Merge pull request rails#6776 from raggi/cache_control

Ensure that cache-control headers are merged

Author: José Valim

actionpack/lib/action_dispatch/http/cache.rb

@@ -84,17 +84,29 @@ def etag=(etag)
         LAST_MODIFIED = "Last-Modified".freeze
         ETAG          = "ETag".freeze
         CACHE_CONTROL = "Cache-Control".freeze
+        SPESHUL_KEYS  = %w[extras no-cache max-age public must-revalidate]
+
+        def cache_control_headers
+          cache_control = {}
+          if cc = self[CACHE_CONTROL]
+            cc.delete(' ').split(',').each do |segment|
+              directive, argument = segment.split('=', 2)
+              case directive
+              when *SPESHUL_KEYS
+                key = directive.tr('-', '_')
+                cache_control[key.to_sym] = argument || true
+              else
+                cache_control[:extras] ||= []
+                cache_control[:extras] << segment
+              end
+            end
+          end
+          cache_control
+        end
 
         def prepare_cache_control!
-          @cache_control = {}
+          @cache_control = cache_control_headers
           @etag = self[ETAG]
-
-          if cache_control = self[CACHE_CONTROL]
-            cache_control.split(/,\s*/).each do |segment|
-              first, last = segment.split("=")
-              @cache_control[first.to_sym] = last || true
-            end
-          end
         end
 
         def handle_conditional_get!
@@ -110,14 +122,24 @@ def handle_conditional_get!
         MUST_REVALIDATE       = "must-revalidate".freeze
 
         def set_conditional_cache_control!
-          return if self[CACHE_CONTROL].present?
+          control = {}
+          cc_headers = cache_control_headers
+          if extras = cc_headers.delete(:extras)
+            @cache_control[:extras] ||= []
+            @cache_control[:extras] += extras
+            @cache_control[:extras].uniq!
+          end
 
-          control = @cache_control
+          control.merge! cc_headers
+          control.merge! @cache_control
 
           if control.empty?
             headers[CACHE_CONTROL] = DEFAULT_CACHE_CONTROL
           elsif control[:no_cache]
             headers[CACHE_CONTROL] = NO_CACHE
+            if control[:extras]
+              headers[CACHE_CONTROL] += ", #{control[:extras].join(', ')}"
+            end
           else
             extras  = control[:extras]
             max_age = control[:max_age]

actionpack/test/controller/render_test.rb

@@ -116,6 +116,12 @@ def conditional_hello_with_expires_now
     render :action => 'hello_world'
   end
 
+  def conditional_hello_with_cache_control_headers
+    response.headers['Cache-Control'] = 'no-transform'
+    expires_now
+    render :action => 'hello_world'
+  end
+
   def conditional_hello_with_bangs
     render :action => 'hello_world'
   end
@@ -1512,6 +1518,12 @@ def test_expires_now
     assert_equal "no-cache", @response.headers["Cache-Control"]
   end
 
+  def test_expires_now
+    get :conditional_hello_with_cache_control_headers
+    assert_match /no-cache/, @response.headers["Cache-Control"]
+    assert_match /no-transform/, @response.headers["Cache-Control"]
+  end
+
   def test_date_header_when_expires_in
     time = Time.mktime(2011,10,30)
     Time.stubs(:now).returns(time)