rusk: use prev_state_root for verification

rusk/benches/block_ingestion.rs

@@ -118,6 +118,7 @@ fn bench_accept(
     let generator = PublicKey::new(*DUSK_CONSENSUS_KEY).into_inner();
 
     let txs = Arc::new(txs);
+    let prev_root = rusk.state_root();
 
     for n_txs in N_TXS {
         let rusk = rusk.clone();
@@ -131,6 +132,7 @@ fn bench_accept(
                     let txs = txs[..*n_txs].to_vec();
 
                     rusk.accept_transactions(
+                        prev_root,
                         BLOCK_HEIGHT,
                         BLOCK_GAS_LIMIT,
                         BLOCK_HASH,

rusk/src/lib/node/rusk.rs

@@ -121,10 +121,12 @@ impl Rusk {
         let block_gas_limit = self.block_gas_limit;
         let generator = params.generator_pubkey.inner();
         let to_slash = params.to_slash.clone();
+        let prev_state_root = params.prev_state_root;
 
         let voters = &params.voters_pubkey[..];
 
-        let mut session = self.new_block_session(block_height, None)?;
+        let mut session =
+            self.new_block_session(block_height, prev_state_root)?;
 
         let mut block_gas_left = block_gas_limit;
 
@@ -179,7 +181,8 @@ impl Rusk {
                     // transaction, since it is technically valid.
                     if gas_spent > block_gas_left {
                         info!("Skipping {tx_id_hex} due gas_spent {gas_spent} greater than left: {block_gas_left}");
-                        session = self.new_block_session(block_height, None)?;
+                        session = self
+                            .new_block_session(block_height, prev_state_root)?;
 
                         for spent_tx in &spent_txs {
                             // We know these transactions were correctly
@@ -259,6 +262,7 @@ impl Rusk {
     #[allow(clippy::too_many_arguments)]
     pub fn verify_transactions(
         &self,
+        prev_commit: [u8; 32],
         block_height: u64,
         block_hash: Hash,
         block_gas_limit: u64,
@@ -267,7 +271,7 @@ impl Rusk {
         slashing: Vec<Slash>,
         voters: &[Voter],
     ) -> Result<(Vec<SpentTransaction>, VerificationOutput)> {
-        let session = self.new_block_session(block_height, None)?;
+        let session = self.new_block_session(block_height, prev_commit)?;
 
         accept(
             session,
@@ -292,6 +296,7 @@ impl Rusk {
     #[allow(clippy::too_many_arguments)]
     pub fn accept_transactions(
         &self,
+        prev_commit: [u8; 32],
         block_height: u64,
         block_gas_limit: u64,
         block_hash: Hash,
@@ -305,7 +310,7 @@ impl Rusk {
         VerificationOutput,
         Vec<ContractEvent>,
     )> {
-        let session = self.new_block_session(block_height, None)?;
+        let session = self.new_block_session(block_height, prev_commit)?;
 
         let (spent_txs, verification_output, session, events) = accept(
             session,
@@ -472,9 +477,9 @@ impl Rusk {
     pub(crate) fn new_block_session(
         &self,
         block_height: u64,
-        commit: Option<[u8; 32]>,
+        commit: [u8; 32],
     ) -> Result<Session> {
-        let mut session = self._session(block_height, commit)?;
+        let mut session = self._session(block_height, Some(commit))?;
         let _: CallReceipt<()> = session
             .call(STAKE_CONTRACT, "before_state_transition", &(), u64::MAX)
             .expect("before_state_transition to success");

rusk/src/lib/node/vm.rs

@@ -45,6 +45,7 @@ impl VMExecution for Rusk {
 
     fn verify_state_transition(
         &self,
+        prev_commit: [u8; 32],
         blk: &Block,
         voters: &[Voter],
     ) -> anyhow::Result<VerificationOutput> {
@@ -57,6 +58,7 @@ impl VMExecution for Rusk {
 
         let (_, verification_output) = self
             .verify_transactions(
+                prev_commit,
                 blk.header().height,
                 blk.header().hash,
                 blk.header().gas_limit,
@@ -72,6 +74,7 @@ impl VMExecution for Rusk {
 
     fn accept(
         &self,
+        prev_root: [u8; 32],
         blk: &Block,
         voters: &[Voter],
     ) -> anyhow::Result<(
@@ -88,6 +91,7 @@ impl VMExecution for Rusk {
 
         let (txs, verification_output, stake_events) = self
             .accept_transactions(
+                prev_root,
                 blk.header().height,
                 blk.header().gas_limit,
                 blk.header().hash,

rusk/tests/common/state.rs

@@ -103,6 +103,7 @@ pub fn generator_procedure(
     missed_generators: Vec<BlsPublicKey>,
     expected: Option<ExecuteResult>,
 ) -> anyhow::Result<Vec<SpentTransaction>> {
+    let prev_root = rusk.state_root();
     let expected = expected.unwrap_or(ExecuteResult {
         executed: txs.len(),
         discarded: 0,
@@ -146,6 +147,7 @@ pub fn generator_procedure(
         to_slash,
         voters_pubkey: voters.clone(),
         max_txs_bytes: usize::MAX,
+        prev_state_root: prev_root,
     };
 
     let (transfer_txs, discarded, execute_output) =
@@ -176,10 +178,12 @@ pub fn generator_procedure(
     )
     .expect("valid block");
 
-    let verify_output = rusk.verify_state_transition(&block, &voters)?;
+    let verify_output =
+        rusk.verify_state_transition(prev_root, &block, &voters)?;
     info!("verify_state_transition new verification: {verify_output}",);
 
-    let (accept_txs, accept_output, _) = rusk.accept(&block, &voters)?;
+    let (accept_txs, accept_output, _) =
+        rusk.accept(prev_root, &block, &voters)?;
 
     assert_eq!(accept_txs.len(), expected.executed, "all txs accepted");
 
@@ -210,6 +214,7 @@ pub fn generator_procedure2(
     expected: Option<ExecuteResult>,
     generator: Option<BlsPublicKey>,
 ) -> anyhow::Result<(Vec<SpentTransaction>, [u8; 32])> {
+    let prev_root = rusk.state_root();
     let expected = expected.unwrap_or(ExecuteResult {
         executed: txs.len(),
         discarded: 0,
@@ -254,6 +259,7 @@ pub fn generator_procedure2(
         to_slash,
         voters_pubkey: voters.clone(),
         max_txs_bytes: usize::MAX,
+        prev_state_root: prev_root,
     };
 
     let (transfer_txs, discarded, execute_output) =
@@ -284,10 +290,12 @@ pub fn generator_procedure2(
     )
     .expect("valid block");
 
-    let verify_output = rusk.verify_state_transition(&block, &voters)?;
+    let verify_output =
+        rusk.verify_state_transition(prev_root, &block, &voters)?;
     info!("verify_state_transition new verification: {verify_output}",);
 
-    let (accept_txs, accept_output, _) = rusk.accept(&block, &voters)?;
+    let (accept_txs, accept_output, _) =
+        rusk.accept(prev_root, &block, &voters)?;
 
     assert_eq!(accept_txs.len(), expected.executed, "all txs accepted");