+<!--
+ - helper template to do conflict resolution between various headings with the same inferred ID attribute/tag from the headerlink template
+ - this conflict resolution is necessary to prevent malformed HTML output (multiple id attributes with the same value)
+ - and it fixes xsltproc warnings during compilation of HTML man pages
+ -
+ - A simple top-to-bottom numbering scheme is implemented for nodes with the same ID value to derive unique ID values for HTML output.
+ - It uses two parameters:
+ templateID the proposed ID string to use which must be checked for conflicts
+ keyNode the context node which 'produced' the given templateID.
+ -
+ - Conflicts are detected solely based on keyNode, templateID is not taken into account for that purpose.
+ -->
+<xsl:template name="generateID">
+ <!-- node which generatedID needs to assume as the 'source' of the ID -->
+ <xsl:param name="keyNode"/>
+ <!-- suggested value for generatedID output, a contextually meaningful ID string -->
+ <xsl:param name="templateID"/>
+ <xsl:variable name="conflictSource" select="preceding::refsect1/title|preceding::refsect1/info/title|
+ preceding::refsect2/title|preceding::refsect2/info/title|
+ preceding::varlistentry/term[1]"/>
+ <xsl:variable name="conflictCount" select="count($conflictSource[. = $keyNode])"/>
+ <xsl:choose>
+ <!-- special case conflictCount = 0 to preserve compatibility with URLs generated by previous versions of this XSL stylesheet where possible -->
+ <xsl:when test="$conflictCount = 0">
+ <xsl:value-of select="$templateID"/>
+ </xsl:when>
+ <xsl:otherwise>
+ <xsl:value-of select="concat($templateID, $conflictCount)"/>
+ </xsl:otherwise>
+ </xsl:choose>
+</xsl:template>
+
+<!--
+ - a helper template to abstract over the structure of generated subheading + permalink HTML output
+ - It helps reduce tedious repetition and groups all actual markup output (as opposed to URL/ID logic) in a single location.
+ -->
+<xsl:template name="permalink">
+ <xsl:param name="nodeType"/> <!-- local name of the element node to generate, e.g. 'h2' for <h2></h2> -->
+ <xsl:param name="nodeContent"/> <!-- nodeset to apply further templates to obtain the content of the subheading/term -->
+ <xsl:param name="linkTitle"/> <!-- value for title attribute of generated permalink, e.g. 'this is a permalink' -->
+
+ <!-- parameters passed to generateID template, otherwise unused. -->
+ <xsl:param name="keyNode"/>
+ <xsl:param name="templateID"/>
+
+ <!--
+ - If stable URLs with fragment markers (references to the ID) turn out not to be important:
+ - generatedID could simply take the value of generate-id(), and various other helper templates may be dropped entirely.
+ - Alternatively if xsltproc is patched to generate reproducible generate-id() output the same simplifications can be
+ - applied at the cost of breaking compatibility with URLs generated from output of previous versions of this stylesheet.
+ -->
+ <xsl:variable name="generatedID">
+ <xsl:call-template name="generateID">
+ <xsl:with-param name="keyNode" select="$keyNode"/>
+ <xsl:with-param name="templateID" select="$templateID"/>
+ </xsl:call-template>
+ </xsl:variable>
+
+ <xsl:element name="{$nodeType}">