Server crashes in calculate_key_len on query with ORDER BY

#3  <signal handler called>

#4  0x00007f5a5132af45 in calculate_key_len (table=0x7f5a464a3870, key=4294967295, buf=0x7f5a4658b048 "\001", keypart_map=0) at 10.1-orderby-fixes/sql/table.cc:3427

#5  0x00007f5a5146e842 in handler::prepare_index_key_scan_map (this=0x7f5a4647c888, key=0x7f5a4658b048 "\001", keypart_map=0) at 10.1-orderby-fixes/sql/handler.h:2618

#6  0x00007f5a512a82f5 in join_read_always_key (tab=0x7f5a4645b998) at 10.1-orderby-fixes/sql/sql_select.cc:18378

#7  0x00007f5a512a694a in sub_select (join=0x7f5a4658a0c0, join_tab=0x7f5a4645b998, end_of_records=false) at 10.1-orderby-fixes/sql/sql_select.cc:17635

#8  0x00007f5a512a6208 in do_select (join=0x7f5a4658a0c0, fields=0x7f5a48b457b8, table=0x0, procedure=0x0) at 10.1-orderby-fixes/sql/sql_select.cc:17298

#9  0x00007f5a51281d1a in JOIN::exec_inner (this=0x7f5a4658a0c0) at 10.1-orderby-fixes/sql/sql_select.cc:3093

#10 0x00007f5a5127ef72 in JOIN::exec (this=0x7f5a4658a0c0) at 10.1-orderby-fixes/sql/sql_select.cc:2388

#11 0x00007f5a512825cb in mysql_select (thd=0x7f5a48b41070, rref_pointer_array=0x7f5a48b45918, tables=0x7f5a465892b8, wild_num=1, fields=..., conds=0x7f5a46589d80, og_num=1, order=0x7f5a46589fb8, group=0x0, having=0x0, proc_param=0x0, select_options=2147748608, result=0x7f5a4658a0a0, unit=0x7f5a48b44fb8, select_lex=0x7f5a48b456a0) at 10.1-orderby-fixes/sql/sql_select.cc:3320

#12 0x00007f5a5127854e in handle_select (thd=0x7f5a48b41070, lex=0x7f5a48b44ef0, result=0x7f5a4658a0a0, setup_tables_done_option=0) at 10.1-orderby-fixes/sql/sql_select.cc:372

#13 0x00007f5a5124a8ac in execute_sqlcom_select (thd=0x7f5a48b41070, all_tables=0x7f5a465892b8) at 10.1-orderby-fixes/sql/sql_parse.cc:5729

#14 0x00007f5a51240ef1 in mysql_execute_command (thd=0x7f5a48b41070) at 10.1-orderby-fixes/sql/sql_parse.cc:2808

#15 0x00007f5a5124dad2 in mysql_parse (thd=0x7f5a48b41070, rawbuf=0x7f5a46589088 "SELECT * FROM t1 WHERE f1 < 3 AND f2 IS NULL ORDER BY f1", length=56, parser_state=0x7f5a45fb51c0) at 10.1-orderby-fixes/sql/sql_parse.cc:7011

#16 0x00007f5a5123dbc0 in dispatch_command (command=COM_QUERY, thd=0x7f5a48b41070, packet=0x7f5a48b37071 "", packet_length=56) at 10.1-orderby-fixes/sql/sql_parse.cc:1468

#17 0x00007f5a5123c9e0 in do_command (thd=0x7f5a48b41070) at 10.1-orderby-fixes/sql/sql_parse.cc:1092

#18 0x00007f5a513694cc in do_handle_one_connection (thd_arg=0x7f5a48b41070) at 10.1-orderby-fixes/sql/sql_connect.cc:1394

#19 0x00007f5a51369211 in handle_one_connection (arg=0x7f5a48b41070) at 10.1-orderby-fixes/sql/sql_connect.cc:1305

#20 0x00007f5a518f45b2 in pfs_spawn_thread (arg=0x7f5a4e0226f0) at 10.1-orderby-fixes/storage/perfschema/pfs.cc:1860

#21 0x00007f5a50953b50 in start_thread (arg=<optimized out>) at pthread_create.c:304

#22 0x00007f5a4e9ea20d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112

CREATE TABLE t1 (f1 INT, f2 INT, f3 INT, KEY(f2),KEY(f2,f1)) ENGINE=MyISAM;

INSERT INTO t1 VALUES (1,5,0),(2,6,0);

SELECT * FROM t1 WHERE f1 < 3 AND f2 IS NULL ORDER BY f1;