fix

internal/ethapi/api.go

@@ -1478,21 +1478,30 @@ func DoEstimateGas(ctx context.Context, b Backend, args TransactionArgs, blockNr
 
 	// Reject the transaction as invalid if it still fails at the highest allowance
 	if hi == cap {
-		ok, res, err := executable(hi)
+		ok, result, err := executable(hi)
 		if err != nil {
 			return 0, err
 		}
 
 		if !ok {
-			if res.Err != vm.ErrOutOfGas {
-				if len(res.ReturnData) > 0 {
-					return 0, newRevertError(res.ReturnData)
+			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
+					}
+				}
+				return 0, estimateGasError{
+					error:  "always failing transaction",
+					vmerr:  result.Err,
+					revert: revert,
 				}
-				return 0, res.Err
 			}
-
 			// Otherwise, the specified gas cap is too low
-			return 0, fmt.Errorf("gas required exceeds allowance (%d)", cap)
+			return 0, estimateGasError{error: fmt.Sprintf("gas required exceeds allowance (%d)", cap)}
 		}
 	}
 	return hexutil.Uint64(hi), nil