Analysis: Some recursive json functions dont check for stack control
Fix: Add check_stack_overrun(). The last argument is NULL because it is not
used

Passing $opt_parallel as $childs is wrong: child can be killed before
it connects and you will never decrement $childs for this.

Another problem is (and that is the cause of this bug): child can be
killed and never close server socket. This can happen f.ex. after
unmaskable KILL signal. In such case the socket is closed by reaping
the child but that never happens inside reading the socket loop in
run_test_server().

The proper design is the waitless reap of children inside the socket
loop and if there is no more children we finish the socket loop. Since
there is Windows variation where we don't control the children via
waitpid(), all the clients must normally close the socket and only
this can finish the socket loop. For Unix variation we reckon that
case as all children closed the socket but not all yet died and for
that we do final waiting waitpid() (was done before the patch as
well).

To be more complete, we now handle 3 end-of-game scenarios in Unix:

   1. all children closed socket, all children died: everything is
      handled by the socket loop;

   2. all children closed socket, not all yet died: we wait for alive
      children to die after exiting the socket loop;

   3. not all children closed socket, all children died: everything is
      handled by the socket loop.

For Windows end-of-game scenario is only one:

   All children close the socket.

The case for "Unknown process $ret_pid exited" is never known to be
valid. Such state is not documented for waitpid().

66832e3a introduced change that prints core dumps in very detailed
format. That's completely out of user-friendliness but serves as a
measure for debugging hard-reproducible bugs.

The proper way to implement this:

  1. it must be controlled by command-line and environment variable;
  2. detailed traces must be default for buildbots only, for user
     invocations normal stack traces should be printed.

Options for control are: MTR_PRINT_CORE and --print-core that accept
the following values:

  no	         Don't print core
  short	       	 Print stack trace of failed thread
  medium	 Print stack traces of all threads
  detailed       Print all stack traces with debug context
  custom:<code>  Use debugger commands <code> to print stack trace

Default setting is: short (see env_or_default() call in pre_setup())

For environment variable wrong values are silently ignored (falls back
to default setting, see env_or_default()).

Command-line option --print-core (or -C) overrides environment
variable. Its default value is 'short' if not specified explicitly
(same env_or_default() call in pre_setup()). Explicit values are
checked for validity.

--print-method option can specify by which debugger we print
cores. For Windows there is only one choice: cdb. For Unix the values
are: gdb, dbx, lldb, auto. Default value is: auto

In 'auto' we try to use all possible debuggers until success.

setup_boot_args(), setup_client_args(), setup_args() traversing
datastructures on each invocation. Even if performance is not
important to perl script (though it definitely saves some CO2), this
nonetheless provokes some code-reading questions. Reading and
debugging such code is not convenient.

The better way is to prepare all the data in advance in an easily
readable form as well as do the validation step before any further
processing.

Use mtr_report() instead of die() like the other code does.

TODO: do_args() does even more data processing magic. Prepare that
data according the above strategy in advance in pre_setup() if possible.

GetOpt::Long bundling option for convenient one-char verbosity levels:

  -v    General verbosity (file and execute operations)
  -vv   High verbosity (algorithmic considerations)
  -vvv  Debug verbosity (anything else)

Do we still need this Sun Studio hack?

On all Unix platforms, link libexecinfo as system library,
if it contains backtrace_symbols_fd function, and libc does not contain
this function

Also remove cmake/os/OpenBSD.cmake, as after the fix it serves no purpose.

Remove table_count from Query_tables_list (not used, moved to MYSQL_LOCK).

Rename table_count from LEX to avoid mixing it with other counters of tables.

1. For INSERT..SELECT statements: don't include table/view the data
   is inserted into in the list of leaf tables
2. Remove duplicated and dead code related to table_count

Problem:
========
When using sequences, the function
sequence_definition::write(TABLE *table, bool all_fields)
is used to save DML/DDL updates to sequence tables (e.g. nextval,
setval, and alter). Prior to this patch, the value all_fields was
always false when invoked via nextval and setval, which forced the
bitmap to only include changed columns.

Solution:
========
Change all_fields when invoked via nextval and setval to be reliant
on binlog_row_image, such that it is false when binlog_row_image is
MINIMAL, and true otherwise.

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

followup for 57f5c319

This reverts the revert 4f62dfe6
and fixes the hang that was introduced when ctrl_mutex was removed.

The test mariabackup.compress_qpress covers this code, but the
test is skipped if a stand-alone qpress executable is not available.
It is not available in many software repositories, possibly because
the code base has not been updated since 2010.

This was tested with an executable that was compile from the source
code at http://www.quicklz.com/qpress-11-source.zip (after adding
a missing #include <unistd.h> for the definition of isatty()).

Compared to the grandparent commit (before the revert), the changes
are as follows:

comp_thread_ctxt_t::done_cond: A separate condition for completed
compression, signaling that thd->to_len has been updated.

compress_write(): Replace some threads[i] with thd.
Reset thd->to_len = 0 after consuming the compressed data.

compress_worker_thread_func(): After consuming the uncompressed
data, set thd->data_avail = FALSE. After compressing, signal
thd->done_cond.

This reverts commit 863c3eda.

