SHOW EXPLAIN: Assertion `table_list->table' fails in find_field_in_table_ref if FOR contains a non-numeric value

mysqld: sql/sql_base.cc:6555: Field* find_field_in_table_ref(THD*, TABLE_LIST*, const char*, uint, const char*, const char*, const char*, Item**, bool, bool, uint*, bool, TABLE_LIST**): Assertion `table_list->table' failed.

#6  0x00007fd301bd5d4d in __GI___assert_fail (assertion=0xd1e09b "table_list->table", file=<optimized out>, line=6555, function=<optimized out>) at assert.c:81

#7  0x00000000005b7c3b in find_field_in_table_ref (thd=0x3c901f0, table_list=0x3dcea90, name=0x3dcde38 "a", length=1, item_name=0x3dcde38 "a", db_name=0x0, table_name=0x0, ref=0x3dcf060, check_privileges=true, allow_rowid=true, cached_field_index_ptr=0x3dcdefc, register_tree_change=true, actual_table=0x7fd2f72b8970) at sql/sql_base.cc:6555

#8  0x00000000005b8795 in find_field_in_tables (thd=0x3c901f0, item=0x3dcde40, first_table=0x3dcea90, last_table=0x0, ref=0x3dcf060, report_error=IGNORE_EXCEPT_NON_UNIQUE, check_privileges=true, register_tree_change=true) at sql/sql_base.cc:6854

#9  0x00000000007dd5ea in Item_field::fix_fields (this=0x3dcde40, thd=0x3c901f0, reference=0x3dcf060) at sql/item.cc:4966

#10 0x000000000060e6d1 in mysql_execute_command (thd=0x3c901f0) at sql/sql_parse.cc:2169

#11 0x0000000000618555 in mysql_parse (thd=0x3c901f0, rawbuf=0x3dcdd98 "SHOW EXPLAIN FOR a", length=18, parser_state=0x7fd2f72b9500) at sql/sql_parse.cc:5763

#12 0x000000000060bc48 in dispatch_command (command=COM_QUERY, thd=0x3c901f0, packet=0x3d8af81 "SHOW EXPLAIN FOR a", packet_length=18) at sql/sql_parse.cc:1056

#13 0x000000000060aeff in do_command (thd=0x3c901f0) at sql/sql_parse.cc:795

#14 0x000000000070d67f in do_handle_one_connection (thd_arg=0x3c901f0) at sql/sql_connect.cc:1253

#15 0x000000000070d06a in handle_one_connection (arg=0x3c901f0) at sql/sql_connect.cc:1168

#16 0x0000000000c04a73 in pfs_spawn_thread (arg=0x3e13b90) at storage/perfschema/pfs.cc:1015

#17 0x00007fd302917efc in start_thread (arg=0x7fd2f72ba700) at pthread_create.c:304

#18 0x00007fd301c8a59d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x3dcdd98): SHOW EXPLAIN FOR a

Connection ID (thread ID): 2

Status: NOT_KILLED

version-info

revision-id: psergey@askmonty.org-20120812110753-nrmgrwy63msc7vbq

date: 2012-08-12 15:07:53 +0400

build-date: 2012-08-17 05:31:57 +0400

revno: 3483

SHOW EXPLAIN FOR a;