Fix OrderedHash#replace

Signed-off-by: Michael Koziarski <michael@koziarski.com>

activesupport/lib/active_support/ordered_hash.rb

@@ -120,6 +120,13 @@ module ActiveSupport
         dup.merge!(other_hash)
       end
 
+      # When replacing with another hash, the initial order of our keys must come from the other hash -ordered or not.
+      def replace(other)
+        super
+        @keys = other.keys
+        self
+      end
+
       def inspect
         "#<OrderedHash #{super}>"
       end

activesupport/test/ordered_hash_test.rb

@@ -191,4 +191,11 @@ class OrderedHashTest < Test::Unit::TestCase
       assert_equal "odd number of arguments for Hash", $!.message
     end
   end
+
+  def test_replace_updates_keys
+    @other_ordered_hash = ActiveSupport::OrderedHash[:black, '000000', :white, '000000']
+    original = @ordered_hash.replace(@other_ordered_hash)
+    assert_same original, @ordered_hash
+    assert_equal @other_ordered_hash.keys, @ordered_hash.keys
+  end
 end