title: Issue with namespaces when copying from different document xslt 2.0
body: <p>I am using this stylesheet to create an opf file for epub using an ncx file (which is the table of contents in epub) as primary input:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;xsl:stylesheet version='2.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform' xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:fn='http://www.w3.org/2005/xpath-functions' exclude-result-prefixes='xsl xs fn' xpath-default-namespace="http://www.daisy.org/z3986/2005/ncx/" xmlns="http://www.idpf.org/2007/opf" xmlns:dc="http://purl.org/dc/elements/1.1/" &gt;
      &lt;xsl:output method='xml' version='1.0' encoding='UTF-8' indent='no'/&gt;
  
  &lt;xsl:param name="imgs" select="doc('../../EPUB/images.xml')"    /&gt;
  
      &lt;xsl:template match='/'&gt;
      &lt;xsl:result-document href="EPUB/META-INF/container.xml" method="xml" encoding="UTF-8"&gt;
          &lt;container xmlns="urn:oasis:names:tc:opendocument:xmlns:container" version="1.0"&gt;
           &lt;rootfiles&gt;
           &lt;rootfile full-path="OPS/output.opf" media-type="application/oebps-package+xml"/&gt;
           &lt;/rootfiles&gt;
           &lt;/container&gt;
      &lt;/xsl:result-document&gt;
          &lt;package version="2.0" unique-identifier="ID100"&gt;
              &lt;metadata&gt;
                  &lt;dc:title&gt;E-Pub&lt;/dc:title&gt;
                  &lt;dc:language&gt;de&lt;/dc:language&gt;
                  &lt;dc:identifier id="ID100"&gt;epub&lt;/dc:identifier&gt;
                  &lt;dc:creator&gt;sd&lt;/dc:creator&gt;
              &lt;/metadata&gt;
              &lt;manifest&gt;
                  &lt;item id="nav" href="nav.ncx" media-type="application/x-dtbncx+xml"/&gt;
                  &lt;item id="css" href="Style/styles.css" media-type="text/css"/&gt;
                  &lt;xsl:apply-templates select="//navPoint[content]"/&gt;
                  &lt;xsl:copy-of select="$imgs"/&gt;
              &lt;/manifest&gt;
              &lt;spine toc="nav"&gt;
                  &lt;xsl:apply-templates select="//navPoint[content]" mode="toc"/&gt;
              &lt;/spine&gt;
          &lt;/package&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="ncx"&gt;
          &lt;xsl:apply-templates/&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="head"&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="meta"&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="docTitle"&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="navMap"&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="navLabel"&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="text"&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="navPoint[content]"&gt;
          &lt;item id="{@id}" href="{content/@src}" media-type="application/xhtml+xml"/&gt;
      &lt;/xsl:template&gt;
      &lt;xsl:template match="navPoint[content]" mode="toc"&gt;
          &lt;itemref idref="{@id}"/&gt;
      &lt;/xsl:template&gt;
  &lt;/xsl:stylesheet&gt;
  </code></pre>
  
  <p>Everything works fine except copying the content of the file referenced by the imgs parameter. That file looks like this:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;images&gt;
      &lt;item id="d1e267_1" &gt;
      &lt;item id="d1e398_4" /&gt;
      &lt;item id="d1e653_5" /&gt;
  &lt;!-- etc. --&gt;
  &lt;/images&gt;
  </code></pre>
  
  <p>When I copy this document like shown in my stylesheet, the root element <code>&lt;images&gt;</code> is copied into the output as well, with an empty <code>xmlns=""</code> attribute.</p>
  
  <pre><code>&lt;images xmlns=""&gt;
      &lt;item id="d1e267_1" &gt;
      &lt;item id="d1e398_4" /&gt;
      &lt;item id="d1e653_5" /&gt;
  &lt;!-- etc. --&gt;
  &lt;/images&gt;
  </code></pre>
  
  <p>And if I add the <code>images</code> element to the doc-function, nothing gets copied, I guess because images is not in the declared default namespace. I only want to copy the <code>item</code> elements.</p>
  
  <p>How do I handle this namespace here? I already declare a default namespace (for the ncx file) and I already declare an unprefixed namespace.</p>