Changing BlockReward contract address in spec.json

[varasev]

Title

  Title: "multi" option for BlockReward in spec.json
  Layer: Parity engine

Abstract

To make BlockReward contract changeable in the future there should be a way to change contract's address in spec.json after that is deployed. The current version of Parity (1.11.4-beta) doesn't have that option. We need to change Parity's implementation to support that feature.

Rationale

Parity 1.11.4 doesn't have "multi" option in spec.json for BlockReward contract. Therefore, once the BlockReward has been deployed, it cannot be changed.

To be able to change BlockReward address we need to add the same "multi" option as it's done for validator set: https://wiki.parity.io/Validator-Set.html#multi-set

Specification

Introduction to BlockReward: openethereum/parity-ethereum#8419

Implementation

Repo to see it's working: https://github.com/varasev/test-block-reward

[varasev]

Done in openethereum/parity-ethereum#10875.