From 97d472bf6aae5be5ff223c95f148b6da1016ecd4 Mon Sep 17 00:00:00 2001
From: MadMaurice <madmaurice@zom.bi>
Date: Sat, 10 Apr 2021 22:35:50 +0200
Subject: [PATCH] equal: nil equals nil

---
 lib/Minilisp.pm | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/Minilisp.pm b/lib/Minilisp.pm
index e01a4ba..df1d8ac 100644
--- a/lib/Minilisp.pm
+++ b/lib/Minilisp.pm
@@ -199,7 +199,11 @@ sub lisp_format {
 
 sub lisp_equal {
   my ($a, $b) = @_;
-  if ( ref($a) eq "ARRAY" && ref($b) eq "ARRAY" )
+  if ( !defined($a) && !defined($b) )
+    {
+      return LISP_TRUE;
+    }
+  elsif ( ref($a) eq "ARRAY" && ref($b) eq "ARRAY" )
     {
       return LISP_FALSE unless scalar(@$a) == scalar(@$b);