heteroprio: check that graph is available before accessing it

src/sched_policies/heteroprio.c

@@ -2745,6 +2745,13 @@ static double get_job_NOD(struct _starpu_heteroprio_data *hp, struct _starpu_job
 
 	struct _starpu_graph_node *node = job->graph_node;
 
+	if(!node)
+	{
+		// No information because the graph isn't available
+		_starpu_graph_wrunlock();
+		return 0.f;
+	}
+
 	unsigned n;
 	for(n=0;n<node->n_outgoing;++n)
 	{
@@ -2782,6 +2789,13 @@ static double get_job_NRT(struct _starpu_heteroprio_data *hp, struct _starpu_job
 
 	struct _starpu_graph_node *node = job->graph_node;
 
+	if(!node)
+	{
+		// No information because the graph isn't available
+		_starpu_graph_wrunlock();
+		return 0.f;
+	}
+
 	unsigned n;
 	for(n=0;n<node->n_outgoing;++n)
 	{
@@ -2885,6 +2899,13 @@ static double get_job_successors_best_time_sum(struct _starpu_heteroprio_data *h
 
 	struct _starpu_graph_node *node = job->graph_node;
 
+	if(!node)
+	{
+		// No information because the graph isn't available
+		_starpu_graph_wrunlock();
+		return 0.f;
+	}
+
 	unsigned n;
 	for(n=0;n<node->n_outgoing;++n)
 	{