fix archiver

l1-contracts/src/core/messagebridge/Inbox.sol

@@ -92,7 +92,8 @@ contract Inbox is IInbox {
     // this is the global leaf index and not index in the l2Block subtree
     // such that users can simply use it and don't need access to a node if they are to consume it in public.
     // trees are constant size so global index = tree number * size + subtree index
-    uint256 index = (inProgress - 1) * SIZE + currentTree.insertLeaf(leaf);
+    uint256 index =
+      (inProgress - Constants.INITIAL_L2_BLOCK_NUM) * SIZE + currentTree.insertLeaf(leaf);
     totalMessagesInserted++;
     emit MessageSent(inProgress, index, leaf);
 

yarn-project/archiver/src/archiver/kv_archiver_store/message_store.ts

@@ -61,16 +61,18 @@ export class MessageStore {
       void this.#lastSynchedL1Block.set(messages.lastProcessedL1BlockNumber);
 
       for (const message of messages.retrievedData) {
-        if (message.index >= this.#l1ToL2MessagesSubtreeSize) {
+        // inbox event emits index the whole tree. We need index in the L1 to L2 message subtree.
+        // reverse of what is done in inbox.sol
+        const indexInTheWholeTree = message.index;
+        const indexInSubtree =
+          indexInTheWholeTree -
+          (message.blockNumber - BigInt(INITIAL_L2_BLOCK_NUM)) * BigInt(NUMBER_OF_L1_L2_MESSAGES_PER_ROLLUP);
+        if (indexInSubtree >= this.#l1ToL2MessagesSubtreeSize) {
           throw new Error(`Message index ${message.index} out of subtree range`);
         }
-        const key = `${message.blockNumber}-${message.index}`;
+        const key = `${message.blockNumber}-${indexInSubtree}`;
         void this.#l1ToL2Messages.setIfNotExists(key, message.leaf.toBuffer());
 
-        const indexInTheWholeTree =
-          (message.blockNumber - BigInt(INITIAL_L2_BLOCK_NUM)) * BigInt(NUMBER_OF_L1_L2_MESSAGES_PER_ROLLUP) +
-          message.index;
-
         const indices = this.#l1ToL2MessageIndices.get(message.leaf.toString()) ?? [];
         indices.push(indexInTheWholeTree);
         void this.#l1ToL2MessageIndices.set(message.leaf.toString(), indices);

yarn-project/circuit-types/src/messaging/inbox_leaf.ts

@@ -6,7 +6,7 @@ export class InboxLeaf {
   constructor(
     /** L2 block number in which the message will be included. */
     public readonly blockNumber: bigint,
-    /** Index of the leaf in L2 block message subtree. */
+    /** Index of the leaf in the whole tree. */
     public readonly index: bigint,
     /** Leaf in the subtree/message hash. */
     public readonly leaf: Fr,