From 3cbe387cd67bea743fa496b86f349037f771f231 Mon Sep 17 00:00:00 2001
From: Matthieu Vachon <matt@streamingfast.io>
Date: Fri, 20 Dec 2024 16:20:00 -0500
Subject: [PATCH] Added a backward compatibility fix for aligning with Firehose
 2.3

---
 eth/tracers/firehose.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/eth/tracers/firehose.go b/eth/tracers/firehose.go
index 63b9893776..223edae42b 100644
--- a/eth/tracers/firehose.go
+++ b/eth/tracers/firehose.go
@@ -643,6 +643,13 @@ func (f *Firehose) completeTransaction(receipt *types.Receipt) *pbeth.Transactio
 	f.removeLogBlockIndexOnStateRevertedCalls()
 	f.assignOrdinalAndIndexToReceiptLogs()
 
+	if *f.applyBackwardCompatibility {
+		// Known Firehose issue: Failed call logging a log with no topics were not fixed in the old Firehose instrumentation
+		// leading to them to be rendered as `topics: [""]` instead of `topics: nil` like successful calls.
+		// Here we re-apply this bogus behavior.
+		f.noTopicsLogOnFailedCallSetToEmptyHash()
+	}
+
 	if *f.applyBackwardCompatibility {
 		// Known Firehose issue: This field has never been populated in the old Firehose instrumentation
 	} else {
@@ -757,6 +764,18 @@ func (f *Firehose) assignOrdinalAndIndexToReceiptLogs() {
 	}
 }
 
+func (f *Firehose) noTopicsLogOnFailedCallSetToEmptyHash() {
+	for _, call := range f.transaction.Calls {
+		if call.StateReverted {
+			for _, log := range call.Logs {
+				if len(log.Topics) == 0 {
+					log.Topics = make([][]byte, 1)
+				}
+			}
+		}
+	}
+}
+
 // OnCallEnter implements the EVMLogger interface to initialize the tracing operation.
 func (f *Firehose) OnCallEnter(depth int, typ byte, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
 	opCode := vm.OpCode(typ)