make BSON::OrderedHash equal to other types of hashes in both directions

lib/bson/ordered_hash.rb

@@ -27,9 +27,12 @@ module BSON
 
     def ==(other)
       begin
-        !other.nil? &&
-          keys == other.keys &&
-          values == other.values
+        case other
+        when BSON::OrderedHash
+           keys == other.keys && values == other.values
+        else
+          !other.nil? && keys.size == other.keys.size && keys.all? {|x| self[x] == other[x] }
+        end
       rescue
         false
       end

test/mongo_bson/ordered_hash_test.rb

@@ -140,6 +140,16 @@ class OrderedHashTest < Test::Unit::TestCase
     assert_equal ['crab', 'apple', 3, 'foo'], @oh.values
   end
 
+  def test_equality_with_hash
+    o = BSON::OrderedHash.new
+    o[:a] = 1
+    o[:b] = 2
+    o[:c] = 3
+    r = {:a => 1, :b => 2, :c => 3}
+    assert r == o
+    assert o == r
+  end
+
   def test_update
     other = BSON::OrderedHash.new
     other['f'] = 'foo'