From 3bb50ce3af214c6435d08000d04343227a31fe0f Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Thu, 25 Jul 2013 10:21:17 -0500
Subject: [PATCH] handle possible stack expansion or gc

---
 packages/yap-lbfgs/yap_lbfgs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/yap-lbfgs/yap_lbfgs.c b/packages/yap-lbfgs/yap_lbfgs.c
index 57008eaa6..0b852976d 100644
--- a/packages/yap-lbfgs/yap_lbfgs.c
+++ b/packages/yap-lbfgs/yap_lbfgs.c
@@ -51,6 +51,7 @@ static lbfgsfloatval_t evaluate(
 {
   YAP_Term call;
   YAP_Bool result;
+  YAP_Int s1;
 
   YAP_Term t[3];
 
@@ -61,6 +62,8 @@ static lbfgsfloatval_t evaluate(
   call = YAP_MkApplTerm(fcall3, 3, t);
   g=g_tmp;  
 
+  
+  s1 = YAP_InitSlot(call);
   optimizer_status=OPTIMIZER_STATUS_CB_EVAL;
   result=YAP_CallProlog(call);
   optimizer_status=OPTIMIZER_STATUS_RUNNING;
@@ -71,6 +74,7 @@ static lbfgsfloatval_t evaluate(
     return FALSE;
   }
 
+  call = YAP_GetFromSlot( s1 );
   if (YAP_IsFloatTerm(YAP_ArgOfTerm(1,call))) {
     return (lbfgsfloatval_t) YAP_FloatOfTerm(YAP_ArgOfTerm(1,call));
   } else if (YAP_IsIntTerm(YAP_ArgOfTerm(1,call))) {