From 5de340e79f1d11973b7c7bbec82f320fc92b9c99 Mon Sep 17 00:00:00 2001
From: Joshua Peek <josh@joshpeek.com>
Date: Tue, 19 Aug 2008 19:20:10 -0500
Subject: [PATCH] Ensure objects cached with MemoryStore are immutable

---
 activesupport/lib/active_support/cache/memory_store.rb | 2 +-
 activesupport/test/caching_test.rb                     | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/activesupport/lib/active_support/cache/memory_store.rb b/activesupport/lib/active_support/cache/memory_store.rb
index 7ac6f35357..f3e4b8c13b 100644
--- a/activesupport/lib/active_support/cache/memory_store.rb
+++ b/activesupport/lib/active_support/cache/memory_store.rb
@@ -22,7 +22,7 @@ module ActiveSupport
       def write(name, value, options = nil)
         @guard.synchronize do
           super
-          @data[name] = value
+          @data[name] = value.freeze
         end
       end
 
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index ce27b464f8..9ea9389448 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -120,4 +120,10 @@ class MemoryStoreTest < Test::Unit::TestCase
   def test_fetch_with_forced_cache_miss
     @cache.fetch('foo', :force => true) { 'bar' }
   end
+
+  def test_store_objects_should_be_immutable
+    @cache.write('foo', 'bar')
+    assert_raise(ActiveSupport::FrozenObjectError) { @cache.read('foo').gsub!(/.*/, 'baz') }
+    assert_equal 'bar', @cache.read('foo')
+  end
 end