Merging two nodes does not preserve the longest history

[pangoSE]

Hi
Merging two nodes does not always preserve the longest history.
Is it possible to implement this?

Cheers

[stoecker]

As far as I remember it preserves the history of the oldest node (i.e. lower id).

[Don-vip]

Yes:

    /**
     * Find which node to merge into (i.e. which one will be left)
     *
     * @param candidates the collection of candidate nodes
     * @return the selected target node
     */
    public static Node selectTargetNode(Collection<Node> candidates) {
        Node oldestNode = null;
        Node targetNode = null;
        Node lastNode = null;
        for (Node n : candidates) {
            if (!n.isNew()) {
                // Among existing nodes, try to keep the oldest used one
                if (!n.getReferrers().isEmpty()) {
                    if (targetNode == null || n.getId() < targetNode.getId()) {
                        targetNode = n;
                    }
                } else if (oldestNode == null || n.getId() < oldestNode.getId()) {
                    oldestNode = n;
                }
            }
            lastNode = n;
        }
        return Optional.ofNullable(targetNode).orElse(oldestNode != null ? oldestNode : lastNode);
    }

[pangoSE]

Thanks for the quick response.