fix: track block in MMR (#2353)

Author: SantiagoPittella

CHANGELOG.md

@@ -1,23 +1,9 @@
 # Changelog
 
-## 0.14.0 (TBD)
-
-### Features
-
-- Enable `CodeBuilder` to add advice map entries to compiled scripts ([#2275](https://github.com/0xMiden/miden-base/pull/2275)).
-- Added `BlockNumber::MAX` constant to represent the maximum block number ([#2324](https://github.com/0xMiden/miden-base/pull/2324)).
-
-### Changes
-
-- [BREAKING] Renamed `WellKnownComponent` to `StandardAccountComponent`, `WellKnownNote` to `StandardNote`, and `WellKnownNoteAttachment` to `StandardNoteAttachment` ([#2332](https://github.com/0xMiden/miden-base/pull/2332)).
-- Skip requests to the `DataStore` for asset vault witnesses which are already in transaction inputs ([#2298](https://github.com/0xMiden/miden-base/pull/2298)).
-- [BREAKING] refactored `TransactionAuthenticator::get_public_key()` method to return `Arc<PublicKey> `instead of `&PublicKey` ([#2304](https://github.com/0xMiden/miden-base/pull/2304)).
-- [BREAKING] Renamed `NoteInputs` to `NoteStorage` to better reflect that values are stored data associated with a note rather than inputs ([#1662](https://github.com/0xMiden/miden-base/issues/1662), [#2316](https://github.com/0xMiden/miden-base/issues/2316)).
-- Removed `NoteType::Encrypted` ([#2315](https://github.com/0xMiden/miden-base/pull/2315)).
-
-# 0.13.3 (TBD)
+## 0.13.3 (2026-01-27)
 
 - Added standards for working with `NetworkAccountTarget` attachments ([#2338](https://github.com/0xMiden/miden-base/pull/2338)).
+- Fixed `PartialBlockchain::add_block()` not adding block headers to the `blocks` map when `track=true`, which caused `prune_to()` to never untrack old blocks, leading to unbounded memory growth ([#2353](https://github.com/0xMiden/miden-base/pull/2353)).
 
 ## 0.13.2 (2026-01-21)
 

Cargo.lock

@@ -21,7 +21,7 @@ homepage     = "https://miden.xyz"
 license      = "MIT"
 repository   = "https://github.com/0xMiden/miden-base"
 rust-version = "1.90"
-version      = "0.13.2"
+version      = "0.13.3"
 
 [profile.release]
 codegen-units = 1

Cargo.toml

@@ -178,14 +178,18 @@ impl PartialBlockchain {
     /// provided block header is for the next block in the chain.
     ///
     /// If `track` parameter is set to true, the authentication path for the provided block header
-    /// will be added to this partial blockchain.
+    /// will be added to this partial blockchain, and the block header will be stored for later
+    /// retrieval.
     ///
     /// # Panics
     /// Panics if the `block_header.block_num` is not equal to the current chain length (i.e., the
     /// provided block header is not the next block in the chain).
     pub fn add_block(&mut self, block_header: &BlockHeader, track: bool) {
         assert_eq!(block_header.block_num(), self.chain_length());
         self.mmr.add(block_header.commitment(), track);
+        if track {
+            self.blocks.insert(block_header.block_num(), block_header.clone());
+        }
     }
 
     /// Drop every block header whose number is strictly less than `to.end`.
@@ -492,4 +496,51 @@ mod tests {
             assert!(!chain.mmr().is_tracked(block_num as usize));
         }
     }
+
+    #[test]
+    fn add_block_with_track_adds_to_blocks() {
+        let mut blockchain = PartialBlockchain::default();
+        let header = int_to_block_header(0);
+
+        blockchain.add_block(&header, true);
+
+        assert!(blockchain.contains_block(0.into()));
+        assert_eq!(blockchain.num_tracked_blocks(), 1);
+    }
+
+    #[test]
+    fn add_block_without_track_does_not_add_to_blocks() {
+        let mut blockchain = PartialBlockchain::default();
+        let header = int_to_block_header(0);
+
+        blockchain.add_block(&header, false);
+
+        assert!(!blockchain.contains_block(0.into()));
+        assert_eq!(blockchain.num_tracked_blocks(), 0);
+    }
+
+    #[test]
+    fn prune_to_removes_tracked_blocks() {
+        let mut blockchain = PartialBlockchain::default();
+        // Add 10 blocks with tracking
+        for i in 0..10u32 {
+            let header = int_to_block_header(i);
+            blockchain.add_block(&header, true);
+        }
+        assert_eq!(blockchain.num_tracked_blocks(), 10);
+
+        // Prune to keep only last 4
+        blockchain.prune_to(..6.into());
+
+        assert_eq!(blockchain.num_tracked_blocks(), 4);
+        for i in 0u32..6 {
+            assert!(!blockchain.contains_block(i.into()));
+            // Verify the underlying MMR also untracked the block
+            assert!(!blockchain.mmr().is_tracked(i as usize));
+        }
+        for i in 6u32..10 {
+            assert!(blockchain.contains_block(i.into()));
+            assert!(blockchain.mmr().is_tracked(i as usize));
+        }
+    }
 }