Return-to-top and disabling the top-most crumb.

[Paul Millar <paul@astro.gla.ac.uk>]

Hi,

Here's a couple of minor tweaks and fixes for the XSLT in the DocBook XSL: 
Complete Guide (4th ed).  I don't know if these issues are already "well 
known"---apologies if they are.

[Perhaps this isn't the correct forum for what is, in effect, errata; but, the 
Sagehill people are certainly active here and the fixes may be of general 
interest.]

First, the return-to-top sample customisation, available from:

	http://www.sagehill.net/docbookxsl/ReturnToTop.html

doesn't quite work.  Specifically, the link is obtained using the 
chunk-filename template.  This generates a filename that includes the dir 
dbhtml PI value.  Since the link is a relative URI, this is wrong: the 
resulting link will have the dbhtml dir PI specified twice.

Simply replacing the call to chuck-filename with a call to the 
recursive-chunk-filename template works for me, although I'm not sufficient 
au fait with chunking to say if this is always safe.

The second is a stylistic (and perhaps trivial) addition to the support for 
bread crumbs, available here:
  http://www.sagehill.net/docbookxsl/HTMLHeaders.html#BreadCrumbs

The following includes a test that disables the output for the top-most 
element, and so top-most chunk.  Personally, I find the single bread crumb to 
be something of a distraction since (at this level) it isn't a link.

  <xsl:template name="user.header.content">
    <xsl:if test="boolean(../..)">
      <xsl:call-template name="breadcrumbs"/>
    </xsl:if>
  </xsl:template>

Other people might perfer to include it, though (e.g., for UI consistency), so 
perhaps there should be an option to control this behaviour.

HTH,

Paul.