Add a testcase.

Part#1: Revert the patch that caused it:

commit 291be494
Author: Igor Babaev <igor@askmonty.org>
Date:   Thu Sep 24 22:02:00 2020 -0700

    MDEV-23811: With large number of indexes optimizer chooses an inefficient plan

- mysqlnd from PHP < 7.3
- mysql-connector-python any version
- mysql-connector-java any version

Relaxed check about garbage at the end of the packet in case of no parameters.
Added check for array binding.
Fixed test according to the new paradigm (allow junk at the end of the packet)

This regression was introduced in
commit afc9d00c.
This is a partial backport of
commit 199863d7 from 10.4.

 MDEV-24033: SIGSEGV in __memcmp_avx2_movbe from queue_insert | SIGSEGV in __memcmp_avx2_movbe from native_compare

The issue here was the system variable max_sort_length was being applied
to decimals and it was truncating the value for decimals to the number
of bytes set by max_sort_length.
This was leading to a buffer overflow as the values were written
to the buffer without truncation and then we moved the offset to
the number of bytes(set by max_sort_length), that are needed for comparison.

The fix is to not apply max_sort_length for fixed size types like INT,
DECIMALS and only apply max_sort_length for CHAR, VARCHARS, TEXT and
BLOBS.

Test itself is not deterministic.

Use 9 byte (min length packet)

and restore the test modified in the same commit
(the non-replication related deadlock will be reported separately)

Implement a different fix for
"MDEV-19232: Floating point precision / value comparison problem"

Instead of truncating decimal values after every division,
truncate them for comparison purposes.

This reverts commit 62d73df6 but keeps the test.

followup for 3e807d25 and eae10a87

In case of direct execution(stmtid=-1, mariadb_stmt_execute_direct in C
API) application is in control of how many parameters client sends to
the server. In case this number is not equal to actual query parameters
number, the server may start to interprete packet data incorrectly, e.g.
starting from the size of null bitmap. And that could cause it to crash
at some point. The commit introduces some additional COM_STMT_EXECUTE
packet sanity checks:
- checking that "types sent" byte is set, and the value is equal to 1.
  if it's not direct execution, then that value is 0 or 1.
- checking that parameter type value is a valid type, and parameter
  flags value is 0 or only "unsigned" bit is set
- added more checks that read does not go beyond the end of the packet

mariabackup deallocated uninitialized
write_filt_ctxt.u.wf_incremental_ctxt in xtrabackup_copy_datafile() when
some table should be skipped due to parsed DDL redo log record.

Old SDK is missing #define SECURITY_MAX_SID_STRING_CHARACTERS

Remove unnecessary condition and add necessary include
for non debug Galera library.

All relevant InnoDB changes from MySQL 5.7.32 have been applied
in preceding commits.

Tighten access control - deny FILE_CREATE_PIPE_INSTANCE permission to
everyone except current user (the one that runs mysqld)

Patch removes dict_index_t::stats_latch. Table/index statistics now
protected with dict_sys->mutex. That way statistics computation can
happen in parallel in several threads and dict_sys->mutex will be locked
only for a short period of time.

This patch is a joint work with Marko Mäkelä

dict_index_t::lock: make mutable which allows to pass const pointer
when only lock is touched in an object

btr_height_get()
btr_get_size(): make index argument const for better type safety

btr_estimate_number_of_different_key_vals(): now returns computed values
instead of setting fields in dict_index_t directly

remove everything related to dict_index_t::stats_latch

dict_stats_index_set_n_diff(): now returns computed values instead
of setting fields in dict_index_t directly

dict_stats_analyze_index():  now returns computed values instead
of setting fields in dict_index_t directly

Reviewed by: Marko Mäkelä

Let us introduce a dummy variable innodb_max_purge_lag_wait
for waiting that the InnoDB history list length is below
the user-specified limit. Specifically,

SET GLOBAL innodb_max_purge_lag_wait=0;

should wait for all history to be purged. This could be useful
when upgrading from an older version to MariaDB 10.3 or later,
to avoid hitting MDEV-15912.

Note: the history cannot be purged if there exist transactions
that may see old versions.

Reviewed by: Vladislav Vaintroub

session_track_system_variables and max_relay_log_size.

lock LOCK_global_system_variables around the get_one_variable() call
in the Session_sysvars_tracker::store_variable().

