5 files changed, 12 insertions, 4 deletions
diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 23ac619f50..8eaaee5100 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,5 @@
+## Rails 6.0.0.beta2 (February 25, 2019) ##
+
 *   Make debug exceptions works in an environment where ActiveStorage is not loaded.
 
     *Tomoyuki Kurosawa*
diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index 083b762f5a..eb43ff9c63 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -146,7 +146,7 @@ module ActionController
 
       def write(string)
         unless @response.committed?
-          @response.set_header "Cache-Control", "no-cache"
+          @response.headers["Cache-Control"] ||= "no-cache"
           @response.delete_header "Content-Length"
         end
 
diff --git a/actionpack/lib/action_pack/gem_version.rb b/actionpack/lib/action_pack/gem_version.rb
index c7cb3cb91e..8007cfe35b 100644
--- a/actionpack/lib/action_pack/gem_version.rb
+++ b/actionpack/lib/action_pack/gem_version.rb
@@ -10,7 +10,7 @@ module ActionPack
     MAJOR = 6
     MINOR = 0
     TINY  = 0
-    PRE   = "beta1"
+    PRE   = "beta2"
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
   end
diff --git a/actionpack/test/dispatch/debug_exceptions_test.rb b/actionpack/test/dispatch/debug_exceptions_test.rb
index 6914fb66f9..c33b0e1c14 100644
--- a/actionpack/test/dispatch/debug_exceptions_test.rb
+++ b/actionpack/test/dispatch/debug_exceptions_test.rb
@@ -39,7 +39,7 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
     def call(env)
       env["action_dispatch.show_detailed_exceptions"] = @detailed
       req = ActionDispatch::Request.new(env)
-      template = ActionView::Template.new(File.read(__FILE__), __FILE__, ActionView::Template::Handlers::Raw.new, {})
+      template = ActionView::Template.new(File.read(__FILE__), __FILE__, ActionView::Template::Handlers::Raw.new, format: :html)
 
       case req.path
       when "/pass"
diff --git a/actionpack/test/dispatch/live_response_test.rb b/actionpack/test/dispatch/live_response_test.rb
index b673fd3805..f2459112b2 100644
--- a/actionpack/test/dispatch/live_response_test.rb
+++ b/actionpack/test/dispatch/live_response_test.rb
@@ -51,11 +51,17 @@ module ActionController
         assert_equal ["omg"], @response.body_parts
       end
 
-      def test_cache_control_is_set
+      def test_cache_control_is_set_by_default
         @response.stream.write "omg"
         assert_equal "no-cache", @response.headers["Cache-Control"]
       end
 
+      def test_cache_control_is_set_manually
+        @response.set_header("Cache-Control", "public")
+        @response.stream.write "omg"
+        assert_equal "public", @response.headers["Cache-Control"]
+      end
+
       def test_content_length_is_removed
         @response.headers["Content-Length"] = "1234"
         @response.stream.write "omg"