The error-injection inject_mdev8031 simulates a deadlock kill in a specific
place, by setting killed_for_retry to RETRY_KILL_KILLED directly. If a real
deadlock kill triggers at the same time, it is possible for the thread to
complete its transaction retry and set rgi_slave to NULL before the real
readlock kill can complete in the background. This will cause a segfault
due to null-pointer access.

Fix by changing the error injection to do a real background deadlock kill,
which ensures that the thread will wait for any pending background kills to
complete.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Item::val_str() sets the Item::null_value flag, so call it before checking
the flag, not after.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

This commit addresses the file leakage problem encountered with the mysql_upgrade --check-if-upgrade-is-needed command.

see also 4eca64e3

- InnoDB should write all zeros into a table and its indexes
statistics members when table is unreadable.

followup for ad796aaa

ha_innobase::compare_key_parts(): If a full column index is
being replaced with a column prefix index, return Compare_keys::NotEqual.

Consider this query
SELECT t1.* FROM t1, (SELECT t2.b FROM t2 WHERE NOT EXISTS
(SELECT 1 FROM t3) GROUP BY b) sq where sq.b = t1.a;

If SELECT 1 FROM t3 is expensive, for example t3 has >
thd->variables.expensive_subquery_limit, first evaluation is deferred to
mysql_derived_fill().  There it is noted that, in the above case
 NOT EXISTS (SELECT 1 FROM t3) is constant and false.

This causes the join variable zero_result_cause to be set to
"Impossible WHERE noticed after reading const tables" and the handler
for this join is never "opened" via handler::ha_open.

When mysql_derived_fill() is called for the next group of results, this
unopened handler is not taken into account.

reviewed by Igor Babaev (igor@mariadb.com)

row_ins_clust_index_entry_low(): Invoke btr_set_instant() in the same
mini-transaction that has successfully inserted the metadata record.
In this way, if inserting the metadata record fails before any
undo log record was written for it, the index root page will remain
consistent.

innobase_instant_try(): Remove the btr_set_instant() call.

Reviewed by: Thirunarayanan Balathandayuthapani
Tested by: Matthias Leich

Like all IF NOT EXISTS syntax, a Note should be generated.

The original commit of Seqeuences cleared the IF NOT EXISTS part
in the sql/sql_yacc.yy with lex->create_info.init(). Without this
bit set there was no way it could do anything other than error.

To remedy this removal, the sql_yacc.yy components have been
minimised as they where all set at the beginning of the ALTER.
This way the opt_if_not_exists correctly set the IF_EXISTS flag.

In MDEV-13005 (bb4dd70e) the error code changed, requiring
ER_UNKNOWN_SEQUENCES to be handled in the function
No_such_table_error_handler::handle_condition.

Allow for a CI system to be almost out of space, or having so
little use, that the Total space is the same as available or used.

Thanks Otto Kekäläinen for the bug report and testing.

MDEV-20286 mariabackup fails when innodb_max_dirty_pages_pct contains a fraction (is not an integer)

This is a port of the Percona Server commit 5265f42e290573e9591f8ca28ab66afc051f89a3

which is the same as their bug PXB-1807: xtrabackup does not accept fractional values for
innodb_max_dirty_pages_pct

Problem:

Variable specified as double in MySQL server, but read as long in the
xtrabackup. This causes xtrabackup to fail at startup when the value
contains decimal point.

Fix:

Make xtrabackup to interpret the value as double to be compatible with
server.

ha_innobase::check_if_supported_inplace_alter(): On ALTER_OPTIONS,
if innodb_file_per_table=1 and the table resides in the system tablespace,
require that the table be rebuilt (and moved to an .ibd file).

Reviewed by: Thirunarayanan Balathandayuthapani
Tested by: Matthias Leich

This test was using a sleep of 1 second in an attempt to ensure that the
timestamp that is part of an InnoDB status string would increase.
This not only prolongs the test execution time by 1+1 seconds, but it
also is inaccurate. It is possible that the actual sleep duration is
less than a second.

Let us wait for the creation of the file ib_buffer_pool and then wait
for the buffer pool dump completion. In that way, the test can complete
in a dozen or two milliseconds (1% of the previous duration) and work
more reliably.

