I have noticed that if I have an application layout (app/views/layouts/
application.html.erb) and I copy it to a backup file (e.g., app/views/
layouts/application.html.erb.bak) and then make changes to the
original, for some reason Rails seems to want to refer to the .bak
file rather than the original file. So, changes that I make to the
original file are effectively ignored. I've now been caught by this
anomaly twice now. I think it's time that I understood it. An
explanation would be appreciated. Thanks.