Per bug report, cycles was woefully insufficient to
detect any implementation error.

MariaDB server crashes on ARM (weak memory model architecture) while
concurrently executing l_find to load node->key and add_to_purgatory
to store node->key = NULL. l_find then uses key (which is NULL), to
pass it to a comparison function.

The specific problem is the out-of-order execution that happens on a
weak memory model architecture. Two essential reorderings are possible,
which need to be prevented.

a) As l_find has no barriers in place between the optimistic read of
the key field lf_hash.cc#L117 and the verification of link lf_hash.cc#L124,
the processor can reorder the load to happen after the while-loop.

In that case, a concurrent thread executing add_to_purgatory on the same
node can be scheduled to store NULL at the key field lf_alloc-pin.c#L253
before key is loaded in l_find.

b) A node is marked as deleted by a CAS in l_delete lf_hash.cc#L247 and
taken off the list with an upfollowing CAS lf_hash.cc#L252. Only if both
CAS succeed, the key field is written to by add_to_purgatory. However,
due to a missing barrier, the relaxed store of key lf_alloc-pin.c#L253
can be moved ahead of the two CAS operations, which makes the value of
the local purgatory list stored by add_to_purgatory visible to all threads
operating on the list. As the node is not marked as deleted yet, the
same error occurs in l_find.

This change three accesses to be atomic.

* optimistic read of key in l_find lf_hash.cc#L117
* read of link for verification lf_hash.cc#L124
* write of key in add_to_purgatory lf_alloc-pin.c#L253

Reviewers: Sergei Vojtovich, Sergei Golubchik

Fixes: MDEV-23510 / d30c1331a18d875e553f3fcf544997e4f33fb943

This bug was introduced by commit be00e279
The commit was applied for the task MDEV-6480 that allowed to remove top
level disjuncts from WHERE conditions if the range optimizer evaluated them
as always equal to FALSE/NULL.
If such disjuncts are removed the WHERE condition may become an AND formula
and if this formula contains multiple equalities the field JOIN::item_equal
must be updated to refer to these equalities. The above mentioned commit
forgot to do this and it could cause crashes for some queries.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

restore the old behavior where without a debugger mtr does not
wait for mysqld to start. It was broken in feacc0aa

close_connections() in mysqld.cc sends a signal to all threads.
But InnoDB is too busy purging, doesn't react immediately.
close_connections() waits 20 seconds, which isn't enough in this
particular case, and then unlinks all threads from
the list and forcibly closes their vio connection.

InnoDB background  threads have no vio connection to close, but
they're unlinked all the same. So when later they finally notice
the shutdown request and try to unlink themselves, they fail to
assert that they're still linked.

Fix: don't assert_linked, as another thread can unlink this THD anytime

MDEV-20330 Combination of "," (comma), cross join and left join fails to parse

Fix a potential deadlock bug between locks ctrl_mutex and entry->mutex

MySQL documentation isn't going to help our
users and we shouldn't refer to it.

The bug occurs where the float token containing a dot with an 'e'
notation was dropped from the request completely.

This causes a manner of invalid SQL statements like:

select id 1.e, char 10.e(id 2.e), concat 3.e('a'12356.e,'b'1.e,'c'1.1234e)1.e, 12 1.e*2 1.e, 12 1.e/2 1.e, 12 1.e|2 1.e, 12 1.e^2 1.e, 12 1.e%2 1.e, 12 1.e&2 from test;

To be parsed correctly as if it was:

select id, char(id), concat('a','b','c'), 12*2, 12/2, 12|2, 12^2, 12%2, 12&2 from test.test;

This correct parsing occurs when e is followed by any of:

( ) . , | & % * ^ /

this patch moves cpack summury and description for optional packages
to the appropriate CMakeLists.txt files

Currently, SST scripts assume that the filename specified in
the --log-bin-index argument either does not contain an extension
or uses the standard ".index" extension. Similar assumptions are
used for the log_bin_index parameter read from the configuration
file. This commit adds support for arbitrary extensions for the
index file paths.

If the server is started with the --innodb-force-recovery argument
on the command line, then during SST this argument can be passed to
mariabackup only at the --prepare stage, and accordingly it must be
removed from the --mysqld-args list (and it is not should be passed
to mariabackup otherwise).

This commit fixes a flaw in the SST scripts and add a test that
checks the ability to run the joiner node in a configuration that
uses --innodb-force-recovery=1.

This bug led to reporting bogus messages "No database selected" for DELETE
statements if they used subqueries in their WHERE conditions and these
subqueries contained references to CTEs.
The bug happened because the grammar rule for DELETE statement did not
call the function LEX::check_cte_dependencies_and_resolve_references() and
as a result of it references to CTEs were not identified as such.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

This bug concerned only CREATE TABLE statements of the form
  CREATE TABLE <table name> AS <with clause> <union>.
For such a statement not all references to CTE used in <union> were resolved.
As a result a bogus message was reported for the first unresolved reference.
This happened because for such statements the function resolving references
to CTEs LEX::check_cte_dependencies_and_resolve_references() was called
prematurely in the parser.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

Remove section that was trying to rename default-character-set to character-set-server

This seems to be an old workaround for some upgrade warning, which did not
work for some time already, because the ini filename was not initialized.

fil_space_decrypt(): change signature to return status via dberr_t only.
Also replace impossible condition with an assertion and prove it via
test cases.

