ensure you're actually working with real lines, not assuming the return value is an array you can mutate, fixes #6

config.ru

@@ -5,10 +5,13 @@ require 'rack/livereload'
 
 use Rack::Logger
 use Rack::LiveReload
+run Rack::Directory.new('.')
+
+if false
 
 get '/' do
   File.read('index.html')
 end
 
 run Sinatra::Application
-
+end

lib/rack/livereload.rb

@@ -49,10 +49,14 @@ module Rack
       else
         status, headers, body = @app.call(env)
 
+        new_body = body.dup
+
         if !ignored?(env['PATH_INFO']) && !bad_browser?(env['HTTP_USER_AGENT'])
           if headers['Content-Type'][%r{text/html}]
             content_length = 0
 
+            new_body = []
+
             body.each do |line|
               if !headers['X-Rack-LiveReload'] && line['</head>']
                 host_to_use = (@options[:host] || env['HTTP_HOST'] || 'localhost').gsub(%r{:.*}, '')
@@ -75,13 +79,15 @@ module Rack
               end
 
               content_length += line.length
+
+              new_body << line
             end
 
             headers['Content-Length'] = content_length.to_s
           end
         end
 
-        [ status, headers, body ]
+        [ status, headers, new_body ]
       end
     end