Missing head in abi encoded tuple for function

[rockfridrich]

An offset of the data needed to be encoded into tuple is missing for contract call functions.

Example:
If a tuple is used as the first argument of function, then there should be 32 (0000000000000000000000000000000000000000000000000000000000000020) put between signature and encoded structure.

How to reproduce:
Call getOrderInfo((address,address,address,address,uint256,uint256,uint256,uint256,uint256,uint256,bytes,bytes) function on the 0x exchange contract with the next set of parameters:

let network: Network = GethNetwork(url: "InfuraUrl")

let exchangeContract = EthAddress(
    hex: "0x4f833a24e1f95d70f028921e27040ca56e09ab0b"
)

let kittiesContract = EthAddress(
    hex: "0x06012c8cf97bead5deae237070f9587f8e7a266d"
)

let sender = EthAddress(
    hex: "0x0aD9Fb61a07BAC25625382B63693644497f1B204"
)

let receiver = EthAddress(
    hex: "0x4dB6d56Bbb49DD66abC7be5D671fDdF9a5255Cc5"
)

let zero = EthAddress(
    hex: "0x0000000000000000000000000000000000000000"
)

let makerAssetData = EncodedABIFunction(
    signature: SimpleString(
        string: "ERC721Token(address,uint256)"
    ),
    parameters: [
        ABIAddress(
            address: kittiesContract
        ),
        ABIUnsignedNumber(
            origin: EthNumber(value: 478404)
        )
    ]
)

let takerAssetData = EncodedABIFunction(
    signature: SimpleString(
        string: "ERC721Token(address,uint256)"
    ),
    parameters: [
        ABIAddress(
            address: kittiesContract
        ),
        ABIUnsignedNumber(
            origin: EthNumber(value: 392919)
        )
    ]
)

let orderInfo = EncodedABIFunction(
    signature: SimpleString(
        string: "getOrderInfo((" +
            "address," +
            "address," +
            "address," +
            "address," +
            "uint256," +
            "uint256," +
            "uint256," +
            "uint256," +
            "uint256," +
            "uint256," +
            "bytes," +
        "bytes))"
    ),
    parameters: [
        ABITuple(
            parameters: [
                // makerAddress
                ABIAddress(
                    address: sender
                ),
                // takerAddress
                ABIAddress(
                    address: receiver
                ),
                // feeRecipientAddress
                ABIAddress(
                    address: zero
                ),
                // senderAddress
                ABIAddress(
                    address: zero
                ),
                // makerAssetAmount
                ABIUnsignedNumber(
                    origin: EthNumber(value: 1)
                ),
                // takerAssetAmount
                ABIUnsignedNumber(
                    origin: EthNumber(value: 1)
                ),
                // makerFee
                ABIUnsignedNumber(
                    origin: EthNumber(value: 0)
                ),
                // takerFee
                ABIUnsignedNumber(
                    origin: EthNumber(value: 0)
                ),
                // expiration timestamp
                ABIUnsignedNumber(
                    origin: EthNumber(value: 1569523685)
                ),
                // salt
                ABIUnsignedNumber(
                    origin: EthNumber(value: Int(Date.init().timeIntervalSince1970 * 1000))
                ),
                // makerAssetData
                ABIVariableBytes(
                    origin: makerAssetData
                ),
                // takerAssetData
                ABIVariableBytes(
                    origin: takerAssetData
                )
            ]
        )
    ]
)

do {
    
    let call = try EthContractCall(
        network: network,
        contractAddress: exchangeContract,
        functionCall: orderInfo
        ).value()
    
} catch {
    print(error)
}

More information could be found here — https://medium.com/b2expand/abi-encoding-explanation-4f470927092d

[abdulowork]

What is the expected value of orderInfo.value()?

[rockfridrich]

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