Revert part of 64094e12 because mysqld_safe isn't just used for
Debian. As such references to specific packaging files like
/etc/mysql/debian.cnf shouldn't have passed a review.

There's also no history of why 64094e12 was needed based on
the history of debian/patches/38_scripts__mysqld_safe.sh__signals.dpatch

Other distos have survived without mysqld_safe handling signals.

c902d5a4 changed this to bash.
This isn't approprate as mysqld_safe is used by FreeBSD where
there is no bash by default.

The original reason to use bash seems related to MDEV-3279 which
was a dash bug fixed in 2009 - https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=3800d4934391b144fd261a7957aea72ced7d47ea

Working around 9 year old fixed bugs shouldn't be done here.

The problem described in the bug report happened because the code
did not test check_cols(1) after fix_fields() in a few places.

Additionally, fix_fields() could be called multiple times for SP variables,
because they are all fixed at a early stage in append_for_log().

Solution:
1. Adding a few helper methods
   - fix_fields_if_needed()
   - fix_fields_if_needed_for_scalar()
   - fix_fields_if_needed_for_bool()
   - fix_fields_if_needed_for_order_by()
  and using it in many cases instead of fix_fields() where
  the "fixed" status is not definitely known to be "false".

2. Adding DBUG_ASSERT(!fixed) into Item_splocal*::fix_fields()
   to catch double execution.

3. Adding tests.

As a good side effect, the patch removes a lot of duplicate code (~60 lines):

   if (!item->fixed &&
       item->fix_fields(..) &&
       item->check_cols(1))
     return true;

After a failed ADD INDEX, dict_index_remove_from_cache_low()
could iterate the index fields and dereference a freed virtual
column object when trying to remove the index from the v_indexes
of the virtual column.

This regression was caused by a merge of
MDEV-16119 InnoDB lock->index refers to a freed object.

ha_innobase_inplace_ctx::clear_added_indexes(): Detach the
indexes of uncommitted indexes from virtual columns, so that
the iteration in dict_index_remove_from_cache_low() can be avoided.

ha_innobase::prepare_inplace_alter_table(): Ignore uncommitted
corrupted indexes when rejecting ALTER TABLE. (This minor bug was
revealed by the extension of the test case.)

dict_index_t::detach_columns(): Detach an index from virtual columns.
Invoked by both dict_index_remove_from_cache_low() and
ha_innobase_inplace_ctx::clear_added_indexes().

dict_col_t::detach(const dict_index_t& index): Detach an index from
a column.

dict_col_t::is_virtual(): Replaces dict_col_is_virtual().

dict_index_t::has_virtual(): Replaces dict_index_has_virtual().

log_crypt_101_read_block(): Mimic MariaDB 10.1, and use the first
encryption key if the key for the checkpoint cannot be found.
Redo log encryption key rotation was ultimately disabled
in MDEV-9422 (MariaDB 10.1.13) due to design issues. So, from
MariaDB 10.1.13 onwards only one log encryption key should matter.

recv_log_format_0_recover(): Add the parameter 'bool crypt'.
Indicate when the log cannot be decrypted for upgrade, instead of
making a possibly false claim that the log requires crash recovery.

init_crypt_key(): Remove extra space from a message.

just before they're sent to the client. Because mysql->host
value is known only after the connection is established,
and it's needed for the "_sever_host" attribute.

This fixes ASAN use-after-free warning in rpl tests

followup for ee8dfc68

MDEV-15991 Server crashes in setup_on_expr upon calling SP or function executing DML on versioned tables

Do not try to set versioning conditions on every SP call. It may work
incorrectly, but it's a general bug described in MDEV-774.
This patch makes system versioning stuff consistent with other code and
also fixes a use-after-free bug.

Closes #756

* Always-false vers_select_conds_t::from_query
* Debug helpers

Closes #684

This partially reverts commit dc0a7660.

Make mariadb crc32 lib platform independent

It looks strange that someone can make use of 2 crc libraries
(Power64 or AArch64) at the same time.

The patch sets macros 'CRC32_LIBRARY' to make platform independence as an optional crc32 library.

Change-Id: I68bbf73cafb6a12f7fb105ad57d117b114a8c4af
Signed-off-by: Yuqi Gu <yuqi.gu@arm.com>

Just spacing out the links on separate linkes, they were running together
in a block of text and could be a little hard for some people to
differentiate where one begins and the next ends. Seems silly, but just
trying to help in the formatting a bit.

This bug caused crashes for queries with unreferenced non-recursive
CTEs specified by unions.It happened because the function
st_select_lex_unit::prepare() tried to use the value of the field 'derived'
that could not be set for unferenced CTEs as there was no derived
table associated with an unreferenced CTE.

INNOBASE_DEFAULTS: Replace ALTER_ADD_COLUMN with the more appropriate
ALTER_ADD_STORED_BASE_COLUMN. This clean-up causes no change of
behaviour, because ALGORITHM=INPLACE would be refused for
ALTER_ADD_STORED_GENERATED_COLUMN, and default values are not computed
nor substituted for ALTER_ADD_VIRTUAL_COLUMN.

Disable /permissive- flag, so MFC  is found, and upgrade_wizard is built.

