If a table is altered using the MDEV-11369/MDEV-15562/MDEV-13134
ALGORITHM=INSTANT, it can force the table to use a non-canonical
format:

* A hidden metadata record at the start of the clustered index
is used to store each column's DEFAULT value. This makes it possible
to add new columns that have default values without rebuilding the table.

* Starting with MDEV-15562 in MariaDB Server 10.4, a BLOB in the
hidden metadata record is used to store column mappings. This makes
it possible to drop or reorder columns without rebuilding the table.
This also makes it possible to add columns to any position or drop
columns from any position in the table without rebuilding the table.

If a column is dropped without rebuilding the table, old records
will contain garbage in that column's former position, and new records
will be written with NULL values, empty strings, or dummy values.

This is generally not a problem. However, there may be cases where
users may want to avoid putting a table into this format.
For example, users may want to ensure that future UPDATE operations
after an ADD COLUMN will be performed in-place, to reduce write
amplification. (Instantly added columns are essentially always
variable-length.) Users might also want to avoid bugs similar to
MDEV-19916, or they may want to be able to export tables to
older versions of the server.

We will introduce the option innodb_instant_alter_column_allowed,
with the following values:

* never (0): Do not allow instant add/drop/reorder,
to maintain format compatibility with MariaDB 10.x and MySQL 5.x.
If the table (or partition) is not in the canonical format, then
any ALTER TABLE (even one that does not involve instant column
operations) will force a table rebuild.

* add_last (1, default in 10.3): Store a hidden metadata record that
allows columns to be appended to the table instantly (MDEV-11369).
In 10.4 or later, if the table (or partition) is not in this format,
then any ALTER TABLE (even one that does not involve column changes)
will force a table rebuild.

Starting with 10.4:

* add_drop_reorder (2, default): Like 'add_last', but allow the
metadata record to store a column map, to support instant
add/drop/reorder of columns (MDEV-15562).

		partition does rebuild

- In ha_innobase::commit_inplace_alter_table() assumes that all partition
should do the same kind of alter operations. During DDL, if one partition
requires table rebuild and other partition doesn't need rebuild
then all partition should be forced to rebuild.

MDEV-22019: Sig 11 in next_breadth_first_tab | max_sort_length setting + double GROUP BY leads to crash

No need to create a temp table for aggregation if we have encountered some error.

MDEV-7861 main.innodb_mysql_lock fails sporadically in buildbot

Empty comment has a correct length.

If async slave thread (slave SQL handler), becomes a BF victim, it may occasionally happen that rollbacker thread is used to carry out the rollback instead of the async slave thread.
This can happen, if async slave thread has flagged "idle" state when BF thread tries to figure out how to kill the victim.
The issue was possible to test by using a galera cluster as slave for external master, and issuing high load of conflicting writes through async replication and directly against galera cluster nodes.
However, a deterministic mtr test for the "conflict window" has not yet been worked on.

The fix, in this patch makes sure that async slave thread state is never set to IDLE. This prevents the rollbacker thread to intervene.
The wsrep_query_state change was refactored to happen by dedicated function to make controlling the idle state change in one place.

This bug could cause a crash for any query that used a derived table/view/CTE
whose specification was a SELECT with a GROUP BY clause and a FROM list
containing 32 or more table references.
The problem appeared only in the cases when the splitting optimization
could be applied to such derived table/view/CTE.

MDEV-22006 runtime error: null pointer passed as argument 2, which is declared to never be null in JOIN::copy_ref_ptr_array()

Do not memcpy() a zero-length buffer

		redo log during recovery

- InnoDB unnecessarily reads the page even though it has fully initialized
buffered redo log records. Allow the page initialization redo log to
apply for the page in buf_page_get_gen() during recovery.
- Renamed buf_page_get_gen() to buf_page_get_low()
- Newly added buf_page_get_gen() will check for buffered redo log for
the particular page id during recovery
- Added new function buf_page_mtr_lock() which basically latches the page
for the given latch type.
- recv_recovery_create_page() is inline function which creates a page
if it has page initialization redo log records.

MDEV-19658 UBSAN: runtime error: load of value 2779096485, which is not a valid value for type 'enum_binlog_format'

This is an uninitialized read.

THD::THD: initialize current_stmt_binlog_format member

Update submodule, change the source file list
rename CACHE_LINE_SIZE in ut0counter, so it does not conflics with
rocksdb sources, which also defines this constant now.

simplify fix

field_ref_zero: make bigger

buf_is_zeroes(): remove a loop and check in one go

buf_is_zeroes(): stop assuming that argument buffer size
is always a multiply of 4096. And thus stop reading past
that buffer.

Making a linked list of dtuple_t is needed only for inserting
records. It's better to store tuples in a non-intrusive
container to not affect all other use cases of dtuple_t

dtuple_t::tuple_list: removed, it was 2 * sizeof(void*) bytes

ins_node_t::entry_list: now it's std::vector<dtuple_t*>

ins_node_t::entry: now it's std::vector<dtuple_t*>::iterator

DBUG_EXECUTE_IF("row_ins_skip_sec": this dead code removed

move span.h to a proper place to make it available for the whole server

Reformat it.

