### ClickHouse release v20.12.5.18-stable FIXME as compared to v20.12.5.14-stable

#### Improvement
* Backported in [#19149](https://github.com/ClickHouse/ClickHouse/issues/19149): Explicitly set uid / gid of clickhouse user & group to the fixed values (101) in clickhouse-server images. [#19096](https://github.com/ClickHouse/ClickHouse/pull/19096) ([filimonov](https://github.com/filimonov)).

#### Bug Fix
* Backported in [#18267](https://github.com/ClickHouse/ClickHouse/issues/18267): Fix indeterministic functions with predicate optimizer. This fixes [#17244](https://github.com/ClickHouse/ClickHouse/issues/17244). [#17273](https://github.com/ClickHouse/ClickHouse/pull/17273) ([Winter Zhang](https://github.com/zhang2014)).
* Backported in [#19655](https://github.com/ClickHouse/ClickHouse/issues/19655): fix data type convert issue for mysql engine ... [#18124](https://github.com/ClickHouse/ClickHouse/pull/18124) ([bo zeng](https://github.com/mis98zb)).
* Backported in [#18311](https://github.com/ClickHouse/ClickHouse/issues/18311): Fix inserting a row with default value in case of parsing error in the last column. Fixes [#17712](https://github.com/ClickHouse/ClickHouse/issues/17712). [#18182](https://github.com/ClickHouse/ClickHouse/pull/18182) ([Jianmei Zhang](https://github.com/zhangjmruc)).
* Backported in [#18229](https://github.com/ClickHouse/ClickHouse/issues/18229): Fix possible incomplete query result while reading from `MergeTree*` in case of read backoff (message `<Debug> MergeTreeReadPool: Will lower number of threads` in logs). Was introduced in [#16423](https://github.com/ClickHouse/ClickHouse/issues/16423). Fixes [#18137](https://github.com/ClickHouse/ClickHouse/issues/18137). [#18216](https://github.com/ClickHouse/ClickHouse/pull/18216) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#18630](https://github.com/ClickHouse/ClickHouse/issues/18630): `SELECT JOIN` now requires the `SELECT` privilege on each of the joined tables. This PR fixes [#17654](https://github.com/ClickHouse/ClickHouse/issues/17654). [#18232](https://github.com/ClickHouse/ClickHouse/pull/18232) ([Vitaly Baranov](https://github.com/vitlibar)).
* Backported in [#19202](https://github.com/ClickHouse/ClickHouse/issues/19202): `SELECT count() FROM table` now can be executed if only one any column can be selected from the `table`. This PR fixes [#10639](https://github.com/ClickHouse/ClickHouse/issues/10639). [#18233](https://github.com/ClickHouse/ClickHouse/pull/18233) ([Vitaly Baranov](https://github.com/vitlibar)).
* Backported in [#19162](https://github.com/ClickHouse/ClickHouse/issues/19162): Fix index analysis of binary functions with constant argument which leads to wrong query results. This fixes [#18364](https://github.com/ClickHouse/ClickHouse/issues/18364). [#18373](https://github.com/ClickHouse/ClickHouse/pull/18373) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#19716](https://github.com/ClickHouse/ClickHouse/issues/19716): Disable constant folding for subqueries on the analysis stage, when the result cannot be calculated. [#18446](https://github.com/ClickHouse/ClickHouse/pull/18446) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#18601](https://github.com/ClickHouse/ClickHouse/issues/18601): Fix bug which may lead to `ALTER` queries hung after corresponding mutation kill. Found by thread fuzzer. [#18518](https://github.com/ClickHouse/ClickHouse/pull/18518) ([alesapin](https://github.com/alesapin)).
* Backported in [#18577](https://github.com/ClickHouse/ClickHouse/issues/18577): Fix possible `Pipeline stuck` error while using `ORDER BY` after subquery with `RIGHT` or `FULL` join. [#18550](https://github.com/ClickHouse/ClickHouse/pull/18550) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#18606](https://github.com/ClickHouse/ClickHouse/issues/18606): Add FixedString Data type support. I'll get this exception "Code: 50, e.displayText() = DB::Exception: Unsupported type FixedString(1)" when replicating data from MySQL to ClickHouse. This patch fixes bug [#18450](https://github.com/ClickHouse/ClickHouse/issues/18450) Also fixes [#6556](https://github.com/ClickHouse/ClickHouse/issues/6556). [#18553](https://github.com/ClickHouse/ClickHouse/pull/18553) ([awesomeleo](https://github.com/awesomeleo)).
