program-test: Fix realloc in native mode (#32818)

program-test/src/lib.rs

@@ -334,8 +334,8 @@ impl solana_sdk::program_stubs::SyscallStubs for SyscallStubs {
             let new_data = borrowed_account.get_data();
             let new_len = new_data.len();
 
-            // Resize account_info data (grow-only)
-            if account_info.data_len() < new_len {
+            // Resize account_info data
+            if account_info.data_len() != new_len {
                 account_info.realloc(new_len, false)?;
             }
 

program-test/tests/realloc.rs

@@ -0,0 +1,116 @@
+use {
+    solana_program_test::{processor, ProgramTest},
+    solana_sdk::{
+        account_info::{next_account_info, AccountInfo},
+        entrypoint::ProgramResult,
+        instruction::{AccountMeta, Instruction},
+        program::invoke,
+        pubkey::Pubkey,
+        signature::{Keypair, Signer},
+        system_instruction,
+        sysvar::rent,
+        transaction::Transaction,
+    },
+};
+
+fn process_instruction(
+    _program_id: &Pubkey,
+    accounts: &[AccountInfo],
+    _input: &[u8],
+) -> ProgramResult {
+    let account_info_iter = &mut accounts.iter();
+    let account_info = next_account_info(account_info_iter)?;
+    let destination_info = next_account_info(account_info_iter)?;
+    let owner_info = next_account_info(account_info_iter)?;
+    let token_program_info = next_account_info(account_info_iter)?;
+    invoke(
+        &Instruction::new_with_bytes(
+            *token_program_info.key,
+            &[9], // close account
+            vec![
+                AccountMeta::new(*account_info.key, false),
+                AccountMeta::new(*destination_info.key, false),
+                AccountMeta::new_readonly(*owner_info.key, true),
+            ],
+        ),
+        &[
+            account_info.clone(),
+            destination_info.clone(),
+            owner_info.clone(),
+        ],
+    )?;
+    Ok(())
+}
+
+#[tokio::test]
+async fn realloc_smaller_in_cpi() {
+    let program_id = Pubkey::new_unique();
+    let program_test = ProgramTest::new(
+        "program-test-realloc",
+        program_id,
+        processor!(process_instruction),
+    );
+    let mut context = program_test.start_with_context().await;
+
+    let token_2022_id = Pubkey::try_from("TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb").unwrap();
+    let mint = Keypair::new();
+    let account = Keypair::new();
+    let rent = context.banks_client.get_rent().await.unwrap();
+    let mint_space = 82;
+    let account_space = 165;
+    let transaction = Transaction::new_signed_with_payer(
+        &[
+            system_instruction::create_account(
+                &context.payer.pubkey(),
+                &mint.pubkey(),
+                rent.minimum_balance(mint_space),
+                mint_space as u64,
+                &token_2022_id,
+            ),
+            Instruction::new_with_bytes(
+                token_2022_id,
+                &[0; 35], // initialize mint
+                vec![
+                    AccountMeta::new(mint.pubkey(), false),
+                    AccountMeta::new_readonly(rent::id(), false),
+                ],
+            ),
+            system_instruction::create_account(
+                &context.payer.pubkey(),
+                &account.pubkey(),
+                rent.minimum_balance(account_space),
+                account_space as u64,
+                &token_2022_id,
+            ),
+            Instruction::new_with_bytes(
+                token_2022_id,
+                &[1], // initialize account
+                vec![
+                    AccountMeta::new(account.pubkey(), false),
+                    AccountMeta::new_readonly(mint.pubkey(), false),
+                    AccountMeta::new_readonly(account.pubkey(), false),
+                    AccountMeta::new_readonly(rent::id(), false),
+                ],
+            ),
+            Instruction::new_with_bytes(
+                program_id,
+                &[], // close account
+                vec![
+                    AccountMeta::new(account.pubkey(), false),
+                    AccountMeta::new(mint.pubkey(), false),
+                    AccountMeta::new_readonly(account.pubkey(), true),
+                    AccountMeta::new_readonly(token_2022_id, false),
+                ],
+            ),
+        ],
+        Some(&context.payer.pubkey()),
+        &[&context.payer, &mint, &account],
+        context.last_blockhash,
+    );
+
+    context
+        .banks_client
+        .process_transaction(transaction)
+        .await
+        .unwrap();
+}