Description:
------------
The PHP5 XSL extension does not seem to create directories when using the <exsl:document> element.

Reproduce code:
---------------
XML file (test.xml):
<?xml version="1.0"?>
<a>
        <b>test1</b>
        <b>test2</b>
</a>

XSLT file (test.xsl):
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"
    xmlns:exsl="http://exslt.org/common"
    extension-element-prefixes="exsl">
<xsl:output method="html" indent="yes" encoding="US-ASCII"/>

<xsl:template match="a">
        <exsl:document href="output/test.html" method="html">
        <xsl:for-each select="b">
                <p><xsl:value-of select="."/></p>
        </xsl:for-each>
        </exsl:document>
</xsl:template>
</xsl:stylesheet>

PHP file (exslt.php):
<?php
$xml = new DomDocument;
$xml->load('test.xml');

$xsl = new DomDocument;
$xsl->load('test.xsl');

$proc = new xsltprocessor;
$proc->importStyleSheet($xsl);
$proc->transformToXML($xml);
?>


Expected result:
----------------
Running 'xsltproc test.xsl test.xml' gives a directory 'output' with file 'test.html' containing '<p>test1</p><p>test2</p>'.

Running 'php exslt.php' should give the same result.

Actual result:
--------------
Warning: XSLTProcessor::transformToXml(output/test.html): failed to open stream: No such file or directory in /var/www/experiment/exslt.php on line 10

Warning: No such file or directoryruntime error: file /var/www/experiment/test.xsl element document in /var/www/experiment/exslt.php on line 10

Warning: xsltDocumentElem: unable to save to output/test.html in /var/www/experiment/exslt.php on line 10

Note: when an empty directory 'output' is created before running 'php exslt.php', the file 'test.html' is created correctly.