Why does <topichead> allow the "copy-to" attribute on it?

[Radu Coravu <radu_coravu@sync.ro>]

Hi,

The specification says that <topichead> allows the copy-to attribute on it:

> http://docs.oasis-open.org/dita/v1.2/os/spec/langref/topichead.html#topichead

Why so? The topichead does not point to a certain resource, it is just 
an empty node in the TOC hierarchy.
The DITA OT processing throws a NPE when the copy-to attribute is set on 
the <topichead>.

Regards,
Radu

Radu Coravu
<oXygen/>  XML Editor, Schema Editor and XSLT Editor/Debugger
http://www.oxygenxml.com