Is there any way to get emacs to actually check the contents of files on disk when determining this?
E.g. if I have some unsaved changes to a file, and temporarily switch source control branches (to make changes to other files), then switch back again, I want to be able to continue editing where I left off without this prompt. (the prompt would be much more trustworthy and useful if it only warned me when the file had really changed)
I think it currently goes by timestamp or something.