Constuctors from a contigous container are fixed
to use cont.data() instead of cont.begin()

span<>::index_type is replaced with span<>::size_type

In my micro-benchmarks memcmp(4196) 3 times faster than old
implementation. Also, it's generally better to use as less
reinterpret_casts<> as possible.

buf_is_zeroes(): renamed from buf_page_is_zeroes() and
argument changed to span<> for convenience.

st_::span<T>::const_iterator: fixed

page_zip-verify_checksum(): make argument byte* instead of void*

           prepared statement

The method Item_func_in::build_clone() that builds a clone item for an
Item_func_in item first calls a generic method Item_func::build_item()
that builds the the clones for the arguments of the Item_func_in item
to be cloned, creates a copy of the Item_func_in object and attaches the
clones for the arguments to this copy. Then the method Item_func_in::build_clone()
makes the copy fully independent on the copied object in order to
guarantee a proper destruction of the clone. The fact is the copy of the
Item_func_in object is registered as any other item object and should be
destructed as any other item object.
If the method Item_func::build_item fails to build a clone of an argument
then it returns 0. In this case no copy of the Item_func_in object should
be created. Otherwise the finalizing actions for this copy would not be
performed and the copy would remain in a state that would prevent its
proper destruction.

The code of Item_func_in::build_clone() before this patch created the copy
of the Item_func_in object before cloning the argument items. If this
cloning failed the server crashed when trying to destruct the copy item.

The code of Item_row::build_clone() was changed similarly to the code of
Item_func::build_clone though this code could not cause any problems.

Also, clean up the test innodb_gis.geometry a little further.

Remove CREATE/DROP database.

Remove some unnecessary suppressions, replacements, and
SQL statements.

Populate tables via have_sequence.inc to avoid the creation of
explicit InnoDB record locks in INSERT...SELECT. This will remove
some gaps in AUTO_INCREMENT values.

After MDEV-12353, the consistency check that I originally added for
commit 1b9fe0bb
(InnoDB Plugin for MySQL 5.1) started randomly failing.

It turns out that the IMPORT TABLESPACE code was always incorrect:
it did not update the (redundantly stored) tablespace ID
in index tree root pages. It only does that for page headers
and BLOB pointers.

PageConverter::update_index_page(): Update the tablespace ID
in the BTR_SEG_TOP and BTR_SEG_LEAF of index root pages.

The problem happened in these line:

uval0= (ulonglong) (val0_negative ? -val0 : val0);
uval1= (ulonglong) (val1_negative ? -val1 : val1);

return check_integer_overflow(val0_negative ? -(longlong) res : res,
                              !val0_negative);

when unary minus was performed on -9223372036854775808.
This behavior is undefined in C/C++.

Several macros such as sint2korr() and uint4korr() are using the
arithmetic + operator while a bitwise or operator would suffice.

GCC 5 and clang 5 and later can detect patterns consisting of
bitwise or and shifts by multiples of 8 bits, such as those used
in the InnoDB function mach_read_from_4(). They actually translate
that verbose low-level code into high-level machine language
(i486 bswap instruction or fused into the Haswell movbe instruction).

We should do the same for MariaDB Server code that is outside InnoDB.

Note: The Microsoft C compiler is lacking this optimization.
There, we might consider using _byteswap_ushort(), _byteswap_ulong(),
_byteswap_uint64(). But, those would lead to unaligned reads, which are
bad for reasons stated in MDEV-20277. Besides, outside InnoDB,
most data is already being stored in the native little-endian format
of that compiler.

fil_delete_tablespace(): Remove the unused parameter drop_ahi,
and add the parameter if_exists=false. We want to suppress
error messages if we know that the tablespace has been discarded.

dict_table_rename_in_cache(): Pass the new parameter to
fil_delete_tablespace(), that is, do not complain about
missing tablespace if the tablespace has been discarded.

row_make_new_pathname(): Declare as static.

row_drop_table_for_mysql(): Tolerate !table->data_dir_path
when the tablespace has been discarded.

row_rename_table_for_mysql(): Skip part of the RENAME TABLE
when fil_space_get_first_path() returns NULL.

buf_pool_resize(): Simplify the fault injection
for innodb.buf_pool_resize_oom.

innodb.buf_pool_resize_oom: Use a small buffer pool.

innodb.innodb_buffer_pool_load_now: Make use of the sequence engine,
to avoid creating explicit InnoDB record locks. Clean up the
accesses to information_schema.innodb_buffer_page_lru.

Tests fixed.
MBR::Within() function fixed.

- This issue is caused by MDEV-19176
(bba59abb).
- Problem is that there is miscalculation of available memory during
recovery if innodb_buffer_pool_instances > 1.
- Ignore the buffer pool instance while calculating available_memory
- Removed recv_n_pool_free_frames variable and use buf_pool_get_n_pages()
instead.