gistfile1.txt

commit c9a6811cc39b6fe9a3a8cf460b89eccecc9b5135
Author: Dave Grijalva <grijalva@gmail.com>
Date:   Wed Aug 25 15:52:17 2010 -0700

    fixed encoding of negative bignums

diff --git a/lib/bert/encode.rb b/lib/bert/encode.rb
index 98ef5b2..73606f5 100644
--- a/lib/bert/encode.rb
+++ b/lib/bert/encode.rb
@@ -78,7 +78,7 @@ module BERT
     end
 
     def write_bignum(num)
-      n = (num.to_s(2).size / 8.0).ceil
+      n = (num.abs.to_s(2).size / 8.0).ceil
       if n < 256
         write_1 SMALL_BIGNUM
         write_1 n
diff --git a/test/encoder_test.rb b/test/encoder_test.rb
index b304c3e..0241990 100644
--- a/test/encoder_test.rb
+++ b/test/encoder_test.rb
@@ -82,6 +82,9 @@ class EncoderTest < Test::Unit::TestCase
     should "handle bignums" do
       bert = [131,110,8,0,0,0,232,137,4,35,199,138].pack('c*')
       assert_equal bert, BERT::Encoder.encode(10_000_000_000_000_000_000)
+
+      bert = [131,110,8,1,0,0,232,137,4,35,199,138].pack('c*')
+      assert_equal bert, BERT::Encoder.encode(-10_000_000_000_000_000_000)
     end
 
     should "leave other stuff alone" do