create_table_info_t::create_foreign_keys(): Make the create_name buffer
long enough for both the database and table name. It is still not long
enough to hold partition or subpartition names. Because we do never
supported FOREIGN KEY constraints on partitions, we can simply skip
the call to innobase_convert_name() on CREATE TABLE.

MDEV-22719 Long unique keys are not created when individual key_part->length < max_key_length but SUM(key_parts->length) > max_key_length

Make UNIQUE HASH key in case when key_info->key_length > max_key_length

MDEV-21804 Assertion `marked_for_read()' failed upon INSERT into table with long unique blob under binlog_row_image=NOBLOB

Problem:- Calling mark_columns_per_binlog_row_image() earlier may change the
result of mark_virtual_columns_for_write() , Since it can set the bitmap on
for virtual column, and henceforth  mark_virtual_column_deps(field) will
never be called in mark_virtual_column_with_deps.

This bug is not specific for long unique, It also fails for this case
   create table t2(id int primary key, a blob, b varchar(20) as (LEFT(a,2)));

lock_check_trx_id_sanity(): Because the argument of UNIV_LIKELY
or __builtin_expect() can be less than sizeof(trx_id_t) on 32-bit
systems, it cannot reliably perform an implicit comparison to 0.

Bit operators (~ ^ | & << >>) and the function BIT_COUNT()
always called val_int() for their arguments.
It worked correctly only for INT type arguments.

In case of DECIMAL and DOUBLE arguments it did not work well:
the argument values were truncated to the maximum SIGNED BIGINT value
of 9223372036854775807.

Fixing the code as follows:

- If the argument if of an integer data type,
  it works using val_int() as before.

- If the argument if of some other data type, it gets the argument value
  using val_decimal(), to avoid truncation, and then converts the result
  to ulonglong.

Using Item_handled_func to switch between the two approaches easier.

As an additional advantage, with Item_handled_func it will be easier
to implement overloading in the future, so data type plugings will be able
to define their own behavioir of bit operators and BIT_COUNT().

Moving the code from the former val_int() implementations
as methods to Longlong_null, to avoid code duplication in the
INT and DECIMAL branches.

page_zip_fields_decode(): Do not dereference index=NULL.
Instead, return NULL early. The only caller does not care
about the values of output parameters in that case.

This bug was introduced in MySQL 5.7.6 by
mysql/mysql-server@9eae0edb7a8e4004328e61157f5f3b39cebe1b2b
and in MariaDB 10.2.2 by
commit 2e814d47.

Thanks to my son for pointing this out after investigating
the output of a static analysis tool.

fil_aio_callback(): Remove a bogus assertion that was added in
commit b1ab211d (MDEV-15053).
We will have !bpage for any write by buf_flush_freed_page().

buf_page_init_for_read(): Initialize the output parameter of
buf_buddy_alloc().

Compiler tells something about argument-dependent lookup. I do not
understand how that ADL works. But I know that such operators should
be free functions, instead of methods:
http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Ro-symmetric

Such syntax defines 'friend' free functions.

When processing a query with a recursive CTE a temporary table is used for
each recursive reference of the CTE. As any temporary table it uses its own
mem-root for table definition structures. Due to specifics of the current
implementation of ANALYZE stmt command this mem-root can be freed only at
the very of query processing. Such deallocation of mem-root memory happens
in close_thread_tables(). The function looks through the list of the tmp
tables rec_tables attached to the THD of the query and frees corresponding
mem-roots. If the query uses a stored function then such list is created
for each query of the function. When a new rec_list has to be created the
old one has to be saved and then restored at the proper moment.
The bug occurred because only one rec_list for the query containing CTE was
created. As a result close_thread_tables() freed tmp mem-roots used for
rec_tables prematurely destroying some data needed for the output produced
by the ANALYZE command.

Polling for srv_purge_should_exit() once every millisecond is enough.

- commit ea37b144 (MDEV-16678) caused
a regression. when purge thread tries to open the table for virtual
column computation, there is no need to acquire MDL for the table.
Because purge thread already hold MDL for the table

The background drop table queue in InnoDB is a work-around for
cases where the SQL layer is requesting DDL on tables on which
transactional locks exist.

One such case are XA transactions. Our test case exploits the
fact that the recovery of XA PREPARE transactions will
only resurrect InnoDB table locks, but not MDL that should
block any concurrent DDL.

srv_shutdown_t: Introduce the srv_shutdown_state=SRV_SHUTDOWN_INITIATED
for the initial part of shutdown, to wait for the background drop
table queue to be emptied.

srv_shutdown_bg_undo_sources(): Assign
srv_shutdown_state=SRV_SHUTDOWN_INITIATED
before waiting for the background drop table queue to be emptied.

row_drop_tables_for_mysql_in_background(): On slow shutdown, if
no active transactions exist (excluding ones that are in
XA PREPARE state), skip any tables on which locks exist.

row_drop_table_for_mysql(): Do not unnecessarily attempt to
drop InnoDB persistent statistics for tables that have
already been added to the background drop table queue.

row_mysql_close(): Relax an assertion, and free all memory
even if innodb_force_recovery=2 would prevent the background
drop table queue from being emptied.

This race condition was introduced by
commit ad6171b9 (MDEV-22456).

In the observed case, two threads were executing
btr_search_drop_page_hash_index() on the same block,
to free a stale entry that was attached to a dropped index.
Both threads were holding an S latch on the block.

We must prevent the double-free of block->index by holding
block->lock in exclusive mode.

btr_search_guess_on_hash(): Do not invoke
btr_search_drop_page_hash_index(block) to get rid of
stale entries, because we are not necessarily holding
an exclusive block->lock here.

buf_defer_drop_ahi(): New function, to safely drop stale
entries in buf_page_mtr_lock(). We will skip the call to
btr_search_drop_page_hash_index(block) when only requesting
bufferfixing (no page latch), because in that case, we should
not be accessing the adaptive hash index, and we might get
a deadlock if we acquired the page latch.

btr_search_sys_free(): Free btr_search_sys->hash_tables.

The leak was introduced in commit ad2bf112.

Allow targets for building "noinstall" zip, and debuginfo zip.

It looks buffer over flow of spider_unique_id_buf. It requires to analyze on reproducing environment, but I extend this first.

Fix issue caused by using spider_bgs_mode = 2 when Spider use limit_mode = 1 internally for data nodes.