Here is a complete solution that renames the prefixes, so that there
are no two different namespaces with the same prefix:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:xs="http://www.w3.org/2001/XMLSchema"
 xmlns:my="my:my">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:variable name="vNamespaces" select="//namespace::*[not(name()='xml')]"/>
 <xsl:variable name="vPrefixes" select="$vNamespaces/name()"/>

 <xsl:template match="node()|@*">
  <xsl:copy>
   <xsl:apply-templates select="node()|@*"/>
  </xsl:copy>
 </xsl:template>

  <xsl:template match="/*">
     <xsl:copy>
       <xsl:copy-of select="@*"/>
       <xsl:for-each-group select="$vPrefixes" group-by=".">
         <xsl:for-each-group select="$vNamespaces[name()=current()]"
group-by=".">
           <xsl:namespace name="unique-{name()}-{position()}" select="."/>
         </xsl:for-each-group>
       </xsl:for-each-group>
       <xsl:apply-templates select="node()"/>
     </xsl:copy>
   </xsl:template>

   <xsl:template match="*/*">
    <xsl:variable name="vNSUri" select="namespace-uri()"/>
    <xsl:variable name="vPrefix" select="prefix-from-QName(xs:QName(name()))"/>

    <xsl:variable name="vNewPrefix" select=
     "my:new-prefix(substring-before(name(),':'), $vNSUri)"/>

     <xsl:element name="{$vNewPrefix}:{local-name()}" namespace="{$vNSUri}">
      <xsl:apply-templates select="@*|node()"/>
     </xsl:element>
   </xsl:template>

   <xsl:template match="*/*/@*">
    <xsl:variable name="vNSUri" select="namespace-uri()"/>
    <xsl:variable name="vPrefix" select="prefix-from-QName(xs:QName(name()))"/>

    <xsl:variable name="vNewPrefix" select=
     "my:new-prefix(prefix-from-QName(xs:QName(name())), $vNSUri)"/>

    <xsl:attribute name="{$vNewPrefix}:{local-name()}" namespace="{$vNSUri}"
                   select="."/>
   </xsl:template>

   <xsl:function name="my:new-prefix" as="xs:string">
    <xsl:param name="pPrefix" as="xs:string"/>
    <xsl:param name="pNSUri" as="xs:string"/>
      <xsl:for-each-group select="$vNamespaces[name()=$pPrefix]" group-by=".">
        <xsl:if test=". eq $pNSUri">
          <xsl:sequence select="concat('unique-',name(),'-', position())"/>
        </xsl:if>
      </xsl:for-each-group>
   </xsl:function>
 </xsl:stylesheet>

When this transformation is applied to the provided XML document:

<Test xmlns="A">
     <ns1:element xmlns:ns1="B">Hello</ns1:element>
     <ns1:element xmlns:ns1="C">C</ns1:element>
 </Test>

the correct result is produced:

<Test xmlns="A" xmlns:unique--1="A" xmlns:unique-ns1-1="B"
xmlns:unique-ns1-2="C">
     <unique-ns1-1:element>Hello</unique-ns1-1:element>
     <unique-ns1-2:element>C</unique-ns1-2:element>
 </Test>

Note:

I wanted to use the function:

    prefix-from-QName()

however it requires an xs:QName as argument and an xs:QName
constructor only accepts *literal* strings as arguments.

The question arizes then: What is the above function useful for?

Cheers,

Dimitre

On Sun, Jan 13, 2013 at 11:29 AM, Costello, Roger L. <costello@xxxxxxxxx> wrote:
> Hi Folks,
>
> I found this wonderful code [1] from Michael Kay to move the namespace declarations up onto the root element:
>
>   <xsl:template match="/*">
>     <xsl:copy>
>       <xsl:copy-of select="@*, //namespace::*, child::node()"/>
>     </xsl:copy>
>   </xsl:template>
>
> That works great, provided the XML document doesn't have the same namespace prefix bound to different namespaces. For example, it fails on this XML document:
>
> <Test xmlns="A">
>     <ns1:element xmlns:ns1="B">Hello</ns1:element>
>     <ns1:element xmlns:ns1="C">C</ns1:element>
> </Test>
>
> Notice that the namespace prefix, ns1, is bound to two different namespaces.
>
> Applying the XSLT program to the XML document results in this  error:
>
>     Cannot create two namespace nodes with the same
>     prefix mapped to different URIs (prefix=ns1, URI=C,
>     URI=B)
>
> How do I move the namespace declarations up onto the root element, while taking in account that the XML document may contain a namespace prefix that is bound to different namespaces?
>
> /Roger
>
> [1] http://www.mhonarc.org/archive/html/xsl-list/2009-10/msg00153.html
>



-- 
Cheers,
Dimitre Novatchev
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