Memory was leaked when ALTER TABLE is attempted on a table
that contains corrupted indexes.
The memory leak was reported by AddressSanitizer for the test
innodb.innodb_corrupt_bit. The leak was introduced into
MariaDB Server 10.0.26, 10.1.15, 10.2.1 by the following:

commit c081c978
Merge: 1d21b221 a482e76e
Author: Sergei Golubchik <serg@mariadb.org>
Date:   Tue Jun 21 14:11:02 2016 +0200

   Merge branch '5.5' into bb-10.0

- fix the test to avoid false-negatives before MDEV-5114 patch;
- fix the race condition which made the test fail on slow builders

Ability to print lock type added.
Restoring correct lock type for CREATE VIEW added.

MariaDB Server 10.0.28 and 10.1.19 merged code from Percona XtraDB
that introduced support for compressed columns. Much but not all
of this code was disabled by placing #ifdef HAVE_PERCONA_COMPRESSED_COLUMNS
around it.

Among the unused but not disabled code is code to access
some new system tables related to compressed columns.

The creation of these system tables SYS_ZIP_DICT and SYS_ZIP_DICT_COLS
would cause a crash in --innodb-read-only mode when upgrading
from an earlier version to 10.0.28 or 10.1.19.

Let us remove all the dead code related to compressed columns.
Users who already upgraded to 10.0.28 and 10.1.19 will have the two
above mentioned empty tables in their InnoDB system tablespace.
Subsequent versions of MariaDB Server will completely ignore those tables.

The patch fixes two test failures:
- on slow builders, sometimes a connection attempt which should
  fail due to the exceeded number of thread_pool_max_threads
  actually succeeds;
- on even slow builders, MTR sometimes cannot establish the
  initial connection, and check-testcase fails prior to the
  test start

The problem with check-testcase was caused by connect-timeout=2
which was set for all clients in the test config file. On slow
builders it might be not enough.
There is no way to override it for the pre-test check, so it needed
to be substantially increased or removed.

The other problem was caused by a race condition between sleeps
that the test performs in existing connections and the connect
timeout for the connection attempt which was expected to fail.
If sleeps finished before the connect-timeout was exceeded, it
would allow the connection to succeed.

To solve each problem without making the other one worse,
connect-timeout should be configured dynamically during the test.
Due to the nature of the test (all connections must be busy
at the moment when we need to change the timeout, and cannot execute
SET GLOBAL ...), it needs to be done independently from the server.

The solution:
- recognize 'connect_timeout' as a connection option in mysqltest's
  "connect" command;
- remove connect-timeout from the test configuration file;
- use the new connect_timeout option for those connections which
  are expected to fail;
- re-arrange the test flow to allow running a huge SLEEP
  without affecting the test execution time (because it would be
  interrupted after the main test flow is finished).

The test is still subject to false negatives, e.g. if the connection
fails due to timeout rather than due to the exceeded number of
allowed threads, or if the connection on extra port succeeds due
to a race condition and not because the special logic for the extra
port. But those false negatives have always been possible there
on slow builders, they should not be critical because faster builders
should catch such failures if they appear.

Problem:- In replication if slave has extra persistent column then these
column are not computed while applying write-set from master.

Solution:- While applying row events from server, we will generate values
for extra persistent columns.

Test is very slow with valgrind, and pointless because it is
initially about a race condition which is hardly achievable
with valgrind

Essentially revert MDEV-6759, which addressed a double free of memory
by removing the freeing altogether, introducing the memory leaks.
No double free was observed when running the test suite -DWITH_ASAN.

Replace some mem_heap_free(foreign->heap) with dict_foreign_free(foreign)
so that the calls can be located and instrumented more easily when needed.

Role names with trailing whitespaces are truncated in length as of
956e92d9 to fix MDEV-8609. The problem
is that the code that creates role mappings expects the string to be null
terminated.

Add the null terminator to account for that as well. In the future
the rest of the code can be cleaned up to never assume c style strings
but only LEX_STRINGS.

MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))

Different fix. Don't allow Item_func_sp to be evaluated unless
all tables are prelocked.

Extend the test case to make sure Item_func_sp::val_str is called
(the table must have at least one row for that).

Revert "MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))"

This reverts commit 035a5ac6.

Two minor problems and one regression:
1. caching the value in str_result. Other Item methods may use it,
   destroying the cache. See, for example, Item::save_in_field, where
   str_result is moved to use a local buffer (this failed main.grant)
2. Item_func_conv_charset::safe is now set too late, it's initialized
   only in val_str() but checked before that, this failed many tests
   in optimized builds.

to fix 1 - use tmp_result instead of str_result, to fix 2, use
the else branch in the Item_func_conv_charset constructor to set
safe purely from charset properties.

