From 5048fd10280b4556bceb22a849057b925f968452 Mon Sep 17 00:00:00 2001
From: Marius van der Wijden <m.vanderwijden@live.de>
Date: Tue, 2 Jun 2020 14:05:16 +0200
Subject: [PATCH] internal/ethapi: unified handling of errors in DoEstimateGas

---
 internal/ethapi/api.go | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 4a412650f4..1cb165adc6 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -999,19 +999,16 @@ func DoEstimateGas(ctx context.Context, b Backend, args CallArgs, blockNrOrHash
 		}
 		if failed {
 			if result != nil && result.Err != vm.ErrOutOfGas {
-				var revert string
 				if len(result.Revert()) > 0 {
-					ret, err := abi.UnpackRevert(result.Revert())
-					if err != nil {
-						revert = hexutil.Encode(result.Revert())
-					} else {
-						revert = ret
+					reason, err := abi.UnpackRevert(result.Revert())
+					if err == nil {
+						return 0, &revertError{
+							error:   errors.New("execution reverted"),
+							errData: reason,
+						}
 					}
 				}
-				return 0, revertError{
-					error:   errors.New("always failing transaction"),
-					errData: revert,
-				}
+				return 0, result.Err
 			}
 			// Otherwise, the specified gas cap is too low
 			return 0, fmt.Errorf("gas required exceeds allowance (%d)", cap)