indexed parameters are shifted by one when decoding logs

[mistersandman]

Expected behavior

decodeLog in AbiCoder.js (here) should return a map from all event parameter names to their decoded data with respect to the type specified in the ABI.

Actual behavior

The data used to decode indexed parameters of events is shifted by one topic (i.e. the first indexed parameter uses the data from topics[0] when it should in fact use topics[1]). Note that the first topic (topics[0]) is always defined to be the hash of the event signature.

Steps to reproduce the behavior

Use getPastEvents to query for an event with at least one indexed parameter and compare the result value of the event with the raw value.

Error Logs

no error

Versions

web3.js 1.0.0-beta.46

[mistersandman]

Small example to reproduce, querying past Transfer events from block 7205796 of the Wrapped ETH (WETH) contract:

const Web3 = require('web3');

let web3 = new Web3('https://mainnet.infura.io/metamask');

let wethAbi = [{ "anonymous": false, "inputs": [{ "indexed": true, "name": "src", "type": "address" }, { "indexed": true, "name": "dst", "type": "address" }, { "indexed": false, "name": "wad", "type": "uint256" }], "name": "Transfer", "type": "event" }];
let wethAddress = '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2';
let wethContract = new web3.eth.Contract(wethAbi, wethAddress);

wethContract.getPastEvents('Transfer', { fromBlock: 7205796, toBlock: 7205796 }).then((events) => {
    console.log(events[0].transactionHash);
    console.log(events[0].returnValues.src);
    console.log(events[0].returnValues.dst);
    console.log(events[0].raw.topics);
});

The output is:

0x72cbb7c4f9c3990b2f7d3351a8ea733fed9681c0f09169b65400a571089568e9 // tx hash
0xFC378dAA952ba7f163c4a11628f55a4df523b3EF // src address
0x260e92D7b25c9315d068b2c3Ca5f234D0Cf9e505 // dst address
0: "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef" // topics array with 3 entries
1: "0x000000000000000000000000260e92d7b25c9315d068b2c3ca5f234d0cf9e505"
2: "0x0000000000000000000000000681e844593a051e2882ec897ecd5444efe19ff2"

Compare this with the transfer information on Etherscan here. The transfer goes from 260e92d7b25c9315d068b2c3ca5f234d0cf9e505 to 0681e844593a051e2882ec897ecd5444efe19ff2, however the returnValues of the event gives the source address as destination address and 0xFC378dAA952ba7f163c4a11628f55a4df523b3EF as the source address, which is the last 256 bits of events[0].raw.topics[0]. Note that source and destination address parameters in the Transfer event are indexed. Decoding indexed parameter arguments erroneously starts with the first entry in the topics array. It should start with the second entry, since the first entry is the hash of the event signature.

[pixelmatrix]

I'm seeing something similar with beta.46.

When I subscribe to Transfer events, i'm seeing the to and from values being swapped. The event signature is:

event Transfer(address indexed _from, address indexed _to, uint256 indexed _tokenId);

The raw event log is:

topics: [
  "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
  "0x000000000000000000000000c20c5ccb44e6092c712a1b895df6d72ea53b40f5",
  "0x000000000000000000000000f30c09bc05d3d4c5b4070c989cc7d268265d0a3c",
  "0x2a057186f17ec59a722759e94470b239925c609effd8e5936702b0729f2cfaaa"
]

Decoded return values:

returnValues: {
  0: "0xFC378dAA952ba7f163c4a11628f55a4df523b3EF"
  1: "0xc20c5CCB44E6092C712A1B895DF6D72eA53B40F5"
  2: "1387553214243979768995578582844225663590104631868"
  from: "0xFC378dAA952ba7f163c4a11628f55a4df523b3EF"
  to: "0xc20c5CCB44E6092C712A1B895DF6D72eA53B40F5"
  tokenId: "1387553214243979768995578582844225663590104631868"
}

[chiro-hiro]

I have the same issue:

//New offer
event NewOffer(
    address indexed maker,
    uint256 indexed offerId,
    address indexed tokenAddress,
    uint256 offerType,
    uint128 startDate,
    uint128 endDate,
    uint256 amount,
    uint256 price,
    uint256 minimum
);

