Test added

test/integration/app.rb

@@ -49,6 +49,18 @@ get '/send_file' do
   send_file file
 end
 
+get '/streaming' do
+  headers['Content-Length'] = '46'
+  stream do |out|
+    out << "It's gonna be legen -\n"
+    sleep 0.5
+    out << " (wait for it) \n"
+    puts headers
+    sleep 1
+    out << "- dary!\n"
+  end
+end
+
 class Subclass < Sinatra::Base
   set :out, nil
   get '/subclass/async' do

test/integration_test.rb

@@ -96,4 +96,9 @@ class IntegrationTest < Test::Unit::TestCase
     response = server.get_response '/send_file'
     assert response['Content-Length']
   end
-end
+
+  it "doesn't ignore Content-Length header when streaming" do
+    response = server.get_response '/streaming'
+    assert response['Content-Length'], '46'
+  end
+end