small bug in markdownify to prevent barfing with a nil message

app/helpers/markdownify_helper.rb

@@ -6,6 +6,7 @@ require File.expand_path("#{Rails.root}/lib/diaspora/markdownify")
 
 module MarkdownifyHelper
   def markdownify(message, render_options={})
+    return '' if message.blank?
     markdown_options = {
       :autolink            => true,
       :fenced_code_blocks  => true,

spec/helpers/markdownify_helper_spec.rb

@@ -290,6 +290,10 @@ describe MarkdownifyHelper do
       end
     end
 
+    it 'does not barf is message is nil' do
+      markdownify(nil).should == ''
+    end
+
     context 'performance' do
       before do
         @message = "HHello,Hello_, I _am a strong robot.*Hello, I am *a strong robot.Hello, I am a strong robot.Hello, I am a strong robot.Hello, I am a strong robot.Hello, I am a **strong robot.Hello, I am _a _strong *robot**.Hello*, I am a strong "