MyBB

MyBB generates links to nonexistent profiles - we can delete users, but on index or forumdisplay, there are sill links to "profiles".
Of course when we try to open this link, we have a message:

The member you specified is either invalid or doesn't exist.

MyBB should determine nonexistent profiles - maybe good choice is to delete lastposteruid when we delete user?
Script will continue to have lastposter username, and build_profile_link can return only username.
This is contained in the code, but for unknown reasons to me unused in index and forumdisplay:

function build_profile_link($username="", $uid=0, $target="", $onclick="")
{
    global $mybb, $lang;

    if(!$username && $uid == 0)
    {
        // Return Guest phrase for no UID, no guest nickname
        return $lang->guest;
    }
    elseif($uid == 0)
    {
        // Return the guest's nickname if user is a guest but has a nickname
        return $username;
    }
(...)