MDEV-30154: Assertion `strcasecmp(rolename, public_name.str) || acl_public == role' failed in acl_update_role on GRANT ... TO PUBLIC

Reset of acl_public was made too early (before saving it to restore in case
of error).

--header applied an ORDER BY to ensure that the header
row was the first row in the output given UNION ALL
doesn't in the standard enforce the order.

We change that now only add the ORDER BY if --order-by-primary
is used.

An assumption that if UNION ALL change to a different behaviour
the resulting mysqldump-header test may also change.

commit_try_rebuild(): Only invoke trx_t::drop_table_statistics()
if both InnoDB statistics tables are accessible (and exclusively
locked by the current transaction). This avoids a crash due to
ut_a(sym_node->table != NULL) in pars_retrieve_table_def().

The crash was repeated on a partial copy of a MariaDB 10.3 data
directory that lacked the *.ibd files for the statistics tables.

fil_space_t::flush<false>(): If the CLOSING flag is set,
the file may already have been closed, resulting in EBADF
being returned by fdatasync(). In any case, the
thread that had set the flag should take care of invoking
os_file_flush_func().

The crash occurred during the execution of FLUSH TABLES...FOR EXPORT.

Tested by: Matthias Leich

Also refer to the service file for startup.

Also include the ftp.mariadb.org script rather than old name.

This turns out to be a too expensive call to use for every freed page,
especially under global buffer pool mutex protection.

Also, the usefulness of proactive shrinking of the buffer pool on Windows
this is seems questionable - there is no OOM killer, and the OS will
shrink working sets itself.

This fixes up 25b91c3f

galera_sr.GCF-1060 'innodb'              w2 [ fail ]  timeout after 900 seconds

galera_3nodes.galera_ssl_reload At line 50: mysql_shutdown failed
galera_3nodes.galera_ssl_reload : MDEV-30172 At line 50: mysql_shutdown failed
galera_3nodes.GCF-354 : mysqltest: At line 39: query 'DROP TABLE test.t1' failed: 1047: WSREP has not yet prepared node for application use
galera_3nodes.GCF-354 : mysqltest: At line 30: query 'INSERT INTO test.t1 values (1)' failed: 1180: Got error 6 "No such device or address"

galera_wan : [ERROR] WSREP: /home/buildbot/buildbot/build/gcs/src/gcs_state_msg.cpp:gcs_state_msg_get_quorum():947: Failed to establish quorum.