Assertion `fixed == 1' failed in virtual String* Item_func_conv_charset::val_str(String*)

CREATE TABLE t1 (f1 CHAR(3) CHARACTER SET utf8 NULL, f2 CHAR(3) CHARACTER SET latin1 NULL);

INSERT INTO t1 VALUES ('foo','bar');

SELECT * FROM t1 WHERE f2 >= SOME ( SELECT f1 FROM t1 );

mysqld: /data/src/10.1/sql/item_strfunc.cc:3403: virtual String* Item_func_conv_charset::val_str(String*): Assertion `fixed == 1' failed

.

#7  0x00007f00c9a47312 in __GI___assert_fail (assertion=0x7f00ccc27e44 "fixed == 1", file=0x7f00ccc27fb8 "/data/src/10.1/sql/item_strfunc.cc", line=3403, function=0x7f00ccc29500 <Item_func_conv_charset::val_str(String*)::__PRETTY_FUNCTION__> "virtual String* Item_func_conv_charset::val_str(String*)") at assert.c:101

#8  0x00007f00cc51b87a in Item_func_conv_charset::val_str (this=0x7f00c08e6e18, str=0x7f00c08e6ff0) at /data/src/10.1/sql/item_strfunc.cc:3403

#9  0x00007f00cc1996f4 in Item::str_result (this=0x7f00c08e6e18, tmp=0x7f00c08e6ff0) at /data/src/10.1/sql/item.h:1040

#10 0x00007f00cc4aef42 in Item_cache_str::cache_value (this=0x7f00c08e6f00) at /data/src/10.1/sql/item.cc:9101

#11 0x00007f00cc4b4d1e in Item_cache::has_value (this=0x7f00c08e6f00) at /data/src/10.1/sql/item.h:5050

#12 0x00007f00cc4af139 in Item_cache_str::val_str (this=0x7f00c08e6f00, str=0x7f00c08e6ce0) at /data/src/10.1/sql/item.cc:9141

#13 0x00007f00cc4b98c3 in Arg_comparator::compare_string (this=0x7f00c08e6c58) at /data/src/10.1/sql/item_cmpfunc.cc:831

#14 0x00007f00cc4cbfbe in Arg_comparator::compare (this=0x7f00c08e6c58) at /data/src/10.1/sql/item_cmpfunc.h:88

#15 0x00007f00cc4bc5a5 in Item_func_le::val_int (this=0x7f00c08e6ba0) at /data/src/10.1/sql/item_cmpfunc.cc:1788

#16 0x00007f00cc4bbb29 in Item_in_optimizer::val_int (this=0x7f00c08e4dd8) at /data/src/10.1/sql/item_cmpfunc.cc:1538

#17 0x00007f00cc4b828a in Item_func_nop_all::val_int (this=0x7f00c08e3d50) at /data/src/10.1/sql/item_cmpfunc.cc:354

#18 0x00007f00cc28e6ec in JOIN::exec_inner (this=0x7f00c08e3f28) at /data/src/10.1/sql/sql_select.cc:2624

#19 0x00007f00cc28dfef in JOIN::exec (this=0x7f00c08e3f28) at /data/src/10.1/sql/sql_select.cc:2518

#20 0x00007f00cc29155d in mysql_select (thd=0x7f00c2bfa070, rref_pointer_array=0x7f00c2bfe400, tables=0x7f00c08e22a0, wild_num=1, fields=..., conds=0x7f00c08e3d50, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147748608, result=0x7f00c08e3f08, unit=0x7f00c2bfda88, select_lex=0x7f00c2bfe188) at /data/src/10.1/sql/sql_select.cc:3451

#21 0x00007f00cc28702c in handle_select (thd=0x7f00c2bfa070, lex=0x7f00c2bfd9c0, result=0x7f00c08e3f08, setup_tables_done_option=0) at /data/src/10.1/sql/sql_select.cc:384

#22 0x00007f00cc257382 in execute_sqlcom_select (thd=0x7f00c2bfa070, all_tables=0x7f00c08e22a0) at /data/src/10.1/sql/sql_parse.cc:5894

#23 0x00007f00cc24d28f in mysql_execute_command (thd=0x7f00c2bfa070) at /data/src/10.1/sql/sql_parse.cc:2960

#24 0x00007f00cc25aaba in mysql_parse (thd=0x7f00c2bfa070, rawbuf=0x7f00c08e2088 "SELECT * FROM t1 WHERE f2 >= SOME ( SELECT f1 FROM t1 )", length=55, parser_state=0x7f00cd1a65e0) at /data/src/10.1/sql/sql_parse.cc:7314

#25 0x00007f00cc2494e4 in dispatch_command (command=COM_QUERY, thd=0x7f00c2bfa070, packet=0x7f00c453e071 "SELECT * FROM t1 WHERE f2 >= SOME ( SELECT f1 FROM t1 )", packet_length=55) at /data/src/10.1/sql/sql_parse.cc:1486

#26 0x00007f00cc24821b in do_command (thd=0x7f00c2bfa070) at /data/src/10.1/sql/sql_parse.cc:1107

#27 0x00007f00cc37de63 in do_handle_one_connection (thd_arg=0x7f00c2bfa070) at /data/src/10.1/sql/sql_connect.cc:1350

#28 0x00007f00cc37dbc7 in handle_one_connection (arg=0x7f00c2bfa070) at /data/src/10.1/sql/sql_connect.cc:1262

#29 0x00007f00cc65f090 in pfs_spawn_thread (arg=0x7f00c9027ef0) at /data/src/10.1/storage/perfschema/pfs.cc:1860

#30 0x00007f00cb9490a4 in start_thread (arg=0x7f00cd1a7b00) at pthread_create.c:309

#31 0x00007f00c9b0187d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111