conn open ack does not succeed in the happy case

[vitorenesduarte]

Crate

modules

Summary of Bug

The conn open ack handler requires a connection to have the counterparty connection id set (line 36):

https://github.com/informalsystems/ibc-rs/blob/02aef9cf5055a3817579b555c84289b99d5d08a8/modules/src/ics03_connection/handler/conn_open_ack.rs#L33-L45

However, if the connection is in the Init state (the happy/normal case), the counterparty connection id is unknown, in which case the conn open ack fails with a ConnectionMismatch.

This issue was found during the MBT work (#546).

Version

02aef9c

Steps to Reproduce

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate milestone (priority) applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned