From a14915ca4baae40f08d288a38b8bfb595500ad90 Mon Sep 17 00:00:00 2001
From: Jeremy Evans <code@jeremyevans.net>
Date: Wed, 21 Jun 2023 09:44:30 -0700
Subject: [PATCH] Do not have Enumeratory::Lazy#zip mark result as packed

Fixes [Bug #19569]
---
 enumerator.c                      | 1 -
 test/ruby/test_lazy_enumerator.rb | 5 +++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/enumerator.c b/enumerator.c
index b33c171371..1058e331bb 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -2369,7 +2369,6 @@ lazy_zip_arrays_func(VALUE proc_entry, struct MEMO *result, VALUE memos, long me
         rb_ary_push(ary, rb_ary_entry(RARRAY_AREF(arrays, i), count));
     }
     LAZY_MEMO_SET_VALUE(result, ary);
-    LAZY_MEMO_SET_PACKED(result);
     rb_ary_store(memos, memo_index, LONG2NUM(++count));
     return result;
 }
diff --git a/test/ruby/test_lazy_enumerator.rb b/test/ruby/test_lazy_enumerator.rb
index 32bf097318..22127e903a 100644
--- a/test/ruby/test_lazy_enumerator.rb
+++ b/test/ruby/test_lazy_enumerator.rb
@@ -282,6 +282,11 @@ class TestLazyEnumerator < Test::Unit::TestCase
     assert_equal(3, a.current)
   end
 
+  def test_zip_map_lambda_bug_19569
+    ary = [1, 2, 3].to_enum.lazy.zip([:a, :b, :c]).map(&:last).to_a
+    assert_equal([:a, :b, :c], ary)
+  end
+
   def test_take
     a = Step.new(1..10)
     assert_equal(1, a.take(5).first)