Fix bug 1178

diff --git a/lib/fdpgen/layout.c b/lib/fdpgen/layout.c
index a43d6ff02323b28f286f521900bb06b8a4043111..5696a3a9035bf99380bbe8da8b81f0673bdd5c1c 100644 (file)
--- a/lib/fdpgen/layout.c
+++ b/lib/fdpgen/layout.c
@@ -482,6 +482,10 @@ static graph_t *deriveGraph(graph_t * g, layout_info * infop)
     /* create derived nodes from remaining nodes */
     for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
        if (!DNODE(n)) {
+           if (PARENT(n) && (PARENT(n) != GPARENT(g))) {
+               agerr (AGERR, "node \"%s\" is contained in two non-comparable clusters \"%s\" and \"%s\"\n", n->name, g->name, PARENT(n)->name);
+               exit (1);
+           }
            PARENT(n) = g;
            if (IS_CLUST_NODE(n))
                continue;