MFC code is not standard C++, so it doesn not play well with /permissive-

commit 2dbeebdb accidentally changed
ALTER_COLUMN_OPTION and ALTER_COLUMN_STORAGE_TYPE to be separate flags.
InnoDB and Mroonga are only checking for the latter;
the example storage engine is checking for the former only.

The impact of this bug should be incorrect operation of Mroonga when
the column options GROONGA_TYPE, FLAGS are changed.

InnoDB does not define any column options, only table options,
so the flag ALTER_COLUMN_OPTION should never have been set.

Also, remove the unused flag ALTER_DROP_HISTORICAL.

Fix type mismatches in the unit test mdev10259().

btr_search_info_get_ref_count(): Do not return early if !table->space.
We can simply access table->space_id even after the tablespace has
been discarded.

btr_get_search_latch(): Relax a debug assertion to allow
!index->table->space.

Include all the Makefiles that define variables that can be useful
within debian/rules. This includes buildflags.mk as well.

Use the standard variable names and don't define our own.

For details see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=852728

For details see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=865737

Also fixes MDEV-14727, MDEV-14491
InnoDB: Error: Waited for 5 secs for hash index ref_count (1) to drop to 0
by replacing the flawed wait logic in dict_index_remove_from_cache_low().

On DISCARD TABLESPACE, there is no need to drop the adaptive hash index.
We must drop it on IMPORT TABLESPACE, and eventually on DROP TABLE or
DROP INDEX. As long as the dict_index_t object remains in the cache
and the table remains inaccessible, the adaptive hash index entries
to orphaned pages would not do any harm. They would be dropped when
buffer pool pages are reused for something else.

btr_search_drop_page_hash_when_freed(), buf_LRU_drop_page_hash_batch():
Remove the parameter zip_size, and pass 0 to buf_page_get_gen().

buf_page_get_gen(): Ignore zip_size if mode==BUF_PEEK_IF_IN_POOL.

buf_LRU_drop_page_hash_for_tablespace(): Drop the adaptive hash index
even if the tablespace is inaccessible.

buf_LRU_drop_page_hash_for_tablespace(): New global function, to drop
the adaptive hash index.

buf_LRU_flush_or_remove_pages(), fil_delete_tablespace():
Remove the parameter drop_ahi.

dict_index_remove_from_cache_low(): Actively drop the adaptive hash index
if entries exist. This should prevent InnoDB hangs on DROP TABLE or
DROP INDEX.

row_import_for_mysql(): Drop any adaptive hash index entries for the table.

row_drop_table_for_mysql(): Drop any adaptive hash index for the table,
except if the table resides in the system tablespace. (DISCARD TABLESPACE
does not apply to the system tablespace, and we do no want to drop the
adaptive hash index for other tables than the one that is being dropped.)

row_truncate_table_for_mysql(): Drop any adaptive hash index entries for
the table, except if the table resides in the system tablespace.

When the transaction isolation level is SERIALIZABLE, or when
a locking read is performed in the REPEATABLE READ isolation level,
InnoDB must lock delete-marked records in order to prevent another
transaction from inserting something.

However, at READ UNCOMMITTED or READ COMMITTED isolation level or
when the parameter innodb_locks_unsafe_for_binlog is set, the
repeatability of the reads does not matter, and there is no need
to lock any records.

row_search_for_mysql(): Skip locks on delete-marked committed records
upfront, instead of invoking row_unlock_for_mysql() afterwards.
The unlocking never worked for secondary index records.

MDEV-13834 10.2 wrongly recognizes 10.1.10 innodb_encrypt_log=ON data as after-crash and refuses to start

infos[]: Allocate enough entries to accommodate all keys from both
checkpoint pages.

infos_used: The size of infos[].

get_crypt_info(): Merge to the only caller, log_crypt_101_read_block().

log_crypt_101_read_block(): Do not validate the log block checksum,
because it will not be valid when upgrading from MariaDB 10.1.10.
Instead, check that the encryption key exists.

log_crypt_101_read_checkpoint(): Append to infos[] instead of overwriting.

Use a compatible xargs command-line arguments.

All packages in group 'essential' are by default installed on all
Debian and Ubuntu systems, and there is no need to mark them as
dependencies for any binary.

(This change matches how debian/control is in downstream Debian.org)

(This change matches how debian/rules is in downstream Debian.org)

We have carried along this patch as a patch inside our sources
since 2012 (commit cfd4fcb0).

The validity of this has thus been vetted in production for years
and the review done now did not find otherwise.

A race in dash causes mysqld_safe to occasionally loop infinitely.
Fix by using bash instead.

https://bugs.launchpad.net/ubuntu/+source/mysql-dfsg-5.0/+bug/675185

As this is the last patch, we can also clean away usage of dpatch.

We have carried along this patch as a patch inside our sources
since 2012 (commit cfd4fcb0).

This same patch has been used also in MySQL packaging at Oracle
and in downstream Debian.org packages for both MySQL and MariaDB.

The validity of this has thus been vetted in production for years
and the review done now did not find otherwise.

Code contributed to Oracle with
http://forge.mysql.com/wiki/Sun_Contributor_Agreement

Reported as http://bugs.mysql.com/bug.php?id=31361