insertAdjacentHTML and normalization of text nodes

Hi,

I have noticed that insertAdjacentHTML behaves differently in the latest
Chrome/Safari and Firefox/IE for text nodes:

var d = document.createElement('div');
d.appendChild(document.createTextNode('abc'));
d.insertAdjacentHTML('beforeend', 'def');
console.log(d.childNodes.length);

While Chrome/Safari adds a separate text node, Firefox/IE update the
previously added text node. This is problematic if you try to get the nodes
which were inserted.

Since the spec does not mention anything about normalization of text nodes,
I have the feeling that FF/IE violate the spec here. Is that correct? If
not, would it be possible to define the exact behaviour for text nodes in
the spec?

- Joel