IS NULL search operator produces no WHERE SQL with spatial fields

[cjhewett]

Steps to reproduce

CREATE TABLE `t` (
 `point` POINT DEFAULT NULL
) ENGINE=InnoDB;

INSERT INTO `t` (`point`) VALUES (NULL), (PointFromText('POINT(1 1)'));

2. Go to Search tab on phpmyadmin
3. Change point operator to "IS NULL" (or "IS NOT NULL")
4. Click Go

Expected behaviour

Results should show 1 entry for the NULL point

Actual behaviour

No WHERE clause is added to SQL so whole table is returned

Server configuration

Operating system:
CentOS
Web server:
Apache/2.4.6
Database:
10.2.12-MariaDB
PHP version:
5.6.33
phpMyAdmin version:
4.7.7

[aroralakshya]

isempty function works with null values.