CborObject.GetTransaction: requiredSigners are not deserialized correctly

[maxee]

When creating a transaction via the Cardano Serialization Lib which contains one or more additional required signers, these are not correctly parsed when deserializing the CBOR via CardanoSharp.Wallet.

However, when the same transaction is build via the Cardano Serialization Lib without the additional required signers, everything works as expected.

Example (not working as expected, with required signers)

Having the following CBOR constructed by the CSL containing required signers set via CSL's method add_required_signer:

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

When this CBOR is deserialized by this library into an instance of Transaction and then serialized back to CBOR, the resulting CBOR is not identical to the one created by the CSL:

Code to deserialize/serialize:

var cborToSign = "84a7008182...2f75f5f6";
var cbor = CBORObject.DecodeFromBytes(Convert.FromHexString(cborToSign), new CBOREncodeOptions("keepkeyorder=true"));

var transaction = cbor.GetTransaction();

var cborOut = Convert.ToHexString(transaction.GetCBOR().EncodeToBytes()).ToLowerInvariant();

The CBOR constructed by this library after deserialization/serialization is different than the original CSL cbor most likely lacking the required signers being deserialized.

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

Example (working as expected, no required signers)

When the CBOR constructed by the CSL does not contain additional required signers, everything works as expected.

Original CSL CBOR:

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

Deserialized => Serialized CBOR via this library (identical to the original one):

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