Add OPTION_GTID_BEGIN to applying side thread. This is needed to avoid
intermediate commits when CREATE TABLE AS SELECT is applied, causing
one more GTID to be consumed with respect to executing node.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

Return an error if user attempts to use SEQUENCEs in combination with
streaming replication in a Galera cluster. This is currently not
supported.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

row_import_read_meta_data(): Use ER_NOT_SUPPORTED_YET instead of
ER_IO_READ_ERROR to have a matching error message pattern.

AKA rpl.rpl_parallel, binlog_encryption.rpl_parallel fails in
buildbot with timeout in include

A replication parallel worker thread can deadlock with another
connection running SHOW SLAVE STATUS. That is, if the replication
worker thread is in do_gco_wait() and is killed, it will already
hold the LOCK_parallel_entry, and during error reporting, try to
grab the err_lock. SHOW SLAVE STATUS, however, grabs these locks in
reverse order. It will initially grab the err_lock, and then try to
grab LOCK_parallel_entry. This leads to a deadlock when both threads
have grabbed their first lock without the second.

This patch implements the MDEV-31894 proposed fix to optimize the
workers_idle() check to compare the last in-use relay log’s
queued_count==dequeued_count for idleness. This removes the need for
workers_idle() to grab LOCK_parallel_entry, as these values are
atomically updated.

Huge thanks to Kristian Nielsen for diagnosing the problem!

Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>
Andrei Elkin <andrei.elkin@mariadb.com>

Add a test case that demonstrates a working setup as described in MDEV-26632.
This requires --gtid-ignore-duplicates=1 and --gtid-strict-mode=0.

In A->B->C, B filters some (but not all) events from A. C is promoted to
create A->C->B, and the current GTID position in B contains a GTID from A that
is not present in C (due to filtering). Demonstrate that B can still connect
with GTID to C, starting at the "hole" in the binlog stream on C originating
from A.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Omit `state` when selecting processlist to verify which threads are running.
The state changes as threads are running (enter_state()), and this causes
sporadic test failures.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

The test was populating unnecessarily large tables and
restarting the server several times for no real reason.

Let us hope that a smaller version of the test will produce more
stable results. Occasionally, some unencrypted contents in the table t2
was revealed in the old test.

MDEV-32965:  Assertion `thd->active_stmt_arena_to_use()-> is_stmt_prepare_or_first_sp_execute() || thd->active_stmt_arena_to_use()-> is_conventional() || thd->active_stmt_arena_to_use()->state == Query_arena::STMT_SP_QUERY_ARGUMENTS' failed

This patch fixes too strong condition in assert at the method
  Item_func_group_concat::fix_fields
that is true in case of a stored routine and obviously broken
for a prepared statement.

The data type of the column INFORMATION_SCHEMA.GLOBAL_STATUS.VARIABLE_VALUE
is a character string. Therefore, if we want to compare some values as
integers, we must explicitly cast them to integer type, to avoid an
awkward comparison where '10'<'9' because the first digit is smaller.

Also in the startup, lets not "Error" on attempting to install a
mysql.plugin that is already there. We use the 'if_not_exists'
parameter to true to downgrade this to a "Note".

Also corrects: MDEV-32041 "plugin already loaded" should be a Warning, not an Error

Because --delete-master-logs immediately purges logs after flushing,
it is possible the binlog dump thread would still be using the old
log when the purge executes, disallowing the file from being
deleted.

This patch institutes a work-around in the test as follows:
 1) temporarily stop the slave so there is no chance the old binlog
is still being referenced.
 2) set master_use_gtid=Slave_pos so the slave can still appear
up-to-date on the master after the master flushes/purges its logs
(while the slave is offline). Otherwise (i.e. if using binlog
file/pos), the slave would point to a purged log file, and receive
an error immediately upon connecting to the master.

Reviewed By
============
Andrei Elkin <andrei.elkin@mariadb.com>

Remove ORACLE from the (session) sql_mode in connections made with sql
service to run init queries

The connection is new and the global variable value takes effect
rather than the session value from the caller of spider_db_init.

specify algorithm/lock explicitly, don't depend on server settings

This should fix certain CI builds where the spider suite test files
and the main suite test files do not follow the same relative paths
relations as the mariadb source.

