From 4260b3b41690368eb4cf4923fc3930bf43a4946e Mon Sep 17 00:00:00 2001
From: Tyera Eulberg <tyera@solana.com>
Date: Wed, 28 Oct 2020 16:59:11 -0600
Subject: [PATCH] Sample votes from ancestors back to root

---
 runtime/src/bank.rs                 | 16 +++++++++++++---
 sdk/src/stake_weighted_timestamp.rs |  3 ++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index 3d1168cc5b..dbcbb21c60 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -60,7 +60,7 @@ use solana_sdk::{
     slot_hashes::SlotHashes,
     slot_history::SlotHistory,
     stake_weighted_timestamp::{
-        calculate_stake_weighted_timestamp, EstimateType, TIMESTAMP_SLOT_RANGE,
+        calculate_stake_weighted_timestamp, EstimateType, DEPRECATED_TIMESTAMP_SLOT_RANGE,
     },
     system_transaction,
     sysvar::{self},
@@ -1489,7 +1489,13 @@ impl Bank {
             .filter_map(|(pubkey, (_, account))| {
                 VoteState::from(&account).and_then(|state| {
                     let timestamp_slot = state.last_timestamp.slot;
-                    if self.slot().checked_sub(timestamp_slot)? <= TIMESTAMP_SLOT_RANGE as u64 {
+                    if (self
+                        .feature_set
+                        .is_active(&feature_set::timestamp_bounding::id())
+                        && self.ancestors.contains_key(&timestamp_slot))
+                        || self.slot().checked_sub(timestamp_slot)?
+                            <= DEPRECATED_TIMESTAMP_SLOT_RANGE as u64
+                    {
                         Some((
                             pubkey,
                             (state.last_timestamp.slot, state.last_timestamp.timestamp),
@@ -9695,7 +9701,7 @@ mod tests {
         let validator_vote_keypairs1 = ValidatorVoteKeypairs::new_rand();
         let validator_keypairs = vec![&validator_vote_keypairs0, &validator_vote_keypairs1];
         let GenesisConfigInfo {
-            genesis_config,
+            mut genesis_config,
             mint_keypair: _,
             voting_keypair: _,
         } = create_genesis_config_with_vote_accounts(
@@ -9703,6 +9709,10 @@ mod tests {
             &validator_keypairs,
             vec![10_000; 2],
         );
+        genesis_config
+            .accounts
+            .remove(&feature_set::timestamp_bounding::id())
+            .unwrap();
         let mut bank = Bank::new(&genesis_config);
         assert_eq!(
             bank.get_timestamp_estimate(EstimateType::Unbounded, None),
diff --git a/sdk/src/stake_weighted_timestamp.rs b/sdk/src/stake_weighted_timestamp.rs
index 54733844fc..2ea172cd87 100644
--- a/sdk/src/stake_weighted_timestamp.rs
+++ b/sdk/src/stake_weighted_timestamp.rs
@@ -10,7 +10,8 @@ use std::{
     time::Duration,
 };
 
-pub const TIMESTAMP_SLOT_RANGE: usize = 16;
+pub const TIMESTAMP_SLOT_RANGE: usize = 32;
+pub const DEPRECATED_TIMESTAMP_SLOT_RANGE: usize = 16; // Deprecated.  Remove in the Solana v1.6.0 timeframe
 const MAX_ALLOWABLE_DRIFT_PERCENTAGE: u32 = 25;
 
 pub enum EstimateType {