Use max_connections in calculation, top prevent possible deadlock, if
max_connection is high.

Do *not* check if socket is closed by another thread. This is
race-condition prone, unnecessary, and harmful. VIO state was introduced
to debug the errors, not to change the behavior.

Rather than checking if socket is closed, add a DBUG_ASSERT that it is
*not* closed, because this is an actual logic error, and can potentially
lead to all sorts of funny behavior like writing error packets to Innodb
files.

Unlike closesocket(), shutdown(2) is not actually race-condition prone,
and it breaks poll() and read(), and it worked for longer than a decade,
and it does not need any state check in the code.

Let us skip the recently added test main.mysql-interactive if
an instrumented ncurses library is not available.

In InnoDB, let us work around an uninstrumented libnuma, by
declaring that the objects returned by numa_get_mems_allowed()
are initialized.

Starting with clang-16, MemorySanitizer appears to check that
uninitialized values not be passed by value nor returned.
Previously, it was allowed to copy uninitialized data in such cases.

get_foreign_key_info(): Remove a local variable that was passed
uninitialized to a function.

DsMrr_impl: Initialize key_buffer, because DsMrr_impl::dsmrr_init()
is reading it.

test_bind_result_ext1(): MYSQL_TYPE_LONG is 32 bits, hence we must
use a 32-bit type, such as int. sizeof(long) differs between
LP64 and LLP64 targets.

maria_repair_parallel() clears the MY_THREAD_SPECIFIC flag for allocations
since it uses different threads. But it still did one _ma_alloc_buffer()
call as thread-specific which would later assert if another thread needed
to extend the buffer with realloc.

This patch, due to Monty, removes the MY_THREAD_SPECIFIC flag for
allocations that need to realloc in different threads, and preserves
it for those that are allocated/freed in the user's thread.

Also fixes MDEV-33562.
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Remove work-around that disables bulk insert optimization in replication

The root cause of the original problem is now fixed (MDEV-33475). Though the
bulk insert optimization will still be disabled in replication, as it is
only enabled in special circumstances meant for loading a mysqldump.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

An earlier patch for MDEV-13577 fixed the most common instances of this, but
missed one case for tables without primary key when the scan reaches the end
of the table. This patch adds similar code to handle this case, converting
the error to HA_ERR_RECORD_CHANGED when doing optimistic parallel apply.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

This patch makes the server wait for the manager thread to actually start
before proceeding with server startup.

Without this, if thread scheduling is really slow and the server shutdowns
quickly, then it is possible that the manager thread is not yet started when
shutdown_performance_schema() is called. If the manager thread starts at just
the wrong moment and just before the main server reaches exit(), the thread
can try to access no longer available performance schema data. This was seen
as occasional assertion in the main.bootstrap test.

As an additional improvement, make sure to run all pending actions before
exiting the manager thread.
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

it was generating broken spec files

eliminate_item_equal() uses quick_fix_field() for Item objects it creates.
It computes some of their attributes on its own (see update_used_tables()
call) but it doesn't update not_null_tables_cache.

Recompute not_null_tables_cache also. Not computing it is currently
harmless, except for producing MSAN error when some other code
propagates the wrong value of not_null_tables_cache to other item.

cmake bug #14362

- Suppress the "Difficult to find free blocks" warning
globally to avoid many different test case failing.

- Demote the error information in validate_first_page() to note.
So first page can recovered from doublewrite buffer and can throw
error in case the page wasn't found in doublewrite buffer.

to iterate over all status variables one should use
LOCK_all_status_vars not LOCK_status

this fixes sporadic mutex lock inversion in plugins.password_reuse_check:
* acl_cache->lock is taken over complex operations that might increment
  status counters (under LOCK_status).
* acl_cache->lock is needed to get the values of Acl% status variables
  when iterating over status variables

it broke tests on Windows. Use SEARCH_ABORT instead.
also, remove redundant features and simplify

when changing charset from latin1 to utf8, adjust max_length accordingly

Follow-up to fix comiler warings caused by present of
the clause override in declaration of the method Item_param::cleanup

MDEV-33622 Server crashes when the UPDATE statement (which has duplicate key) is run after setting a low thread_stack

This was caused by wrong allocation of variable on stack.
(Was allocating 4K of data instead of 512 bytes).

No test case as the original MDEV test cases is not usable for mtr.

UPDATE statement that is run in PS mode and uses positional parameter
handles columns declared with the clause DEFAULT NULL incorrectly in
case the clause DEFAULT is passed as actual value for the positional
parameter of the prepared statement. Similar issue happens in case
an expression specified in the DEFAULT clause of table's column definition.

The reason for incorrect processing of columns declared as DEFAULT NULL
is that setting of null flag for a field being updated was missed
in implementation of the method Item_param::assign_default().
The reason for incorrect handling of an expression in DEFAULT clause is
also missed saving of a field inside implementation of the method
Item_param::assign_default().

log_free_check(): Assert that the current thread is not holding
lock_sys.latch in any mode.

This fixes up commit 5f2dcd11

signal_hand(): Remove the cmake -DWITH_DBUG_TRACE=ON instrumentation.
It can cause a crash on shutdown when the only other thread is
waiting in wait_for_signal_thread_to_end().

innodb.autoinc_debug: Correct the test case for predictable deadlock.

In the JSON functions, the debug injection for stack overflows is
inaccurate and may cause actual stack overflows. Let us simply
inject stack overflow errors without actually relying on the ability
of check_stack_overrun() to do so.

Reviewed by: Rucha Deodhar

Fix a scenario where `mariabackup --prepare` fails with assertion
`!m_modifications || !recv_no_log_write'  in `mtr_t::commit()`. This
happens if the prepare step of the backup encounters a data directory
which happens to store wsrep xid position in TRX SYS page (this is no
longer the case since 10.3.5). And since MDEV-17458,
`trx_rseg_array_init()` handles this case by copying the xid position
to rollback segments, before clearing the xid from TRX SYS page.
However, this step should be avoided when `trx_rseg_array_init()` is
invoked from mariabackup. The relevant code was surrounded by the
condition `srv_operation == SRV_OPERATION_NORMAL`. An additional check
ensures that we are not trying to copy a xid position which has
already zeroed.

MDEV-33502 Slowdown when running nested statement with many partitions
caused this error as I failed to take into account bigendian architectures.

This patch also introduces bitmap_import() and bitmap_export() to be used
when one wants to store bitmaps in files/logs in a portable way.
Reviewed-by: Kristian Nielsen <knielsen@knielsen-hq.org>