But this introduces a regression, constant strings can no longer be
converted, say, from utf8 to latin1 (because 'safe' will be false).
This fails few tests too. There is no way to fix it without reverting
the commit and converting constants, as before, in the constructor.

MDEV-11162 Assertion `num_records == m_idx_array.size()' failed in Filesort_buffer::alloc_sort_buffer(uint, uint)

Updating result for the group_by_innodb.test

MDEV-11162 Assertion `num_records == m_idx_array.size()' failed in Filesort_buffer::alloc_sort_buffer(uint, uint)

When JOIN::destroy() is called for a JOIN object that has
   - join->tmp_join != NULL
   - also has join->table[0]->sort

then the latter was not cleaned up.
This could cause a memory leak and/or asserts in the subsequent queries.

Fixed by adding a cleanup call.

truncate unused IO_CACHE backing store files in binlog_cache_data
to release the disk space they were occupying

        Rpl_filter::parse_filter_rule() made NULL-safe.

Update mysqldump man page

check for VIEW/DERIVED fields

MDEV-10713: signal 11 error on multi-table update - crash in handler::increment_statistics or in make_select or assertion failure pfs_thread == ((PFS_thread*) pthread_getspecific((THR_PFS)))

Move expression execution out of Item constructor.

Exclude untouched in prepare phese subqueries from the select/unit tree
because they became unreachable by execution.

The problem was that null_value was not set to "false" on a well-formed row.
If an ill-formed row was followed by a well-forned row, null_value remained
"true" in the call of Item::send() for the well-formed row.

Check for readline before checking for curses headers, because
MYSQL_CHECK_READLINE fails when curses is not found, but
CHECK_INCLUDE_FILES simply remembers the fact and continues.  So if
there's no curses, MYSQL_CHECK_READLINE will abort, the user will then
installs curses and continue the build. Thus, CHECK_INCLUDE_HEADERS
will remember that there is no curses, but other checks from
MYSQL_CHECK_READLINE will remember that curses are there. It will
result in inconsistent HAVE_xxx defines.

be consistent and don't include the table name into the error message,
no other CREATE TABLE error does it.

(the crash happened, because thd->lex->query_tables was NULL)

Don't assume that a word of n bytes can match a word of
at most n * charset->mbmaxlen bytes, always go for the worst.

Due to the collation used on the roles_mapping_hash, key comparison
would work in a case-insensitive manner. This is incorrect from the
roles mapping perspective. Make use of a case-sensitive collation for that hash,
the same one used for the acl_roles hash.

The function Item_func_isnull::update_used_tables() must
handle the case when the predicate is over not nullable
column in a special way.
This is actually a bug of MariaDB 5.3/5.5, but it's probably
hard to demonstrate that it can cause problems there.

Test intentionally crashes the server, thus corrupted pages possible.

MDEV-11343 LOAD DATA INFILE fails to load data with an escape character followed by a multi-byte character

Partially backporting MDEV-9874 from 10.2 to 10.0

READ_INFO::read_field() raised the ER_INVALID_CHARACTER_STRING error
when reading an escape character followed by a multi-byte character.

Raising wellformedness errors in READ_INFO::read_field() was wrong,
because the main goal of READ_INFO::read_field() is to *unescape* the
data which was presumably escaped using mysql_real_escape_string(),
using the same character set with the one specified in
"LOAD DATA INFILE ... CHARACTER SET ..." (or assumed by default).

During LOAD DATA, multi-byte characters are not always scanned as a single
entity! In case of escaped data, parts of a multi-byte character can be
scanned on different loop iterations. So the old code erroneously tested
welformedness in the middle of a multi-byte character.

Moreover, the data after unescaping can go into a BLOB field, not a text field.
Wellformedness tests are meaningless in this case.

Ater this patch, wellformedness is only checked later, during
Field::store(str,length,cs) time. The loop that scans bytes only
makes sure to revert the changes made by mysql_real_escape_string().

Note, in some cases users can supply data which did not really go through
mysql_real_escape_string() and was escaped by some other means,
or was not escaped at all. The file reported in this MDEV contains
the string "\ä", which is an example of such improperly escaped data, as
- either there should be two backslashes:   "\\ä"
- or there should be no backslashes at all: "ä"
mysql_real_escape_string() could not generate "\ä".

MDEV-11171 Assertion `m_cpp_buf <= ptr && ptr <= m_cpp_buf + m_buf_length' failed in Lex_input_stream::body_utf8_append(const char*, const char*)