interaction.c: interaction_dump: don't crash on empty interactions (ie those with...

diff --git a/src/math/interaction.c b/src/math/interaction.c
index 706092476ec2b3bb8f3f391de37338ffe2ccdbed..a36755b541265fbc3da3e1ca8fcc465ec0ea120e 100644 (file)
--- a/src/math/interaction.c
+++ b/src/math/interaction.c
@@ -146,11 +146,14 @@ void
 interaction_dump (const struct interaction *i)
 {
   int v = 0;
-  printf ("%s", var_get_name (i->vars[v]));
-  for (v = 1; v < i->n_vars; ++v)
+  if ( i->n_vars == 0)
     {
-      printf (" * %s", var_get_name (i->vars[v]));
+      printf ("(empty)\n");
+      return;
     }
+  printf ("%s", var_get_name (i->vars[v]));
+  for (v = 1; v < i->n_vars; ++v)
+    printf (" * %s", var_get_name (i->vars[v]));
   printf ("\n");
 }