pandoc/test/command/6541.md

% pandoc -f docbook -t markdown -s
<?xml version="1.0"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<book>

<bookinfo>
<title>Title</title>
<author>
<firstname>Firstname</firstname><surname>Lastname</surname>
</author>
<releaseinfo>1.17</releaseinfo>
</bookinfo>

<para>Text.</para>

</book>
^D
---
author: Firstname Lastname
releaseinfo: 1.17
title: Title
---

Text.