This mutex can be freed when server shuts down (when thread_count goes down to 0)
, but it is still used inside THD::~THD() when Statement_map is destroyed.

The fix is to call Statement_map::reset() at the point where thread_count
is still positive, and avoid locking LOCK_prepared_stmt_count in THD
destructor.

Closes #983, #984

During database recovery, a transaction with wsrep XID is
recovered from InnoDB in prepared state. However, when the
transaction is looked up with trx_get_trx_by_xid() in
innobase_commit_by_xid(), trx->xid gets cleared in
trx_get_trx_by_xid_low() and commit time serialization history
write does not update the wsrep XID in trx sys header for
that recovered trx. As a result the transaction gets
committed during recovery but the wsrep position does not
get updated appropriately.

As a fix, we preserve trx->xid for Galera over transaction
commit in recovery phase.

Fix authored by: Teemu Ollakka (GaleraCluster) and Marko Mäkelä.

	modified:   mysql-test/suite/galera/disabled.def
	modified:   mysql-test/suite/galera/r/galera_gcache_recover_full_gcache.result
	modified:   mysql-test/suite/galera/r/galera_gcache_recover_manytrx.result
	modified:   mysql-test/suite/galera/t/galera_gcache_recover_full_gcache.test
	modified:   mysql-test/suite/galera/t/galera_gcache_recover_manytrx.test
	modified:   storage/innobase/trx/trx0trx.cc
	modified:   storage/xtradb/trx/trx0trx.cc

MDEV-18129 Backup fails for encrypted tables: mariabackup: Database page corruption detected at page 1

If an encrypted table is created during backup, then
mariabackup --backup could wrongly fail.

This caused a failure of the test mariabackup.huge_lsn once on buildbot.

This is due to the way how InnoDB creates .ibd files. It would first
write a dummy page 0 with no encryption information. Due to this,
xb_fil_cur_open() could wrongly interpret that the table is not encrypted.
Subsequently, page_is_corrupted() would compare the computed page
checksum to the wrong checksum. (There are both "before" and "after"
checksums for encrypted pages.)

To work around this problem, we introduce a Boolean option
--backup-encrypted that is enabled by default. With this option,
Mariabackup will assume that a nonzero key_version implies that the
page is encrypted. We need this option in order to be able to copy
encrypted tables from MariaDB 10.1 or 10.2, because unencrypted pages
that were originally created before MySQL 5.1.48 could contain nonzero
garbage in the fields that were repurposed for encryption.

Later, MDEV-18128 would clean up the way how .ibd files are created,
to remove the need for this option.

page_is_corrupted(): Add missing const qualifiers, and do not check
space->crypt_data unless --skip-backup-encrypted has been specified.

xb_fil_cur_read(): After a failed page read, output a page dump.

This is a regression caused by
commit 8c43f963
that was part of the MDEV-12112 fixes.

page_is_corrupted(): Never interpret page_no=0 as encrypted.

This is a regression after MDEV-13671.

The bug is related to key part prefix lengths wich are stored in SYS_FIELDS.
Storage format is not obvious and was handled incorrectly which led to data
dictionary corruption.

SYS_FIELDS.POS actually contains prefix length too in case if any key part
has prefix length.

innobase_rename_column_try(): fixed prefixes handling

Tests for prefixed indexes added too.

Closes #1063

would not hide more interesting information, like invalid memory accesses.


some "leaks" are expected
- partly this is due to weird options parsing, that runs twice, and
does not free memory after the first run.
- also we do not mind to exit()  whenever it makes sense, without full
cleanup.

MDEV-17470 Orphan temporary files after interrupted ALTER cause InnoDB: Operating system error number 17 and eventual fatal error 71

Orphan #sql* tables may remain after ALTER TABLE
was interrupted by timeout or KILL or client disconnect.

This is a regression caused by MDEV-16515.

Similar to temporary tables (MDEV-16647), we had better ignore the
KILL when dropping the original table in the final part of ALTER TABLE.

Closes #1020

This fixes a regression that was introduced in MySQL 5.6.6
in an error handling code path, in the following change:

commit 024f363d6b5f09b20d1bba411af55be95c7398d3
Author: kevin.lewis@oracle.com <>
Date:   Fri Jun 15 09:01:42 2012 -0500

    Bug #14169459 INNODB; DROP TABLE DOES NOT DELETE THE IBD FILE
    FOR A TEMPORARY TABLE.

Docs grammar fixed

When using a wrong key, all encrypted pages will look corrupted,
and occasionally the test may access other pages than
the clustered index root page.

- Refactor code to isolate page validation in page_is_corrupted() function.

- Introduce --extended-validation parameter(default OFF) for mariabackup
--backup to enable decryption of encrypted uncompressed pages during
backup.

