Description:
------------
When using input encoding of charset=iso-8859-1 domDocument() 
fails to output the ascii code 200 (e grave) using saveXML()

Reproduce code:
---------------
Here's some example code that shows the problem:

<?
  header("Content-Type: text/html; charset=iso-8859-1");
  error_reporting(E_ALL);
  $domfather = new domDocument('1.0', 'iso-8859-1');
  $node = $domfather->createElement("xxx", chr(200));
  $domfather->appendChild($node);
  echo "<pre>";
  echo htmlspecialchars($domfather->saveXML());
  $nodelist =  $domfather->getElementsByTagName("xxx");
  $data = $nodelist->item(0)->nodeValue;
  echo $data;
  echo strlen($data);
?>

Expected result:
----------------
I was expecting the saveXML() to output the e grave symbol (ascii 
200)

iso-8859-1 character mapping is here:

http://old.no/charmap/iso-8859-1.html

and shows that ascii is completely valid.

Please notice that the data is provided correctly when I ask for 
it by node.  the failure is just when using the saveXML() 
function.

Actual result:
--------------
The output from my server is below.  When I retrieve 
the node's data back, it is as expected.  But it's the saveXML() 
code that seems to have a problem. I suspect the problem is with 
the utf-8 -> iso-8859 conversion before output.

Warning:  DOMDocument::saveXML() [function.DOMDocument-saveXML]: 
output conversion failed due to conv error in /Library/Tenon/
WebServer/WebSites/realtyjuggler.com/subscription/test.php on line 
23

Warning:  DOMDocument::saveXML() [function.DOMDocument-saveXML]: 
Bytes: 0xC8 0x3C 0x2F 0x78 in /Library/Tenon/WebServer/WebSites/
realtyjuggler.com/subscription/test.php on line 23

<?xml version="1.0" encoding="iso-8859-1"?>
<xxx>?1