Bring the Anchor v1 copies in line with v2 where the Anchor version allows

CHANGELOG.md

@@ -4,6 +4,35 @@ All notable changes to this repository are documented here.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [2026-09-23] - Anchor v1 copies match their v2 counterparts where the version allows
+
+A scan of every `anchor/` and `anchor-v1/` pair, comparing function names,
+error variants, account fields, constants and seeds, and listing every v2
+program commit since July that left its v1 copy untouched, found these
+differences that the Anchor version does not force:
+
+- The transfer-hook `counter` and `account-data-as-seed` v1 copies still had
+  the bug v2 fixed in August: the hook computed the new transfer count and
+  dropped it, because `counter_account` was not `mut`, so the count read one
+  after every transfer. Both now write the count back and report an overflow
+  with the new `CounterOverflow` error instead of `AmountTooBig`, and each
+  test reads the counter back after the hooked transfer.
+- Interest-bearing (v1): `check_mint_data` becomes `check_rate_authority`
+  with v2's signature, taking the parsed `InterestBearingConfig`. The
+  handlers read the extension with anchor-spl's `get_mint_extension_data`.
+- Account fields that v2 declares `pub` are `pub` in the v1 copies of
+  account-data, checking-accounts, program-derived-addresses, rent,
+  transfer-sol and nft-operations.
+- Order book (v1): `OrderTreeRoot` derives `Default` like the v2 copy,
+  replacing a hand-written impl.
+
+What the scan still reports is forced by the Anchor version: v2's
+transfer-hook `entrypoint` fallback, the local session-token reader that
+replaces the v1-only `session-keys` crate, the `last_restart_slot` syscall
+wrapper (the v1 copies make the same restart check through the sysvar), the
+wincode span in rent, zero-copy padding, the Pyth account traits, and the
+betting market's borrow-release helper.
+
 ## [2026-09-23] - Order book tests cover the deepest critbit path
 
 A critbit tree does not rebalance, so asks at doubling prices stretch the path

basics/account-data/anchor-v1/programs/anchor-program-example/src/instructions/create.rs

@@ -4,15 +4,15 @@ use anchor_lang::prelude::*;
 #[derive(Accounts)]
 pub struct CreateAddressInfoAccountConstraints<'info> {
     #[account(mut)]
-    payer: Signer<'info>,
+    pub payer: Signer<'info>,
 
     #[account(
         init,
         payer = payer,
         space = AddressInfo::DISCRIMINATOR.len() + AddressInfo::INIT_SPACE,
     )]
-    address_info: Account<'info, AddressInfo>,
-    system_program: Program<'info, System>,
+    pub address_info: Account<'info, AddressInfo>,
+    pub system_program: Program<'info, System>,
 }
 
 pub fn handle_create_address_info(

basics/checking-accounts/anchor-v1/programs/anchor-program-example/src/lib.rs

@@ -15,16 +15,16 @@ pub mod checking_account_program {
 // This is a simple example and does not include all possible constraints and types
 #[derive(Accounts)]
 pub struct CheckingAccountsAccountConstraints<'info> {
-    payer: Signer<'info>, // checks account is signer
+    pub payer: Signer<'info>, // checks account is signer
 
     /// CHECK: No checks performed, example of an unchecked account
     #[account(mut)]
-    account_to_create: UncheckedAccount<'info>,
+    pub account_to_create: UncheckedAccount<'info>,
     /// CHECK: Perform owner check using constraint
     #[account(
         mut,
         owner = id()
     )]
-    account_to_change: UncheckedAccount<'info>,
-    system_program: Program<'info, System>, // checks account is executable, and is the system program
+    pub account_to_change: UncheckedAccount<'info>,
+    pub system_program: Program<'info, System>, // checks account is executable, and is the system program
 }

basics/program-derived-addresses/anchor-v1/programs/anchor-program-example/src/instructions/create.rs

@@ -4,7 +4,7 @@ use anchor_lang::prelude::*;
 #[derive(Accounts)]
 pub struct CreatePageVisitsAccountConstraints<'info> {
     #[account(mut)]
-    payer: Signer<'info>,
+    pub payer: Signer<'info>,
 
