From 67bf14fffd28e35068e841b22792ce8a5ef55d23 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andrej=20Buko=C5=A1ek?= <andrej.bukosek@gmail.com>
Date: Mon, 8 Mar 2021 15:20:52 +0100
Subject: [PATCH] go/consensus: Exclude expired nodes from validator set at
 genesis time

---
 .changelog/3763.bugfix.md                   |  3 ++
 go/consensus/tendermint/api/genesis.go      |  6 ++++
 go/consensus/tendermint/api/genesis_test.go | 33 +++++++++++++--------
 3 files changed, 30 insertions(+), 12 deletions(-)
 create mode 100644 .changelog/3763.bugfix.md

diff --git a/.changelog/3763.bugfix.md b/.changelog/3763.bugfix.md
new file mode 100644
index 00000000000..21c36ef31e9
--- /dev/null
+++ b/.changelog/3763.bugfix.md
@@ -0,0 +1,3 @@
+go/consensus: Exclude expired nodes from validator set at genesis time
+
+The validator set selection algorithm now properly ignores expired nodes.
diff --git a/go/consensus/tendermint/api/genesis.go b/go/consensus/tendermint/api/genesis.go
index 51093dbdb53..f88775b64a4 100644
--- a/go/consensus/tendermint/api/genesis.go
+++ b/go/consensus/tendermint/api/genesis.go
@@ -160,6 +160,12 @@ func convertValidators(d *genesis.Document) ([]tmtypes.GenesisValidator, error)
 			continue
 		}
 
+		// Skip expired nodes.
+		if openedNode.IsExpired(uint64(d.Beacon.Base)) {
+			continue
+		}
+
+		// Calculate voting power from stake.
 		var power int64
 		if d.Scheduler.Parameters.DebugBypassStake {
 			power = 1
diff --git a/go/consensus/tendermint/api/genesis_test.go b/go/consensus/tendermint/api/genesis_test.go
index aa14a12e2cf..f20b0a54173 100644
--- a/go/consensus/tendermint/api/genesis_test.go
+++ b/go/consensus/tendermint/api/genesis_test.go
@@ -12,6 +12,7 @@ import (
 	"github.com/oasisprotocol/oasis-core/go/common/node"
 	"github.com/oasisprotocol/oasis-core/go/common/quantity"
 
+	beacon "github.com/oasisprotocol/oasis-core/go/beacon/api"
 	genesis "github.com/oasisprotocol/oasis-core/go/genesis/api"
 	registry "github.com/oasisprotocol/oasis-core/go/registry/api"
 	scheduler "github.com/oasisprotocol/oasis-core/go/scheduler/api"
@@ -43,16 +44,20 @@ func TestValidatorConversionTopK(t *testing.T) {
 		return e, se
 	}
 
-	mknod := func(ent entity.Entity, num int) *node.MultiSignedNode {
+	mknod := func(ent entity.Entity, num int, expired bool) *node.MultiSignedNode {
 		nods := memorySigner.NewTestSigner(fmt.Sprintf("test node %d", num))
 		n := node.Node{
-			ID:       nods.Public(),
-			EntityID: ent.ID,
-			Roles:    node.RoleValidator,
+			ID:         nods.Public(),
+			EntityID:   ent.ID,
+			Expiration: 1000,
+			Roles:      node.RoleValidator,
 			Consensus: node.ConsensusInfo{
 				ID: nods.Public(),
 			},
 		}
+		if expired {
+			n.Expiration = 1
+		}
 		sn, err := node.MultiSignNode(
 			[]signature.Signer{nods},
 			registry.RegisterGenesisNodeSignatureContext,
@@ -71,16 +76,20 @@ func TestValidatorConversionTopK(t *testing.T) {
 	e4, se4 := mkent(4)
 	e5, se5 := mkent(5)
 
-	sn0 := mknod(e0, 0)
-	sn1 := mknod(e1, 1)
-	sn2 := mknod(e2, 2)
-	sn3 := mknod(e3, 3)
-	sn4 := mknod(e4, 4)
-	sn5 := mknod(e4, 5)
+	sn0 := mknod(e0, 0, false)
+	sn1 := mknod(e1, 1, false)
+	sn2 := mknod(e2, 2, false)
+	sn3 := mknod(e3, 3, false)
+	sn4 := mknod(e4, 4, false)
+	sn5 := mknod(e4, 5, false)
+	sn6 := mknod(e5, 6, true)
 
 	base := scheduler.BaseUnitsPerVotingPower.ToBigInt().Uint64()
 
 	doc := &genesis.Document{
+		Beacon: beacon.Genesis{
+			Base: beacon.EpochTime(123),
+		},
 		Scheduler: scheduler.Genesis{
 			Parameters: scheduler.ConsensusParameters{
 				MinValidators:          1,
@@ -93,7 +102,7 @@ func TestValidatorConversionTopK(t *testing.T) {
 				se0, se1, se2, se3, se4, se5,
 			},
 			Nodes: []*node.MultiSignedNode{
-				sn0, sn1, sn2, sn3, sn4, sn5,
+				sn0, sn1, sn2, sn3, sn4, sn5, sn6,
 			},
 		},
 		Staking: staking.Genesis{
@@ -103,7 +112,7 @@ func TestValidatorConversionTopK(t *testing.T) {
 				staking.NewAddress(e2.ID): mkacct(base * 3000),
 				staking.NewAddress(e3.ID): mkacct(base * 4000),
 				staking.NewAddress(e4.ID): mkacct(base * 5000),
-				staking.NewAddress(e5.ID): mkacct(base * 6000),
+				staking.NewAddress(e5.ID): mkacct(base * 10000),
 			},
 		},
 	}