startOfDocument(Node*) and endOfDocument(Node*) return a null VisiblePosition if the document is non-editable and contains only an editable pocket

[Justin Garcia]

startOfDocument(Node*) and endOfDocument(Node*) return a null VisiblePosition if the document is non-editable and contains only an editable pocket. I don't think I can construct a test case for this.

VisiblePosition endOfDocument(const Node* node)
{
    if (!node || !node->document() || !node->document()->documentElement())
        return VisiblePosition();
    
    Element* doc = node->document()->documentElement();
    return VisiblePosition(lastPositionInNode(doc), DOWNSTREAM);
}

<rdar://problem/9139718>

[Enrica Casucci]

This has been fixed as part of revision 173287.