[apparmor] [PATCH 09/10] Split the nodeset used in computing the dfa into two sets, accepting and non-accepting, and have the proto-state use them.

[Seth Arnold]

Can you explain the complicated condition at the end of the split operation?

static void split_node_types(NodeSet *nodes, NodeSet **anodes, NodeSet **nnodes)
 {
    *anodes = *nnodes = NULL;
    for (NodeSet::iterator i = nodes->begin(); i != nodes->end(); ) {
        If ((*i)->is_accept()) {
            if (!*anodes)
                *anodes = new NodeSet;
            (*anodes)->insert(*i);
            NodeSet::iterator k = i++;
            nodes->erase(k);
        } else
             i++;
    }
 
    if (nodes->size() > 0 || !*anodes) {
        *nnodes = nodes;
    } else {
        delete nodes;
    }
}

(Please forgive the formatting, blackberry is surely not vim.)

I'm going around in circles trying to understand why || was used and how these conditions make sense in the end. I think I'd feel better if all the non-accept nodes were appended to nnodes in the body of the loop instead, but I'm not convinced that would be the same behavior.

What am I missing?

Thanks