minor: patch for JRuby 1.9 MD5 comparison bug

lib/mongo.rb

@@ -50,4 +50,9 @@ require 'mongo/exceptions'
 require 'mongo/gridfs/grid_ext'
 require 'mongo/gridfs/grid'
 require 'mongo/gridfs/grid_io'
+if RUBY_PLATFORM =~ /java/
+  require 'mongo/gridfs/grid_io_fix'
+end
 require 'mongo/gridfs/grid_file_system'
+
+

lib/mongo/gridfs/grid_io_fix.rb

@@ -0,0 +1,38 @@
+# encoding: UTF-8
+
+# --
+# Copyright (C) 2008-2010 10gen Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ++
+
+module Mongo
+  class GridIO
+
+    # This fixes a comparson issue in JRuby 1.9
+    def get_md5
+      md5_command            = BSON::OrderedHash.new
+      md5_command['filemd5'] = @files_id
+      md5_command['root']    = @fs_name
+      @server_md5 = @files.db.command(md5_command)['md5']
+      if @safe
+        @client_md5 = @local_md5.hexdigest
+        if @local_md5.to_s != @server_md5.to_s
+          raise GridMD5Failure, "File on server failed MD5 check"
+        end
+      else
+        @server_md5
+      end
+    end
+  end
+end