6 files changed, 45 insertions, 24 deletions
diff --git a/actionpack/lib/abstract_controller/rendering.rb b/actionpack/lib/abstract_controller/rendering.rb
index 9f192c54f7..a6fb0dbe1d 100644
--- a/actionpack/lib/abstract_controller/rendering.rb
+++ b/actionpack/lib/abstract_controller/rendering.rb
@@ -60,9 +60,7 @@ module AbstractController
     end
 
     DEFAULT_PROTECTED_INSTANCE_VARIABLES = Set.new %i(
-      @_action_name @_response_body @_formats @_prefixes @_config
-      @_view_context_class @_view_renderer @_lookup_context
-      @_routes @_db_runtime
+      @_action_name @_response_body @_formats @_prefixes
     )
 
     # This method should return a hash with assigns.
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index 56a8d2e5f4..d546d7260c 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -251,9 +251,10 @@ module ActionController
     setup_renderer!
 
     # Define some internal variables that should not be propagated to the view.
-    PROTECTED_IVARS = AbstractController::Rendering::DEFAULT_PROTECTED_INSTANCE_VARIABLES + [
-      :@_params, :@_response, :@_request,
-      :@_view_runtime, :@_stream, :@_url_options, :@_action_has_layout ]
+    PROTECTED_IVARS = AbstractController::Rendering::DEFAULT_PROTECTED_INSTANCE_VARIABLES + %i(
+      @_params @_response @_request @_config @_url_options @_action_has_layout @_view_context_class
+      @_view_renderer @_lookup_context @_routes @_view_runtime @_db_runtime @_helper_proxy
+    )
 
     def _protected_ivars # :nodoc:
       PROTECTED_IVARS
diff --git a/actionpack/lib/action_controller/metal/helpers.rb b/actionpack/lib/action_controller/metal/helpers.rb
index d3853e2e83..22493dea50 100644
--- a/actionpack/lib/action_controller/metal/helpers.rb
+++ b/actionpack/lib/action_controller/metal/helpers.rb
@@ -5,7 +5,7 @@ module ActionController
   #
   # In addition to using the standard template helpers provided, creating custom helpers to
   # extract complicated logic or reusable functionality is strongly encouraged. By default, each controller
-  # will include all helpers. These helpers are only accessible on the controller through <tt>.helpers</tt>
+  # will include all helpers. These helpers are only accessible on the controller through <tt>#helpers</tt>
   #
   # In previous versions of \Rails the controller will include a helper which
   # matches the name of the controller, e.g., <tt>MyController</tt> will automatically
@@ -113,5 +113,10 @@ module ActionController
         all_helpers_from_path(helpers_path)
       end
     end
+
+    # Provides a proxy to access helpers methods from outside the view.
+    def helpers
+      @_helper_proxy ||= view_context
+    end
   end
 end
diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index 6055fde4f7..5d395cd8bd 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -163,14 +163,6 @@ module ActionController
         end
       end
 
-      def each
-        @response.sending!
-        while str = @buf.pop
-          yield str
-        end
-        @response.sent!
-      end
-
       # Write a 'close' event to the buffer; the producer/writing thread
       # uses this to notify us that it's finished supplying content.
       #
@@ -210,6 +202,14 @@ module ActionController
       def call_on_error
         @error_callback.call
       end
+
+      private
+
+        def each_chunk(&block)
+          while str = @buf.pop
+            yield str
+          end
+        end
     end
 
     class Response < ActionDispatch::Response #:nodoc: all
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index ecd21f29ce..ed2edcbe06 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -554,6 +554,8 @@ module ActionController
         end
         @request.query_string = ''
 
+        @response.sent!
+
         @response
       end
 
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index fa4c54701a..1515d59df3 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -68,7 +68,13 @@ module ActionDispatch # :nodoc:
     alias_method :headers,  :header
 
     delegate :[], :[]=, :to => :@header
-    delegate :each, :to => :@stream
+
+    def each(&block)
+      sending!
+      x = @stream.each(&block)
+      sent!
+      x
+    end
 
     CONTENT_TYPE = "Content-Type".freeze
     SET_COOKIE   = "Set-Cookie".freeze
@@ -97,10 +103,10 @@ module ActionDispatch # :nodoc:
 
       def body
         @str_body ||= begin
-                        buf = ''
-                        each { |chunk| buf << chunk }
-                        buf
-                      end
+          buf = ''
+            each { |chunk| buf << chunk }
+          buf
+        end
       end
 
       def write(string)
@@ -112,10 +118,13 @@ module ActionDispatch # :nodoc:
       end
 
       def each(&block)
-        @response.sending!
-        x = @buf.each(&block)
-        @response.sent!
-        x
+        if @str_body
+          return enum_for(:each) unless block_given?
+
+          yield @str_body
+        else
+          each_chunk(&block)
+        end
       end
 
       def abort
@@ -129,6 +138,12 @@ module ActionDispatch # :nodoc:
       def closed?
         @closed
       end
+
+      private
+
+        def each_chunk(&block)
+          @buf.each(&block) # extract into own method
+        end
     end
 
     def self.create(status = 200, header = {}, body = [], default_headers: self.default_headers)