Check for position info in graph

diff --git a/cmd/mingle/minglemain.c b/cmd/mingle/minglemain.c
index 90c3705e930604412d98cdc93be2e8599b0192cd..1e87c1c65154344432bed55bcf0ac899708ea1a9 100644 (file)
--- a/cmd/mingle/minglemain.c
+++ b/cmd/mingle/minglemain.c
@@ -139,6 +139,10 @@ bundle (Agraph_t* g, opts_t* opts)
                fprintf (stderr, "Error: could not convert graph %s (%s) into matrix\n", agnameof(g), fname);
                return 1;
     }
+    if (x == NULL) {
+               fprintf (stderr, "Error: graph %s (%s) has missing \"pos\" information\n", agnameof(g), fname);
+               return 1;
+    }
 
        A = SparseMatrix_symmetrize(A, TRUE);
        ia = A->ia; ja = A->ja;