db4-upgrade.xsl: book/bookinfo/abstract not preserved

[Mathieu Malaterre <mathieu.malaterre@gmail.com>]

Hi there,

  did anyone noticed that book/bookinfo/abstract was lost during a
db4-upgrade.xsl process ?

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd";>
<book>
    <title></title>
  <bookinfo>
    <title></title>
    <abstract>
      <para>keep me</para>
    </abstract>
  </bookinfo>
</book>

becomes:

<!-- Converted by db4-upgrade version 1.0 -->

<book xmlns="http://docbook.org/ns/docbook"; version="5.0">

  <info><title/>


  </info>
</book>

should I fill a bug report ?

thanks,
-- 
Mathieu