Abigen v1.9.25 bytes32 interface conversion bug

[albertchon]

System information

Geth version: geth version 1.9.25, abigen version 1.9.25-stable
OS & Version: OSX
Commit hash : e7872729012a4871397307b12cc3f4772ffcbec6

Expected behaviour

After generating contract bindings using abigen version 1.9.25-stable, I tried calling a view function getOrderRelevantStates (see below)

// GetOrderRelevantStates is a free data retrieval call binding the contract method 0xe25cabf7.
//
// Solidity: function getOrderRelevantStates((address,address,address,address,uint256,uint256,uint256,uint256,uint256,uint256,bytes,bytes,bytes,bytes)[] orders, bytes[] signatures) view returns((uint8,bytes32,uint256,bytes32,uint8,bytes32,uint256)[] ordersInfo, uint256[] fillableTakerAssetAmounts, bool[] isValidSignature)
func (f *FuturesCaller) GetOrderRelevantStates(opts *bind.CallOpts, orders []Order, signatures [][]byte) (struct {
	OrdersInfo                []DerivativeOrderInfo
	FillableTakerAssetAmounts []*big.Int
	IsValidSignature          []bool
}, error) {
	var out []interface{}
	err := f.contract.Call(opts, &out, "getOrderRelevantStates", orders, signatures)

	outstruct := new(struct {
		OrdersInfo                []DerivativeOrderInfo
		FillableTakerAssetAmounts []*big.Int
		IsValidSignature          []bool
	})

	outstruct.OrdersInfo = out[0].([]DerivativeOrderInfo)
	outstruct.FillableTakerAssetAmounts = out[1].([]*big.Int)
	outstruct.IsValidSignature = out[2].([]bool)

	return *outstruct, err

}

where the DerivativeOrderInfo struct is defined as

// DerivativeOrderInfo is an auto generated low-level Go binding around an user-defined struct.
type DerivativeOrderInfo struct {
	OrderStatus                 uint8
	OrderHash                   [32]byte
	OrderTakerAssetFilledAmount *big.Int
	SubAccountID                [32]byte
	Direction                   uint8
	MarketID                    [32]byte
	EntryPrice                  *big.Int
}

It's expected this call should work successfully without any panics.

Actual behaviour

However, this results in the following panic

panic: interface conversion: interface {} is []struct { OrderStatus uint8 "json:\"orderStatus\""; OrderHash [32]uint8 "json:\"orderHash\""; OrderTakerAssetFilledAmount *big.Int "json:\"orderTakerAssetFilledAmount\""; SubAccountID [32]uint8 "json:\"subAccountID\""; Direction uint8 "json:\"direction\""; MarketID [32]uint8 "json:\"marketID\""; EntryPrice *big.Int "json:\"entryPrice\"" }, not []wrappers.DerivativeOrderInfo

The OrderHash, SubAccountID, and MarketID fields are attempting to be converted as [32]uint8 instead of [32]byte as expected.

We manually fixed this in our contract binding wrapper here but this should be fixed on the abigen level obviously.

[MariusVanDerWijden]

@albertchon Could you maybe share your solidity contract so that I can reproduce the issue better?

Edit: nevermind, I built a contract that can repro this issue