feat(validations): guard "unstake-it-all" rule behind V2_1 guard

Author: aesedepece

node/src/actors/chain_manager/mod.rs

@@ -5189,7 +5189,7 @@ mod tests {
         // Unstake all for validator 2
         process_unstake_transactions(
             &mut stakes,
-            [unstake_txn_1.clone()],
+            [unstake_txn_1.clone()].iter(),
             block_epoch,
             10_000_000_000_000,
         )
@@ -5254,7 +5254,7 @@ mod tests {
         // Unstake all again for validator 2
         process_unstake_transactions(
             &mut stakes,
-            [unstake_txn_2],
+            [unstake_txn_2].iter(),
             block_epoch,
             10_000_000_000_000,
         )

validations/src/validations.rs

@@ -1465,7 +1465,9 @@ pub fn validate_unstake_transaction<'a>(
     min_stake_nanowits: u64,
     unstake_delay: u64,
 ) -> Result<(u64, u32, Vec<&'a ValueTransferOutput>), anyhow::Error> {
-    if get_protocol_version(Some(epoch)) <= ProtocolVersion::V1_8 {
+    let protocol_version = get_protocol_version(Some(epoch));
+
+    if protocol_version <= ProtocolVersion::V1_8 {
         return Err(TransactionError::NoUnstakeTransactionsAllowed.into());
     }
 
@@ -1514,10 +1516,11 @@ pub fn validate_unstake_transaction<'a>(
             .into());
         }
     };
-    
+
+    // Introduced in V2_1:
     // Apply a protocol-level "rule of convenience", where an amount to unstake of u64::MAX actually
     // means "unstake all my stake".
-    if amount_to_unstake == u64::MAX {
+    if protocol_version >= ProtocolVersion::V2_1 && amount_to_unstake == u64::MAX {
         amount_to_unstake = staked_amount;
     }