* This makes the table getters and setters idempotent.
  Slight performance decrease: When running on a Tabular user table, we
  set fields (in memory) that have previously been set.

The code was "hiding' a get - set - get sequence of calls for
User_table_json. This is now more apparent. The first "get" is required
to obtain the "adjusted" privileges based on which MariaDB version wrote
the privileges in global_priv.

The second get is required for User_table_tabular, to map column
privileges to actual newly introduced privileges
For example SUPER column marked as YES maps to
GLOBAL_SUPER_ADDED_SINCE_USER_TABLE_ACLS, which is a set of more
granular privileges.

Privilege checking functions should be grouped in sql_acl.

Creating an object copy would imply that the destructor would delete the
underlying same HASH object for both instances. That would lead to a
double free and thus a crash.

During insert, the value isn't mutated so we can accept a const ptr.

Delete the copy constructor for Dynamic_array and use proper move
semantics for acl_dbs.

The String isn't mutated so it can be marked as const.

* conflicting types for grn_object_columns
Make sure functions have the same signature in c and header files.

log_t::write_checkpoint(), log_t::resize_start(): Invoke buf_flush_ahead()
with buf_pool.get_oldest_modification(0)+1 so that another checkpoint will
be invoked, to complete the log resizing.

Tested by: Oleg Smirnov (on Microsoft Windows, where this hung most often)

ha_innobase::delete_table(): Also on DROP SEQUENCE, do try to drop any
persistent statistics. They should really not be created for
SEQUENCE objects (which internally are 1-row no-rollback tables),
but that is how happened to always work.

i_s_innodb_buffer_page_get_info(): Correct a condition.
After crash recovery, there may be some buffer pool pages in FREED state,
containing garbage (invalid data page contents). Let us ignore such pages
in the INFORMATION_SCHEMA output.

The test innodb.innodb_defragment_fill_factor will be removed, because
the queries that it is invoking on information_schema.innodb_buffer_page
would start to fail. The defragmentation feature was removed in
commit 7ca89af6 in MariaDB Server 11.1.

Tested by: Matthias Leich

btr_search_hash_table_validate(), btr_search_validate(): Add the
parameter THD for checking if the statement has been killed.
Any non-QUICK CHECK TABLE will validate the entire adaptive hash index
for all InnoDB tables, which may be extremely slow when running
multiple concurrent CHECK TABLE.

During the upgrade procedure on Windows mysqld.exe is started with
the named pipe connection protocol. mysqladmin.exe then pings the
server to check if is up and running. Command line looks like:
   mysqladmin.exe --protocol=pipe --socket=mysql_upgrade_service_xxx ping
But the "socket" parameter resets the "protocol" which was previously
initialized with the "pipe" value, setting it to "socket".
As a result, connection cannot be established and the upgrade
procedure fails.
"socket" in Windows is used to pass the name of the pipe so resetting
the protocol is not valid in this case.

This commit fixes resetting of the "protocol" parameter with "socket"
parameter in the case when protocol has been previously initialized
to "pipe" value

During the upgrade procedure on Windows mysqld.exe is started with
the named pipe connection protocol. mysqladmin.exe then pings the
server to check if is up and running. Command line looks like:
   mysqladmin.exe --protocol=pipe --socket=mysql_upgrade_service_xxx ping
But the "socket" parameter resets the "protocol" which was previously
initialized with the "pipe" value, setting it to "socket".
As a result, connection cannot be established and the upgrade
procedure fails.
"socket" in Windows is used to pass the name of the pipe so resetting
the protocol is not valid in this case.

This commit fixes resetting of the "protocol" parameter with "socket"
parameter in the case when protocol has been previously initialized
to "pipe" value

Set the histogram_type to be DOUBLE_PREC_HB as
it originally was.

The fix is in replacing the waiting for the whole purge finishing
with the the waiting for only delete-marked records purging finishing.

Reviewed by: Marko Mäkelä

- InnoDB bulk insert operation aborts the server for redundant
table. InnoDB miscalculates the record size in temporary file
for the redundant table. CHAR in redundant row format table
always fixed length, but in temporary file, it is variable-length
for variable-length character sets.

The issue is caused by MDEV-30400 fix.

There are two cursors in btr_estimate_n_rows_in_range() - p1 and p2, but
both share the same mtr. Each cursor contains mtr savepoint for the
previously fetched block to release it then the current block is
fetched.

Before MDEV-30400 the block was released with
mtr_t::release_block_at_savepoint(), it just unfixed a block and
released its page patch. In MDEV-30400 it was replaced with
mtr_t::rollback_to_savepoint(), which does the same as the former
mtr_t::release_block_at_savepoint(ulint begin, ulint end) but also
erases the corresponding slots from mtr memo, what invalidates any
stored mtr's memo savepoints, greater or equal to "begin".

The idea of the fix is to get rid of savepoints at all in
btr_estimate_n_rows_in_range() and
btr_estimate_n_rows_in_range_on_level(). As
mtr_t::rollback_to_savepoint() erases elements from mtr_t::m_memo, we
know what element of mtr_t::m_memo can be deleted on the certain case,
so there is no need to store savepoints.

See also the following slides for details:
https://docs.google.com/presentation/d/1RFYBo7EUhM22ab3GOYctv3j_3yC0vHtBY9auObZec8U

Reviewed by: Marko Mäkelä

recv_sys_t::parse(): For undo tablespace truncation mini-transactions,
remember the start_lsn instead of the end LSN. This is what we expect
after commit 461402a5 (MDEV-30479).

mysql.proc. The table is probably corrupted"

Analysis: When mysql_upgrade runs statements for upgrade, characterset is
converted to utf8mb4 because server starts with old_mode that interprets
utf8 to utf8mb4, but mysql.proc table has "utf8mb3" as hardcoded, so
it crashes with corrupted table.

Fix: Changed Table_check_intact::check() definition to allow both
utf8mb3 and utf8mb4 by checking prefix and changing the upgrade scripts
to explicitly use utf8mb3

MDEV-29253 Detect incompatible MySQL partition scheme and either convert
them or report to user and in error log.

This task is about converting in place MySQL 5.6 and 5.7 partition tables
to MariaDB as part of mariadb-upgrade.

- Update TABLE_SHARE::init_from_binary_frm_image() to be able to read
  MySQL frm files with partitions.
- Create .par file, if it do not exists, on open of partitioned table.

Executing mariadb-upgrade will create all the missing .par files.
The MySQL .frm file will be changed to MariaDB format after next
ALTER TABLE.

Other changes:
- If we are using stored mysql_version to distingush between MySQL and
  MariaDB  .frm file information, do not upgrade mysql_version in the
  .frm file as part of CHECK TABLE .. FOR UPGRADE as this would cause
  problems next time we parse the .frm file.

- Moved view checks after privilege tables are fixed. This is to avoid
  warnings about wrongly defined mysql.proc when checking views.
- Don't use stat tables before they have been fixed.
- Don't run mysql_fix_view() if 'FOR MYSQL' is used if the view is
  already a MariaDB view.
- Added 'FOR UPGRADE' as an option for 'REPAIR VIEW' to be able to
  detect if the REPAIR command comes from mariadb_upgrade. In this
  case we get a warning, instead of an error, if a definer of a view
  does not exists.

In this case, one would end up calling my_error(ER_BAD_DB_ERROR, ...)
with a null ptr for DB, which caused a NULL ptr dereference.