Fixed

General

• The config parser now correctly detects and errors on self-referencing environment variables (#7737)
• Internal functions for handling headers should no longer corrupt message bodies if appended (#7752)

JetStream

• Raft single node elections now transition into leader state correctly (#7642)
• R1 streams will no longer incorrectly drift last sequence when exceeding limits (#7658)
• Deleted streams are no longer wrongfully revived if stalled on an upper-layer catchup (#7668)
• A panic that could happen when receiving a shutdown signal while JetStream is still starting up has been fixed (#7683)
• JetStream usage stats now correctly reflect purged whole blocks when optimising large purges (#7685)
• Recovering JetStream encryption keys now happens independently of the stream index recovery, fixing some cases where the key could be reset unexpectedly if the index is rebuilt (#7678)
• Non-replicated file-based consumers now detect corrupted state on disk and are deleted automatically (#7691)
• A panic that could occur when a compact and a hash check run concurrently on a store has been fixed (#7697)
• Raft no longer allows a repeat vote for the same term after a stepdown or leadership transfer (#7698)
• Replicated consumers are no longer incorrectly deleted if they become leader just as JetStream is about to shut down (#7699)
• Fixed an issue where a single truncated block could prevent storing new messages in the filestore (#7704)
• Fixed a concurrent map iteration/write panic that could occur on WorkQueue streams during partitioning (#7708)
• Fixed a deadlock that could occur on shutdown when adding streams (#7710)
• Required API level errors are now only returned after other checks, preventing unexpected replies from other servers (#7711)
• A data race on mirror consumers has been fixed (#7716)
• JetStream no longer leaks subscriptions in a cluster when a stream import/export is set up that overlaps the $JS.> namespace (#7720)
• The filestore will no longer waste CPU time rebuilding subject state for WALs (#7721)
• Configuring cluster_traffic in config mode has been fixed (#7723)
• Subject intersection no longer misses certain subjects with specific patterns of overlapping filters, which could affect consumers, num pending calculations etc (#7728, #7741, #7744, #7745)
• Multi-filtered next message lookups in the filestore can now skip blocks when faster to do so (#7750)
• The binary search for start times now handles deleted messages correctly (#7751)
• Consumer updates will now only recalculate num pending when the filter subjects are changed (#7753)
• Consumer info calls will no longer recalculate num pending (#7758)
• Consumers on replicated interest or workqueue streams should no longer lose interest or cause desyncs after having their filter subjects updated (#7773)
• Interest-based streams will no longer start more check interest state goroutines when there are existing running ones (#7769)

Complete Changes

https://github.com/nats-io/nats-server/compare/v2.12.3...v2.12.4