partially revert 76063c2a. Item::clone() is not an all-purpose
Item copying machine, it was specifically created for pushdown
of predicates into derived tables and views and it does not
copy everything. In particular, it does not copy Item_func_regex.

Fix the bug differently by preserving the old constraint name.
But keep setting automatic_name=true to have it regenerated
for cases like ALTER TABLE ... ADD CONSTRAINT.

Cause: no table->update_handler cloned at the moment of
vers_insert_history_row(). update_handler is needed because there
can't be several inited indexes at once in the same handler. First
index is inited by QUICK_RANGE_SELECT::reset(). Then when history row
is inserted check_duplicate_long_entry_key() is done and it requires
another index.

We may end up with an empty leaf page (containing only an ADD COLUMN
metadata record) that is not the root page.

innobase_add_instant_try(): Disable an optimization for a non-canonical
empty table that contains a metadata record somewhere else than in
the root page.

btr_pcur_store_position(): Tolerate a non-canonical empty table.

Ever since commit 947efe17
InnoDB no longer writes binlog position in one place.
It will not at all be written to the TRX_SYS page, and
instead it will be written to the undo log header page that
changes the transaction state.

trx_rseg_mem_restore(): Recover the information from the latest
written page.

MDEV-24463 : galera.galera_sst_mysqldump_with_key MTR failed: 'INSERT failed: 1213: Deadlock found when trying to get lock

We need to complete SST if both new and old start positions are
not same as initial positions. If they are initial positions
just set local uuid and seqno.

I_S tables were materialized too late, an attempt to use table
statistics before the table was created caused a crash.

Let's move table creation up. it only needs read_set to
be calculated properly, this happens in JOIN::optimize_inner(),
after semijoin transformation.

Note that tables are not populated at that point, so most of the
statistics would make no sense anyway. But at least field sizes
will be correct. And it won't crash.

MDEV-24596 : Assertion `state_ == s_exec || state_ == s_quitting' failed in wsrep::client_state::disable_streaming

There were multiple problems here
* wsrep_trx_fragment_size should not be set when wsrep is disabled or provider is not loaded
* wsrep_trx_fragment_unit should not be set when wsrep is disabled or provider is not loaded
* wsrep_debug has no effect if wsrep is disabled or provider is not loaded
* wsrep_start_position should not be set when wsrep is disabled or provider is not loaded any other value than default
* wsrep_start_position should be changed only when we are joiner or initialized
* wsrep_start_position should be allowed to set only a value that exits, thus
we need to add error handling to wsrep_sst_complete

Fix for MDEV-23033 fixes a problem in replication applying of transactions, which contain cascading foreign key delete for a table, which has indexed virtual column.
This fix adds slave_fk_event_map flag for table, to mark when the prelocking is needed for applying of a transaction.
See commit 608b0ee5 for more details.
However, this fix is targeted for async replication only, Rows_log_event::do_apply_event() has condition to rule out galera replication from the fix domain, and use cases suffering from MDEV-23033 and related MDEV-21153 will fail in galera cluster.

The fix in this commit removes the condition to rule out the setting of slave_fk_event_map flag from galera replication, and makes the fix in MDEV-23033 effective for galera replication as well.

However, the above fix has caused regressions for some galera_sr suite tests, which run tests for streaming replication.
This regression can be observed e.g. by: /mtr galera_sr.galera_sr_multirow_rollback  --mysqld=--slave_run_triggers_for_rbr=yes
These galera_sr suite tests were failing in last phase of replication applying, where actual transaction is already applied, and streaming replication related meta data needs to be updated in wsrep system tables.
Opening the wsrep system tables failed for corrupt data in THD::lex:query_tables_list. The fix in this commit uses back query table list for the duration of fragment update operation.

Finally, a mtr test for virtual column support has been added. galera.galera_virtual_column.test has as first test a scenario from MDEV-21153

new fix
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Fix for MDEV-23033 fixes a problem in replication applying of transactions, which contain cascading foreign key delete for a table, which has indexed virtual column.
This fix adds slave_fk_event_map flag for table, to mark when the prelocking is needed for applying of a transaction.
See commit 608b0ee5 for more details.
However, this fix is targeted for async replication only, Rows_log_event::do_apply_event() has condition to rule out galera replication from the fix domain, and use cases suffering from MDEV-23033 and related MDEV-21153 will fail in galera cluster.

The fix in this commit removes the condition to rule out the setting of slave_fk_event_map flag from galera replication, and makes the fix in MDEV-23033 effective for galera replication as well.

Finally, a mtr test for virtual column support has been added. galera.galera_virtual_column.test has as first test a scenario from MDEV-21153
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

MDEV-24577: Fix warnings generated during compilation of plugin/auth_pam/testing/pam_mariadb_mtr.c on FreeBSD

Compiler warnings generated on building MariaDB server for BSD has the same
reason as in case building is performed on MacOS. Both platforms do use
clang as a C/C++ compiler. So, fix the compiler warnings in case the compiler
is clang doesn't matter what kind of building platform do we use for building.

