consensus: dexcon: disqualify dead node (#280)

Since a qualified node might fail stopped, we need to remove them from
qualified nodes to maintain network integrity. We do this by inspect the
previous round to see if there are dead nodes. A dead node is a notary
set node that does not propose any block in the previous round. We
disqualify them by fining them so their staked value is 1 wei below
minStake. This make them unqualified for being notary set in the follow
on rounds.

1 files changed, 4 insertions, 0 deletions

diff --git a/dex/downloader/testchain_test.go b/dex/downloader/testchain_test.go
index 722159bc0..15528c509 100644
--- a/dex/downloader/testchain_test.go
+++ b/dex/downloader/testchain_test.go
@@ -342,3 +342,7 @@ func (g *govStateFetcher) GetStateForConfigAtRound(round uint64) *vm.GovernanceS
 	}
 	return nil
 }
+
+func (g *govStateFetcher) NotarySetNodeKeyAddresses(round uint64) (map[common.Address]struct{}, error) {
+	return make(map[common.Address]struct{}), nil
+}