Check if tracer is actually set before checking if its Firehose tra…

…cer via `OnBlockUpdate != nil`

arbos/block_processor.go

@@ -478,7 +478,7 @@ func ProduceBlockAdvanced(
 	tmpBlock := types.NewBlock(header, &types.Body{Transactions: complete}, receipts, trie.NewStackTrie(nil))
 	blockHash := tmpBlock.Hash()
 
-	if tracer != nil {
+	if tracer != nil && tracer.OnBlockUpdate != nil {
 		tracer.OnBlockUpdate(tmpBlock, big.NewInt(1))
 	}
 	for _, receipt := range receipts {

arbos/tx_processor.go

@@ -146,7 +146,7 @@ func (p *TxProcessor) StartTxHook() (endTxNow bool, gasUsed uint64, err error, r
 
 	// Only Firehose tracer has OnBlockUpdate defined, we can use
 	tracer := evm.Config.Tracer
-	if evm.Config.Tracer.OnBlockUpdate != nil {
+	if tracer != nil && tracer.OnBlockUpdate != nil {
 		// FIXME: It seems having the `Firehose` tracer enabled causes a problem since most probably, the series
 		// of tracer call below don't respect the `Firehose` tracer's expectations.
 		tracer = nil

arbos/util/tracing.go

@@ -89,7 +89,7 @@ func (info *TracingInfo) MockCall(input []byte, gas uint64, from, to common.Addr
 	tracer := info.Tracer
 
 	// Only Firehose tracer has OnBlockUpdate defined, we can use
-	if info.Tracer.OnBlockUpdate != nil {
+	if tracer != nil && tracer.OnBlockUpdate != nil {
 		// FIXME: It seems having the `Firehose` tracer enabled causes a problem since most probably, the series
 		// of tracer call below don't respect the `Firehose` tracer's expectations.
 		tracer = nil

arbos/util/transfer.go

@@ -34,7 +34,7 @@ func TransferBalance(
 
 	// Only Firehose tracer has OnBlockUpdate defined, we can use
 	tracer := evm.Config.Tracer
-	if evm.Config.Tracer.OnBlockUpdate != nil {
+	if tracer != nil && tracer.OnBlockUpdate != nil {
 		// FIXME: It seems having the `Firehose` tracer enabled causes a problem since most probably, the series
 		// of tracer call below don't respect the `Firehose` tracer's expectations.
 		tracer = nil