RUBY-287 OrderedHash#replace

lib/bson/ordered_hash.rb

@@ -94,6 +94,11 @@ module BSON
         collect { |k, v| v }
       end
 
+      def replace(other)
+        @ordered_keys = other.keys
+        super
+      end
+
       def merge(other)
         oh = self.dup
         oh.merge!(other)

test/bson/ordered_hash_test.rb

@@ -76,6 +76,20 @@ class OrderedHashTest < Test::Unit::TestCase
     assert_equal @ordered_keys, @oh.keys
   end
 
+  def test_replace
+    h1 = BSON::OrderedHash.new
+    h1[:a] = 1
+    h1[:b] = 2
+
+    h2 = BSON::OrderedHash.new
+    h2[:c] = 3
+    h2[:d] = 4
+    h1.replace(h2)
+
+    assert_equal [:c, :d], h1.keys
+    assert_equal [3, 4], h1.values
+  end
+
   def test_to_a_order_preserved
     assert_equal @ordered_keys, @oh.to_a.map {|m| m.first}
   end