From feb70d01466f4ba65fcea4e1f70a561a4fe81303 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Sun, 25 Nov 2012 23:35:59 +0000
Subject: [PATCH] fix absolute_file_name with empty arguments.

---
 pl/consult.yap | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pl/consult.yap b/pl/consult.yap
index a8825ede8..6d4fd5440 100644
--- a/pl/consult.yap
+++ b/pl/consult.yap
@@ -649,8 +649,10 @@ absolute_file_name(File0,File) :-
 '$full_filename'(F0,F,G) :-
 	'$absolute_file_name'(F0,[access(read),file_type(source),file_errors(fail),solutions(first),expand(true)],F,G).
 
+% fix wrong argument order, TrueFileName should be last.
 absolute_file_name(File,TrueFileName,Opts) :-
-	( var(TrueFileName) ; atom(TrueFileName) ), !,
+	( var(TrueFileName) -> true ; atom(TrueFileName), TrueFileName \= [] ),
+	!,
 	absolute_file_name(File,Opts,TrueFileName).
 absolute_file_name(File,Opts,TrueFileName) :-
 	'$absolute_file_name'(File,Opts,TrueFileName,absolute_file_name(File,Opts,TrueFileName)).