art_iter_prefix depth goes over key_len

[lmcmgig]

With a specific data set, the art_iter_prefix find a full_match and goes deeper of the key_len.

// Bail if the prefix does not match
if (n->partial_len) {
[...]
// if there is a full match, go deeper
depth = depth + n->partial_len;
}
[...]
child = find_child(n, key[depth]); //KABOOUM when key_len is less than the depth

Simply change? :

            // If we've matched the prefix, iterate on this node
            if (prefix_len && ((depth + prefix_len) == key_len)) {
                return recursive_iter(n, cb, data);

            // If mismatch or no match, search is terminated
            } else if(prefix_len < n->partial_len) {
                return 0;
            }

Not 100% sure is the optimal solution.