Prevent conflict between mime types and Object methods

Assuming the type ":touch", Collector.new was calling
send(:touch), which instead of triggering method_missing
and generating a new collector method, actually
invoked the private method `touch` inherited from
Object.

By generating the method for each mime type as it
is registered, the private methods on Object can
never be reached by `send`, because the `Collector`
will have them before `send` is called on it.

To do this, a callback mechanism was added to Mime::Type

This allows someone to add a callback for whenever
a new mime type is registered. The callback then
gets called with the new mime as a parameter.

This is then used in AbstractController::Collector
to generate new collector methods after each mime
is registered.

1 files changed, 4 insertions, 0 deletions

diff --git a/actionpack/lib/abstract_controller/collector.rb b/actionpack/lib/abstract_controller/collector.rb
index 492329c401..09b9e7ddf0 100644
--- a/actionpack/lib/abstract_controller/collector.rb
+++ b/actionpack/lib/abstract_controller/collector.rb
@@ -16,6 +16,10 @@ module AbstractController
       generate_method_for_mime(mime)
     end
 
+    Mime::Type.register_callback do |mime|
+      generate_method_for_mime(mime) unless self.instance_methods.include?(mime.to_sym)
+    end
+
   protected
 
     def method_missing(symbol, &block)