From 0546df7ac38f252b819698b524e223ea7da3a793 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Mon, 1 Mar 2010 22:30:31 +0000
Subject: [PATCH] fix goal_expansion

---
 pl/modules.yap | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/pl/modules.yap b/pl/modules.yap
index e84aeff15..192058c52 100644
--- a/pl/modules.yap
+++ b/pl/modules.yap
@@ -297,7 +297,8 @@ module(N) :-
 '$module_expansion'(M:G,G1,GO,_,CM,_,HVars) :- !,
 	'$module_expansion'(G,G1,GO,M,M,HM,HVars).
 '$module_expansion'(G, G1, GO, CurMod, MM, HM, HVars) :-
-	'$do_expand'(CurMod:G, CurMod:GI), !,
+	'$pred_goal_expansion_on',
+	'$do_expand'(G, CurMod, GI), !,
 	'$module_expansion'(GI, G1, GO, CurMod, MM, HM, HVars).
 '$module_expansion'(G, G1, GO, CurMod, MM, HM,HVars) :-
 	% is this imported from some other module M1?
@@ -310,24 +311,25 @@ module(N) :-
 '$module_expansion'(G, G1, GO, CurMod, MM, HM, HVars) :-
 	'$complete_goal_expansion'(G, CurMod, MM, HM, G1, GO, HVars).
 
-expand_goal(G, NG) :-
-	'$current_module'(Mod),
-	'$do_expand'(G, M, NG), !.
+expand_goal(G, G) :-
+	var(G), !.
 expand_goal(M:G, M:NG) :-
 	'$do_expand'(G, M, NG), !.
+expand_goal(G, NG) :- 
+	'$current_module'(Mod),
+	'$do_expand'(G, M, NG), !.
 expand_goal(G, G).
 	
-'$do_expand'(G, CurMod, NG) :-
-	'$pred_goal_expansion_on',
-	( user:goal_expansion(G, CurMod, GI)
+'$do_expand'(G, CurMod, GI) :-
+	(
+	 '$pred_exists'(goal_expansion(G,GI), CurMod),
+	 call(CurMod:goal_expansion(G, GI))
+	->
+	 true
+	;
+	 user:goal_expansion(G, CurMod, GI)
 	->
 	  true
-	;
-	  (
-	   '$pred_exists'(goal_expansion(G,GI), CurMod)
-	  ->
-	   call(CurMod:goal_expansion(G, GI))
-	  )
 	;
 	  user:goal_expansion(G, GI)
 	).