Copy PR #420 from Scryer. Fixes triska#27

mthom/scryer-prolog#420

clpz.pl

@@ -7375,22 +7375,26 @@
 
 verify_attributes(Var, Other, Gs) :-
         % portray_clause(Var = Other),
-        (   get_attr(Var, clpz, clpz_attr(_,_,_,Dom,Ps,Q)) ->
+        (   get_atts(Var, clpz(CLPZ)) ->
+            CLPZ = clpz_attr(_,_,_,Dom,Ps,Q),
             (   nonvar(Other) ->
                 (   integer(Other) -> true
                 ;   type_error(integer, Other)
                 ),
                 domain_contains(Dom, Other),
                 phrase(trigger_props(Ps), [Q], [_]),
                 Gs = [phrase(do_queue, [Q], _)]
-            ;   fd_get(Other, OD, OPs),
-                domains_intersection(OD, Dom, Dom1),
-                append_propagators(Ps, OPs, Ps1),
-                new_queue(Q0),
-                variables_same_queue([Var,Other]),
-                phrase((fd_put(Other,Dom1,Ps1),
-                        trigger_props(Ps1)), [Q0], _),
+            ;   (   get_atts(Other, clpz(clpz_attr(_,_,_,OD,OPs,_))) ->
+                    domains_intersection(OD, Dom, Dom1),
+                    append_propagators(Ps, OPs, Ps1),
+                    new_queue(Q0),
+                    variables_same_queue([Var,Other]),
+                    phrase((fd_put(Other,Dom1,Ps1),
+                            trigger_props(Ps1)), [Q0], _),
                 Gs = [phrase(do_queue, [Q0], _)]
+                ;   put_atts(Other, clpz(CLPZ)),
+                    Gs = []
+                )
             )
         ;   Gs = []
         ).