I often create empty files that I know I'm going to need. Ocassionally, for somewhat convoluted but valid reasons, I have to rename them before I get contents in them. I just noticed that when renaming an empty file, the filename gets changed but the tab does not. If I switch away and back to the tab in question, it changes to that of an unsaved file and if I then close it, I get the standard "Do you want to save this before closing?" dialog. I could be wrong about this, but it seems to me that renaming shouldn't care whether the file has contents or not.