Expected result:

{
    '0': '0x12583F7627099D8C89A68112C15B83628E72CBE7',
    '1': '0',
    '2': '0x5562779B00A8Ad6344586E23F940d9e4E202F849',
    '3': '13',
    '4': '1550123168',
    '5': '2414123168',
    '6': '1000000',
    '7': '1000',
    '8': '100',
    maker: '0x12583F7627099D8C89A68112C15B83628E72CBE7',
    offerId: '0',
    tokenAddress: '0x5562779B00A8Ad6344586E23F940d9e4E202F849',
    offerType: '13',
    startDate: '1550123168',
    endDate: '2414123168',
    amount: '1000000',
    price: '1000',
    minimum: '100'
}

Which was I received:

{
    '0': '0x5562779B00A8Ad6344586E23F940d9e4E202F849',
    '1': '104729827731522621819118954356228975471770127335',
    '2': '0x0000000000000000000000000000000000000000',
    '3': '13',
    '4': '1550123168',
    '5': '2414123168',
    '6': '1000000',
    '7': '1000',
    '8': '100',
    maker: '0x5562779B00A8Ad6344586E23F940d9e4E202F849',
    offerId: '104729827731522621819118954356228975471770127335',
    tokenAddress: '0x0000000000000000000000000000000000000000',
    offerType: '13',
    startDate: '1550123168',
    endDate: '2414123168',
    amount: '1000000',
    price: '1000',
    minimum: '100'
}

To me, it was happened to both 1.0.0beta45 and 1.0.0beta46.

[nivida]

Thanks all for the detailed information! I will fix and release it asap.

[kevholder]

I think I'm still seeing this error in web3 1.2.6

const data = '0x000000000000000000000000000000000000000000000004eee0f1dc808c0000';
const inputs = [ { indexed: true, name: 'user', type: 'address' },
  { indexed: false, name: 'amount', type: 'uint256' },
  { indexed: true, name: 'depositIndex', type: 'uint256' } ];
const topics = [ 'd9acabe6e09d178728ba5c366661c5be0621b4770f216305b059ec175b37e0b4',
  '000000000000000000000000a8a07f09def5e6a4462df90068c11abf6224e865',
  '000000000000000000000000000000000000000000000000000000000000000f' ];
const res = web3.eth.abi.decodeLog(inputs, data, topics);
console.log(res);
/*
Result {
  '0': '0x6661C5bE0621b4770F216305B059EC175B37e0B4',
  '1': '91000000000000000000',
  '2': '962689635349389981377523555802656161741058402405',
  __length__: 3,
  user: '0x6661C5bE0621b4770F216305B059EC175B37e0B4',
  amount: '91000000000000000000',
  depositIndex: '962689635349389981377523555802656161741058402405' }
*/

// depositIndex should be a small integer...

[pseudonaut]

Error is still occuring for me as well on web3 1.2.6 using web3.eth.abi.decodeLog()...

0: "17"
1: "40736905663348235180449726993715947561663541068933497753637381325270891332134"
2: "1000000000000000000000"
3: "0x0000000000000000000000000000000000000011"
4: "0x6B175474E89094C44Da98b954EedeAC495271d0F"
5: "1250"
6: "5"
7: "1591287895"
8: "0"
9: "0"
length: 10
_amount: "1000000000000000000000"
_apr: "1250"
_asset: "0x6B175474E89094C44Da98b954EedeAC495271d0F"
_borrower: "0x0000000000000000000000000000000000000011"
_collateralPercentageRequirement: "0"
_communityID: "17"
_fee: "0"
_firstPaymentUnix: "1591287895"
_loanID: "40736905663348235180449726993715947561663541068933497753637381325270891332134"
_monthlyPayments: "5"

_loanID / _communityID / _borrower are the 3 indexed params

[pseudonaut]

I fixed above error by adjusting the order of logs sent into the decodeLog in 3rd param:

result.logs[0].topics[1],
result.logs[0].topics[2],
result.logs[0].topics[3],
result.logs[0].topics[0]