always lowercase payreq

[kiwiidb]

When testing out Alby and Bluewallet on regtest, I noticed that Bluewallet puts in the invoice uppercase when calling payinvoice. This caused internal Alby payments to fail, as Alby could not find the invoice in the db.

[bumi]

Can you explain that? why is it relevant that we pass in the invoice in lowercase to the DecodePayReq call?
if we always need it lowercase shouldn't we do it then here:

lndhub.go/lib/service/invoices.go

Line 392 in 8ed306f

func (svc *LndhubService) DecodePaymentRequest(ctx context.Context, bolt11 string) (*lnrpc.PayReq, error) {

?

[kiwiidb]

This variable is not only passed into the DecodePayReq call, but also below, in the AddOutgoingInvoice call. This causes a mismatch between lowercase and an uppercase payment request strings in the database.

[bumi]

ok, but then we should do it there. Making sure that we write lowercase in the DB and also use lowecase when we try too look it up.
Maybe AddOutgoingInvoice will be used somewhere else then we have the same problem again.