Description:
------------
Adding a DTD to an already loaded document properly adds the given Element and Text to the document, but doesn't seem to update the document->doctype properly.



Workaround found: Create a new document with the DTD and import the root node of the document.




Note: It's my first try at reporting a bug, so I apologize if if it is not clear.

Reproduce code:
---------------
$impl= new DomImplementation;
$dtd= $impl->createDocumentType("test", "", "loctest.dtd");
$dom=DOMDocument::load('C:\\Inetpub\\wwwroot\\cgi-bin\\testsDom\\test.xml');
$dom->standalone = "no";

$dom->insertBefore($dtd, $dom->firstChild);
if ($dom->validate())
  echo "Valid";
else
  echo "NOT Valid";


Expected result:
----------------
"Valid"
OR
"NOT Valid"
OR
An error indicating that I cannot add the DTD element

Actual result:
--------------
Notice: DOMDocument::validate() [function.validate]: No DTD given in XML-Document in C:\Inetpub\wwwroot\cgi-bin\testsDom\addDtd.php on line 26