When accessing the Assignment grading page, the following debugging message is shown when Assignments per page option is set to All.: Negative limitnum parameter detected: -1, did you pass the correct arguments?

Initial report of this issue can be found at https://moodle.org/mod/forum/discuss.php?d=264251

I've tested this in v2.6.3 and v2.7.2+ and this issue seems to be introduced from v2.7. There are no issues with v2.6.

This debug message comes from normalise_limit_from_num() in /lib/dml/moodle_database.php, which is introduced from v2.7.

The value of $limitnum passed from the assign module is '-1' of type string so the following check on $limitnum fails:

if ($limitnum === null || $limitnum === '' || $limitnum === -1) {

    $limitnum = 0;

}

Either the value passed from the assign module needs to be an integer or the above check needs to first convert $limitnum to integer.

In v2.6, the value of $limitnum was casted to int in get_records_sql() in /lib/dml/mysqli_native_moodle_database.php as shown:

$limitnum  = (int)$limitnum;