* Backported in [#18643](https://github.com/ClickHouse/ClickHouse/issues/18643): Fix removing of empty parts in `ReplicatedMergeTree` tables, created with old syntax. Fixes [#18582](https://github.com/ClickHouse/ClickHouse/issues/18582). [#18614](https://github.com/ClickHouse/ClickHouse/pull/18614) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#18738](https://github.com/ClickHouse/ClickHouse/issues/18738): Fix Logger with unmatched arg size. [#18717](https://github.com/ClickHouse/ClickHouse/pull/18717) ([sundyli](https://github.com/sundy-li)).
* Backported in [#18949](https://github.com/ClickHouse/ClickHouse/issues/18949): Fixed `Attempt to read after eof` error when trying to `CAST` `NULL` from `Nullable(String)` to `Nullable(Decimal(P, S))`. Now function `CAST` returns `NULL` when it cannot parse decimal from nullable string. Fixes [#7690](https://github.com/ClickHouse/ClickHouse/issues/7690). [#18718](https://github.com/ClickHouse/ClickHouse/pull/18718) ([Winter Zhang](https://github.com/zhang2014)).
* Backported in [#18802](https://github.com/ClickHouse/ClickHouse/issues/18802): Asynchronous distributed INSERTs can be rejected by the server if the setting `network_compression_method` is globally set to non-default value. This fixes [#18741](https://github.com/ClickHouse/ClickHouse/issues/18741). [#18776](https://github.com/ClickHouse/ClickHouse/pull/18776) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#18835](https://github.com/ClickHouse/ClickHouse/issues/18835): Fix *If combinator with unary function and Nullable types. [#18806](https://github.com/ClickHouse/ClickHouse/pull/18806) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#18909](https://github.com/ClickHouse/ClickHouse/issues/18909): Fix possible hang at shutdown in clickhouse-local. This fixes [#18891](https://github.com/ClickHouse/ClickHouse/issues/18891). [#18893](https://github.com/ClickHouse/ClickHouse/pull/18893) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19114](https://github.com/ClickHouse/ClickHouse/issues/19114): Attach partition should reset the mutation. [#18804](https://github.com/ClickHouse/ClickHouse/issues/18804). [#18935](https://github.com/ClickHouse/ClickHouse/pull/18935) ([fastio](https://github.com/fastio)).
* Backported in [#18967](https://github.com/ClickHouse/ClickHouse/issues/18967): Fix bug when mutation with some escaped text (like `ALTER ... UPDATE e = CAST('foo', 'Enum8(\'foo\' = 1')` serialized incorrectly. Fixes [#18878](https://github.com/ClickHouse/ClickHouse/issues/18878). [#18944](https://github.com/ClickHouse/ClickHouse/pull/18944) ([alesapin](https://github.com/alesapin)).
* Backported in [#19008](https://github.com/ClickHouse/ClickHouse/issues/19008): Fix incorrect behavior when `ALTER TABLE ... DROP PART 'part_name'` query removes all deduplication blocks for the whole partition. Fixes [#18874](https://github.com/ClickHouse/ClickHouse/issues/18874). [#18969](https://github.com/ClickHouse/ClickHouse/pull/18969) ([alesapin](https://github.com/alesapin)).
