InnoDB fulltext query containing percent and wildcard character reports syntax error, unexpected $end, expecting FTS_TERM or FTS_NUMB or '*'

CREATE TABLE `tab1` (

	`id` INT(11) NOT NULL,

	`str` TEXT NOT NULL,

	PRIMARY KEY (`id`),

	FULLTEXT INDEX `fulltext1` (`str`)

)

ENGINE=InnoDB

;

-- those queries fail (both in natural language and boolean mode)

select * from tab1 where match(str) against ('%*');

select * from tab1 where match(str) against ('%*%');

select * from tab1 where match(str) against ('*%*');

select * from tab1 where match(str) against ('%*%%');

select * from tab1 where match(str) against ('%*%*');

select * from tab1 where match(str) against ('%*%%*');

select * from tab1 where match(str) against ('*'); -- this is obvious in boolean mode, but not sure why is this problem in natural language mode

/* SQL chyba (1064): syntax error, unexpected $end, expecting FTS_TERM or FTS_NUMB or '*' */

-- suprisingly those queries work fine

select * from tab1 where match(str) against ('**');

select * from tab1 where match(str) against ('%');

select * from tab1 where match(str) against ('%%');

select * from tab1 where match(str) against ('%**');

select * from tab1 where match(str) against ('%%**');