Last inherit failure

[uncomputable]

The last will example from the Simfony crate fails with the latest rust-simplicity version.

I constructed a minimal unit test (see below). Git bisect reveals that the test starts failing at the value byte vector rewrite. Investigating.

#[test]
fn last_will_inherit() {
    //use base64::engine::general_purpose::STANDARD;
    use crate::jet::elements::{ElementsEnv, ElementsUtxo};
    use crate::jet::Elements;
    use bitcoin::hex::FromHex;
    use elements::confidential;
    use elements::hex::ToHex;
    use hashes::Hash;

    fn create_default_transaction(
        lock_time: elements::LockTime,
        sequence: elements::Sequence,
        include_fee_output: bool,
    ) -> elements::Transaction {
        let mut tx = elements::Transaction {
            version: 2,
            lock_time,
            input: vec![elements::TxIn {
                previous_output: elements::OutPoint::default(),
                is_pegin: false,
                script_sig: elements::Script::new(),
                sequence,
                asset_issuance: elements::AssetIssuance::default(),
                witness: elements::TxInWitness::default(),
            }],
            output: vec![elements::TxOut {
                asset: confidential::Asset::default(),
                value: confidential::Value::default(),
                nonce: confidential::Nonce::default(),
                script_pubkey: elements::Script::default(),
                witness: elements::TxOutWitness::default(),
            }],
        };

        if include_fee_output {
            tx.output.push(elements::TxOut::new_fee(
                1_000,
                elements::AssetId::default(),
            ));
        }
        tx
    }

    /// Returns a dummy Elements environment with a provided transaction.
    pub fn dummy_with_tx(tx: elements::Transaction) -> ElementsEnv<Arc<elements::Transaction>> {
        let ctrl_blk: [u8; 33] = [
            0xc0, 0xeb, 0x04, 0xb6, 0x8e, 0x9a, 0x26, 0xd1, 0x16, 0x04, 0x6c, 0x76, 0xe8, 0xff,
            0x47, 0x33, 0x2f, 0xb7, 0x1d, 0xda, 0x90, 0xff, 0x4b, 0xef, 0x53, 0x70, 0xf2, 0x52,
            0x26, 0xd3, 0xbc, 0x09, 0xfc,
        ];
        let num_inputs = tx.input.len();

        ElementsEnv::new(
            Arc::new(tx),
            vec![
                ElementsUtxo {
                    script_pubkey: elements::Script::default(),
                    asset: confidential::Asset::default(),
                    value: confidential::Value::default(),
                };
                num_inputs
            ],
            0,
            Cmr::from_byte_array([0; 32]),
            elements::taproot::ControlBlock::from_slice(&ctrl_blk).unwrap(),
            None,
            elements::BlockHash::all_zeros(),
        )
    }

    /// Returns a dummy Elements environment with the given locktime and sequence.
    pub fn dummy_with(
        lock_time: elements::LockTime,
        sequence: elements::Sequence,
        include_fee_output: bool,
    ) -> ElementsEnv<Arc<elements::Transaction>> {
        let default_tx = create_default_transaction(lock_time, sequence, include_fee_output);
        dummy_with_tx(default_tx)
    }

    // let prog_base64 = "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";
    // let wit_base64 = "dVIBu2KwqLjRj9EvwClR6jmYukK/xmZNqvig0imMrUPNwhNYx8gvN2VCddwv6oyFitvpe6ySgotJilojcATbbwA="; // simfony::update
    // let wit_base64 = "OqkA3bFYVFxox+iX4BSo9RzMXSFf4zMm1XxQaRTGVqHm4QmsY+QXm7KhOu4X9UZCxW30vdZJQUWkxS0RuAJtt4A="; // simfony::master
    // let prog_bytes = base64::Engine::decode(&STANDARD, prog_base64).unwrap();
    // let wit_bytes = base64::Engine::decode(&STANDARD, wit_base64).unwrap();
    //
    // println!("{}", prog_bytes.as_hex());
    // println!("{}", wit_bytes.as_hex());

    let prog_hex = "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";
    // let wit_hex = "755201bb62b0a8b8d18fd12fc02951ea3998ba42bfc6664daaf8a0d2298cad43cdc21358c7c82f37654275dc2fea8c858adbe97bac92828b498a5a237004db6f00"; // simfony::update
    let wit_hex = "3aa900ddb158545c68c7e897e014a8f51ccc5d215fe33326d57c506914c656a1e6e109ac63e4179bb2a13aee17f54642c56df4bdd6494145a4c52d11b8026db780"; // simfony::master
    let prog_bytes = Vec::<u8>::from_hex(prog_hex).unwrap();
    let wit_bytes = Vec::<u8>::from_hex(wit_hex).unwrap();

    let prog = BitIter::from(prog_bytes);
    let witness = BitIter::from(wit_bytes);
    let prog = RedeemNode::<Elements>::decode(prog, witness).unwrap();

    // let mut mac = BitMachine::for_program(&prog).unwrap();
    let mut mac = BitMachine::for_program(&prog);
    let lock_time = elements::LockTime::ZERO;
    let sequence = elements::Sequence::from_height(25920);
    let env = dummy_with(lock_time, sequence, false);
    assert_eq!(
        env.c_tx_env().sighash_all().to_hex(),
        "0197352cfe81b504a15a30dba12faada120e2753ea9a9a4c2e6dbaadf1263b45"
    );
    mac.exec(&prog, &env).expect("execution should succeed");
}

[uncomputable]

I have a feeling that the issue is related to the encoding of sum values.

[apoelstra]

I will try to look at this tomorrow -- one thing that might help is to write a comparative fuzz test between master and the released version and see if we can produce values that encode differently on the two versions.