Assertion `gathered_length == thd->lex->comment.length' failed in binlog_defragment

SET @a= '42';

--error ER_BASE64_DECODE_ERROR

BINLOG @a, @a;

mysqld: /data/src/10.4/sql/sql_binlog.cc:164: int binlog_defragment(THD*): Assertion `gathered_length == thd->lex->comment.length' failed.

200510 16:09:29 [ERROR] mysqld got signal 6 ;

#7  0x00007f4356031f12 in __GI___assert_fail (assertion=0x5619ce0cff48 "gathered_length == thd->lex->comment.length", file=0x5619ce0cff78 "/data/src/10.4/sql/sql_binlog.cc", line=164, function=0x5619ce0d0100 <binlog_defragment(THD*)::__PRETTY_FUNCTION__> "int binlog_defragment(THD*)") at assert.c:101

#8  0x00005619cd4f6445 in binlog_defragment (thd=0x7f42f4000af0) at /data/src/10.4/sql/sql_binlog.cc:164

#9  0x00005619cd4f674e in mysql_client_binlog_statement (thd=0x7f42f4000af0) at /data/src/10.4/sql/sql_binlog.cc:235

#10 0x00005619cd3ae05a in mysql_execute_command (thd=0x7f42f4000af0) at /data/src/10.4/sql/sql_parse.cc:6020

#11 0x00005619cd3b3ad3 in mysql_parse (thd=0x7f42f4000af0, rawbuf=0x7f42f4012f88 "BINLOG @a, @a", length=13, parser_state=0x7f43480c95c0, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:7900

#12 0x00005619cd3a0083 in dispatch_command (command=COM_QUERY, thd=0x7f42f4000af0, packet=0x7f42f414de31 "BINLOG @a, @a", packet_length=13, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:1842

#13 0x00005619cd39e825 in do_command (thd=0x7f42f4000af0) at /data/src/10.4/sql/sql_parse.cc:1360

#14 0x00005619cd526394 in do_handle_one_connection (connect=0x5619d05bdfc0) at /data/src/10.4/sql/sql_connect.cc:1412

#15 0x00005619cd5260e3 in handle_one_connection (arg=0x5619d05bdfc0) at /data/src/10.4/sql/sql_connect.cc:1316

#16 0x00007f4357fba4a4 in start_thread (arg=0x7f43480ca700) at pthread_create.c:456

#17 0x00007f43560eed0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97