INSERT INTO <TABLE> SELECT ... does not work (even for insert into table select * from table)

MariaDB [test]> insert into fact select * from fact;
Query OK, 360 rows affected, 296 warnings (3.43 sec)
Records: 360 Duplicates: 0 Warnings: 296

in fact, it fails completely in STRICT mode:

MariaDB [test]> set sql_mode=strict_all_tables;
Query OK, 0 rows affected (0.00 sec)

MariaDB [test]> select count from fact;
----------

count

----------

----------
1 row in set (0.01 sec)

MariaDB [test]> insert into fact select * from fact;
ERROR 9999 (HY000): Values saturated% of stage done

Columnstore isn't actually doing the INSERT .. SELECT properly.
See:
git clone https://github.com/greenlion/columnstore_tests.git
sudo yum install php-cli php-mysql php-pear
cd columnstore_tests
git checkout insert_select
php run_tests --record # record results against MyISAM table
php run_tests --debug | tee out.txt #compare to CS table
Examine out.txt and you will find that the operation returns wrong results for CS compared to MyISAM in 197 of 1229 tests.