From f7c3aef8301bb5c1bff19ec3415631534ef7d095 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Thu, 2 Jun 2016 10:52:06 +0100
Subject: [PATCH] don't blow  up with bad modules

---
 C/modules.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/C/modules.c b/C/modules.c
index 6f989eb21..98bcf81c3 100644
--- a/C/modules.c
+++ b/C/modules.c
@@ -405,7 +405,9 @@ restart:
       Term t1 = ArgOfTerm(1, t);
       tmod = t1;
       if (!IsVarTerm(tmod) && !IsAtomTerm(tmod)) {
-        return 0L;
+        if (modp)
+          *modp = tmod;
+        return t;
       }
       t = ArgOfTerm(2, t);
       goto restart;
@@ -423,7 +425,7 @@ static Int yap_strip_module(USES_REGS1) {
     tmod = TermProlog;
   }
   t1 = Yap_YapStripModule(t1, &tmod);
-  if (!t1) {
+  if (!t1 || (!IsVarTerm(tmod) && !IsAtomTerm(tmod))) {
     Yap_Error(TYPE_ERROR_CALLABLE, t1, "trying to obtain module");
     return FALSE;
   }