Index: autoroute.c
===================================================================
--- autoroute.c	(revision 37979)
+++ autoroute.c	(revision 37980)
@@ -1179,7 +1179,7 @@
 		vtp0_init(&layergroupboxes[i]);
 		PCB_COPPER_GROUP_LOOP(PCB->Data, i);
 		{
-			if (!RND_RTREE_EMPTY(layer->line_tree) || !RND_RTREE_EMPTY(layer->arc_tree))
+			if (!RTREE_EMPTY(layer->line_tree) || !RTREE_EMPTY(layer->arc_tree))
 				usedGroup[i] = rnd_true;
 			else
 				usedGroup[i] = rnd_false;
Index: r_legacy.h
===================================================================
--- r_legacy.h	(revision 37979)
+++ r_legacy.h	(revision 37980)
@@ -1,6 +1,8 @@
 /* Recurring legacy rtree operations for autoroute and autoplace
    DO NOT USE IN NEW CODE */
 
+#define RTREE_EMPTY(rt) (((rt) == NULL) || ((rt)->size == 0))
+
 RND_INLINE void r_free_tree_data(rnd_rtree_t *rtree, void (*free)(void *ptr))
 {
 	rnd_rtree_it_t it;