When an ID was specified on a <db:tgroup> the Docbook to HTML conversion would fail with
xsl:attribute: Cannot add attributes to an element if children have been already added to the element.
Assuming I understand XSLT correctly, this is because <xsl:call-template name="IdCheck"/> call was being made directly in <xsl:template match="db:tgroup"> rather than in the element it constructed, causing the xsl:attribute call in IdCheck to try to add the attribute to the original db:tgroup rather than to the new colgroup.
When an ID was specified on a
<db:tgroup>the Docbook to HTML conversion would fail withAssuming I understand XSLT correctly, this is because
<xsl:call-template name="IdCheck"/>call was being made directly in<xsl:template match="db:tgroup">rather than in the element it constructed, causing thexsl:attributecall in IdCheck to try to add the attribute to the originaldb:tgrouprather than to the newcolgroup.