### ClickHouse release v21.8.5.7-lts FIXME as compared to v21.8.4.51-lts

#### Improvement
* Backported in [#27893](https://github.com/ClickHouse/ClickHouse/issues/27893): Allow symlinks for library dictionaty path. [#27815](https://github.com/ClickHouse/ClickHouse/pull/27815) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Backported in [#28154](https://github.com/ClickHouse/ClickHouse/issues/28154): Use Multipart copy upload for large S3 objects. [#27858](https://github.com/ClickHouse/ClickHouse/pull/27858) ([ianton-ru](https://github.com/ianton-ru)).
* Backported in [#28463](https://github.com/ClickHouse/ClickHouse/issues/28463): Do not allow creating StorageMaterializedPostgreSQL with bad arguments. Closes [#28423](https://github.com/ClickHouse/ClickHouse/issues/28423). [#28430](https://github.com/ClickHouse/ClickHouse/pull/28430) ([Kseniia Sumarokova](https://github.com/kssenii)).

#### Bug Fix
* Backported in [#28033](https://github.com/ClickHouse/ClickHouse/issues/28033): Bugfix for windowFunnel's "strict" mode. This fixes [#27469](https://github.com/ClickHouse/ClickHouse/issues/27469). [#27563](https://github.com/ClickHouse/ClickHouse/pull/27563) ([achimbab](https://github.com/achimbab)).
* Backported in [#27782](https://github.com/ClickHouse/ClickHouse/issues/27782): Fix column filtering with union distinct in subquery. Closes [#27578](https://github.com/ClickHouse/ClickHouse/issues/27578). [#27689](https://github.com/ClickHouse/ClickHouse/pull/27689) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Backported in [#27867](https://github.com/ClickHouse/ClickHouse/issues/27867): Prevent crashes for some formats when NULL (tombstone) message was coming from Kafka. Closes [#19255](https://github.com/ClickHouse/ClickHouse/issues/19255). [#27794](https://github.com/ClickHouse/ClickHouse/pull/27794) ([filimonov](https://github.com/filimonov)).
* Backported in [#28346](https://github.com/ClickHouse/ClickHouse/issues/28346): Fix a rare bug in `DROP PART` which can lead to the error `Unexpected merged part intersects drop range`. [#27807](https://github.com/ClickHouse/ClickHouse/pull/27807) ([alesapin](https://github.com/alesapin)).
* Backported in [#27855](https://github.com/ClickHouse/ClickHouse/issues/27855): Fix a couple of bugs that may cause replicas to diverge. [#27808](https://github.com/ClickHouse/ClickHouse/pull/27808) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#27958](https://github.com/ClickHouse/ClickHouse/issues/27958): Fix selecting with extremes from a column of the type `LowCardinality(UUID)`. [#27918](https://github.com/ClickHouse/ClickHouse/pull/27918) ([Vitaly Baranov](https://github.com/vitlibar)).
* Backported in [#27953](https://github.com/ClickHouse/ClickHouse/issues/27953): Check cluster name before creating Distributed table, do not allow to create a table with incorrect cluster name. Fixes [#27832](https://github.com/ClickHouse/ClickHouse/issues/27832). [#27927](https://github.com/ClickHouse/ClickHouse/pull/27927) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#28209](https://github.com/ClickHouse/ClickHouse/issues/28209): Fix cases, when read buffer fails with 'attempt to read after end of file'. Closes [#26149](https://github.com/ClickHouse/ClickHouse/issues/26149). [#28150](https://github.com/ClickHouse/ClickHouse/pull/28150) ([Filatenkov Artur](https://github.com/FArthur-cmd)).

#### Build/Testing/Packaging Improvement
* Backported in [#28031](https://github.com/ClickHouse/ClickHouse/issues/28031): Temporarily switched ubuntu apt repository to mirror ru.archive.ubuntu.com as default one(archive.ubuntu.com) is not responding from our CI. [#28016](https://github.com/ClickHouse/ClickHouse/pull/28016) ([Ilya Yatsishin](https://github.com/qoega)).

#### Bug Fix (user-visible misbehaviour in official stable or prestable release)

* Backported in [#27974](https://github.com/ClickHouse/ClickHouse/issues/27974): Fix handling null value with type of Nullable(String) in function JSONExtract. This fixes [#27929](https://github.com/ClickHouse/ClickHouse/issues/27929) and [#27930](https://github.com/ClickHouse/ClickHouse/issues/27930) . This was introduced in https://github.com/ClickHouse/ClickHouse/pull/25452 . [#27939](https://github.com/ClickHouse/ClickHouse/pull/27939) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#28117](https://github.com/ClickHouse/ClickHouse/issues/28117): Fix extremely rare segfaults on shutdown due to incorrect order of context/config reloader shutdown. [#28088](https://github.com/ClickHouse/ClickHouse/pull/28088) ([nvartolomei](https://github.com/nvartolomei)).
* Backported in [#28180](https://github.com/ClickHouse/ClickHouse/issues/28180): Fixed possible excessive number of conditions moved from `WHERE` to `PREWHERE` (optimization controlled by settings `optimize_move_to_prewhere`). [#28139](https://github.com/ClickHouse/ClickHouse/pull/28139) ([lthaooo](https://github.com/lthaooo)).
* Backported in [#28254](https://github.com/ClickHouse/ClickHouse/issues/28254): Fix incorrect behavior in `clickhouse-keeper` when list watches (`getChildren`) triggered with `set` requests for children. [#28190](https://github.com/ClickHouse/ClickHouse/pull/28190) ([alesapin](https://github.com/alesapin)).
* Backported in [#28342](https://github.com/ClickHouse/ClickHouse/issues/28342): Fix a rare bug in `clickhouse-keeper` when the client can receive a watch response before request-response. [#28197](https://github.com/ClickHouse/ClickHouse/pull/28197) ([alesapin](https://github.com/alesapin)).
* Backported in [#28263](https://github.com/ClickHouse/ClickHouse/issues/28263): Fix possible read of uninitialized memory for queries with `Nullable(LowCardinality)` type and extremes. Fixes [#28165](https://github.com/ClickHouse/ClickHouse/issues/28165). [#28205](https://github.com/ClickHouse/ClickHouse/pull/28205) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#28292](https://github.com/ClickHouse/ClickHouse/issues/28292): Fix inconsistent result in queries with `ORDER BY` and `Merge` tables with enabled setting `optimize_read_in_order`. [#28266](https://github.com/ClickHouse/ClickHouse/pull/28266) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#28402](https://github.com/ClickHouse/ClickHouse/issues/28402): Fix intersecting parts due to new part had been replaced with an empty part. [#28310](https://github.com/ClickHouse/ClickHouse/pull/28310) ([Azat Khuzhin](https://github.com/azat)).