Protected node's file attachment access denied when bypass password permission is given

How to reproduce the bug:

- Create a custom content type with a file field
- Password protect this content type
- Have a user role with "bypass password for view"
- Try to display the node with this user (this will work fine)
- Try to display the node's file attachment with this user (this will return access denied error)

How I fixed it:

I fixed it on my local drupal by adding this code snippet, line 792:

if (user_access('edit protected content')) {
  return;
}

Let me know if you want me to pull request, and how to do it, i'd be glad to do it.