1 files changed, 19 insertions, 0 deletions
diff --git a/test/ruby/test_iseq.rb b/test/ruby/test_iseq.rb
index 8e6087f667..924c144702 100644
--- a/test/ruby/test_iseq.rb
+++ b/test/ruby/test_iseq.rb
@@ -859,6 +859,25 @@ class TestISeq < Test::Unit::TestCase
     end
   end
 
+  def test_serialize_anonymous_outer_variables
+    iseq = RubyVM::InstructionSequence.compile(<<~'RUBY')
+      obj = Object.new
+      def obj.test
+        [1].each do
+          raise "Oops"
+        rescue
+          return it
+        end
+      end
+      obj
+    RUBY
+
+    binary = iseq.to_binary # [Bug # 21370]
+    roundtripped_iseq = RubyVM::InstructionSequence.load_from_binary(binary)
+    object = roundtripped_iseq.eval
+    assert_equal 1, object.test
+  end
+
   def test_loading_kwargs_memory_leak
     assert_no_memory_leak([], "#{<<~"begin;"}", "#{<<~'end;'}", rss: true)
     a = iseq_to_binary(RubyVM::InstructionSequence.compile("foo(bar: :baz)"))