fix(protocol): fix getLastSyncedBlock by writing the block's verifiedTransitionId

packages/protocol/contracts/L1/ITaikoL1.sol

@@ -36,5 +36,5 @@ interface ITaikoL1 {
 
     /// @notice Gets the configuration of the TaikoL1 contract.
     /// @return Config struct containing configuration parameters.
-    function getConfig() external view returns (TaikoData.Config memory);
+    function getConfig() external pure returns (TaikoData.Config memory);
 }

packages/protocol/contracts/L1/TaikoL1.sol

@@ -222,7 +222,7 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
     }
 
     /// @inheritdoc ITaikoL1
-    function getConfig() public view virtual override returns (TaikoData.Config memory) {
+    function getConfig() public pure virtual override returns (TaikoData.Config memory) {
         // All hard-coded configurations:
         // - treasury: the actual TaikoL2 address.
         // - anchorGasLimit: 250_000 (based on internal devnet, its ~220_000

packages/protocol/contracts/L1/libs/LibProving.sol

@@ -127,7 +127,7 @@ library LibProving {
 
         local.blockId = blk.blockId;
 
-        if (LibUtils.shouldSyncStateRoot(_config.stateRootSyncInternal, local.blockId)) {
+        if (LibUtils.willSyncStateRoot(_config.stateRootSyncInternal, local.blockId)) {
             local.stateRoot = _tran.stateRoot;
         }
 
@@ -387,8 +387,6 @@ library LibProving {
         uint256 reward; // reward to the new (current) prover
 
         if (_ts.contester != address(0)) {
-            // assert(_blk.livenessBond == 0);
-
             if (_local.sameTransition) {
                 // The contested transition is proven to be valid, contester loses the game
                 reward = _rewardAfterFriction(_ts.contestBond);

packages/protocol/contracts/L1/libs/LibUtils.sol

@@ -230,7 +230,7 @@ library LibUtils {
         return _blockId % segmentSize == (_isBlockProposed ? 0 : segmentSize >> 1);
     }
 
-    function shouldSyncStateRoot(
+    function willSyncStateRoot(
         uint256 _stateRootSyncInternal,
         uint256 _blockId
     )

packages/protocol/contracts/L1/libs/LibVerifying.sol

@@ -19,8 +19,9 @@ library LibVerifying {
         uint32 lastVerifiedTransitionId;
         uint16 tier;
         bytes32 blockHash;
-        bytes32 stateRoot;
+        bytes32 syncStateRoot;
         uint64 syncBlockId;
+        uint32 syncTransitionId;
         address prover;
         ITierRouter tierRouter;
     }
@@ -139,9 +140,13 @@ library LibVerifying {
                     tier: local.tier
                 });
 
-                if (LibUtils.shouldSyncStateRoot(_config.stateRootSyncInternal, local.blockId)) {
-                    local.stateRoot = ts.stateRoot;
-                    local.syncBlockId = local.blockId;
+                if (LibUtils.willSyncStateRoot(_config.stateRootSyncInternal, local.blockId)) {
+                    bytes32 stateRoot = ts.stateRoot;
+                    if (stateRoot != 0) {
+                        local.syncStateRoot = stateRoot;
+                        local.syncBlockId = local.blockId;
+                        local.syncTransitionId = local.tid;
+                    }
                 }
 
                 ++local.blockId;
@@ -163,13 +168,20 @@ library LibVerifying {
                 }
                 if (!_tko.batchTransfer(provers, bonds)) revert L1_BATCH_TRANSFER_FAILED();
 
-                if (local.stateRoot != 0) {
+                if (local.syncStateRoot != 0) {
                     _state.slotA.lastSyncedBlockId = local.syncBlockId;
                     _state.slotA.lastSynecdAt = uint64(block.timestamp);
 
+                    // We write the synced block's verifiedTransitionId to storage
+                    local.slot = local.syncBlockId % _config.blockRingBufferSize;
+                    _state.blocks[local.slot].verifiedTransitionId = local.syncTransitionId;
+
                     ISignalService(_resolver.resolve(LibStrings.B_SIGNAL_SERVICE, false))
                         .syncChainData(
-                        _config.chainId, LibStrings.H_STATE_ROOT, local.syncBlockId, local.stateRoot
+                        _config.chainId,
+                        LibStrings.H_STATE_ROOT,
+                        local.syncBlockId,
+                        local.syncStateRoot
                     );
                 }
             }

packages/protocol/contracts/bridge/Bridge.sol

@@ -685,7 +685,9 @@ contract Bridge is EssentialContract, IBridge {
     }
 
     /// @dev Suggested by OpenZeppelin and copied from
-    /// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/83c7e45092dac350b070c421cd2bf7105616cf1a/contracts/metatx/ERC2771Forwarder.sol#L327C1-L370C6
+    /// https://github.com/OpenZeppelin/openzeppelin-contracts/
+    /// blob/83c7e45092dac350b070c421cd2bf7105616cf1a/contracts/
+    /// metatx/ERC2771Forwarder.sol#L327C1-L370C6
     ///
     /// @dev Checks if the requested gas was correctly forwarded to the callee.
     /// As a consequence of https://eips.ethereum.org/EIPS/eip-150[EIP-150]:

packages/protocol/test/L1/TaikoL1.t.sol

@@ -4,7 +4,7 @@ pragma solidity 0.8.24;
 import "./TaikoL1TestBase.sol";
 
 contract TaikoL1_NoCooldown is TaikoL1 {
-    function getConfig() public view override returns (TaikoData.Config memory config) {
+    function getConfig() public pure override returns (TaikoData.Config memory config) {
         config = TaikoL1.getConfig();
         // over-write the following
         config.maxBlocksToVerify = 0;

packages/protocol/test/L1/TaikoL1LibProvingWithTiers.t.sol

@@ -4,7 +4,7 @@ pragma solidity 0.8.24;
 import "./TaikoL1TestBase.sol";
 
 contract TaikoL1Tiers is TaikoL1 {
-    function getConfig() public view override returns (TaikoData.Config memory config) {
+    function getConfig() public pure override returns (TaikoData.Config memory config) {
         config = TaikoL1.getConfig();
 
         config.maxBlocksToVerify = 0;
@@ -423,7 +423,7 @@ contract TaikoL1LibProvingWithTiers is TaikoL1TestBase {
 
         bytes32 parentHash = GENESIS_BLOCK_HASH;
         for (uint256 blockId = 1; blockId < conf.blockMaxProposals * 3; blockId++) {
-            bool storeStateRoot = LibUtils.shouldSyncStateRoot(syncInternal, blockId);
+            bool storeStateRoot = LibUtils.willSyncStateRoot(syncInternal, blockId);
             console2.log("blockId:", blockId);
             console2.log("storeStateRoot:", storeStateRoot);
 

packages/protocol/test/L1/TaikoL1TestGroupBase.sol

@@ -4,7 +4,7 @@ pragma solidity 0.8.24;
 import "./TaikoL1TestBase.sol";
 
 contract TaikoL1New is TaikoL1 {
-    function getConfig() public view override returns (TaikoData.Config memory config) {
+    function getConfig() public pure override returns (TaikoData.Config memory config) {
         config = TaikoL1.getConfig();
         config.maxBlocksToVerify = 0;
         config.blockMaxProposals = 10;