Retrievals work when last block lands on payment interval

[hannahhoward]

Goals

Handle the case when the last block sent lands on a payment interval, removing the need for a final payment.

Previously, if the last block corresponded with a payment interval, a cascading set of failures occurred preventing the deal from completing.

Implementation

Client Side:

• Record the "ClientEventAllBlocksReceived" event when status is "DealStatusFundsNeeded" or "DealStatusSendFunds" (sets AllBlocksReceived = true)
• When receiving the "ClientEventComplete" event, if we are in "DealStatusOngoing" rather than "DealStatusFinalizing", put deal in "DealStatusCheckComplete" which runs a state handler to make sure AllBlocksReceived = true before moving to DealStatusComplete (or error otherwise)

Provider Side:

• In revalidator, in OnComplete, if we have no additional payment needed, just send DealStatusComplete back in the voucher result, and return nil error status which will cause data transfer to finish
• Allow DealStatusComplete (triggered by data transfer completing) to run from DealStatusBlocksComplete as well as DealStatusFinalizing

[ingar]

👍

The state diagrams are getting hairy!