fix several issues with goal expansion, crashing after attribute_goals is called

src/prolog/lib/atts.pl

@@ -18,7 +18,8 @@
 
 '$default_attr_list'([PG | PGs], Module, AttrVar) -->
     (  { '$module_of'(Module, PG) } -> [Module:put_atts(AttrVar, PG)]
-    ;  { true } ),
+    ;  true
+    ),
     '$default_attr_list'(PGs, Module, AttrVar).
 '$default_attr_list'([], _, _) --> [].
 

src/prolog/lib/builtins.pl

@@ -160,6 +160,7 @@ comma_errors(G1, G2, B) :- '$call_with_default_policy'(','(G1, G2, B)).
 :- non_counted_backtracking (;)/3.
 ;(G1, G4, B) :- compound(G1),
 		'$call_with_default_policy'(G1 = ->(G2, G3)),
+		!,
 		(G2 -> G3 ; '$set_cp'(B), G4).
 ;(G1, G2, B) :- G1 == !, '$set_cp'(B), G2.
 ;(G1, G2, B) :- G2 == !, G1, '$set_cp'(B).

src/prolog/lib/dcgs.pl

@@ -7,16 +7,7 @@
 
 user:term_expansion(Term0, (Head :- Body)) :-
     dcg_rule(Term0, Term),
-    Term = (Head :- Body0),
-    unravel_commas(Body0, Body).
-
-unravel_commas(((A, B), C), Body) :-
-    !,
-    unravel_commas((B, C), Body0),
-    unravel_commas((A, Body0), Body).
-unravel_commas((A, B), (A, Body0)) :-
-    !, unravel_commas(B, Body0).
-unravel_commas(Body, Body).
+    Term = (Head :- Body).
 
 phrase(GRBody, S0) :-
     phrase(GRBody, S0, []).