Crash when count distinct COLUMNSTORE_FILES

[root@mg-cstore ~]# /etc/init.d/columnstore start
Starting MariaDB Columnstore Database Platform
[root@mg-cstore ~]# mysqladmin create mgtest
[root@mg-cstore ~]# mysql -A mgtest
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 5
Server version: 10.1.25-MariaDB Columnstore 1.0.10-1

Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [mgtest]> create table t1 (id int, blah varchar(64)) engine=columnstore;
Query OK, 0 rows affected (0.90 sec)

MariaDB [mgtest]> insert into t1 select seq, null from seq_1_to_1000;
Query OK, 1000 rows affected (1.21 sec)
Records: 1000 Duplicates: 0 Warnings: 0

MariaDB [mgtest]> select count from information_schema.COLUMNSTORE_FILES;
----------

count

----------

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

MariaDB [mgtest]> select count(FILENAME) from information_schema.COLUMNSTORE_FILES;
-----------------

-----------------

-----------------
1 row in set (0.02 sec)

MariaDB [mgtest]> select distinct FILENAME from information_schema.COLUMNSTORE_FILES;
------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------
3 rows in set (0.02 sec)

MariaDB [mgtest]> select count(distinct FILENAME) from information_schema.COLUMNSTORE_FILES;
ERROR 2013 (HY000): Lost connection to MySQL server during query

MariaDB [mgtest]> select count(distinct table_schema) from information_schema.tables;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 3
Current database: mgtest

------------------------------

------------------------------

------------------------------
1 row in set (0.00 sec)

MariaDB [mgtest]> select count(distinct FILENAME) from information_schema.COLUMNSTORE_FILES;
ERROR 2013 (HY000): Lost connection to MySQL server during query

Crash log:

/usr/local/mariadb/columnstore/mysql//bin/mysqld(my_print_stacktrace+0x29)[0xb33e39]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(handle_fatal_signal+0x46a)[0x72179a]
/lib64/libpthread.so.0(+0xf7e0)[0x7f17343f07e0]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN15Field_varstring7cmp_maxEPKhS1_j+0x13)[0x708653]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_downheap+0x120)[0xb33940]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z13merge_buffersP10Sort_paramP11st_io_cacheS2_PhP10st_buffpekS5_S5_i+0x3e3)[0x71ec33]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(Z11merge_indexP10Sort_paramPhP10st_buffpekjP11st_io_cacheS5+0x38)[0x71f0f8]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN6Unique5mergeEP5TABLEPhb+0x27d)[0x662ccd]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(ZN6Unique4walkEP5TABLEPFiPvjS2_ES2+0x221)[0x6631a1]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN19Aggregator_distinct5endupEv+0x120)[0x7b8bc0]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN14Item_sum_count7val_intEv+0x16)[0x7b5c66]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN4Item4sendEP8ProtocolP6String+0x20c)[0x73a1ac]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN8Protocol19send_result_set_rowEP4ListI4ItemE+0x10c)[0x54530c]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN11select_send9send_dataER4ListI4ItemE+0x55)[0x58caa5]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z14end_send_groupP4JOINP13st_join_tableb+0x366)[0x5ea186]
/usr/local/mariadb/columnstore/mysql//bin/mysqld[0x5f4e2b]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN4JOIN10exec_innerEv+0xf83)[0x609cc3]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_ZN4JOIN4execEv+0x4e)[0x60b38e]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x21e)[0x60b61e]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z13handle_selectP3THDP3LEXP13select_resultm+0x276)[0x60c516]
/usr/local/mariadb/columnstore/mysql//bin/mysqld[0x5b44ac]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z21mysql_execute_commandP3THD+0x548b)[0x5bd6eb]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x25e)[0x5bf2fe]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x1e9c)[0x5c3f1c]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z10do_commandP3THD+0xed)[0x5c419d]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(_Z24do_handle_one_connectionP3THD+0x1e4)[0x680a84]
/usr/local/mariadb/columnstore/mysql//bin/mysqld(handle_one_connection+0x40)[0x680b10]
/lib64/libpthread.so.0(+0x7aa1)[0x7f17343e8aa1]
/lib64/libc.so.6(clone+0x6d)[0x7f1732671bcd]