fix: AORRTC segfault when no nearest neighbors are within distance threshold (#79)

* fixes aorrtc segfault when no nearest neighbors are within distance threshold

* tweak comment

* ran clang-format

* format attempt

Author: wernerpe

src/impl/vamp/planning/aorrtc.hh

@@ -69,6 +69,12 @@ namespace vamp::planning
             auto temp_node = NNNode{0, cost, c};
             nn->nearestR(temp_node, NNNode::distance(temp_node, root), near_list);
 
+            // Explicitly handle case where no neighbors are within r distance.
+            if (near_list.empty())
+            {
+                return {root, c.distance(root.array)};
+            }
+
             const auto *new_nearest_node = &near_list[0];
             float new_nearest_distance = c.distance(new_nearest_node->array);