From 095cd68cacafcc73652638bb987dd6ee3b8319c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Mon, 26 Nov 2012 09:23:25 +0000
Subject: [PATCH] prevent failure in listing X

---
 pl/listing.yap | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pl/listing.yap b/pl/listing.yap
index 771c83c47..305d6603b 100644
--- a/pl/listing.yap
+++ b/pl/listing.yap
@@ -35,7 +35,7 @@ listing(V) :-
 
 '$listing'(V,Mod,Stream) :- var(V), !,
 	'$current_predicate_no_modules'(Mod,_,Pred),
-        '$list_clauses'(Stream,Mod,Pred).
+        ( '$list_clauses'(Stream,Mod,Pred) ; true ).
 '$listing'(M:V,_,Stream) :- !,
 	'$listing'(V,M,Stream).
 '$listing'([],_,_) :- !.