JavaScriptGenerator should only sets output_buffer for the duration of the update block

2 files changed, 12 insertions, 10 deletions

diff --git a/actionpack/lib/action_view/helpers/capture_helper.rb b/actionpack/lib/action_view/helpers/capture_helper.rb
index 720e2da8cc..e86ca27f31 100644
--- a/actionpack/lib/action_view/helpers/capture_helper.rb
+++ b/actionpack/lib/action_view/helpers/capture_helper.rb
@@ -122,14 +122,15 @@ module ActionView
         nil
       end
 
-      private
-        def with_output_buffer(buf = '')
-          self.output_buffer, old_buffer = buf, output_buffer
-          yield
-          output_buffer
-        ensure
-          self.output_buffer = old_buffer
-        end
+      # Use an alternate output buffer for the duration of the block.
+      # Defaults to a new empty string.
+      def with_output_buffer(buf = '') #:nodoc:
+        self.output_buffer, old_buffer = buf, output_buffer
+        yield
+        output_buffer
+      ensure
+        self.output_buffer = old_buffer
+      end
     end
   end
 end
diff --git a/actionpack/lib/action_view/helpers/prototype_helper.rb b/actionpack/lib/action_view/helpers/prototype_helper.rb
index edb43844a4..8c8c22dd4a 100644
--- a/actionpack/lib/action_view/helpers/prototype_helper.rb
+++ b/actionpack/lib/action_view/helpers/prototype_helper.rb
@@ -580,9 +580,10 @@ module ActionView
       class JavaScriptGenerator #:nodoc:
         def initialize(context, &block) #:nodoc:
           @context, @lines = context, []
-          @context.output_buffer = @lines if @context
           include_helpers_from_context
-          @context.instance_exec(self, &block)
+          @context.with_output_buffer(@lines) do
+            @context.instance_exec(self, &block)
+          end
         end
 
         private