From: Paulo Moura <pmoura@logtalk.org>
Date: Sun, 16 May 2021 22:49:21 +0000 (+0100)
Subject: Fix current_predicate/1 predicate error checking
X-Git-Tag: v0.9.0~63^2
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=0e263dd7536dff8a98ae6f94b62bbd45051c0b2a;p=scryer-prolog.git

Fix current_predicate/1 predicate error checking
---

diff --git a/src/lib/builtins.pl b/src/lib/builtins.pl
index 334deb66..616a2b0d 100644
--- a/src/lib/builtins.pl
+++ b/src/lib/builtins.pl
@@ -1083,8 +1083,17 @@ abolish(Pred) :-
 
 
 current_predicate(Pred) :-
-    (  nonvar(Pred), Pred \= _ / _
-    -> throw(error(type_error(predicate_indicator, Pred), current_predicate/1))
+    (  var(Pred) ->
+       '$get_next_db_ref'(Ref, _),
+       '$iterate_db_refs'(Ref, Pred)
+    ;  Pred \= _/_ ->
+       throw(error(type_error(predicate_indicator, Pred), current_predicate/1))
+    ;  Pred = Name/Arity,
+       (  nonvar(Name), \+ atom(Name)
+       ;  nonvar(Arity), \+ integer(Arity)
+       ;  integer(Arity), Arity < 0
+       ) ->
+       throw(error(type_error(predicate_indicator, Pred), current_predicate/1))
     ;  '$get_next_db_ref'(Ref, _),
        '$iterate_db_refs'(Ref, Pred)
     ).