     #[account(
         init,
@@ -16,8 +16,8 @@ pub struct CreatePageVisitsAccountConstraints<'info> {
         ],
         bump,
     )]
-    page_visits: Account<'info, PageVisits>,
-    system_program: Program<'info, System>,
+    pub page_visits: Account<'info, PageVisits>,
+    pub system_program: Program<'info, System>,
 }
 
 pub fn handle_create_page_visits(

basics/program-derived-addresses/anchor-v1/programs/anchor-program-example/src/instructions/increment.rs

@@ -3,7 +3,7 @@ use anchor_lang::prelude::*;
 
 #[derive(Accounts)]
 pub struct IncrementPageVisitsAccountConstraints<'info> {
-    user: SystemAccount<'info>,
+    pub user: SystemAccount<'info>,
     #[account(
         mut,
         seeds = [
@@ -12,7 +12,7 @@ pub struct IncrementPageVisitsAccountConstraints<'info> {
         ],
         bump = page_visits.bump,
     )]
-    page_visits: Account<'info, PageVisits>,
+    pub page_visits: Account<'info, PageVisits>,
 }
 
 pub fn handle_increment_page_visits(

basics/rent/anchor-v1/programs/rent-example/src/lib.rs

@@ -55,6 +55,6 @@ pub struct CreateSystemAccountAccountConstraints<'info> {
 
 #[derive(AnchorSerialize, AnchorDeserialize, Debug)]
 pub struct AddressData {
-    name: String,
-    address: String,
+    pub name: String,
+    pub address: String,
 }

basics/transfer-sol/anchor-v1/programs/transfer-sol/src/instructions/transfer_sol_with_cpi.rs

@@ -4,10 +4,10 @@ use anchor_lang::system_program;
 #[derive(Accounts)]
 pub struct TransferSolWithCpiAccountConstraints<'info> {
     #[account(mut)]
-    payer: Signer<'info>,
+    pub payer: Signer<'info>,
     #[account(mut)]
-    recipient: SystemAccount<'info>,
-    system_program: Program<'info, System>,
+    pub recipient: SystemAccount<'info>,
+    pub system_program: Program<'info, System>,
 }
 
 pub fn handler(context: Context<TransferSolWithCpiAccountConstraints>, amount: u64) -> Result<()> {

basics/transfer-sol/anchor-v1/programs/transfer-sol/src/instructions/transfer_sol_with_program.rs

@@ -15,10 +15,10 @@ pub struct TransferSolWithProgramAccountConstraints<'info> {
         mut,
         owner = crate::ID // value of declare_id!()
     )]
-    payer: UncheckedAccount<'info>,
+    pub payer: UncheckedAccount<'info>,
 
     #[account(mut)]
-    recipient: SystemAccount<'info>,
+    pub recipient: SystemAccount<'info>,
 }
 
 // Directly modifying lamports is only possible if the program is the owner of the account

finance/order-book/anchor-v1/programs/order-book/src/state/order_book.rs

@@ -247,12 +247,3 @@ impl OrderBook {
         }
     }
 }
-
-impl Default for OrderTreeRoot {
-    fn default() -> Self {
-        Self {
-            maybe_node: 0,
-            leaf_count: 0,
-        }
-    }
-}

finance/order-book/anchor-v1/programs/order-book/src/state/slab/ordertree.rs

@@ -22,7 +22,7 @@ pub const MAX_TREE_NODES: usize = 1024;
 ///
 /// `maybe_node` is only meaningful when `leaf_count > 0` - a freshly-zeroed
 /// root represents an empty tree.
-#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+#[derive(Copy, Clone, Default, bytemuck::Pod, bytemuck::Zeroable)]
 #[repr(C)]
 pub struct OrderTreeRoot {
     pub maybe_node: NodeHandle,

tokens/nft-operations/anchor-v1/programs/mint-nft/src/instructions/create_collection.rs

@@ -19,7 +19,7 @@ use super::validate_metadata_strings;
 #[derive(Accounts)]
 pub struct CreateCollectionAccountConstraints<'info> {
     #[account(mut)]
-    user: Signer<'info>,
+    pub user: Signer<'info>,
 
