From 3702f9bdfd73a567c2bc6b417e44349318ea7f79 Mon Sep 17 00:00:00 2001
From: Thomas Vachuska <tom@opennetworking.org>
Date: Mon, 19 Mar 2018 15:21:50 -0700
Subject: [PATCH] ONOS-7490 Fixed NPE in Suurballe graph search.

Change-Id: Ib84e788988961e3802b8a09b8702df1f75380ae3
---
 .../src/main/java/org/onlab/graph/SuurballeGraphSearch.java | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/utils/misc/src/main/java/org/onlab/graph/SuurballeGraphSearch.java b/utils/misc/src/main/java/org/onlab/graph/SuurballeGraphSearch.java
index 395a00fff3..ca4be92b90 100644
--- a/utils/misc/src/main/java/org/onlab/graph/SuurballeGraphSearch.java
+++ b/utils/misc/src/main/java/org/onlab/graph/SuurballeGraphSearch.java
@@ -69,8 +69,10 @@ public class SuurballeGraphSearch<V extends Vertex, E extends Edge<V>> extends D
                 public Weight weight(E edge) {
                     return edge instanceof ReverseEdge ?
                             weightf.getInitialWeight() :
-                            weightf.weight(edge).merge(firstDijkstra.cost(edge.src()))
-                                    .subtract(firstDijkstra.cost(edge.dst()));
+                            (weightf.weight(edge).isNegative() ?
+                                    new ScalarWeight(-1.0) :
+                                    weightf.weight(edge).merge(firstDijkstra.cost(edge.src()))
+                                            .subtract(firstDijkstra.cost(edge.dst())));
                 }
 
                 @Override