* Backported in [#19192](https://github.com/ClickHouse/ClickHouse/issues/19192): Fixed very rare deadlock at shutdown. [#18977](https://github.com/ClickHouse/ClickHouse/pull/18977) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#19094](https://github.com/ClickHouse/ClickHouse/issues/19094): Disable `optimize_move_functions_out_of_any` because optimization is not always correct. This closes [#18051](https://github.com/ClickHouse/ClickHouse/issues/18051). This closes [#18973](https://github.com/ClickHouse/ClickHouse/issues/18973). [#18981](https://github.com/ClickHouse/ClickHouse/pull/18981) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19068](https://github.com/ClickHouse/ClickHouse/issues/19068): Join tries to materialize const columns, but our code waits for them in other places. [#18982](https://github.com/ClickHouse/ClickHouse/pull/18982) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Backported in [#19051](https://github.com/ClickHouse/ClickHouse/issues/19051): Fix inserting of `LowCardinality` column to table with `TinyLog` engine. Fixes [#18629](https://github.com/ClickHouse/ClickHouse/issues/18629). [#19010](https://github.com/ClickHouse/ClickHouse/pull/19010) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#19083](https://github.com/ClickHouse/ClickHouse/issues/19083): Fix possible error `Expected single dictionary argument for function` if use function `ignore` with `LowCardinality` argument. Fixes [#14275](https://github.com/ClickHouse/ClickHouse/issues/14275). [#19016](https://github.com/ClickHouse/ClickHouse/pull/19016) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#19047](https://github.com/ClickHouse/ClickHouse/issues/19047): Make sure `groupUniqArray` returns correct type for argument of Enum type. This closes [#17875](https://github.com/ClickHouse/ClickHouse/issues/17875). [#19019](https://github.com/ClickHouse/ClickHouse/pull/19019) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19128](https://github.com/ClickHouse/ClickHouse/issues/19128): Restrict `MODIFY TTL` queries for `MergeTree` tables created in old syntax. Previously the query succeeded, but actually it had no effect. [#19064](https://github.com/ClickHouse/ClickHouse/pull/19064) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#19565](https://github.com/ClickHouse/ClickHouse/issues/19565): Fixed `There is no checkpoint` error when inserting data through http interface using `Template` or `CustomSeparated` format. Fixes [#19021](https://github.com/ClickHouse/ClickHouse/issues/19021). [#19072](https://github.com/ClickHouse/ClickHouse/pull/19072) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#19232](https://github.com/ClickHouse/ClickHouse/issues/19232): Fix startup bug when clickhouse was not able to read compression codec from `LowCardinality(Nullable(...))` and throws exception `Attempt to read after EOF`. Fixes [#18340](https://github.com/ClickHouse/ClickHouse/issues/18340). [#19101](https://github.com/ClickHouse/ClickHouse/pull/19101) ([alesapin](https://github.com/alesapin)).
* Backported in [#19180](https://github.com/ClickHouse/ClickHouse/issues/19180): Fix infinite reading from file in `ORC` format (was introduced in [#10580](https://github.com/ClickHouse/ClickHouse/issues/10580)). Fixes [#19095](https://github.com/ClickHouse/ClickHouse/issues/19095). [#19134](https://github.com/ClickHouse/ClickHouse/pull/19134) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#19269](https://github.com/ClickHouse/ClickHouse/issues/19269): Fix bug when concurrent `ALTER` and `DROP` queries may hang while processing ReplicatedMergeTree table. [#19237](https://github.com/ClickHouse/ClickHouse/pull/19237) ([alesapin](https://github.com/alesapin)).
* Backported in [#19424](https://github.com/ClickHouse/ClickHouse/issues/19424): Fix error `Cannot convert column now64() because it is constant but values of constants are different in source and result`. Continuation of [#7156](https://github.com/ClickHouse/ClickHouse/issues/7156). [#19316](https://github.com/ClickHouse/ClickHouse/pull/19316) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#19553](https://github.com/ClickHouse/ClickHouse/issues/19553): Fix system.parts _state column (LOGICAL_ERROR when querying this column, due to incorrect order). [#19346](https://github.com/ClickHouse/ClickHouse/pull/19346) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#19469](https://github.com/ClickHouse/ClickHouse/issues/19469): - Fix default value in join types with non-zero default (e.g. some Enums). Closes [#18197](https://github.com/ClickHouse/ClickHouse/issues/18197). [#19360](https://github.com/ClickHouse/ClickHouse/pull/19360) ([Vladimir C](https://github.com/vdimir)).
