Abstracts are placed outside "info" in DocBook

[gsmecher]

In an attempt to generate a DocBook tag, I'm approximating the advice given in the manual (https://asciidoctor.org/docs/user-manual/#user-abstract):

= Article Title

[abstract]
--
Paragraph 1.

Paragraph 2.
--

== First Section

In a DocBook flow, this ends up non-compliant XML:

$ asciidoctor -b docbook5 test.adoc
$ jing docbook.rng test.xml
test.xml:9:30: error: element "abstract" not allowed here; expected element "acknowledgements", "address", "anchor", "annotation", "appendix", "bibliography", "bibliolist", "blockquote", "bridgehead", "calloutlist", "caution", "classsynopsis", "cmdsynopsis", "colophon", "constraintdef", "constructorsynopsis", "destructorsynopsis", "epigraph", "equation", "example", "fieldsynopsis", "figure", "formalpara", "funcsynopsis", "glossary", "glosslist", "important", "index", "indexterm", "informalequation", "informalexample", "informalfigure", "informaltable", "itemizedlist", "literallayout", "mediaobject", "methodsynopsis", "msgset", "note", "orderedlist", "para", "procedure", "productionset", "programlisting", "programlistingco", "qandaset", "refentry", "remark", "revhistory", "screen", "screenco", "screenshot", "sect1", "section", "segmentedlist", "sidebar", "simpara", "simplelist", "simplesect", "synopsis", "table", "task", "tip", "toc", "variablelist" or "warning"

The DocBook XML is pretty straightforward:

<?xml version="1.0" encoding="UTF-8"?>
<?asciidoc-toc?>
<?asciidoc-numbered?>
<article xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en">
<info>
<title>Article Title</title>
<date>2020-03-18</date>
</info>
<abstract>
<simpara>Paragraph 1.</simpara>
<simpara>Paragraph 2.</simpara>
</abstract>
<section xml:id="_first_section">
<title>First Section</title>

</section>
</article>

The "abstract" tag falls outside the "info" scope, where it's not allowed.

Thanks (as always) for your hard work on asciidoctor. It's an amazing tool.

[mojavelinux]

Ah, this was a change in DocBook 5. (See https://tdg.docbook.org/tdg/4.5/abstract vs https://tdg.docbook.org/tdg/5.1/abstract) It was allowed as child of article in DocBook 4.5.

Since the DocBook 4.5 converter was created first, the DocBook 5 converter inherited this placement. Now that the DocBook 4.5 converter has been pulled out of this repository, we can make this update directly to the DocBook 5 converter without the need for any special logic.

[mojavelinux]

I'll admit, this change is really unfortunate because it breaks the document traversal that the converter does. There's an assumption in that hierarchy that the abstract is part of the body, not the header. And there's a lot of places the abstract can be defined that we now have to account for.

[mojavelinux]

The only way I could figure out how to do this is to remove the abstract from the document tree then restore it afterwards. It's not pretty, but it gets the job done.