### ClickHouse release v21.3.4.25-lts FIXME as compared to v21.3.3.14-lts
#### Bug Fix
* Backported in [#21928](https://github.com/ClickHouse/ClickHouse/issues/21928): Fix Avro format parsing for Kafka. Fixes [#21437](https://github.com/ClickHouse/ClickHouse/issues/21437). [#21438](https://github.com/ClickHouse/ClickHouse/pull/21438) ([Ilya Golshtein](https://github.com/ilejn)).
* Backported in [#22089](https://github.com/ClickHouse/ClickHouse/issues/22089): In case if query has constant `WHERE` condition, and setting `optimize_skip_unused_shards` enabled, all shards may be skipped and query could return incorrect empty result. [#21550](https://github.com/ClickHouse/ClickHouse/pull/21550) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#21793](https://github.com/ClickHouse/ClickHouse/issues/21793): `std::terminate` was called if there is an error writing data into s3. [#21624](https://github.com/ClickHouse/ClickHouse/pull/21624) ([Vladimir C](https://github.com/vdimir)).
* Backported in [#21746](https://github.com/ClickHouse/ClickHouse/issues/21746): Start accepting connections after DDLWorker and dictionaries initialization. [#21676](https://github.com/ClickHouse/ClickHouse/pull/21676) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#21749](https://github.com/ClickHouse/ClickHouse/issues/21749): Fix concurrent `OPTIMIZE` and `DROP` for `ReplicatedMergeTree`. [#21716](https://github.com/ClickHouse/ClickHouse/pull/21716) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#21878](https://github.com/ClickHouse/ClickHouse/issues/21878): Fix possible crashes in aggregate functions with combinator Distinct, while using two-level aggregation. This is a follow-up fix of https://github.com/ClickHouse/ClickHouse/pull/18365 . Can only reproduced in production env. No test case available yet. cc @CurtizJ. [#21818](https://github.com/ClickHouse/ClickHouse/pull/21818) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#22051](https://github.com/ClickHouse/ClickHouse/issues/22051): Fix deadlock in first catboost model execution. Closes [#13832](https://github.com/ClickHouse/ClickHouse/issues/13832). [#21844](https://github.com/ClickHouse/ClickHouse/pull/21844) ([Kruglov Pavel](https://github.com/Avogar)).
* Backported in [#21993](https://github.com/ClickHouse/ClickHouse/issues/21993): Fix wrong `ORDER BY` results when a query contains window functions, and optimization for reading in primary key order is applied. Fixes [#21828](https://github.com/ClickHouse/ClickHouse/issues/21828). [#21915](https://github.com/ClickHouse/ClickHouse/pull/21915) ([Alexander Kuzmenkov](https://github.com/akuzm)).
* Backported in [#22180](https://github.com/ClickHouse/ClickHouse/issues/22180): Fix reading the HTTP POST request with "multipart/form-data" content type. [#21936](https://github.com/ClickHouse/ClickHouse/pull/21936) ([Ivan](https://github.com/abyss7)).
* Backported in [#21982](https://github.com/ClickHouse/ClickHouse/issues/21982): Prevent hedged connections overlaps (`Unknown packet 9 from server` error). [#21941](https://github.com/ClickHouse/ClickHouse/pull/21941) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#21980](https://github.com/ClickHouse/ClickHouse/issues/21980): Reverted [#15454](https://github.com/ClickHouse/ClickHouse/issues/15454) that may cause significant increase in memory usage while loading external dictionaries of hashed type. This closes [#21935](https://github.com/ClickHouse/ClickHouse/issues/21935). [#21948](https://github.com/ClickHouse/ClickHouse/pull/21948) ([Maksim Kita](https://github.com/kitaisreal)).
* Backported in [#22139](https://github.com/ClickHouse/ClickHouse/issues/22139): The function `decrypt` was lacking a check for the minimal size of data encrypted in AEAD mode. This closes [#21897](https://github.com/ClickHouse/ClickHouse/issues/21897). [#22064](https://github.com/ClickHouse/ClickHouse/pull/22064) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#22185](https://github.com/ClickHouse/ClickHouse/issues/22185): Fix uncaught exception in InterserverIOHTTPHandler. [#22146](https://github.com/ClickHouse/ClickHouse/pull/22146) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#22205](https://github.com/ClickHouse/ClickHouse/issues/22205): Use finalize() over next() for nested writers. [#22147](https://github.com/ClickHouse/ClickHouse/pull/22147) ([Azat Khuzhin](https://github.com/azat)).
* LRUCache fix exception unsafe element insertion [#21891](https://github.com/ClickHouse/ClickHouse/pull/21891) ([Maksim Kita](https://github.com/kitaisreal)).
* 21.3: quick fix for broken resolution of apt.llvm.org on Yandex infra [#22047](https://github.com/ClickHouse/ClickHouse/pull/22047) ([Alexander Kuzmenkov](https://github.com/akuzm)).
