If invoking a NodeFilter ends up deleting a node from the DOM, it's not
enough to only adjust the NodeIterator reference nodes in the
pre-removing steps. We must also adjust the current traversal pointer.
This is not in the spec, but it's how other engines behave, so let's do
the same.
I've encapsulated the Node + before-or-after-flag in a struct called
NodePointer so that we can use the same pre-removing steps for both the
traversal pointer and for the NodeIterator's reference node.
Note that when invoking the NodeFilter, we have to remember the node we
passed to the filter function, so that we can return it if accepted by
the filter.
This gets us another point on Acid3. :^)
These steps run when a node is about to be removed from its parent,
and adjust the position of any live NodeIterators so that they don't
point at a now-removed node.
Note that while this commit implements what's in the DOM specification,
the specification doesn't fully match what other browsers do.
Spec bug: https://github.com/whatwg/dom/issues/907
This patch adds NodeIterator (created via Document.createNodeIterator())
which allows you to iterate through all the nodes in a subtree while
filtering with a provided NodeFilter callback along the way.
This first cut implements the full API, but does not yet handle nodes
being removed from the document while referenced by the iterator. That
will be done in a subsequent patch.