This is a follow-up patch for the following bug reports:
  MDEV-23564: CMAKE failing due to deprecated Apple GSS method
  MDEV-23935: Fix warnings generated during compilation of
              plugin/auth_pam/testing/pam_mariadb_mtr.c on MacOS

MDEV-22285 : Assertion `xid_seqno > wsrep_seqno' failed in trx_rseg_update_wsrep_checkpoint on SET @@global.wsrep_start_position

Actual assertion mentioned on MDEV seems to be already fixed but
setting seqno to -2 will trigger a different assertion

mysqld: /home/jan/mysql/10.4-bugs/wsrep-lib/src/server_state.cpp:702: void wsrep::server_state::sst_received(wsrep::client_service&, int): Assertion `state_ == s_joiner || state_ == s_initialized' failed.

Fixed this by not allowing user to set seqno < -1 (-1 is special
seqno meaning undefined and seqno is initialized to it). MariaDB
releases 10.2 and 10.3 already do not allow to set seqno < -1.

MDEV-23666: Assertion `m_cpp_buf <= ptr && ptr <= m_cpp_buf + m_buf_length' failed in Lex_input_stream::body_utf8_append

On parsing statements for which a starting backtick (`) delimiter doesn't have
a corresponding ending backtick, a current pointer to a position inside a
pre-processed buffer could go beyond the end of the buffer.

This bug report caused by the commit d4967659
  "MDEV-22022 Various mangled SQL statements will crash 10.3 to 10.5 debug builds".

In order to fix the issue both pointers m_ptr and m_cpp_ptr must be
rolled back to previous position in raw input and pre-processed input streams
correspondingly in case end of query reached during parsing.

constellation

Analysis: The decimals is set to NOT_FIXED_DEC for Field_str even if it is
NULL. Unsigned has decimals=0. So Type_std_attributes::decimals is set to 39
(maximum between 0 and 39). This results in incorrect number of decimals
when we have union of unsigned and NULL type.

Fix: Check if the field is created from NULL value. If yes, set decimals to 0
otherwise set it to NOT_FIXED_DEC.

MDEV-18542 : galera_sr.galera-features#56: Test failure: signal 6; mysqltest: Can't connect to local MySQL server

Make test faster

MDEV-21523 : galera.MDEV-16509 MTR failed: timeout after 900 seconds: Can't connect to local MySQL server

Test uses Galera debug sync.

Add wait_condition so that INSERT is replicated before ALTER
and ALTER is replicated before we try to INSERT with new
number of columns.

MDEV-17227 Server crash in TABLE_SHARE::init_from_sql_statement_string upon table discovery with non-existent database

* failed init_from_binary_frm_image can clear share->db_plugin,
  don't use it on the error path
* cleanup the test a bit

force alter_algorithm=DEFAULT in mysql_system_tables_fix.sql,
in case my.cnf sets it to something incompatible

MDEV-20763 Table corruption or Assertion `btr_validate_index(index, 0, false)' failed in row_upd_sec_index_entry with virtual column and EMPTY_STRING_IS_NULL SQL mode

unset empty_string_is_null mode when parsing generated columns in a table,
this mode affects pasring.

the test was doing

--replace_result $con_id con_id
eval SHOW EXPLAIN FOR $con_id;

with the intention of replacing the variable part of the statement
in the result log. But actually replace_result replaces everything
that matches. In particular, when $con_id is 100, the warning

Note   1003    select sleep(100000)

becomes

Note   con_id3    select sleep(con_id000)

MDEV-24524 Assertion `ls->length < 0xFFFFFFFFL && ((ls->length == 0 && !ls->str) || ls->length == strlen(ls->str))' failed in String::append on SELECT from I_S

don't expect return type of a stored function to be valid.
it's read from a table, so can be messed with.
it even can contain \0 bytes in the middle of the type name

MDEV-20502 Queries against spider tables return wrong values for columns following constant declarations.

Add test cases.

MDEV-20502 Queries against spider tables return wrong values for columns following constant declarations.

When executing a query like "select id, 0 as const, val from ...", there are 3 columns(items) in Query->select at handlerton->create_group_by(). After that, MariaDB makes a temporary table with 2 columns. The skipped items are const item, so fixing Spider to skip const items for items at Query->select.

The issue here was we were trying to push an extracted condition for a view into the
underlying table value constructor inside the view.
The fix would be to not push conditions into table value constructors.

		with wrong data type is added

  Inplace alter fails to report error when fts_doc_id column with
wrong data type is added.

prepare_inplace_alter_table_dict(): Should check whether the column
is fts_doc_id. It should be of bigint type, should accept non null
data type and it should be in capital letters.

The fix of MDEV-17556 (commit e25623e7
and commit 61a362c9) has been
omitted due to conflicts and will have to be applied separately later.

- Galera cluster must be in node 1 and 2, and acts as slave for node 3
- Sync point commit_monitor_enter_sync was renamed to
  commit_monitor_master_enter_sync in 4.x
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>