stake-pool: Remove lamport minimum for validator removal by staker (solana-labs#3999)

* stake-pool: Relax lamport minimum for validator removal by staker

* Completely remove the lamport check

Author: joncinque

stake-pool/program/src/processor.rs

@@ -1167,7 +1167,7 @@ impl Processor {
             return Err(StakePoolError::InvalidState.into());
         }
 
-        let (meta, stake) = get_stake_state(stake_account_info)?;
+        let (_, stake) = get_stake_state(stake_account_info)?;
         let vote_account_address = stake.delegation.voter_pubkey;
         let maybe_validator_stake_info = validator_list.find_mut::<ValidatorStakeInfo, _>(|x| {
             ValidatorStakeInfo::memcmp_pubkey(x, &vote_account_address)
@@ -1193,30 +1193,6 @@ impl Processor {
             return Err(StakePoolError::ValidatorNotFound.into());
         }
 
-        let stake_lamports = **stake_account_info.lamports.borrow();
-        let stake_minimum_delegation = stake::tools::get_minimum_delegation()?;
-        let required_lamports = minimum_stake_lamports(&meta, stake_minimum_delegation);
-        if stake_lamports > required_lamports {
-            msg!(
-                "Attempting to remove validator account with {} lamports, must have no more than {} lamports; \
-                reduce using DecreaseValidatorStake first",
-                stake_lamports,
-                required_lamports
-            );
-            return Err(StakePoolError::StakeLamportsNotEqualToMinimum.into());
-        }
-
-        let current_minimum_delegation = minimum_delegation(stake_minimum_delegation);
-        if stake.delegation.stake > current_minimum_delegation {
-            msg!(
-                "Error: attempting to remove stake with delegation of {} lamports, must have no more than {} lamports; \
-                reduce using DecreaseValidatorStake first",
-                stake.delegation.stake,
-                current_minimum_delegation
-            );
-            return Err(StakePoolError::StakeLamportsNotEqualToMinimum.into());
-        }
-
         let new_status = if validator_stake_info.transient_stake_lamports > 0 {
             check_transient_stake_address(
                 program_id,

stake-pool/program/tests/vsa_remove.rs

@@ -212,18 +212,28 @@ async fn fail_with_wrong_validator_list_account() {
 }
 
 #[tokio::test]
-async fn fail_not_at_minimum() {
+async fn success_at_large_value() {
     let (mut context, stake_pool_accounts, validator_stake) = setup().await;
 
-    transfer(
+    let current_minimum_delegation = stake_pool_get_minimum_delegation(
         &mut context.banks_client,
         &context.payer,
         &context.last_blockhash,
-        &validator_stake.stake_account,
-        1_000_001,
     )
     .await;
 
+    let threshold_amount = current_minimum_delegation * 1_000;
+    let _ = simple_deposit_stake(
+        &mut context.banks_client,
+        &context.payer,
+        &context.last_blockhash,
+        &stake_pool_accounts,
+        &validator_stake,
+        threshold_amount,
+    )
+    .await
+    .unwrap();
+
     let error = stake_pool_accounts
         .remove_validator_from_pool(
             &mut context.banks_client,
@@ -232,16 +242,8 @@ async fn fail_not_at_minimum() {
             &validator_stake.stake_account,
             &validator_stake.transient_stake_account,
         )
-        .await
-        .unwrap()
-        .unwrap();
-    assert_eq!(
-        error,
-        TransactionError::InstructionError(
-            0,
-            InstructionError::Custom(StakePoolError::StakeLamportsNotEqualToMinimum as u32)
-        ),
-    );
+        .await;
+    assert!(error.is_none());
 }
 
 #[tokio::test]