Apparently newer libedit is readline-compatible enough
to be detected as a readline, with USE_NEW_READLINE_INTERFACE defined
and USE_LIBEDIT_INTERFACE not defined.

Let's set the locale unconditionally, independently from the
readline/libedit variant. It's already happening anyway now,
unless one specifies --default-character-set explicitly.

optimize_semi_joins() calls update_sj_state() to update semi-join
optimization state in the JOIN class.

greedy_search() algorithm considers different join prefixes,
and then picks one table to put into the join prefix.
Most of the semi-join optimization state is in the table's entry
in the join->positions[cur_prefix_size].

However, it also needs to call update_sj_state() to update the
semi-join optimization state in the JOIN class.

There is one exception, which is the cause of this bug: when we're
inside optimize_semi_join_nests() and are optimizing a subquery,
optimize_semi_joins() does nothing, it doesn't call update_sj_state().

greedy_search() must not do that either.

Add check for path length if CreateFile fails with ERROR_PATH_NOT_FOUND.

This problem was earlier fixed by the patch for MDEV-21445.

prevent %{VERSION} in the shell command to be expanded by rpmbuild

MDEV-26544 Assertion `part_share->auto_inc_initialized' failed in ha_partition::get_auto_increment on INSERT

The partition storage engine ignores return (error) values of
handler::info(). As a result, a query that should be aborted is
not aborted and then the server violates the assertion.

Item_func_xor and Item_cond are both derived class of Item_bool_func.
Spider converts *Item_func_xor to *Item_cond and then calls the member
function argument_list(), which Item_func_xor does not implement.

The convention used for options in mtr are 2 underscores
Prior to this patch, the "parallel" option used only one underscore

- InnoDB mistakenly identifies the non-unique FTS_DOC_ID index as
FTS_DOC_ID_INDEX while loading the table. dict_load_indexes()
should check whether the index is unique before assigning
fts_doc_id_index

Before version 10, GCC would think that a right shift of an
unsigned char returns int. Let us explicitly cast that back,
to silence a bogus -Wconversion warning.

Also, refactor trx_i_s_common_fill_table() to remove dead code.

Warnings about yynerrs in Bison-generated yyparse() will remain for now.

K&R style function definitions are deprecated in all versions of C
and not supported in C2x.

- Redundant InnoDB table fails to set the flags2 while loading
the table. It leads to "Upgrade index name failure" during alter
operation. InnoDB should set the flags2 to FTS_AUX_HEX_NAME when
fts is being loaded

A cleanup for MDEV-25243 ASAN heap-use-after-free in Item_func_sp::execute_impl upon concurrent view DDL and I_S query with view and function

The test was reported to fail sporadicaly with this diff:

--- mysql-test/main/information_schema_tables.result
+++ mysql-test/main/information_schema_tables.reject
@@ -21,6 +21,8 @@
 disconnect con1;
 connection default;
 DROP VIEW IF EXISTS vv;
+Warnings:
+Note	4092	Unknown VIEW: 'test.vv'

in the "The originally reported non-deterministic test" part.
Disabling warnings around the DROP VIEW statement.

MDEV-21310 AUTO_INCREMENT column throws range error on INSERT in partitioned table | Assertion `part_share->auto_inc_initialized || !can_use_for_auto_inc_init()' failed.

The bug is caused by a similar mechanism as MDEV-21027.

The function, check_insert_or_replace_autoincrement, failed to open
all the partitions on INSERT SELECT statements and it results in the
assertion error.

prepare_inplace_alter_table_dict(): If the table will not be rebuilt,
preserve all of the original ROW_FORMAT, including the compressed
page size flags related to ROW_FORMAT=COMPRESSED.

hex_to_ascii(): Add #if around the definition to avoid
clang -Wunused-function. Avoid GCC 5 -Wconversion with a cast.

buf_page_print(): Dump the buffer page 32 bytes (64 hexadecimal digits)
per line. In this way, the limitation in mtr
("Data too long for column 'line'") will not be triggered.

Also, do not bother decoding the page contents, because everything
is present in the hexadecimal output.

dict_index_find_on_id_low(): Merge to dict_index_get_if_in_cache_low().
The direct call in buf_page_print() was prone to crashing, in case the
table definition was concurrently evicted or dropped from the
data dictionary cache.

Spider supports (or at least allows) INSERT DELAYED but the
documentation does not specify spider as a storage engine that supports
"INSERT DELAYED".
Also, although not mentioned in the documentation, "INSERT DELAYED" is
not intended to be executed inside a transaction, as can be seen from
the list of supported storage engines.
The current implementation allows executing a delayed insert on a
remote transactional table and this breaks the consistency ensured by
the transaction.

We too remove "internal_delayed", one of the Spider table parameters.
Documentation says,

> Whether to transmit existence of delay to remote servers when
> executing an INSERT DELAYED statement on local server.

This table parameter is only used for "INSERT DELAYED".

Reviewed by: Nayuta Yanagisawa

MDEV-22590 SIGSEGV in flush_all_key_blocks when changing key_buffer_size / ASAN: heap-use-after-free in flush_all_key_blocks

Take into account that in preparation of a simple key cache for resizing no disk blocks might be assigned to it.

Reviewer: IgorBabaev <igor@mariadb.com>