1 files changed, 29 insertions, 0 deletions
diff --git a/activesupport/test/core_ext/module_test.rb b/activesupport/test/core_ext/module_test.rb
index ec9ecd06ee..dd36a9373a 100644
--- a/activesupport/test/core_ext/module_test.rb
+++ b/activesupport/test/core_ext/module_test.rb
@@ -111,6 +111,24 @@ class DecoratedReserved
   end
 end
 
+class Maze
+  attr_accessor :cavern, :passages
+end
+
+class Cavern
+  delegate_missing_to :target
+
+  attr_reader :maze
+
+  def initialize(maze)
+    @maze = maze
+  end
+
+  def target
+    @maze.passages = :twisty
+  end
+end
+
 class Block
   def hello?
     true
@@ -411,6 +429,17 @@ class ModuleTest < ActiveSupport::TestCase
     assert_respond_to DecoratedTester.new(@david), :extra_missing
   end
 
+  def test_delegate_missing_to_does_not_interfere_with_marshallization
+    maze = Maze.new
+    maze.cavern = Cavern.new(maze)
+
+    array = [maze, nil]
+    serialized_array = Marshal.dump(array)
+    deserialized_array = Marshal.load(serialized_array)
+
+    assert_nil deserialized_array[1]
+  end
+
   def test_delegate_with_case
     event = Event.new(Tester.new)
     assert_equal 1, event.foo