From 1c1d83bd5604ff2109e176f452a7d127132903b7 Mon Sep 17 00:00:00 2001
From: Rob Walker <rob@solana.com>
Date: Fri, 31 May 2019 12:26:45 -0700
Subject: [PATCH] skip syscall_id in hash and delta (#4500)

* skip syscall_id in hash and delta

* add more tests, skip syscalls
---
 runtime/src/accounts.rs | 16 +++++++++++-----
 runtime/src/bank.rs     | 31 ++++++++++++++++++++++++++-----
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/runtime/src/accounts.rs b/runtime/src/accounts.rs
index 9d6d0d873f..5a90c3224b 100644
--- a/runtime/src/accounts.rs
+++ b/runtime/src/accounts.rs
@@ -15,6 +15,7 @@ use solana_sdk::hash::{Hash, Hasher};
 use solana_sdk::native_loader;
 use solana_sdk::pubkey::Pubkey;
 use solana_sdk::signature::{Keypair, KeypairUtil};
+use solana_sdk::syscall;
 use solana_sdk::system_program;
 use solana_sdk::transaction::Result;
 use solana_sdk::transaction::{Transaction, TransactionError};
@@ -450,11 +451,13 @@ impl Accounts {
             |stored_account: &StoredAccount,
              _id: AppendVecId,
              accum: &mut Vec<(Pubkey, u64, Hash)>| {
-                accum.push((
-                    stored_account.meta.pubkey,
-                    stored_account.meta.write_version,
-                    Self::hash_account(stored_account),
-                ));
+                if !syscall::check_id(&stored_account.balance.owner) {
+                    accum.push((
+                        stored_account.meta.pubkey,
+                        stored_account.meta.write_version,
+                        Self::hash_account(stored_account),
+                    ));
+                }
             },
         );
         let mut account_hashes: Vec<_> = accumulator.into_iter().flat_map(|x| x).collect();
@@ -600,6 +603,7 @@ mod tests {
     use solana_sdk::hash::Hash;
     use solana_sdk::instruction::CompiledInstruction;
     use solana_sdk::signature::{Keypair, KeypairUtil};
+    use solana_sdk::syscall;
     use solana_sdk::transaction::Transaction;
     use std::io::Cursor;
     use std::thread::{sleep, Builder};
@@ -1087,6 +1091,8 @@ mod tests {
     fn test_accounts_empty_hash_internal_state() {
         let accounts = Accounts::new(None);
         assert_eq!(accounts.hash_internal_state(0), None);
+        accounts.store_slow(0, &Pubkey::default(), &Account::new(1, 0, &syscall::id()));
+        assert_eq!(accounts.hash_internal_state(0), None);
     }
 
     #[test]
diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index 6cfa40f135..f231ea1cc6 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -1068,12 +1068,11 @@ impl Bank {
     fn hash_internal_state(&self) -> Hash {
         // If there are no accounts, return the same hash as we did before
         // checkpointing.
-        if !self.rc.accounts.has_accounts(self.slot()) {
-            return self.parent_hash;
+        if let Some(accounts_delta_hash) = self.rc.accounts.hash_internal_state(self.slot()) {
+            extend_and_hash(&self.parent_hash, &serialize(&accounts_delta_hash).unwrap())
+        } else {
+            self.parent_hash
         }
-
-        let accounts_delta_hash = self.rc.accounts.hash_internal_state(self.slot());
-        extend_and_hash(&self.parent_hash, &serialize(&accounts_delta_hash).unwrap())
     }
 
     /// Return the number of ticks per slot
@@ -2009,10 +2008,19 @@ mod tests {
             system_transaction::transfer(&mint_keypair, &key1.pubkey(), 1, genesis_block.hash());
         assert_eq!(bank.process_transaction(&tx_transfer_mint_to_1), Ok(()));
         assert_eq!(bank.is_delta.load(Ordering::Relaxed), true);
+
+        let bank1 = new_from_parent(&bank);
+        assert_eq!(bank1.is_delta.load(Ordering::Relaxed), false);
+        assert_eq!(bank1.hash_internal_state(), bank.hash());
+        // ticks don't make a bank into a delta
+        bank.register_tick(&Hash::default());
+        assert_eq!(bank1.is_delta.load(Ordering::Relaxed), false);
+        assert_eq!(bank1.hash_internal_state(), bank.hash());
     }
 
     #[test]
     fn test_is_votable() {
+        // test normal case
         let (genesis_block, mint_keypair) = create_genesis_block(500);
         let bank = Arc::new(Bank::new(&genesis_block));
         let key1 = Keypair::new();
@@ -2030,6 +2038,19 @@ mod tests {
         }
 
         assert_eq!(bank.is_votable(), true);
+
+        // test empty bank with ticks
+        let (genesis_block, _mint_keypair) = create_genesis_block(500);
+        // make an empty bank at slot 1
+        let bank = new_from_parent(&Arc::new(Bank::new(&genesis_block)));
+        assert_eq!(bank.is_votable(), false);
+
+        // Register enough ticks to hit max tick height
+        for i in 0..genesis_block.ticks_per_slot - 1 {
+            bank.register_tick(&hash::hash(format!("hello world {}", i).as_bytes()));
+        }
+        // empty banks aren't votable even at max tick height
+        assert_eq!(bank.is_votable(), false);
     }
 
     #[test]