adds check for :static_cache_control setting to Sinatra::Base.static!

lib/sinatra/base.rb

@@ -708,6 +708,7 @@ module Sinatra
       return unless path.start_with?(public_dir) and File.file?(path)
 
       env['sinatra.static_file'] = path
+      cache_control *settings.static_cache_control if settings.static_cache_control?
       send_file path, :disposition => nil
     end
 
@@ -1339,6 +1340,7 @@ module Sinatra
 
     set :public, Proc.new { root && File.join(root, 'public') }
     set :static, Proc.new { public && File.exist?(public) }
+    set :static_cache_control, false
 
     error ::Exception do
       response.status = 500

test/static_test.rb

@@ -154,4 +154,25 @@ class StaticTest < Test::Unit::TestCase
       assert_equal "bytes */#{length}",response['Content-Range'], "416 response should include actual length"
     end
   end
+
+  it 'does not include static cache control headers by default' do
+    env = Rack::MockRequest.env_for("/#{File.basename(__FILE__)}")
+    status, headers, body = @app.call(env)
+    assert !headers.has_key?('Cache-Control')
+  end
+
+  it 'sets cache control headers on static files if set' do
+    @app.set :static_cache_control, :public
+    env = Rack::MockRequest.env_for("/#{File.basename(__FILE__)}")
+    status, headers, body = @app.call(env)
+    assert headers.has_key?('Cache-Control')
+    assert_equal headers['Cache-Control'], 'public'
+
+    @app.set :static_cache_control, [:public, :must_revalidate, {:max_age => 300}]
+    env = Rack::MockRequest.env_for("/#{File.basename(__FILE__)}")
+    status, headers, body = @app.call(env)
+    assert headers.has_key?('Cache-Control')
+    assert_equal headers['Cache-Control'], 'public, must-revalidate, max-age=300'
+  end
+
 end