Unable to decode serialized TxOut

src/transaction.rs の TxOut と TxOutWitness の定義、および引用された行周辺のシリアライズ動作から始め、提示されたトランザクションと round-trip スニペットで問題を再現します。シリアライズしてデシリアライズした TxOut が rangeproof を保持し、unblind が成功すれば完了です。リポジトリに適切な場所が用意されている場合は、リグレッションテストのカバレッジを追加または更新してください。

There is an issue in serialization of TxOut, we're unable to decode it after serialization.
The problem lyes in the simplicityhl::elements::encode::serialize.
For unblinding it misses Rangeproof inside. For some reason it isn't serialized inside.
TxOut contains TxOutSecrets inside https://github.com/ElementsProject/rust-elements/blob/2d94f5dcb5e4a81838681c71ed8a49b337feecd2/src/transaction.rs#L703, but TxOutWitness has its own serialization https://github.com/ElementsProject/rust-elements/blob/2d94f5dcb5e4a81838681c71ed8a49b337feecd2/src/transaction.rs#L653 while TxOut just truncates it https://github.com/ElementsProject/rust-elements/blob/2d94f5dcb5e4a81838681c71ed8a49b337feecd2/src/transaction.rs#L719.

Here is a quick code snippet to test it:

use std::time::Duration;
        use simplicityhl::elements::{ Transaction, TxOut,};
        use simplicityhl::elements::bitcoin::secp256k1;
        use simplicityhl::elements::encode;
        
        pub const PUBLIC_SECRET_BLINDER_KEY: [u8; 32] = [1; 32];
        let secret_key = SecretKey::from_slice(&PUBLIC_SECRET_BLINDER_KEY).unwrap();

        
        let tx_id = "8e12b0c994293d15b7f43abaeb6c119ce3612ff00246b7ae9079dca90a35031f";
        let url = format!("https://blockstream.info/liquidtestnet/api/tx/{}/hex", tx_id);
        let client = reqwest::blocking::Client::builder()
            .timeout(Duration::from_secs(10))
            .build()
            .unwrap();
        let tx_hex = client
            .get(&url)
            .send()
            .unwrap()
            .error_for_status()
            .unwrap()
            .text()
            .unwrap();
        
        let transaction: Transaction = encode::deserialize(&hex::decode(&tx_hex).unwrap()).unwrap();
        let tx_out_from_reqwest = transaction.output[0].clone();
        assert!(tx_out_from_reqwest.unblind(secp256k1::SECP256K1, secret_key).is_ok());
        
        let tx_out_from_request_serialized = encode::serialize(&tx_out_from_reqwest);
        let tx_out_from_request_deserialized: TxOut = encode::deserialize(&tx_out_from_request_serialized).unwrap();
        
        assert!(tx_out_from_request_deserialized.unblind(secp256k1::SECP256K1, secret_key).is_ok());