don't insert into <header> tags.

lib/rack/livereload.rb

@@ -77,7 +77,7 @@ module Rack
                 template = ERB.new(::File.read(::File.expand_path('../../../skel/livereload.html.erb', __FILE__)))
 
                 if line['<head']
-                  line.gsub!(/<head[^>]*>/) { |match| %{#{match}#{template.result(binding)}} }
+                  line.gsub!(/<head([^(er)]|\s)[^>]*>/) { |match| %{#{match}#{template.result(binding)}} }
                 end
 
                 headers["X-Rack-LiveReload"] = '1'

spec/rack/livereload_spec.rb

@@ -107,6 +107,17 @@ describe Rack::LiveReload do
       end
     end
 
+    context 'in header tags' do
+      let(:page_html) { "<header class='hero'><h1>Just a normal header tag</h1></header>" }
+
+      let(:body_dom) { Nokogiri::XML(body) }
+
+      it 'should not add the livereload js' do
+        body_dom.at_css("header")[:class].should == 'hero'
+        body_dom.css('script').should be_empty
+      end
+    end
+
     context 'not vendored' do
       before do
         middleware.stubs(:use_vendored?).returns(false)