stake-pool: Cleanup documentation in code (#2525)

Author: joncinque

stake-pool/program/src/instruction.rs

@@ -80,7 +80,8 @@ pub enum StakePoolInstruction {
     ///   (Staker only) Adds stake account delegated to validator to the pool's
     ///   list of managed validators.
     ///
-    ///   The stake account will have the rent-exempt amount plus 1 SOL.
+    ///   The stake account will have the rent-exempt amount plus
+    ///   `crate::MINIMUM_ACTIVE_STAKE` (currently 0.001 SOL).
     ///
     ///   0. `[w]` Stake pool
     ///   1. `[s]` Staker
@@ -99,8 +100,9 @@ pub enum StakePoolInstruction {
 
     ///   (Staker only) Removes validator from the pool
     ///
-    ///   Only succeeds if the validator stake account has the minimum of 1 SOL
-    ///   plus the rent-exempt amount.
+    ///   Only succeeds if the validator stake account has the minimum of
+    ///   `crate::MINIMUM_ACTIVE_STAKE` (currently 0.001 SOL) plus the rent-exempt
+    ///   amount.
     ///
     ///   0. `[w]` Stake pool
     ///   1. `[s]` Staker
@@ -109,7 +111,7 @@ pub enum StakePoolInstruction {
     ///   4. `[w]` Validator stake list storage account
     ///   5. `[w]` Stake account to remove from the pool
     ///   6. `[]` Transient stake account, to check that that we're not trying to activate
-    ///   7. `[w]` Destination stake account, to receive the minimum SOL from the validator stake account. Must be
+    ///   7. `[w]` Destination stake account, to receive the minimum SOL from the validator stake account
     ///   8. `[]` Sysvar clock
     ///   9. `[]` Stake program id,
     RemoveValidatorFromPool,
@@ -154,8 +156,9 @@ pub enum StakePoolInstruction {
     /// will do the work of merging once it's ready.
     ///
     /// This instruction only succeeds if the transient stake account does not exist.
-    /// The minimum amount to move is rent-exemption plus 1 SOL in order to avoid
-    /// issues on credits observed when merging active stakes later.
+    /// The minimum amount to move is rent-exemption plus `crate::MINIMUM_ACTIVE_STAKE`
+    /// (currently 0.001 SOL) in order to avoid issues on credits observed when
+    /// merging active stakes later.
     ///
     ///  0. `[]` Stake pool
     ///  1. `[s]` Stake pool staker
@@ -275,11 +278,19 @@ pub enum StakePoolInstruction {
     ///
     ///   Succeeds if the stake account has enough SOL to cover the desired amount
     ///   of pool tokens, and if the withdrawal keeps the total staked amount
-    ///   above the minimum of rent-exempt amount + 1 SOL.
+    ///   above the minimum of rent-exempt amount + 0.001 SOL.
     ///
-    ///   A validator stake account can be withdrawn from freely, and the reserve
-    ///   can only be drawn from if there is no active stake left, where all
-    ///   validator accounts are left with 1 lamport.
+    ///   When allowing withdrawals, the order of priority goes:
+    ///
+    ///   * preferred withdraw validator stake account (if set)
+    ///   * validator stake accounts
+    ///   * transient stake accounts
+    ///   * reserve stake account
+    ///
+    ///   A user can freely withdraw from a validator stake account, and if they
+    ///   are all at the minimum, then they can withdraw from transient stake
+    ///   accounts, and if they are all at minimum, then they can withdraw from
+    ///   the reserve.
     ///
     ///   0. `[w]` Stake pool
     ///   1. `[w]` Validator stake list storage account
@@ -301,8 +312,8 @@ pub enum StakePoolInstruction {
     ///
     ///  0. `[w]` StakePool
     ///  1. `[s]` Manager
-    ///  2. '[]` New manager pubkey
-    ///  3. '[]` New manager fee account
+    ///  2. `[s]` New manager
+    ///  3. `[]` New manager fee account
     SetManager,
 
     ///  (Manager only) Update fee

stake-pool/program/src/processor.rs

@@ -163,7 +163,7 @@ fn create_transient_stake_account<'a>(
 /// Program state handler.
 pub struct Processor {}
 impl Processor {
-    /// Issue a stake_deactivate instruction.
+    /// Issue a delegate_stake instruction.
     #[allow(clippy::too_many_arguments)]
     fn stake_delegate<'a>(
         stake_info: AccountInfo<'a>,
@@ -1389,6 +1389,16 @@ impl Processor {
         stake_pool.check_reserve_stake(reserve_stake_info)?;
         check_stake_program(stake_program_info.key)?;
 
+        if validator_stake_accounts
+            .len()
+            .checked_rem(2)
+            .ok_or(StakePoolError::CalculationFailure)?
+            != 0
+        {
+            msg!("Odd number of validator stake accounts passed in, should be pairs of validator stake and transient stake accounts");
+            return Err(StakePoolError::UnexpectedValidatorListAccountSize.into());
+        }
+
         check_account_owner(validator_list_info, program_id)?;
         let mut validator_list_data = validator_list_info.data.borrow_mut();
         let (validator_list_header, mut validator_slice) =
@@ -1766,9 +1776,7 @@ impl Processor {
         let token_program_info = next_account_info(account_info_iter)?;
         let stake_program_info = next_account_info(account_info_iter)?;
 
-        if *stake_program_info.key != stake_program::id() {
-            return Err(ProgramError::IncorrectProgramId);
-        }
+        check_stake_program(stake_program_info.key)?;
 
         check_account_owner(stake_pool_info, program_id)?;
         let mut stake_pool = try_from_slice_unchecked::<StakePool>(&stake_pool_info.data.borrow())?;
@@ -2102,18 +2110,16 @@ impl Processor {
             deposit_lamports,
         )?;
 
-        if pool_tokens_user > 0 {
-            Self::token_mint_to(
-                stake_pool_info.key,
-                token_program_info.clone(),
-                pool_mint_info.clone(),
-                dest_user_pool_info.clone(),
-                withdraw_authority_info.clone(),
-                AUTHORITY_WITHDRAW,
-                stake_pool.stake_withdraw_bump_seed,
-                pool_tokens_user,
-            )?;
-        }
+        Self::token_mint_to(
+            stake_pool_info.key,
+            token_program_info.clone(),
+            pool_mint_info.clone(),
+            dest_user_pool_info.clone(),
+            withdraw_authority_info.clone(),
+            AUTHORITY_WITHDRAW,
+            stake_pool.stake_withdraw_bump_seed,
+            pool_tokens_user,
+        )?;
 
         if pool_tokens_manager_deposit_fee > 0 {
             Self::token_mint_to(