abi pack method doesn't encode new ABiEncoderV2 features like string[] correctly

[xmxanuel]

It seems like the encoding of solidity function arguments for new pragma experimental ABIEncoderV2; features isn't working correctly.

I tested to encode an array of strings parameter with abigen and the transaction is not successful.

function test(string[] _values) public

The returned encoding from the Pack method in go-ethereum/accounts/abi/argument.go is different from web3.js using the same input parameters.

I compared the encoding for the same inputs with web3.js which supports the new encoding with version 1.0.0-beta.36.

The Unpack seems to work because a test with web3.js and latest geth was successful.

Is go-ethereum up to date with the latest specification?
https://solidity.readthedocs.io/en/develop/abi-spec.html

[xmxanuel]

It might be the Pack method in go-ethereum doesn't add the offsets of the dynamic types inside the array at the beginning correctly.

ABI Encoding Comparison

Solidity Method

function mintDummy(string[] _values) public

Input

values := []string{"hello","aaaaaaaaaaa"}

Expected behaviour

Expected abi encoding (using web3.js)

"0xe71e5caf0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000568656c6c6f000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000b6161616161616161616161000000000000000000000000000000000000000000"

Actual behaviour

abi encoding in go-ethereum

"0xe71e5caf00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000568656c6c6f000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000b6161616161616161616161000000000000000000000000000000000000000000"