2 files changed, 27 insertions, 0 deletions
diff --git a/actionpack/test/controller/url_for_test.rb b/actionpack/test/controller/url_for_test.rb
index ba24e7fac5..088ad73f2f 100644
--- a/actionpack/test/controller/url_for_test.rb
+++ b/actionpack/test/controller/url_for_test.rb
@@ -89,6 +89,13 @@ module AbstractController
         )
       end
 
+      def test_subdomain_may_be_removed_with_blank_string
+        W.default_url_options[:host] = 'api.basecamphq.com'
+        assert_equal('http://basecamphq.com/c/a/i',
+          W.new.url_for(:subdomain => '', :controller => 'c', :action => 'a', :id => 'i')
+        )
+      end
+
       def test_multiple_subdomains_may_be_removed
         W.default_url_options[:host] = 'mobile.www.api.basecamphq.com'
         assert_equal('http://basecamphq.com/c/a/i',
diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index 29703dd5b1..208c0d38a3 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -3322,6 +3322,10 @@ class TestUrlConstraints < ActionDispatch::IntegrationTest
       end
 
       get '/' => ok, :as => :alternate_root, :constraints => { :port => 8080 }
+
+      get '/search' => ok, :constraints => { :subdomain => false }
+
+      get '/logs' => ok, :constraints => { :subdomain => true }
     end
   end
 
@@ -3348,6 +3352,22 @@ class TestUrlConstraints < ActionDispatch::IntegrationTest
     get 'http://www.example.com:8080/'
     assert_response :success
   end
+
+  test "false constraint expressions check for absence of values" do
+    get 'http://example.com/search'
+    assert_response :success
+
+    get 'http://api.example.com/search'
+    assert_response :not_found
+  end
+
+  test "true constraint expressions check for presence of values" do
+    get 'http://api.example.com/logs'
+    assert_response :success
+
+    get 'http://example.com/logs'
+    assert_response :not_found
+  end
 end
 
 class TestInvalidUrls < ActionDispatch::IntegrationTest