Use remote fee policy when constructing route hints

[dangeross]

Fixes #999

[JssDWt]

One comment. I like that listchannels call where the local node is the destination. Smart.

[JssDWt]

If the remote fee policy cannot be found, we should not include the route hint in the response. It should never make sense to include the local channel policy in a route hint.

[dangeross]

Ok, I changed it so that it only adds route hints where the source channel is found

[roeierez]

LGTM

[JssDWt]

I think this should be OK.

Thinking about it, I think there's still the possibility I suppose that there is an open channel with the LSP, but no route hint will be added, because we don't have the remote channel policy of the lsp.

So in the case:

• no route hint in the invoice
• no remote channel policy
• with active channel

There will not be an LSP hint added.

[dangeross]

Thinking about it, I think there's still the possibility I suppose that there is an open channel with the LSP, but no route hint will be added, because we don't have the remote channel policy of the lsp.

Would it make sense then to pass in the lsp_info to get_route_hints() and always override the lsp peer remote fees with the ones in the lsp_info? What do you think @roeierez?

[roeierez]

Thinking about it, I think there's still the possibility I suppose that there is an open channel with the LSP, but no route hint will be added, because we don't have the remote channel policy of the lsp.

Would it make sense then to pass in the lsp_info to get_route_hints() and always override the lsp peer remote fees with the ones in the lsp_info? What do you think @roeierez?

Yes but not always. I think only in case you don't find a channel policy because the policy might change after the channel was opened and if it exists then it is the correct one.

[roeierez]

LGTM