From 63db194140145d67681b5f16c8df8a87fc783d52 Mon Sep 17 00:00:00 2001
From: Paulo Moura <>
Date: Mon, 10 May 2021 00:37:09 +0100
Subject: [PATCH] Fix char_code/2 predicate failure instead of exception on
 non-integer second argument

---
 src/lib/builtins.pl | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lib/builtins.pl b/src/lib/builtins.pl
index 502827b6..49b352e7 100644
--- a/src/lib/builtins.pl
+++ b/src/lib/builtins.pl
@@ -1293,7 +1293,12 @@ char_code(Char, Code) :-
        ;  throw(error(type_error(integer, Code), char_code/2))
        )
     ;  atom_length(Char, 1) ->
-       '$char_code'(Char, Code)
+       (  var(Code) ->
+          '$char_code'(Char, Code)
+       ;  integer(Code) ->
+          '$char_code'(Char, Code)
+       ;  throw(error(type_error(integer, Code), char_code/2))
+       )
     ;  throw(error(type_error(character, Char), char_code/2))
     ).
 
-- 
2.54.0