Returns a 404 error when trying to view/download an attachment that can't be read from disk.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2692 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/attachments_controller.rb

@@ -17,7 +17,7 @@
 
 class AttachmentsController < ApplicationController
   before_filter :find_project
-  before_filter :read_authorize, :except => :destroy
+  before_filter :file_readable, :read_authorize, :except => :destroy
   before_filter :delete_authorize, :only => :destroy
   
   verify :method => :post, :only => :destroy
@@ -64,6 +64,11 @@ private
     render_404
   end
   
+  # Checks that the file exists and is readable
+  def file_readable
+    @attachment.readable? ? true : render_404
+  end
+  
   def read_authorize
     @attachment.visible? ? true : deny_access
   end