     #[account(
         init,
@@ -28,7 +28,7 @@ pub struct CreateCollectionAccountConstraints<'info> {
         mint::authority = mint_authority,
         mint::freeze_authority = mint_authority,
     )]
-    mint: Account<'info, Mint>,
+    pub mint: Account<'info, Mint>,
 
     #[account(
         seeds = [b"authority"],
@@ -39,24 +39,24 @@ pub struct CreateCollectionAccountConstraints<'info> {
 
     #[account(mut)]
     /// CHECK: This account will be initialized by the metaplex program
-    metadata: UncheckedAccount<'info>,
+    pub metadata: UncheckedAccount<'info>,
 
     #[account(mut)]
     /// CHECK: This account will be initialized by the metaplex program
-    master_edition: UncheckedAccount<'info>,
+    pub master_edition: UncheckedAccount<'info>,
 
     #[account(
         init,
         payer = user,
         associated_token::mint = mint,
         associated_token::authority = user
     )]
-    destination: Account<'info, TokenAccount>,
+    pub destination: Account<'info, TokenAccount>,
 
-    system_program: Program<'info, System>,
-    token_program: Program<'info, Token>,
-    associated_token_program: Program<'info, AssociatedToken>,
-    token_metadata_program: Program<'info, Metadata>,
+    pub system_program: Program<'info, System>,
+    pub token_program: Program<'info, Token>,
+    pub associated_token_program: Program<'info, AssociatedToken>,
+    pub token_metadata_program: Program<'info, Metadata>,
 }
 
 /// Creates a collection NFT with caller-supplied metadata.

tokens/token-extensions/interest-bearing/anchor-v1/programs/interest-bearing/src/instructions/initialize.rs

@@ -6,10 +6,14 @@ use anchor_spl::{
         spl_token_2022::{extension::ExtensionType, pod::PodMint},
         InitializeMint2,
     },
-    token_interface::{interest_bearing_mint_initialize, InterestBearingMintInitialize, Token2022},
+    token_2022::spl_token_2022::extension::interest_bearing_mint::InterestBearingConfig,
+    token_interface::{
+        get_mint_extension_data, interest_bearing_mint_initialize, InterestBearingMintInitialize,
+        Token2022,
+    },
 };
 
-use crate::check_mint_data;
+use crate::check_rate_authority;
 
 #[derive(Accounts)]
 pub struct InitializeAccountConstraints<'info> {
@@ -72,9 +76,9 @@ pub fn handler(context: Context<InitializeAccountConstraints>, rate: i16) -> Res
         Some(&context.accounts.payer.key()), // freeze authority
     )?;
 
-    check_mint_data(
+    let config = get_mint_extension_data::<InterestBearingConfig>(
         &context.accounts.mint_account.to_account_info(),
-        &context.accounts.payer.key(),
     )?;
+    check_rate_authority(&config, &context.accounts.payer.key())?;
     Ok(())
 }

tokens/token-extensions/interest-bearing/anchor-v1/programs/interest-bearing/src/instructions/update_rate.rs

@@ -1,9 +1,11 @@
 use anchor_lang::prelude::*;
+use anchor_spl::token_2022::spl_token_2022::extension::interest_bearing_mint::InterestBearingConfig;
 use anchor_spl::token_interface::{
-    interest_bearing_mint_update_rate, InterestBearingMintUpdateRate, Mint, Token2022,
+    get_mint_extension_data, interest_bearing_mint_update_rate, InterestBearingMintUpdateRate, Mint,
+    Token2022,
 };
 
-use crate::check_mint_data;
+use crate::check_rate_authority;
 
 #[derive(Accounts)]
 pub struct UpdateRateAccountConstraints<'info> {
@@ -29,9 +31,9 @@ pub fn handler(context: Context<UpdateRateAccountConstraints>, rate: i16) -> Res
         rate,
     )?;
 
