Compatibility: cannot unmarshal hex number with leading zero digits into Go struct

The ethclient fails parsing a transaction received from ganache over RPC.

Expected Behavior

It should parse the JSON response.

Current Behavior

json: cannot unmarshal hex number with leading zero digits into Go struct field txdata.nonce of type hexutil.Uint64

Possible Solution

ethclient expects the following transaction fields to hex encodings of a number without any leading zeros:

• nonce
• gasPrice
• gasLimit
• value
• input
• v
• r
• s

Therefore a nonce of 0x02 will fail to parse but 0x2 will succeed.

Steps to Reproduce (for bugs)

1. Start a ganache on port 9545 (ganache-cli -p 9545).
2. Connect using web3 (npx truffle console).
3. web3.eth.sendTransaction({from: web3.eth.accounts[0], to: web3.eth.accounts[1], value: 0}) (nonce 0 will be encoded correctly as 0x0).
4. web3.eth.sendTransaction({from: web3.eth.accounts[0], to: web3.eth.accounts[1], value: 0}) (nonce 1 will be encoded incorrectly as 0x01).
5. Use the attached go program to lookup the tx hex returned from step 4.
6. Program crashes.

Context

According to the JSON-RPC specification hex quantity values should be encoded as follows:

When encoding QUANTITIES (integers, numbers): encode as hex, prefix with "0x", the most compact representation (slight exception: zero should be represented as "0x0"). Examples:

0x41 (65 in decimal)
0x400 (1024 in decimal)
WRONG: 0x (should always have at least one digit - zero is "0x0")
WRONG: 0x0400 (no leading zeroes allowed)
WRONG: ff (must be prefixed 0x)

ganache should adhere to the spec.

package main

import (
  "context"
  "log"
  "os"

  "github.com/ethereum/go-ethereum/common"
  "github.com/ethereum/go-ethereum/ethclient"
)

func main() {
  if len(os.Args) != 2 {
    log.Fatal("Usage: ./transaction <tx-hex>")
  }
  h := os.Args[1]
  conn, err := ethclient.Dial("http://localhost:9545")

  if err != nil {
    log.Fatalf("Failed to connect to the Ethereum client: %v", err)
  }

  t, _, err := conn.TransactionByHash(context.Background(), common.HexToHash(h))
  if err != nil {
    log.Fatal(err)
  }
  log.Printf("%#v\n", t)
}

Your Environment

• Version used: All versions, including develop branch.
• Operating System and version: Linux e 4.15.12-x86_64-linode105 SMP Thu Mar 22 02:13:40 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[kaidiren]

+1

ganache version 1.2.2 mac os geth version 1.8.17

json: cannot unmarshal hex number with leading zero digits into Go value of type *hexutil.Big

[fjl]

Xref: https://github.com/trufflesuite/ganache-core/pull/432