Cannot get signers of current transaction

[merl111]

Describe the bug
The native Ledger contract has a method called GetTransactionSigners, which should return a Singer[], for the current executing transaction it returns null though. I am not sure if that's on purpose or not, if it is on purpose, maybe we can expose the signers also on the transaction I can get from Runtime.ScriptContainer.

To Reproduce

using System;
using System.Numerics;
using Neo;
using Neo.SmartContract.Framework;
using Neo.SmartContract.Framework.Native;
using Neo.SmartContract.Framework.Services;

namespace GhostMarket.Exchange;

public class TestContract : SmartContract
{
    public static bool GetSigners()
    {
        var tx = (Transaction)Runtime.ScriptContainer;
        var signers = Ledger.GetTransactionSigners(tx.Hash);
        if (signers == null)
        {
            // for demonstration purposes only
            throw new Exception("signers array is null");
        }


        return true;
    }
}

Expected behavior
Above example contract should not throw the exception, but return true.

Platform:

• Linux x64
• Neo.Smartcontract.Framework 3.4.0
• Neo Express 3.4.18+f8b893e693

[roman-khimov]

That's the same behavior as #2568, it's an intended one for the native Ledger contract. But I agree that this creates some interface asymmetry, it can be solved with another Runtime syscall.

[shargon]

We can fix it with the ScriptContainer