* Backported in [#19437](https://github.com/ClickHouse/ClickHouse/issues/19437): Fix possible buffer overflow in Uber H3 library. See https://github.com/uber/h3/issues/392. This closes [#19219](https://github.com/ClickHouse/ClickHouse/issues/19219). [#19383](https://github.com/ClickHouse/ClickHouse/pull/19383) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19612](https://github.com/ClickHouse/ClickHouse/issues/19612): Fixed very rare bug that might cause mutation to hang after `DROP/DETACH/REPLACE/MOVE PARTITION`. It was partially fixed by [#15537](https://github.com/ClickHouse/ClickHouse/issues/15537) for the most cases. [#19443](https://github.com/ClickHouse/ClickHouse/pull/19443) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#19664](https://github.com/ClickHouse/ClickHouse/issues/19664): Mark distributed batch as broken in case of empty data block in one of files. [#19449](https://github.com/ClickHouse/ClickHouse/pull/19449) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#19508](https://github.com/ClickHouse/ClickHouse/issues/19508): Buffer overflow (on memory read) was possible if `addMonth` function was called with specifically crafted arguments. This fixes [#19441](https://github.com/ClickHouse/ClickHouse/issues/19441). This fixes [#19413](https://github.com/ClickHouse/ClickHouse/issues/19413). [#19472](https://github.com/ClickHouse/ClickHouse/pull/19472) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19541](https://github.com/ClickHouse/ClickHouse/issues/19541): Fix SIGSEGV with merge_tree_min_rows_for_concurrent_read/merge_tree_min_bytes_for_concurrent_read=0/UINT64_MAX. [#19528](https://github.com/ClickHouse/ClickHouse/pull/19528) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#19642](https://github.com/ClickHouse/ClickHouse/issues/19642): Query CREATE DICTIONARY id expression fix. [#19571](https://github.com/ClickHouse/ClickHouse/pull/19571) ([Maksim Kita](https://github.com/kitaisreal)).
* Backported in [#19638](https://github.com/ClickHouse/ClickHouse/issues/19638): `DROP/DETACH TABLE table ON CLUSTER cluster SYNC` query might hang, it's fixed. Fixes [#19568](https://github.com/ClickHouse/ClickHouse/issues/19568). [#19572](https://github.com/ClickHouse/ClickHouse/pull/19572) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#19651](https://github.com/ClickHouse/ClickHouse/issues/19651): Fix use-after-free of the CompressedWriteBuffer in Connection after disconnect. [#19599](https://github.com/ClickHouse/ClickHouse/pull/19599) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#19741](https://github.com/ClickHouse/ClickHouse/issues/19741): Fix wrong result of function `neighbor` for `LowCardinality` argument. Fixes [#10333](https://github.com/ClickHouse/ClickHouse/issues/10333). [#19617](https://github.com/ClickHouse/ClickHouse/pull/19617) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#19699](https://github.com/ClickHouse/ClickHouse/issues/19699): Some functions with big integers may cause segfault. Big integers is experimental feature. This closes [#19667](https://github.com/ClickHouse/ClickHouse/issues/19667). [#19672](https://github.com/ClickHouse/ClickHouse/pull/19672) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19818](https://github.com/ClickHouse/ClickHouse/issues/19818): Fix a segmentation fault in `bitmapAndnot` function. Fixes [#19668](https://github.com/ClickHouse/ClickHouse/issues/19668). [#19713](https://github.com/ClickHouse/ClickHouse/pull/19713) ([Maksim Kita](https://github.com/kitaisreal)).
* Backported in [#19781](https://github.com/ClickHouse/ClickHouse/issues/19781): Fix crash when nested column name was used in `WHERE` or `PREWHERE`. Fixes [#19755](https://github.com/ClickHouse/ClickHouse/issues/19755). [#19763](https://github.com/ClickHouse/ClickHouse/pull/19763) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#19871](https://github.com/ClickHouse/ClickHouse/issues/19871): Fixed stack overflow when using accurate comparison of arithmetic type with string type. [#19773](https://github.com/ClickHouse/ClickHouse/pull/19773) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#19811](https://github.com/ClickHouse/ClickHouse/issues/19811): In previous versions, unusual arguments for function arrayEnumerateUniq may cause crash or infinite loop. This closes [#19787](https://github.com/ClickHouse/ClickHouse/issues/19787). [#19788](https://github.com/ClickHouse/ClickHouse/pull/19788) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19941](https://github.com/ClickHouse/ClickHouse/issues/19941): Deadlock was possible if system.text_log is enabled. This fixes [#19874](https://github.com/ClickHouse/ClickHouse/issues/19874). [#19875](https://github.com/ClickHouse/ClickHouse/pull/19875) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#19937](https://github.com/ClickHouse/ClickHouse/issues/19937): BloomFilter index crash fix. Fixes [#19757](https://github.com/ClickHouse/ClickHouse/issues/19757). [#19884](https://github.com/ClickHouse/ClickHouse/pull/19884) ([Maksim Kita](https://github.com/kitaisreal)).