Crash when CREATE TABLE t1 AS SELECT char(100 using filename)

CREATE OR REPLACE TABLE t1 AS SELECT char(100 using filename);

InnoDB: Failing assertion: *mbmaxlen < 5

#0  0x00007ffff5b9fa28 in raise () from /lib64/libc.so.6

#1  0x00007ffff5ba162a in abort () from /lib64/libc.so.6

#2  0x0000555555f1e640 in innobase_get_cset_width (cset=17, 

    mbminlen=0x7ffff7f28f20, mbmaxlen=0x7ffff7f28f28)

    at /home/bar/maria-git/server-10.1/storage/xtradb/handler/ha_innodb.cc:2408

#3  0x0000555556177613 in dtype_get_mblen (mtype=12, prtype=1114383, 

    mbminlen=0x7ffff7f28f20, mbmaxlen=0x7ffff7f28f28)

    at /home/bar/maria-git/server-10.1/storage/xtradb/include/data0type.ic:98

#4  0x000055555617971a in dict_mem_fill_column_struct (column=0x7ffecf4aa478, 

    col_pos=0, mtype=12, prtype=1114383, col_len=5)

    at /home/bar/maria-git/server-10.1/storage/xtradb/dict/dict0mem.cc:536

#5  0x0000555556178c9d in dict_mem_table_add_col (table=0x7ffecf480378, 

    heap=0x7ffecf448000, name=0x7ffecf4471e9 "char(100 using filename)", 

    mtype=12, prtype=1114383, len=5)

    at /home/bar/maria-git/server-10.1/storage/xtradb/dict/dict0mem.cc:304

#6  0x0000555555f2fc51 in create_table_def (trx=0x7ffecf42cd78, 

    form=0x7ffff7f29a80, table_name=0x7ffff7f293b0 "test/t1", 

    temp_path=0x7ffff7f295b0 "", remote_path=0x7ffff7f297b0 "", flags=1, 

    flags2=80, mode=FIL_SPACE_ENCRYPTION_DEFAULT, key_id=1)

    at /home/bar/maria-git/server-10.1/storage/xtradb/handler/ha_innodb.cc:11536

#7  0x0000555555f31c4e in ha_innobase::create (this=0x7ffecf489088, 

    name=0x7ffff7f2c2e0 "./test/t1", form=0x7ffff7f29a80, 

    create_info=0x7ffff7f2dcb0)