Make st_select_lex::set_explain_type() take into account that JOIN_TABs
it is traversing may be also post-join aggregation JOIN_TABs (which
have pos_in_table_list=NULL, etc).

Add a testcase

Do not run the window function computation step when the select
produces no rows (zero_result_cause!=NULL).
This may cause reads from uninitialized memory.

We still need to run the window function computation step when
the output includes just one row  (for example
SELECT MAX(col), RANK() OVER (...) FROM t1 WHERE 1=0).

This fix also resolves an issue with queries with window functions
producing an output row where should be none, like in
SELECT ROW_NUMBER() FROM t1 WHERE 1=0.

Updated a few test results in the existing tests to reflect this.

during build on 10.2 following files are generated:

  * scripts/galera_new_cluster
  * scripts/galera_recovery
  * support-files/mariadb.service
  * support-files/mariadb.pp

and they are untracked for git. Let's add them to .gitignore

Fixed null pointer dereference in parsing "show full processlist" output
with atoi().

Some  Innodb background thread has NULL in 'Time' column,
thus  backup would crash with when atoi is applied to null pointer.

this failed json.test on fulltest2 builder

because they compile with -Werror=format-security

.files extension is not used by debian packaging, .install is.

Whenever Filesort_tracker has r_loops=0, r_ouptut_rows would be 0, so we should add the value zero
to the member "r_output_rows" explicitly

The warning was introduced by the patch that added
the keyword_sp_verb_clause rule.

Adding keyword_sp_verb_clause into sql_yacc.yy and sql_yacc_ora.yy

This is a partial patch for MDEV-12518 unifying:

- Data types: row_type_body vs field_type_row

Fixing sql_yacc_ora.yy: removing field_type_row adding row_type_body instead

Adjust results for storage_engine tests

Adjust results for tests in non-default suites

Adjust search paths for mariadb_config and make further assignment
conditional

this fixes vcol.upgrade failure

* various cleanups (mostly cosmetic)
* remove useless tests (that were tesing the error condition)
* optimize delete_use_source test (from 6 mins to 50 seconds,
  mainly by removing two huge rollbacks at the end).

single-table deletes only