wrong implode function parameters

[nathanaelmemis]

MysqliDb.php, line 1838:
$this->_query .= ' (' . implode($dataColumns, ', ') . ') ';

should be

$this->_query .= ' (' . implode(', ', $dataColumns) . ') ';

note: this is for the last release

[decMuc]

I find this surprising. I have an insert statement in two different classes – it works in one class, but in the other, I encounter an error in the exact same line. When I swap the line between the classes, it now works in the previously problematic class. I just can't comprehend why it works in one class while being nearly identical to the other.