- mariabackup would still always check checksum on encrypted data,
it is needed to detect  partially written pages.

In MDEV-13103, I made a mistake in the error handling of
page_compressed=1 decryption when the default
innodb_compression_algorithm=zlib is used.
Due to this mistake, with certain versions of zlib,
MariaDB would fail to detect a corrupted page.

The problem was uncovered by the following tests:
mariabackup.unencrypted_page_compressed
mariabackup.encrypted_page_compressed

MDEV-17975 Assertion `! is_set()' or `!is_set() || (m_status == DA_OK_BULK && is_bulk_op())' failed upon REVOKE under LOCK TABLE

open_grant_tables() returns -1/0/1, where -1 is an error, while 1 is not.
Don't store it's return value in bool

Relevant if exists flag are added for create database and drop database.

Write a test case that computes valid crc32 checksums for
an encrypted page, but zeroes out the payload area, so
that the checksum after decryption fails.

xb_fil_cur_read(): Validate the page number before trying
any checksum calculation or decrypting or decompression.
Also, skip zero-filled pages. For page_compressed pages,
ensure that the FIL_PAGE_TYPE was changed. Also, reject
FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED if no decryption was attempted.

Create a new constant MAX_DATA_LENGTH_FOR_KEY.
Replace the value of MAX_KEY_LENGTH to also include the LENGTH and NULL BYTES
of a field.

The fix was accidentally only applied to InnoDB, and encryption tests
were not adjusted.

Workaround glibc bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20116
by making unittest threads joinable. It makes code better anyway.

Problem:
=======
Mariabackup seems to fail to verify the pages of compressed tables.
The reason is that both fil_space_verify_crypt_checksum() and
buf_page_is_corrupted() will skip the validation for compressed pages.

Fix:
====
Mariabackup should call fil_page_decompress() for compressed and encrypted
compressed page. After that, call buf_page_is_corrupted() to
check the page corruption.

Starting with commit 6b698715
the encrypted page checksum is only computed with crc32.
Encrypted data pages that were written earlier can contain
other checksums, but new ones will only contain crc32.

Because of this, it does not make sense to implement strict
checks of innodb_checksum_algorithm for other than strict_crc32.

fil_space_verify_crypt_checksum(): Treat strict_innodb as innodb
and strict_none as none. That is, allow a match from any of the
algorithms none, innodb, crc32. (This is how it worked before the
second MDEV-12112 fix.)

Thanks to Thirunarayanan Balathandayuthapani for pointing this out.

This reverts part of c5427172

fil_space_verify_crypt_checksum(): Add a dummy return statement
in case memory is corrupted and innodb_checksum_algorithm has
an invalid value.

The initial fix only covered a part of Mariabackup.
This fix hardens InnoDB and XtraDB in a similar way, in order
to reduce the probability of mistaking a corrupted encrypted page
for a valid unencrypted one.

This is based on work by Thirunarayanan Balathandayuthapani.

fil_space_verify_crypt_checksum(): Assert that key_version!=0.
Let the callers guarantee that. Now that we have this assertion,
we also know that buf_page_is_zeroes() cannot hold.
Also, remove all diagnostic output and related parameters,
and let the relevant callers emit such messages.
Last but not least, validate the post-encryption checksum
according to the innodb_checksum_algorithm (only accepting
one checksum for the strict variants), and no longer
try to validate the page as if it was unencrypted.

buf_page_is_zeroes(): Move to the compilation unit of the only callers,
and declare static.

xb_fil_cur_read(), buf_page_check_corrupt(): Add a condition before
calling fil_space_verify_crypt_checksum(). This is a non-functional
change.

buf_dblwr_process(): Validate the page only as encrypted or unencrypted,
but not both.

Remove provider defaults check from 'galera_defaults' MTR test

Problem is that if you use bundled yassl AES_CTR is not supported. There is a way to detect that but as we really want to keep this test enabled did not add
skip for missing support. Changed method to AES_CBC as there is no need to
use AES_CTR.

Add check that file key management plugin is found.

with InnoDB, joins, AND/OR conditions

The inited parameter handler is not initialised when we do a quick_select after a table scan.

From time to time Galera adds new parameters or changes defaults to
existing ones. Every time this happens galera_defaults test needs a
fix (and a commit) because it insists on checking these defaults.
This is making life hard because any Galera update may require a fix
to MariaDB code even though it is totally unrelated and defeats the
whole idea of a provider living its own life.
This commit removes checking for provider defaults to avoid false
positive failures on MariaDB side.

After validating the post-encryption checksum on an encrypted page,
Mariabackup should decrypt the page and validate the pre-encryption
checksum as well. This should reduce the probability of accepting
invalid pages as valid ones.

This is a backport and refactoring of a patch that was
originally written by Thirunarayanan Balathandayuthapani
for the 10.2 branch.