SIGFPE in cost_group_min_max on EXPLAIN

SET use_stat_tables='preferably';

CREATE TABLE t (a INT,b INT,KEY i1 (a),KEY i2 (b)) ENGINE=MRG_MyISAM;

ANALYZE LOCAL TABLE t;

EXPLAIN SELECT DISTINCT a FROM t;

Core was generated by `/test/MD180223-mariadb-11.0.1-linux-x86_64-dbg/bin/mariadbd --no-defaults --cor'.

Program terminated with signal SIGFPE, Arithmetic exception.

#0  0x0000559999752099 in cost_group_min_max (out_records=<synthetic pointer>, 

    read_cost=<synthetic pointer>, have_max=false, have_min=false, 

    quick_prefix_records=0, index_tree=0x0, range_tree=0x0, group_key_parts=1, 

    used_key_parts=1, index_info=0x14d104024a50, table=0x14d10401ea88)

    at /test/11.0_dbg/sql/opt_range.cc:15275

15275	               INDEX_BLOCK_FILL_FACTOR_MUL) / file->stats.block_size + 1;

[Current thread is 1 (Thread 0x14d158966640 (LWP 2308294))]

(gdb) bt

#0  0x0000559999752099 in cost_group_min_max (out_records=<synthetic pointer>, read_cost=<synthetic pointer>, have_max=false, have_min=false, quick_prefix_records=0, index_tree=0x0, range_tree=0x0, group_key_parts=1, used_key_parts=1, index_info=0x14d104024a50, table=0x14d10401ea88) at /test/11.0_dbg/sql/opt_range.cc:15275

#1  get_best_group_min_max (param=param@entry=0x14d158963c40, tree=tree@entry=0x0, read_time=<optimized out>) at /test/11.0_dbg/sql/opt_range.cc:14540

#2  0x000055999975484f in SQL_SELECT::test_quick_select (this=this@entry=0x14d1040164e0, thd=thd@entry=0x14d104000d58, keys_to_use=<optimized out>, prev_tables=prev_tables@entry=0, limit=limit@entry=18446744073709551615, force_quick_range=force_quick_range@entry=false, ordered_output=<optimized out>, remove_false_parts_of_where=<optimized out>, only_single_index_range_scan=<optimized out>) at /test/11.0_dbg/sql/opt_range.cc:3072

#3  0x00005599998c9b4f in get_quick_record_count (limit=18446744073709551615, keys=0x14d104015950, table=0x14d10401ea88, select=0x14d1040164e0, thd=0x14d104000d58) at /test/11.0_dbg/sql/sql_select.cc:5190

#4  make_join_statistics (join=join@entry=0x14d104014f50, tables_list=@0x14d1040133f8: {<base_list> = {<Sql_alloc> = {<No data fields>}, first = 0x14d104015718, last = 0x14d104015718, elements = 1}, <No data fields>}, keyuse_array=keyuse_array@entry=0x14d1040152b8) at /test/11.0_dbg/sql/sql_select.cc:5947

#5  0x00005599998d14b9 in JOIN::optimize_inner (this=this@entry=0x14d104014f50) at /test/11.0_dbg/sql/sql_select.cc:2569

#6  0x00005599998d19bc in JOIN::optimize (this=this@entry=0x14d104014f50) at /test/11.0_dbg/sql/sql_select.cc:1897

#7  0x00005599998d1ac5 in mysql_select (thd=thd@entry=0x14d104000d58, tables=0x14d104013800, fields=@0x14d104013498: {<base_list> = {<Sql_alloc> = {<No data fields>}, first = 0x14d1040137b8, last = 0x14d1040137b8, elements = 1}, <No data fields>}, conds=0x0, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2164525829, result=0x14d1040148b0, unit=0x14d104004fa0, select_lex=0x14d1040131e0) at /test/11.0_dbg/sql/sql_select.cc:5132

#8  0x00005599998d2526 in mysql_explain_union (thd=thd@entry=0x14d104000d58, unit=unit@entry=0x14d104004fa0, result=result@entry=0x14d1040148b0) at /test/11.0_dbg/sql/sql_select.cc:29596

#9  0x0000559999837bd7 in execute_sqlcom_select (thd=thd@entry=0x14d104000d58, all_tables=0x14d104013800) at /test/11.0_dbg/sql/sql_parse.cc:6205

#10 0x00005599998434af in mysql_execute_command (thd=thd@entry=0x14d104000d58, is_called_from_prepared_stmt=is_called_from_prepared_stmt@entry=false) at /test/11.0_dbg/sql/sql_parse.cc:3949

#11 0x000055999984a7cf in mysql_parse (thd=thd@entry=0x14d104000d58, rawbuf=<optimized out>, length=<optimized out>, parser_state=parser_state@entry=0x14d1589652c0) at /test/11.0_dbg/sql/sql_parse.cc:8002

#12 0x000055999984c963 in dispatch_command (command=command@entry=COM_QUERY, thd=thd@entry=0x14d104000d58, packet=packet@entry=0x14d10400ae19 "", packet_length=packet_length@entry=32, blocking=blocking@entry=true) at /test/11.0_dbg/sql/sql_class.h:242

#13 0x000055999984e7bc in do_command (thd=0x14d104000d58, blocking=blocking@entry=true) at /test/11.0_dbg/sql/sql_parse.cc:1407

#14 0x000055999999f6e2 in do_handle_one_connection (connect=<optimized out>, connect@entry=0x55999cb199f8, put_in_cache=put_in_cache@entry=true) at /test/11.0_dbg/sql/sql_connect.cc:1416

#15 0x000055999999f941 in handle_one_connection (arg=0x55999cb199f8) at /test/11.0_dbg/sql/sql_connect.cc:1318

#16 0x000014d172461b43 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442

#17 0x000014d1724f3a00 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

15273	  /* Calculate the number of blocks we will touch for the table or range scan */

15274	  num_blocks= (records * key_length / INDEX_BLOCK_FILL_FACTOR_DIV *

15275	               INDEX_BLOCK_FILL_FACTOR_MUL) / file->stats.block_size + 1;

(gdb) p file->stats.block_size

$2 = 0