XOM API for Processing XML with Java

[Elliotte Rusty Harold <elharo AT metalab.unc.edu>]

> The node hierarchy does not prevent cycles
> (aka "I'm my own grandpa").
>
> The simplest example is:
>
>   Element a = new Element("a");
>   a.appendChild(a);
>   // time passes...
>   a.toXML(); // causes a StackOverflowError

I think I see what's going on here. Normally appendChild/insertChild 
check to make sure that the node being inserted does not already have 
a parent. However, that wouldn't catch this problem. I'll write a 
unit test and fix this in CVS shortly.

Is there any way to do this without appending the node itself? Hmm, 
seems like there might be:

a.appendChild(b);
b.appendChild(c);
c.appendChild(a);

This is a problem. It seems like it could require insertChild descend 
the entire subtree to  verify the insertion is OK. Ugly. Does anyone 
see a simple, fast way to fix this?
--

  Elliotte Rusty Harold
  elharo AT metalab.unc.edu
  Processing XML with Java (Addison-Wesley, 2002)
  http://www.cafeconleche.org/books/xmljava
  http://www.amazon.com/exec/obidos/ISBN%3D0201771861/cafeaulaitA