  This bug affected queries with two or more references to a CTE referring
another CTE if the definition of the latter contained an invocation of
a stored function that used a base table. The bug could lead to a bogus
error message or to an assertion failure.
  For any non-first reference to CTE cte1 With_element::clone_parsed_spec()
is called that parses the specification of cte1 to construct the unit
structure for this usage of cte1. If cte1 refers to another CTE cte2
outside of the specification of cte1 then With_element::clone_parsed_spec()
has to be called for cte2 as well. This call is made by the function
LEX::resolve_references_to_cte() within the invocation of the function
With_element::clone_parsed_spec() for cte1.
  When the specification of a CTE is parsed all table references encountered
in it must be added to the global list of table references for the query.
As the specification for the non-first usage of a CTE is parsed at a
recursive call of the parser the function With_element::clone_parsed_spec()
invoked at this recursive call should takes care of appending the list of
table references encountered in the specification of this CTE cte1 to the
list of table references created for the query. And it should do it after
the call of LEX::resolve_references_to_cte() that resolves references to
CTEs defined outside of the specification of cte1 because this call may
invoke the parser again for specifications of other CTEs and  the table
references from their specifications must ultimately appear in the global
list of table references of the query.
  The code of With_element::clone_parsed_spec() misplaced the call of
LEX::resolve_references_to_cte(). As a result LEX::query_tables_last used
for the query that was supposed to point to the field 'next_global' of the
last element in the global list of table references actually pointed to
'next_global' of the previous element.
  The above inconsistency certainly caused serious problems when table
references used in the stored functions invoked in cloned specifications
of CTEs were added to the global list of table references.

Upon investigation, decided this to be a compiler bug
(happens with new compiler, on code that did not change for the last 15 years)

Fixed by de-optimizing single function remove_key(), using MSVC pragma

MDEV-26991: CURRENT_TEST: main.mysql_binary_zero_insert 'grep' is not recognized as an internal or external command, operable program or batch file.

Removed grep from mysqldump command stream and instead,
extend the search_file pattern to search for rows containing
binary zeros instead of any occurance of '00' in the input

This fixes up commit d22c8cae

The previous threads locked need to be released too.

This occurs if the initialization of any of the non-first
mutex/conditition variables errors occurs.

Fix a bug of unreleased lock ctrl_mutex in the method create_worker_threads

added summary/description per package.

When transaction creates or drops temporary tables and afterward its statement
faces an error even the transactional table statement's cached ROW
format events get involved into binlog and are visible after the transaction's commit.

Fixed with proper analysis of whether the errored-out statement needs
to be rolled back in binlog.
For instance a fact of already cached CREATE or DROP for temporary
tables by previous statements alone
does not cause to retain the being errored-out statement events in the
cache.
Conversely, if the statement creates or drops a temporary table
itself it can't be rolled back - this rule remains.

This reverts commit 5d6f3ceb.

When restoring lastinx last_key.keyinfo must be updated as well. The
good example is in _ma_check_index().

The point of failure is extra(HA_EXTRA_NO_KEYREAD) in
ha_maria::get_auto_increment():

  1. extra(HA_EXTRA_KEYREAD) saves lastinx;
  2. maria_rkey() changes index, so the lastinx and last_key.keyinfo;
  3. extra(HA_EXTRA_NO_KEYREAD) restores lastinx but not
     last_key.keyinfo.

So we have discrepancy between lastinx and last_key.keyinfo after 3.

Use better error message when KILL fails even in case TOI
fails.

my_copy_fix_mb() passed MIN(src_length,dst_length) to
my_append_fix_badly_formed_tail(). It could break a multi-byte
character in the middle, which put the question mark to the
destination.

Fixing the code to pass the true src_length to
my_append_fix_badly_formed_tail().

* Fix error handling NULL-pointer reference
* Add mtr-suppression on galera_ssl_upgrade

There is a server startup option --gdb a.k.a. --debug-gdb that requests
signals to be set for more convenient debugging. Most notably, SIGINT
(ctrl-c) will not be ignored, and you will be able to interrupt the
execution of the server while GDB is attached to it.

When we are debugging, the signal handlers that would normally display
a terse stack trace are useless.

When we are debugging with rr, the signal handlers may interfere with
a SIGKILL that could be sent to the process by the environment, and ruin
the rr replay trace, due to a Linux kernel bug
https://lkml.org/lkml/2021/10/31/311

To be able to diagnose bugs in kill+restart tests, we may really need
both a trace before the SIGKILL and a trace of the failure after a
subsequent server startup. So, we had better avoid hitting the problem
by simply not installing those signal handlers.