fix(eth): make trace_filter resilient to null rounds

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 # UNRELEASED
 
+## Bug Fixes
+
+- Make `EthTraceFilter` / `trace_filter` skip null rounds instead of erroring. ([filecoin-project/lotus#12702](https://github.com/filecoin-project/lotus/pull/12702))
+
 # UNRELEASED v1.31.0
 
 See https://github.com/filecoin-project/lotus/blob/release/v1.31.0/CHANGELOG.md

itests/eth_transactions_test.go

@@ -761,7 +761,7 @@ func TestTraceFilter(t *testing.T) {
 	blockTime := 100 * time.Millisecond
 	client, _, ens := kit.EnsembleMinimal(t, kit.MockProofs(), kit.ThroughRPC())
 
-	ens.InterconnectAll().BeginMining(blockTime)
+	bms := ens.InterconnectAll().BeginMining(blockTime)
 
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
 	defer cancel()
@@ -844,7 +844,7 @@ func TestTraceFilter(t *testing.T) {
 	require.NotNil(t, tracesAddressFilter)
 	require.NotEmpty(t, tracesAddressFilter)
 
-	//we should only get our contract deploy transaction
+	// we should only get our contract deploy transaction
 	require.Len(t, tracesAddressFilter, 1)
 	require.Equal(t, 1, tracesAddressFilter[0].TransactionPosition)
 	require.Equal(t, hash, tracesAddressFilter[0].TransactionHash)
@@ -864,8 +864,32 @@ func TestTraceFilter(t *testing.T) {
 	require.NotNil(t, traces)
 	require.NotEmpty(t, traces)
 
-	//we should only get the last two results from the first trace query
+	// we should only get the last two results from the first trace query
 	require.Len(t, tracesAfterCount, 2)
 	require.Equal(t, traces[1].TransactionHash, tracesAfterCount[0].TransactionHash)
 	require.Equal(t, traces[2].TransactionHash, tracesAfterCount[1].TransactionHash)
+
+	// make sure we have null rounds in the chain
+	bms[0].InjectNulls(2)
+	ch, err := client.ChainNotify(ctx)
+	require.NoError(t, err)
+	hc := <-ch // current
+	require.Equal(t, store.HCCurrent, hc[0].Type)
+	beforeNullHeight := hc[0].Val.Height()
+	hc = <-ch // wait for next block
+	require.Equal(t, store.HCApply, hc[0].Type)
+	afterNullHeight := hc[0].Val.Height()
+	require.Greater(t, afterNullHeight, beforeNullHeight+1)
+	hc = <-ch // one more, so "latest" points to the block after nulls
+	require.Equal(t, store.HCApply, hc[0].Type)
+
+	// define filter criteria that spans a null round so it has to at lest consider it
+	toBlock = "latest"
+	filter = ethtypes.EthTraceFilterCriteria{
+		FromBlock: &fromBlock,
+		ToBlock:   &toBlock,
+	}
+	traces, err = client.EthTraceFilter(ctx, filter)
+	require.NoError(t, err)
+	require.Len(t, traces, 3) // still the same traces as before
 }

node/impl/full/eth.go

@@ -1364,6 +1364,9 @@ func (a *EthModule) EthTraceFilter(ctx context.Context, filter ethtypes.EthTrace
 	for blkNum := fromBlock; blkNum <= toBlock; blkNum++ {
 		blockTraces, err := a.EthTraceBlock(ctx, strconv.FormatUint(uint64(blkNum), 10))
 		if err != nil {
+			if errors.Is(err, &api.ErrNullRound{}) {
+				continue
+			}
 			return nil, xerrors.Errorf("cannot get trace for block %d: %w", blkNum, err)
 		}