allow to drop tx after execution

programs/multisig/src/lib.rs

@@ -58,6 +58,7 @@ pub mod serum_multisig {
  pid: Pubkey,
  accs: Vec<TransactionAccount>,
  data: Vec<u8>,
+ successor: Option<Pubkey>,
  ) -> Result<()> {
  let owner_index = ctx
  .accounts
@@ -79,6 +80,7 @@ pub mod serum_multisig {
  tx.multisig = ctx.accounts.multisig.key();
  tx.did_execute = false;
  tx.owner_set_seqno = ctx.accounts.multisig.owner_set_seqno;
+ tx.successor = successor;
 
  Ok(())
  }
@@ -190,6 +192,17 @@ pub mod serum_multisig {
 
  Ok(())
  }
+
+ // Move transaction rent exemption SOL
+ pub fn drop_transaction(ctx: Context<DropTransaction>) -> Result<()> {
+ let tx = ctx.accounts.transaction.to_account_info();
+ let mut tx_balance = tx.try_borrow_mut_lamports()?;
+ let successor = ctx.accounts.successor.to_account_info();
+ let mut successor_balance = successor.try_borrow_mut_lamports()?;
+ **successor_balance = (**successor_balance).checked_add(**tx_balance).unwrap();
+ **tx_balance = 0;
+ Ok(())
+ }
 }
 
 #[derive(Accounts)]
@@ -241,6 +254,18 @@ pub struct ExecuteTransaction<'info> {
  transaction: Box<Account<'info, Transaction>>,
 }
 
+#[derive(Accounts)]
+pub struct DropTransaction<'info> {
+ #[account(
+ mut,
+ constraint = transaction.did_execute,
+ constraint = transaction.successor == Some(*successor.key),
+ )]
+ transaction: Box<Account<'info, Transaction>>,
+ #[account(mut)]
+ successor: AccountInfo<'info>,
+}
+
 #[account]
 pub struct Multisig {
  pub owners: Vec<Pubkey>,
@@ -265,6 +290,8 @@ pub struct Transaction {
  pub did_execute: bool,
  // Owner set sequence number.
  pub owner_set_seqno: u32,
+ // Account which receive rent exemption SOL after transaction executing.
+ pub successor: Option<Pubkey>,
 }
 
 impl From<&Transaction> for Instruction {
@@ -333,4 +360,6 @@ pub enum ErrorCode {
  InvalidThreshold,
  #[msg("Owners must be unique")]
  UniqueOwners,
+ #[msg("Invalid successor account.")]
+ InvalidSuccessor,
 }

tests/multisig.js

@@ -64,7 +64,7 @@ describe("multisig", () => {
 
  const transaction = anchor.web3.Keypair.generate();
  const txSize = 1000; // Big enough, cuz I'm lazy.
- await program.rpc.createTransaction(pid, accounts, data, {
+ await program.rpc.createTransaction(pid, accounts, data, null, {
  accounts: {
  multisig: multisig.publicKey,
  transaction: transaction.publicKey,
@@ -89,6 +89,7 @@ describe("multisig", () => {
  assert.ok(txAccount.multisig.equals(multisig.publicKey));
  assert.deepStrictEqual(txAccount.didExecute, false);
  assert.ok(txAccount.ownerSetSeqno === 0);
+ assert.deepStrictEqual(txAccount.successor, null);
 
  // Other owner approves transactoin.
  await program.rpc.approve({