next=0 hasnext=0
2021-01-11 16:58:46,960:14539:ZOO_DEBUG@get_next_server_in_reconfig@1333: [NEW] count=1 capacity=16 next=1 hasnext=0
2021-01-11 16:58:46,960:14539:ZOO_DEBUG@get_next_server_in_reconfig@1355: Failed to find either new or old
2021-01-11 16:58:46,960:14539:ZOO_DEBUG@zookeeper_connect@2232: [zk] connect()
Assertion failed: loop->watchers[w->fd] == w (../deps/uv/src/unix/core.c: uv__io_stop: 932)

Expected behavior Timeout doesn’t crash node app and closes client connection, so I could recreate client instance and retry to connect.

Desktop (please complete the following information):

• OS: Linux
• Node.js version: v10.23.0