2 files changed, 37 insertions, 6 deletions
diff --git a/railties/test/application/middleware/cache_test.rb b/railties/test/application/middleware/cache_test.rb
index c99666d7e4..b8e0c9be60 100644
--- a/railties/test/application/middleware/cache_test.rb
+++ b/railties/test/application/middleware/cache_test.rb
@@ -81,8 +81,8 @@ module ApplicationTests
       add_to_config "config.action_dispatch.rack_cache = true"
 
       get "/expires/expires_header"
-      assert_equal "miss, store",        last_response.headers["X-Rack-Cache"]
-      assert_equal "max-age=10, public", last_response.headers["Cache-Control"]
+      assert_equal "miss, ignore, store", last_response.headers["X-Rack-Cache"]
+      assert_equal "max-age=10, public",  last_response.headers["Cache-Control"]
 
       body = last_response.body
 
@@ -115,8 +115,8 @@ module ApplicationTests
       add_to_config "config.action_dispatch.rack_cache = true"
 
       get "/expires/expires_etag"
-      assert_equal "miss, store", last_response.headers["X-Rack-Cache"]
-      assert_equal "public",      last_response.headers["Cache-Control"]
+      assert_equal "miss, ignore, store", last_response.headers["X-Rack-Cache"]
+      assert_equal "public",              last_response.headers["Cache-Control"]
 
       body = last_response.body
       etag = last_response.headers["ETag"]
@@ -149,8 +149,8 @@ module ApplicationTests
       add_to_config "config.action_dispatch.rack_cache = true"
 
       get "/expires/expires_last_modified"
-      assert_equal "miss, store", last_response.headers["X-Rack-Cache"]
-      assert_equal "public",      last_response.headers["Cache-Control"]
+      assert_equal "miss, ignore, store", last_response.headers["X-Rack-Cache"]
+      assert_equal "public",              last_response.headers["Cache-Control"]
 
       body = last_response.body
       last = last_response.headers["Last-Modified"]
diff --git a/railties/test/application/middleware/static_test.rb b/railties/test/application/middleware/static_test.rb
new file mode 100644
index 0000000000..0a793f8f60
--- /dev/null
+++ b/railties/test/application/middleware/static_test.rb
@@ -0,0 +1,31 @@
+# encoding: utf-8
+require 'isolation/abstract_unit'
+require 'rack/test'
+
+module ApplicationTests
+  class MiddlewareStaticTest < ActiveSupport::TestCase
+    include ActiveSupport::Testing::Isolation
+    include Rack::Test::Methods
+
+    def setup
+      build_app
+      FileUtils.rm_rf "#{app_path}/config/environments"
+    end
+
+    def teardown
+      teardown_app
+    end
+
+    # Regression test to #8907
+    # See https://github.com/rails/rails/commit/9cc82b77196d21a5c7021f6dca59ab9b2b158a45#commitcomment-2416514
+    test "doesn't set Cache-Control header when it is nil" do
+      app_file "public/foo.html", 'static'
+
+      require "#{app_path}/config/environment"
+
+      get 'foo'
+
+      assert_not last_response.headers.has_key?('Cache-Control'), "Cache-Control should not be set"
+    end
+  end
+end