Some innobase/xtrabackup changes around  from 10.1 are null merged
, in partucular using os_set_file_size to extend tablespaces in server
or mariabackup.
They require non-trivial amount of additional  work in 10.2, due to
innobase differences between 10.1 and 10.2

        Space for the next operation wasn't reserved in
        Item_func_spatial_relate::val_str()

Remove .delta file after it was successfully applied

This incorrect alignment can later lead to memcpy over buffer boundaries,
and to a crash.

Fix incremental prepare to change file size while applying
delta file, if delta file contains page 0 with the new size.

Change fil_space_extend_must_retry() to use this function.

In MariaDB Server 10.1, this problem manifests itself only as
a debug assertion failure in page_zip_decompress() when an insert
requires a page to be decompressed.

In MariaDB 10.1, the encryption of InnoDB data files repurposes the
previously unused field FILE_FLUSH_LSN for an encryption key version.
This field was only used in the first page of each file of the system
tablespace. For ROW_FORMAT=COMPRESSED tables, the field was always
written as 0 until encryption was implemented.

There is no bug in the encryption, because the buffer pool blocks will
not be written to files. Instead, copies of the blocks will be encrypted.
In these encrypted copies, the key version field will be updated before
the buffer is written to the file. The field in the buffer pool is
basically garbage that does not really matter.

Already in MariaDB 10.0, the memset() calls to reset this unused field
in buf_flush_update_zip_checksum() and buf_flush_write_block_low()
are unnecessary, because fsp_init_file_page_low() would guarantee that
the field is always 0 in the buffer pool (unless 10.1 encryption is
used).

Removing the unnecessary memset() calls makes page_zip_decompress()
happy and will prevent a SPATIAL INDEX corruption bug in
MariaDB Server 10.2. In MySQL 5.7.5, as part of WL#6968, the same
field was repurposed for an R-tree split sequence number (SSN) and
these memset() were removed. (Because of the repurposing, MariaDB
encryption is not available for tables that contain SPATIAL INDEX.)

Fixing the asymmetry in the array field_types_merge_rules[][]
which caused data loss when mixing FLOAT + BIGINT in UNIONs
or hybrid functions:

1. FLOAT  + INT    = DOUBLE
2. FLOAT  + BIGINT = FLOAT
3. INT    + FLOAT  = DOUBLE
4. BIGINT + FLOAT  = DOUBLE

Now FLOAT + BIGINT (as in #2) also produces DOUBLE, like the cases #1,#3,#4 do.

TRUE.

        Let's make empty brackets to be the syntax error in the JSON
        paths.

using JSON_UNQUOTE as an argument.

        The coercibility and repertoire should be set properly for the
        JSON_UNQUOTE.

        Check validity to the end of the JSON in the json_length
        function.

        The 'value' state should be saved to be compared against the
        next array item.

not just for creating new files.

Use os_file_set_size() in fil_space_extend_must_retry()

MDEV-13953 mariadb-10.2.9/storage/innobase/row/row0import.cc:3602: possible cut'n'paste error ?
MDEV-13955 mariadb-10.2.9/sql/log_event.cc:7671: possible wrong operator ?

functions.

There is no reason to export IO this functionality from server, if it can
be easily implemented with CRT.

Note: for the sake of compatibility, we do not use _open() on Windows,
but open file with CreateFile, with FILE_SHARE_DELETE flag,
so it can be renamed or deleted when open. Also atomic append flag is used.

Fixes some warnings.

fil_space_extend_must_retry(): If the table is being truncated,
do not call fil_flush_low(). The operation is covered by the
truncate log. File extension during TRUNCATE only occurs
if there are many indexes on the table. With smaller innodb_page_size,
the file extension occurs already with fewer indexes on the table.

This is error-prone and causes warnings on Windows

wrep_sst_common and wsrep_sst_xtrabackup-v2 bugfixes to read sst parameters from configs

The function dict_disable_redo_if_temporary() was supposed to
disable redo logging for temporary tables. It was invoked
unnecessarily for two read-only operations:
row_undo_search_clust_to_pcur() and
dict_stats_update_transient_for_index().

When a table is not temporary and not in the system tablespace,
the tablespace should be flagged for MLOG_FILE_NAME logging.
We do not need this overhead for temporary tables. Therefore,
either mtr_t::set_log_mode() or mtr_t::set_named_space() should
be invoked.

dict_table_t::is_temporary(): Determine if a table is temporary.

dict_table_is_temporary(): Redefined as a macro wrapper for
dict_table_t::is_temporary().

dict_disable_redo_if_temporary(): Remove.

The method handlerton::replace_native_transaction_in_thd was added
into MySQL 5.7 in WL#6860, Binlogging XA-prepared transaction.
In MariaDB we do not have that change yet.

The field dict_table_t::big_rows was only used for determining if
the adaptive hash index should be used when the internal InnoDB SQL
parser is used. That parser is only used for modifying the InnoDB
data dictionary, updating persistent tables, and for fulltext indexes.

This is regression caused by patch of mdev-10767.

1st problem :- mktmp is invoked without '-t' or specifing tmp directory.
2nd problem :- Since eval_log_error redirect stderr to stdout  '2>' will
return nothing. and hence $wr_logfile will be empty.

Patch Credit:- Andrii Nikitin

btr_cur_pessimistic_delete(): Discard a possible record lock also in
the case when the record was the only one in the page. Failure to
do this would corrupt the record lock data structures in a partial
rollback (ROLLBACK TO SAVEPOINT or rolling back a row operation due
to some error, such as a duplicate key in a unique secondary index).

MySQL 5.7 allows the creation of InnoDB tables in a user-created
tablespace, but MariaDB does not. Remove the remaining references.

This is a non-functional change.

wrep_sst_common: Setting "-c ''" for my_print_defaults just takes no values from config at all. $MY_PRINT_DEFAULTS is already set at the top of the script to have --defaults-file and --defaults-extra-file. If WSREP_SST_OPT_CONF if set to "--defaults-file=/etc/my.cnf --defaults-extra-file=/etc/my.extra.cnf", then "my_print_defaults -c "" --defaults-file=/etc/my.cnf" succeeds, but if WSREP_SST_OPT_CONF is empty - no default values are taken at all.
wsrep_sst_xtrabackup-v2: innobackupex does not support --defaults-extra-file, so ${WSREP_SST_OPT_CONF} cannot be used as an argument, it has been changed to ${WSREP_SST_OPT_DEFAULT}. Removed --defaults-file= from INNOMOVE line, because WSREP_SST_OPT_CONF already includes it (INNOBACKUP was fine, INNOMOVE - not).

warning