Fix IsAncestorOf

chain/store/store.go

@@ -471,7 +471,7 @@ func (cs *ChainStore) IsAncestorOf(a, b *types.TipSet) (bool, error) {
 
 	cur := b
 	for !a.Equals(cur) && cur.Height() > a.Height() {
-		next, err := cs.LoadTipSet(b.Parents())
+		next, err := cs.LoadTipSet(cur.Parents())
 		if err != nil {
 			return false, err
 		}

chain/sync_test.go

@@ -709,7 +709,7 @@ func TestSyncInputs(t *testing.T) {
 	}
 }
 
-func TestSyncCheckpoint(t *testing.T) {
+func TestSyncCheckpointHead(t *testing.T) {
 	H := 10
 	tu := prepSyncTest(t, H)
 
@@ -750,3 +750,45 @@ func TestSyncCheckpoint(t *testing.T) {
 	require.Equal(tu.t, p1Head, a.TipSet())
 	tu.assertBad(p1, b.TipSet())
 }
+
+func TestSyncCheckpointEarlierThanHead(t *testing.T) {
+	H := 10
+	tu := prepSyncTest(t, H)
+
+	p1 := tu.addClientNode()
+	p2 := tu.addClientNode()
+
+	fmt.Println("GENESIS: ", tu.g.Genesis().Cid())
+	tu.loadChainToNode(p1)
+	tu.loadChainToNode(p2)
+
+	base := tu.g.CurTipset
+	fmt.Println("Mining base: ", base.TipSet().Cids(), base.TipSet().Height())
+
+	// The two nodes fork at this point into 'a' and 'b'
+	a1 := tu.mineOnBlock(base, p1, []int{0}, true, false, nil)
+	a := tu.mineOnBlock(a1, p1, []int{0}, true, false, nil)
+	a = tu.mineOnBlock(a, p1, []int{0}, true, false, nil)
+
+	tu.waitUntilSyncTarget(p1, a.TipSet())
+	tu.checkpointTs(p1, a1.TipSet().Key())
+
+	require.NoError(t, tu.g.ResyncBankerNonce(a1.TipSet()))
+	// chain B will now be heaviest
+	b := tu.mineOnBlock(base, p2, []int{1}, true, false, nil)
+	b = tu.mineOnBlock(b, p2, []int{1}, true, false, nil)
+	b = tu.mineOnBlock(b, p2, []int{1}, true, false, nil)
+	b = tu.mineOnBlock(b, p2, []int{1}, true, false, nil)
+
+	fmt.Println("A: ", a.Cids(), a.TipSet().Height())
+	fmt.Println("B: ", b.Cids(), b.TipSet().Height())
+
+	// Now for the fun part!! p1 should mark p2's head as BAD.
+
+	require.NoError(t, tu.mn.LinkAll())
+	tu.connect(p1, p2)
+	tu.waitUntilNodeHasTs(p1, b.TipSet().Key())
+	p1Head := tu.getHead(p1)
+	require.Equal(tu.t, p1Head, a.TipSet())
+	tu.assertBad(p1, b.TipSet())
+}

node/impl/full/sync.go

@@ -98,7 +98,7 @@ func (a *SyncAPI) SyncIncomingBlocks(ctx context.Context) (<-chan *types.BlockHe
 }
 
 func (a *SyncAPI) SyncCheckpoint(ctx context.Context, tsk types.TipSetKey) error {
-	log.Warnf("Marking tipset %s as bad", tsk)
+	log.Warnf("Marking tipset %s as checkpoint", tsk)
 	return a.Syncer.SetCheckpoint(tsk)
 }