### ClickHouse release v21.5.6.6-stable FIXME as compared to v21.5.5.12-stable

#### Bug Fix
* Backported in [#24170](https://github.com/ClickHouse/ClickHouse/issues/24170): Fix a rare bug that could lead to a partially initialized table that can serve write requests (insert/alter/so on). Now such tables will be in readonly mode. [#24122](https://github.com/ClickHouse/ClickHouse/pull/24122) ([alesapin](https://github.com/alesapin)).
* Backported in [#24332](https://github.com/ClickHouse/ClickHouse/issues/24332): Set `max_threads = 1` to fix mutation fail of StorageMemory. Closes [#24274](https://github.com/ClickHouse/ClickHouse/issues/24274). [#24275](https://github.com/ClickHouse/ClickHouse/pull/24275) ([flynn](https://github.com/ucasfl)).
* Backported in [#24382](https://github.com/ClickHouse/ClickHouse/issues/24382): Allow empty HTTP headers. Fixes [#23901](https://github.com/ClickHouse/ClickHouse/issues/23901). [#24285](https://github.com/ClickHouse/ClickHouse/pull/24285) ([Ivan](https://github.com/abyss7)).
* Backported in [#24351](https://github.com/ClickHouse/ClickHouse/issues/24351): Fixed a bug in moving Materialized View from Ordinary to Atomic database (`RENAME TABLE` query). Now inner table is moved to new database together with Materialized View. Fixes [#23926](https://github.com/ClickHouse/ClickHouse/issues/23926). [#24309](https://github.com/ClickHouse/ClickHouse/pull/24309) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#24509](https://github.com/ClickHouse/ClickHouse/issues/24509): Fix drop partition with intersect fake parts. In rare cases there might be parts with mutation version greater than current block number. [#24321](https://github.com/ClickHouse/ClickHouse/pull/24321) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#24540](https://github.com/ClickHouse/ClickHouse/issues/24540): Fix incorrect monotonicity of toWeek function. This fixes [#24422](https://github.com/ClickHouse/ClickHouse/issues/24422) . This bug was introduced in https://github.com/ClickHouse/ClickHouse/pull/5212 , and was exposed later by smarter partition pruner. [#24446](https://github.com/ClickHouse/ClickHouse/pull/24446) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#24557](https://github.com/ClickHouse/ClickHouse/issues/24557): Fixed the behavior when query `SYSTEM RESTART REPLICA` or `SYSTEM SYNC REPLICA` is being processed infinitely. This was detected on server with extremely little amount of RAM. [#24457](https://github.com/ClickHouse/ClickHouse/pull/24457) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Backported in [#24598](https://github.com/ClickHouse/ClickHouse/issues/24598): Fix usage of tuples in `CREATE .. AS SELECT` queries. [#24464](https://github.com/ClickHouse/ClickHouse/pull/24464) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#24601](https://github.com/ClickHouse/ClickHouse/issues/24601): Enable reading of subcolumns for distributed tables. [#24472](https://github.com/ClickHouse/ClickHouse/pull/24472) ([Anton Popov](https://github.com/CurtizJ)).

#### NO CL CATEGORY

* Backported in [#24750](https://github.com/ClickHouse/ClickHouse/issues/24750):. [#23276](https://github.com/ClickHouse/ClickHouse/pull/23276) ([Alexey Milovidov](https://github.com/alexey-milovidov)).