Description:
------------
I find a possibly bug, when I wanted to print the structure of a DOMDocument or a DOMDocumentType object.
print_r() outputs the object type correctly, but the properties are missing.

$doc = $imp->createDocument();
$doc->loadXML($xmlString);
print_r($doc->doctype);

the code outputs:

DOMDocumentType Object
(
)

But the subobjects of $doc->doctype exist.


Reproduce code:
---------------
<?php

$doc = new DOMDocument();
$doc->loadXML('<?xml version="1.0" encoding="UTF-8" standalone="no"?><!DOCTYPE book PUBLIC "-//EDUCATIO Kht.//DocBook V4.3-alapu DTD V1.1//HU" "http://www.hik.hu/tankonyvpalyazat/dtd2/tankonyv.dtd"><book></book>');
print_r($doc->doctype);

?>

Expected result:
----------------
something like that:

DOMDocumentType Object
(
  publicId
  systemId
  name
  entities
  notations
  internalSubset
)


Actual result:
--------------
DOMDocumentType Object
(
)