From 02cea2330d6b4822b43a7fbaeacc12ddc8e8b1db Mon Sep 17 00:00:00 2001
From: Marius van der Wijden <m.vanderwijden@live.de>
Date: Fri, 26 Jun 2020 10:19:31 +0000
Subject: [PATCH] eth: returned revert reason in traceTx (#21195)

* eth: returned revert reason in traceTx

* eth: return result data
---
 eth/api_tracer.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/eth/api_tracer.go b/eth/api_tracer.go
index 68a61bea00..125c6fd70c 100644
--- a/eth/api_tracer.go
+++ b/eth/api_tracer.go
@@ -765,10 +765,15 @@ func (api *PrivateDebugAPI) traceTx(ctx context.Context, message core.Message, v
 	// Depending on the tracer type, format and return the output
 	switch tracer := tracer.(type) {
 	case *vm.StructLogger:
+		// If the result contains a revert reason, return it.
+		returnVal := fmt.Sprintf("%x", result.Return())
+		if len(result.Revert()) > 0 {
+			returnVal = fmt.Sprintf("%x", result.Revert())
+		}
 		return &ethapi.ExecutionResult{
 			Gas:         result.UsedGas,
 			Failed:      result.Failed(),
-			ReturnValue: fmt.Sprintf("%x", result.Return()),
+			ReturnValue: returnVal,
 			StructLogs:  ethapi.FormatLogs(tracer.StructLogs()),
 		}, nil