Improve performance of the rendering stack by freezing formats as a sign that they shouldn't be further modified.

3 files changed, 6 insertions, 8 deletions

diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 0823120fc8..1dc2d92c43 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -605,6 +605,8 @@ module ActionMailer #:nodoc:
         templates_name = headers.delete(:template_name) || action_name
 
         each_template(templates_path, templates_name) do |template|
+          self.formats = template.formats
+
           responses << {
             :body => render(:template => template),
             :content_type => template.mime_type.to_s
diff --git a/actionmailer/lib/action_mailer/collector.rb b/actionmailer/lib/action_mailer/collector.rb
index 5431efccfe..bd4f76bbb6 100644
--- a/actionmailer/lib/action_mailer/collector.rb
+++ b/actionmailer/lib/action_mailer/collector.rb
@@ -11,7 +11,6 @@ module ActionMailer #:nodoc:
       @context = context
       @responses = []
       @default_render = block
-      @default_formats = context.formats
     end
 
     def any(*args, &block)
@@ -21,16 +20,12 @@ module ActionMailer #:nodoc:
     end
     alias :all :any
 
-    def custom(mime, options={}, &block)
+    def custom(mime, options={})
       options.reverse_merge!(:content_type => mime.to_s)
       @context.formats = [mime.to_sym]
-      options[:body] = if block
-        block.call
-      else
-        @default_render.call
-      end
+      @context.formats.freeze
+      options[:body] = block_given? ? yield : @default_render.call
       @responses << options
-      @context.formats = @default_formats
     end
   end
 end
\ No newline at end of file
diff --git a/actionmailer/lib/action_mailer/old_api.rb b/actionmailer/lib/action_mailer/old_api.rb
index 4581b31bb9..c7f341d46c 100644
--- a/actionmailer/lib/action_mailer/old_api.rb
+++ b/actionmailer/lib/action_mailer/old_api.rb
@@ -204,6 +204,7 @@ module ActionMailer
         @parts.unshift create_inline_part(@body)
       elsif @parts.empty? || @parts.all? { |p| p.content_disposition =~ /^attachment/ }
         lookup_context.find_all(@template, @mailer_name).each do |template|
+          self.formats = template.formats
           @parts << create_inline_part(render(:template => template), template.mime_type)
         end