Excludes empty sections from pdf

src/pdf/toolcompendiumLatex.xsl

@@ -57,7 +57,7 @@
   <xsl:text>}</xsl:text>
 </xsl:template>
 
-<xsl:template match="section">
+<xsl:template match="section[program|section|struct-ref]">
   <xsl:choose>
     <xsl:when test="count(ancestor::section) = 0">
       <xsl:text>\section{</xsl:text>