From cd03fafb27f2e77d4c87bebd2b28926f20124c4b Mon Sep 17 00:00:00 2001
From: Kyle Banker <kylebanker@gmail.com>
Date: Tue, 12 Oct 2010 15:53:10 -0400
Subject: [PATCH] RUBY-187 ByteBuffer should take another ByteBuffer as initial
 data

---
 lib/bson/byte_buffer.rb | 18 +++++++++++-------
 test/bson/bson_test.rb  |  5 +++++
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/lib/bson/byte_buffer.rb b/lib/bson/byte_buffer.rb
index f4e6016..56bd8da 100644
--- a/lib/bson/byte_buffer.rb
+++ b/lib/bson/byte_buffer.rb
@@ -23,15 +23,19 @@ module BSON
     attr_reader :order
 
     def initialize(initial_data="")
-      if initial_data.is_a?(String)
-        if initial_data.respond_to?(:force_encoding)
-          @str = initial_data.force_encoding('binary')
+      @str = case initial_data
+        when String then
+          if initial_data.respond_to?(:force_encoding)
+            initial_data.force_encoding('binary')
+          else
+            initial_data
+          end
+        when BSON::ByteBuffer then
+          initial_data.to_a.pac('C*')
         else
-          @str = initial_data
-        end
-      else
-        @str = initial_data.pack('C*')
+          initial_data.pack('C*')
       end
+
       @cursor = @str.length
       @order  = :little_endian
       @int_pack_order    = 'V'
diff --git a/test/bson/bson_test.rb b/test/bson/bson_test.rb
index c91a510..f158ec4 100644
--- a/test/bson/bson_test.rb
+++ b/test/bson/bson_test.rb
@@ -74,6 +74,11 @@ class BSONTest < Test::Unit::TestCase
     end
   end
 
+  def test_round_trip
+    doc = {'doc' => 123}
+    @encoder.deserialize(@encoder.serialize(doc))
+  end
+
   # In 1.8 we test that other string encodings raise an exception.
   # In 1.9 we test that they get auto-converted.
   if RUBY_VERSION < '1.9'