-    check_mint_data(
+    let config = get_mint_extension_data::<InterestBearingConfig>(
         &context.accounts.mint_account.to_account_info(),
-        &context.accounts.authority.key(),
     )?;
+    check_rate_authority(&config, &context.accounts.authority.key())?;
     Ok(())
 }

tokens/token-extensions/interest-bearing/anchor-v1/programs/interest-bearing/src/lib.rs

@@ -1,11 +1,5 @@
 use anchor_lang::prelude::*;
-use anchor_spl::token_2022::spl_token_2022::{
-    extension::{
-        interest_bearing_mint::InterestBearingConfig, BaseStateWithExtensions,
-        StateWithExtensions,
-    },
-    state::Mint as MintState,
-};
+use anchor_spl::token_2022::spl_token_2022::extension::interest_bearing_mint::InterestBearingConfig;
 use anchor_spl::token_interface::spl_pod::optional_keys::OptionalNonZeroPubkey;
 
 mod instructions;
@@ -27,16 +21,15 @@ pub mod interest_bearing {
     }
 }
 
-pub fn check_mint_data(mint_account_info: &AccountInfo, authority_key: &Pubkey) -> Result<()> {
-    let mint_data = mint_account_info.data.borrow();
-    let mint_with_extension = StateWithExtensions::<MintState>::unpack(&mint_data)?;
-    let extension_data = mint_with_extension.get_extension::<InterestBearingConfig>()?;
-
+/// Assert the extension names `authority_key` as the account allowed to change
+/// the rate. Both callers read the extension with anchor-spl's
+/// `get_mint_extension_data`, which parses the mint's TLV data.
+pub fn check_rate_authority(config: &InterestBearingConfig, authority_key: &Pubkey) -> Result<()> {
     assert_eq!(
-        extension_data.rate_authority,
+        config.rate_authority,
         OptionalNonZeroPubkey::try_from(Some(*authority_key))?
     );
 
-    msg!("{:?}", extension_data);
+    msg!("{:?}", config);
     Ok(())
 }

tokens/token-extensions/transfer-hook/account-data-as-seed/anchor-v1/programs/transfer-hook/src/instructions/transfer_hook.rs

@@ -19,27 +19,32 @@ pub struct TransferHookAccountConstraints<'info> {
     /// CHECK: ExtraAccountMetaList Account,
     #[account(seeds = [b"extra-account-metas", mint.key().as_ref()], bump)]
     pub extra_account_meta_list: UncheckedAccount<'info>,
-    #[account(seeds = [b"counter", owner.key().as_ref()], bump)]
+    #[account(mut, seeds = [b"counter", owner.key().as_ref()], bump)]
     pub counter_account: Account<'info, CounterAccount>,
 }
 
 pub fn handler(context: Context<TransferHookAccountConstraints>, amount: u64) -> Result<()> {
     // Fail this instruction if it is not called from within a transfer hook
     check_is_transferring(&context)?;
 
-    // Check if the amount is too big
+    // A hook can reject a transfer by returning an error. This one only logs,
+    // so the example stays runnable: `amount` arrives in minor units, so any
+    // transfer of a token with decimals clears 50 immediately. Return
+    // `err!(TransferError::AmountTooBig)` here to make the limit binding, and
+    // pick a threshold in the mint's own minor units.
     if amount > 50 {
         msg!("The amount is too big: {}", amount);
-        //return err!(TransferError::AmountTooBig);
     }
 
-    // Increment the transfer count safely
+    // Increment the transfer count safely and write it back, so the count
+    // survives the transfer that produced it.
     let count = context
         .accounts
         .counter_account
         .counter
         .checked_add(1)
-        .ok_or(TransferError::AmountTooBig)?;
+        .ok_or(TransferError::CounterOverflow)?;
+    context.accounts.counter_account.counter = count;
 
     msg!("This token has been transferred {} times", count);
 

tokens/token-extensions/transfer-hook/account-data-as-seed/anchor-v1/programs/transfer-hook/src/lib.rs

@@ -25,6 +25,8 @@ pub enum TransferError {
     AmountTooBig,
     #[msg("The token is not currently transferring")]
     IsNotCurrentlyTransferring,
+    #[msg("The transfer counter would overflow")]
+    CounterOverflow,
 }
 
 #[program]