p-token: Add optional rent sysvar account

Cargo.toml

@@ -34,3 +34,4 @@ solana-program-option = "3.0.0"
 solana-program-pack = "3.0.0"
 solana-pubkey = "3.0.0"
 solana-system-interface = { version = "2.0", features = ["bincode"] }
+spl-token-interface = { path = "interface" }

interface/src/instruction.rs

@@ -1373,6 +1373,20 @@ pub fn sync_native(
     })
 }
 
+/// Creates a `SyncNative` instruction with the Rent sysvar account
+/// added to the accounts list.
+pub fn sync_native_with_rent_sysvar(
+    token_program_id: &Pubkey,
+    account_pubkey: &Pubkey,
+) -> Result<Instruction, ProgramError> {
+    let mut instruction = sync_native(token_program_id, account_pubkey)?;
+    instruction
+        .accounts
+        .push(AccountMeta::new_readonly(sysvar::rent::id(), false));
+
+    Ok(instruction)
+}
+
 /// Creates a `GetAccountDataSize` instruction
 pub fn get_account_data_size(
     token_program_id: &Pubkey,

pinocchio/interface/src/instruction.rs

@@ -383,8 +383,14 @@ pub enum TokenInstruction {
     ///
     /// Accounts expected by this instruction:
     ///
+    ///   * Using runtime Rent sysvar
     ///   0. `[writable]`  The native token account to sync with its underlying
     ///      lamports.
+    ///
+    ///   * Using Rent sysvar account
+    ///   0. `[writable]`  The native token account to sync with its underlying
+    ///      lamports.
+    ///   1. `[]` Rent sysvar.
     SyncNative,
 
     /// Like [`TokenInstruction::InitializeAccount2`], but does not require the

pinocchio/program/Cargo.toml

@@ -41,7 +41,7 @@ solana-signer = "3.0.0"
 solana-transaction = "3.0.0"
 solana-transaction-error = "3.0.0"
 solana-system-interface = { workspace = true }
-spl-token-interface = "2"
+spl-token-interface = { workspace = true }
 spl-token-2022-interface = "2"
 
 [lints]

pinocchio/program/src/processor/sync_native.rs

@@ -14,12 +14,20 @@ use {
 
 #[inline(always)]
 pub fn process_sync_native(accounts: &[AccountInfo]) -> ProgramResult {
-    let native_account_info = accounts.first().ok_or(ProgramError::NotEnoughAccountKeys)?;
+    let [native_account_info, remaining @ ..] = accounts else {
+        return Err(ProgramError::NotEnoughAccountKeys);
+    };
 
     check_account_owner(native_account_info)?;
 
-    let rent = Rent::get()?;
-    let rent_exempt_reserve = rent.minimum_balance(native_account_info.data_len());
+    let rent_exempt_reserve = if let Some(rent_sysvar_info) = remaining.first() {
+        // SAFETY: single immutable borrow to `rent_sysvar_info`; account ID and length
+        // are checked by `from_account_info_unchecked`.
+        let rent = unsafe { Rent::from_account_info_unchecked(rent_sysvar_info)? };
+        rent.minimum_balance(native_account_info.data_len())
+    } else {
+        Rent::get()?.minimum_balance(native_account_info.data_len())
+    };
 
     // SAFETY: single mutable borrow to `native_account_info` account data and
     // `load_mut` validates that the account is initialized.

pinocchio/program/tests/sync_native.rs

@@ -2,7 +2,7 @@ mod setup;
 
 use {
     crate::setup::TOKEN_PROGRAM_ID,
-    mollusk_svm::{result::Check, Mollusk},
+    mollusk_svm::{result::Check, sysvar::Sysvars, Mollusk},
     pinocchio_token_interface::{
         native_mint,
         state::{
@@ -75,15 +75,20 @@ async fn sync_native() {
         create_token_account(&native_mint, &authority_key, true, 0, &TOKEN_PROGRAM_ID);
     source_account.lamports += 2_000_000_000;
 
-    let instruction =
-        spl_token_interface::instruction::sync_native(&TOKEN_PROGRAM_ID, &source_account_key)
-            .unwrap();
+    let instruction = spl_token_interface::instruction::sync_native_with_rent_sysvar(
+        &TOKEN_PROGRAM_ID,
+        &source_account_key,
+    )
+    .unwrap();
 
     // Executes the sync_native instruction.
 
     let result = mollusk().process_and_validate_instruction_chain(
         &[(&instruction, &[Check::success()])],
-        &[(source_account_key, source_account)],
+        &[
+            (source_account_key, source_account),
+            Sysvars::default().keyed_account_for_rent_sysvar(),
+        ],
     );
 
     result.resulting_accounts.iter().for_each(|(key, account)| {