MDEV-23693 Failing assertion: my_atomic_load32_explicit(&lock->lock_word, MY_MEMORY_ORDER_RELAXED) == X_LOCK_DECR

InnoDB frees the block lock during buffer pool shrinking when other
thread is yet to release the block lock.  While shrinking the
buffer pool, InnoDB allows the page to be freed unless it is buffer
fixed. In some cases, InnoDB releases the latch after unfixing the
block.

Fix:
====
- InnoDB should unfix the block after releases the latch.

- Add more assertion to check buffer fix while accessing the page.

- Introduced block_hint structure to store buf_block_t pointer
and allow accessing the buf_block_t pointer only by passing a
functor. It returns original buf_block_t* pointer if it is valid
or nullptr if the pointer become stale.

- Replace buf_block_is_uncompressed() with
buf_pool_t::is_block_pointer()

This change is motivated by a change in mysql-5.7.32:
mysql/mysql-server@46e60de444a8fbd876cc6778a7e64a1d3426a48d
Bug #31036301 ASSERTION FAILURE: SYNC0RW.IC:429:LOCK->LOCK_WORD

Deadlock is possible between applier thread and local committing thread with active FLUSH TABLE.
Applier thread should skip table share checks and locks when opening table.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

and remove unused files

ANALYSIS:
=========
During Bootstrap, while executing the statements from sql
file passed to the init-file server option, transaction
mem_root was being freed for every statement. This creates
an issue with multi statement transactions especially when a
statement in the transaction has to access the memory used
by the previous statement in the transaction.

FIX:
====
Transaction mem_root is freed whenever a transaction is
committed or rolled-back. Hence explicitly freeing it is not
necessary in the bootstrap implementation.

Change-Id: I40f71d49781bf7ad32d474bb176bd6060c9377dc

`LOCK TABLES view_name` should require
* invoker to have SELECT and LOCK TABLES privileges on the view
* either invoker or definer (only if sql security definer) to
  have SELECT and LOCK TABLES privileges on the used tables/views.

According to https://stackoverflow.com/questions/22827510/how-to-avoid-bad-fd-set-buffer-overflow-crash
it seems that using select instead of poll can cause additional memory
allocations. As we are in a crashed state, we must prevent allocating
any memory (if possible). Thus, switch select call to poll.

Also move some bigger datastructures to global space. The code is not
run in a multithreaded context so best we don't use up stack space
if it's not needed.

Problem:
1. The server terminates abnormally when phrase search doesn't
filter out doc_ids correctly. This problem has been fixed in bug
2. Wrong query result: It's a regression from the bug #22709692 fix.
This fix optimize full-text search query with limit clause.
when FTS expression involves only union operation, we fetch only
number of doc_ids specified with the limit clause.
Fulltext phrase search is not an union operation and we consider
phrase search with plugin parser a union operation.
In phrase search with limit clause, we fetch limited doc_ids for
each token and if any of the selected doc_id does not contain all
tokens in correct order then we do not include that row_id in the
result set.
Therefore phrase search gets fewer number of rows than the qualified
rows exist in the table.

Fix:
Added a condition that phrase search with plugin parser is not a
union operation.

RB: 24925
Reviewed by : Annamalai Gurusami <annamalai.gurusami@oracle.com>

This is a cherry-pick of
mysql/mysql-server@5549920b7a33ef33034461d973a9ecb17ce49799
without a test case, because the test case depends on an n-gram
tokenizer that will be missing from MariaDB until MDEV-10267 is added.

Problem:
In Full-text phrase search, we filter out row that do not contain
all the tokens in the phrase.
If we do not filter out doc_id that doesn't appear in all the
token's doc_id lists then we hit an assert.

Fix:
if any of the token has last doc_id equal to ith doc_id of the first
token doc_id list then filter out rest of the higher doc_ids.

RB: 24909
Reviewed by : Annamalai Gurusami <annamalai.gurusami@oracle.com>

This is a cherry-pick of
mysql/mysql-server@5aa075277dfe84a17a0331c57a6fe9b91dafb4cf
but without a test case, because the test case depends on an n-gram
tokenizer that will be missing from MariaDB until MDEV-10267 is added.

was left over from testing