Syntax error when using MATCH

How to reproduce:

create table testrt (title1 string attribute indexed, title2 string attribute indexed);
insert into testrt (title1, title2) values ('(a)-(b)', 'test');
select * from testrt where match('(@title1) \\)\\-\\(');

You will get the syntax error:

ERROR 1064 (42000): index testrt: syntax error, unexpected ')' near ') \)\-\()'

However, if you add the second field to the query, there will be no errors:

select * from testrt where match('(@title1, title2) \\)\\-\\(');

I know that the query that gives the error can be transformed to the following one, so that there won’t be any errors either:

select * from testrt where match('@title1 \\)\\-\\(');

But I think that the initial query is still correct and it should not throw any errors.

Also, this query will throw the same error:

select * from testrt where match('(@title1 \\)\\-\\('))

Please advise.

Looks like a bug. Can you please file an issue about it on github?