HRN: Allow to set payer_note and quantity on ChannelManager::pay_for_offer_from_human_readable_name

[tnull]

Currently, ChannelManager::pay_for_offer_from_human_readable_name only allows setting the amount_msat and max_total_routing_fee_msat parameters. It should also support setting all the other parameters of pay_for_offer, i.e.,, quantity, payer_note in particular.

[TheBlueMatt]

I'm not sure I understand the desire to set quantity? That is really just a concept for weird too-tightly-integrated webstores that want to have a static offer for buying a widget, and will accept orders of multiple widgets. I guess in theory someone could let you buy widgets by paying to widget@storename, but I'm not entirely convinced that's all that likely?

The payer_note is a bit more understandable, though I still wish we wouldn't have a payer_note at all for privacy reasons (sadly people would complain about the UX...)

[tnull]

I'm not sure I understand the desire to set quantity? That is really just a concept for weird too-tightly-integrated webstores that want to have a static offer for buying a widget, and will accept orders of multiple widgets. I guess in theory someone could let you buy widgets by paying to widget@storename, but I'm not entirely convinced that's all that likely?

It's a spec bug feature, so IMO we should expose it to a) keep the APIs in sync and b) as there will be a user that requests it at some point, so might as well expose it now while we're at it.

The payer_note is a bit more understandable, though I still wish we wouldn't have a payer_note at all for privacy reasons (sadly people would complain about the UX...)

Mhh, well, they don't need to use it to re-identify themselves, no? Any case, it would be handy to have.

[TheBlueMatt]

I guess I see BOLT 12 offers within a BIP 353 TXT record as a different Thing from normal BOLT 12 offers. They're not allowed to have a fixed amount and ISTM as such they shouldn't really be allowed to require a quantity either.