fix(zcoin): add locked notes support for withdrawals #2644

dimxy · 2025-10-08T15:33:42Z

Past PR #2331 added support for unconfirmed notes handling to prevent spent notes reuse and show unconfirmed change notes as unspendable balance. To implement that, PR 2331 added a locked notes DB.
However, that PR added support only for swap transactions, so if a withdrawal is called before or during a swap (while spent notes are not confirmed yet) errors like 18: bad-txns-joinsplit-requirements-not-met may occur when withdrawal and swap transactions are sent to the chain.

This PR adds support for the locked notes DB for zcoin withdrawals as well. The init_withdraw RPC now returns array of rseeds values which are used to access the locked notes DB. Also the init_withdraw RPC returns received_by_me decimal amount which is used to store change value in the locked notes DB. Both rseeds and received_by_me values should be passed along with the transaction in hex to the RPC sending the transaction into the network.

Breaking change
To send zcoin transaction into the network a new z_send_raw_transaction RPC must be used, instead of the old "send_raw_transaction". The z_send_raw_transaction RPC has more parameters:

curl --url "http://127.0.0.1:7783" --data '{ 
  "userpass": "...",
  "mmrpc":"2.0",
  "id": 0,
  "method": "z_send_raw_transaction",
  "params": {
     "coin": "ZOMBIE",
     "rseeds":  [ "0x123..ab4", "0xbcd..789" ], 
     "received_by_me": "123456.7890",
     "tx_hex": "0xabc..123"
  }
}'

The "rseeds", "received_by_me", "tx_hex" fields are returned by init_withdraw RPC.

TODO:
Will we ever support ZIP 32? For future support we could add AccountId field into the locked notes DB.

…sactionRes->SignRawTransactionRes

* dev: fix(TPU): correct dexfee in check balance to prevent swap failures (#2600) fix(tests): fix/remove kmd rewards failing test (#2633) chore(ci): bump CI container image to debian bullseye-slim to match dev (#2641) chore(release): add changelog entries for v2.5.2-beta (#2639) chore(release): bump mm2 version to 2.5.2-beta (#2638) feat(ci): add macos universal2 build (#2628) fix(metrics): remove memory_db size metric (#2632) chore(rust 1.90): make CI clippy/fmt pass Revert "fix(ordermatch): ignore loop-back; clear on null root; reject stale keep-alives (#2580)" Revert "fix(orderbook): validate roots before commit (#2605)"

mariocynicys · 2025-10-20T06:47:27Z

mm2src/coins/z_coin.rs

+impl ZCoin {
+    #[cfg(feature = "run-docker-tests")]
+    pub async fn withdraw_for_tests(&self, req: WithdrawRequest) -> Result<TransactionDetails, MmError<WithdrawError>> {
+        if req.fee.is_some() {
+            return MmError::err(WithdrawError::UnsupportedError(


i think the reason for not using the other init_withdraw/status_withdraw is that it's task managed and need an rpc and a MarketMakerIt to start?

can't we call init_withdraw here and provide a dummy task_handle just for processing this task and polling the status?

Yes, I'd like to.
I remember in the past I once tried to create a dummy task handle but that would have required too much extra code and some task manager refactoring. I was not sure it was worth it then and now I did not go that way too.

onur-ozkan · 2025-10-20T07:39:17Z

mm2src/coins/lp_coins.rs

+/// Request to send zcoin raw transaction with extra parameters
+#[derive(Clone, Debug, Deserialize)]
+pub struct ZcoinSendRawTransactionRequest {
+    coin: String,
+    /// List of rseeds used to create transaction notes, needed to lock sent notes properly
+    pub rseeds: Vec<String>,
+    /// Change amount
+    pub received_by_me: BigDecimal,
+    /// Serialized zcoin transaction
+    pub tx_hex: String,
+}


Can we put this in a better place, like RPC or ZCoin crates?

onur-ozkan · 2025-10-20T07:40:36Z

mm2src/coins/lp_coins.rs

+    /// List of rseeds, for Zcoin
+    pub rseeds: Option<Vec<String>>,


Why is it Optional?

This TransactionDetails struct is common for all coin types, so we just use Option for those fields which may be relevant only for some coin type

Do we encode this type anywhere? If not, we should make it generic enum that takes protocol-specific TransactionDetails (not in this PR). cc @shamardy

onur-ozkan · 2025-10-20T09:14:00Z

mm2src/coins/lp_coins.rs


+/// Request to send zcoin raw transaction with extra parameters
+#[derive(Clone, Debug, Deserialize)]
+pub struct ZcoinSendRawTransactionRequest {


Typo fix:

Suggested change

pub struct ZcoinSendRawTransactionRequest {

pub struct ZCoinSendRawTransactionRequest {

github-actions · 2025-11-30T12:01:25Z