Bug: LNDK doesn't know how to respond to an offer that lists itself as the intro node

[orbitalturtle]

Describe the bug

Currently, if LND/LNDK is chosen as the introduction point in an offer it's trying to pay, it will throw an error. This is a bit of an edge case which is mostly likely to occur in a scenario where we're paying an offer from a node that we're directly connected with.

In this scenario, this is the error:

Error paying for offer: Status { code: Internal, message: "Internal error: Error connecting to peer: Status { code: Unknown, message: "cannot make connection to self", metadata: MetadataMap { headers: {"content-type": "application/grpc"} }, source: None }", metadata: MetadataMap { headers: {"content-type": "application/grpc", "date": "Tue, 18 Jun 2024 21:30:40 GMT", "content-length": "0"} }, source: None }

[jbesraa]

Maybe related to lightningdevkit/rust-lightning#2952

[tnull]

Maybe related to lightningdevkit/rust-lightning#2952

Hm, no, actually not as the issue also occurs for announced channels, i.e., also in the case that works perfectly fine in LDK Node integration tests.

[orbitalturtle]

Note that we should be able to fix this once we've upgraded to LDK v0.0.124 because advance_path_by_one for messages and payments are now exposed.

[carlaKC]

I think you'll still run into issues with the LND payment itself?
Needs LND change: lightningnetwork/lnd#9027