Error with unchecked object in init_callbacks() method

[michal-josef-spacek]

There is code:

sub input_callbacks {
    my $self     = shift;
    my $icbclass = shift;

    if ( defined $icbclass ) {
        $self->{XML_LIBXML_CALLBACK_STACK} = $icbclass;
    }
    return $self->{XML_LIBXML_CALLBACK_STACK};
}

and

sub _init_callbacks {
    my $self = shift;
    my $icb = $self->{XML_LIBXML_CALLBACK_STACK};
    unless ( defined $icb ) {
        $self->{XML_LIBXML_CALLBACK_STACK} = XML::LibXML::InputCallback->new();
        $icb = $self->{XML_LIBXML_CALLBACK_STACK};
    }

    $icb->init_callbacks($self);
}

Which don't control what goes in.

There are weird errors like:

# Can't locate object method "init_callbacks" via package "XML::LibXML::InputCallback=HASH(0x56364e82f280)" (perhaps you forgot to load "XML::LibXML::InputCallback=HASH(0x56364e82f280)"?) at /usr/lib64/perl5/vendor_perl/XML/LibXML.pm line 744.

(from customer)

I think the best way is create check before $icb->init_callbacks($self);