From 5c6c034ec910b3cb3fda3bb91a3965d2a0df97f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Sun, 18 Mar 2012 00:07:06 +0000
Subject: [PATCH] generate type error on second arg to term variables/2 (UN
 198)

---
 C/utilpreds.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/C/utilpreds.c b/C/utilpreds.c
index a0bf851b5..851aa4fc7 100644
--- a/C/utilpreds.c
+++ b/C/utilpreds.c
@@ -1955,6 +1955,11 @@ p_term_variables( USES_REGS1 )	/* variables in term t		 */
 {
   Term out;
 
+  if (!Yap_IsListOrPartialListTerm(ARG2)) {
+    Yap_Error(TYPE_ERROR_LIST,ARG2,"term_variables/2");
+    return FALSE;
+  }
+
   do {
     Term t = Deref(ARG1);
     if (IsVarTerm(t)) {