Fix a mailer bug in Rails 3.

Gemfile

@@ -1,7 +1,7 @@
 source "http://gemcutter.org"
 
 # Need to install Rails from source
-gem "rails", "3.0.0.beta2"
+gem "rails", "3.0.0.beta3"
 gem "warden", "0.10.3"
 gem "sqlite3-ruby", :require => "sqlite3"
 gem "webrat", "0.7"

app/models/devise/mailer.rb

@@ -37,6 +37,13 @@ class Devise::Mailer < ::ActionMailer::Base
       mail(headers)
     end
 
+    # Fix a bug in Rails 3 beta 3
+    def mail(*) #:nodoc:
+      super
+      @_message["template_path"] = nil
+      @_message
+    end
+
     def mailer_sender(mapping)
       if Devise.mailer_sender.is_a?(Proc)
         Devise.mailer_sender.call(mapping.name)