This is a cautionary tale in the use of umbraco.library:GetXmlNodeById(@link), with Umbraco 4.0.4.1

I found an issue on a site I was creating, where the document type was using the "Related Links" property. The page chosen was then deleted, the following code then hung, the server starting a dw20.exe process which consumed about 50% cpu.

<xsl:variable name="linkPage" select="umbraco.library:GetXmlNodeById(@link)"/>

<xsl:variable name="image" select="umbraco.library:GetMedia($linkPage/data [@alias = 'listImage'],0)" />
<img src="{$image/data[@alias = 'umbracoFile']}" height="{$image/data[@alias = 'umbracoHeight']}" width="{$image/data[@alias = 'umbracoWidth']}" />
<xsl:value-of select="$linkPage/data [@alias='pageTitle']" />

So the XSLT was changed to the following, which worked without an issue

<!-- This returns <node> XML, use mode to ensure we do not match another template match
<xsl:apply-templates select="umbraco.library:GetXmlNodeById(@link)"  mode="study" />

<!-- This is not necessary, but would be called if the node id @link is not published -->
<xsl:template match="error" mode="study">
  <!--  Oops: <xsl:value-of select="."/> --> 
</xsl:template>

<xsl:template match="node" mode="study">
     
  <xsl:if test="string-length(./data [@alias = 'listImage']) &gt; 0">
     <xsl:variable name="image" select="umbraco.library:GetMedia(./data [@alias = 'listImage'],0)" />
     <img src="{$image/data[@alias = 'umbracoFile']}" height="{$image/data[@alias = 'umbracoHeight']}" width="{$image/data[@alias = 'umbracoWidth']}" />
  </xsl:if>
  <xsl:value-of select="./data [@alias='pageTitle']" />

</xsl:template>