$MYSQLD_CMD uses .1 as the defaults-group-suffix, which could cause
the use of the default port (3306) or socket, which will fail in
environment where these defaults are already in use by another server.

Adding an extra --defaults-group-suffix=.1.1 does not help, because
the first flag wins.

So we use $MYSQLD_LAST_CMD instead, which uses the correct suffix.

The extra innodb buffer pool warning is irrelevant to the goal of the
test (running --wsrep-recover with --plug-load-add=ha_spider should
not cause hang)

Fix spider init bugs (MDEV-22979, MDEV-27233, MDEV-28218) while
preventing regression on old ones (MDEV-30370, MDEV-29904)

Two things are changed:

First, Spider initialisation is made fully synchronous, i.e. it no
longer happens in a background thread. Adapted from the original fix
by nayuta for MDEV-27233. This change itself would cause failure when
spider is initialised early, by plugin-load-add, due to dependency on
Aria and udf function creation, which are fixed in the second and
third parts below. Requires SQL Service, thus porting earlier versions
requires MDEV-27595

Second, if spider is initialised before udf_init(), create udf by
inserting into `mysql.func`, otherwise do it by `CREATE FUNCTION` as
usual. This change may be generalised in MDEV-31401.

Also factor out some clean-up queries from deinit_spider.inc for use
of spider init tests.

A minor caveat is that early spider initialisation will fail if the
server is bootstrapped for the first time, due to missing `mysql`
database which needs to be created by the bootstrap script.

Removing procedures that were created and dropped during init.

This also fixes a race condition where mtr test with
plugin-load-add=ha_spider.so causes post test check to fail as it
expects the procedures to still be there.

There are several plugins in ha_spider: spider, spider_alloc_mem,
spider_wrapper_protocols, spider_rewrite etc.

INSTALL PLUGIN foo SONAME ha_spider causes all the other ones to be
installed by the init queries where foo is any of the plugins.

This introduces unnecessary complexiy. For example it reads
mysql.plugins to find all other plugins, causing the hack of moving
spider plugin init to a separate thread.

To install all spider related plugins, install soname ha_spider should
be used instead.

This also fixes spurious rows in mysql.plugin when installing say only
the spider plugin with `plugin-load-add=SPIDER=ha_spider.so`:

select * from mysql.plugin;
name	dl
spider_alloc_mem	ha_spider.so # should not be here
spider_wrapper_protocols	ha_spider.so # should not be here

Adapted from part of the reverted commit
c160a115.

This commit fixes a bug where IST could be rejected in favor of SST
when ssl-mode=VERIFY_CA and when mariabackup is used. It also contains
a test and small code simplifications that will make it easier to find
bugs in the future.

We do this in 10.4 at the same place where in 10.5+ dml_init() is
called which does the same thing, among other things.

When QUICK_GROUP_MIN_MAX_SELECT is initialized or being reset
it stores the prefix of the last group of the index chosen for
retrieving data (last_value). Later, when looping through records
at get_next() method, the server checks whether the retrieved
group is the last, and if so, it finishes processing.

At the same time, it looks like there is no need for that additional
check since method next_prefix() returns HA_ERR_KEY_NOT_FOUND
or HA_ERR_END_OF_FILE when there are no more satisfying records.
If we do not perform the check, we do not need to retrieve and
store last_value either.

This commit removes using of last_value from QUICK_GROUP_MIN_MAX_SELECT.

Reviewer: Sergei Petrunia <sergey@mariadb.com>

Problem:
========
- InnoDB should have two keys on the same column for the self
referencing foreign key relation.

Solution:
=========
- Allow self referential foreign key relation to work with one
key.

The binlog.flashback test tries to run using the stmt and mix
binlog_format combinations (because it includes have_log_bin.inc),
yet are meaningless tests because the server starts with the
--flashback option, forcing binlog_format=row.

This patch optimizes test time by removing the stmt and mix format
combinations from running.

Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>