> If there are no differences then emacs should just show this in a message instead of popping up a window with not useful content. Just a simple implementation with advices for the time being for those who prefer this: (advice-add 'diff :around 'my-diff) (defun my-diff (orig-fun &rest args) (flet ((display-buffer (buf) buf)) (apply orig-fun args))) (advice-add 'diff-sentinel :after 'my-diff-sentinel) (defun my-diff-sentinel (code &rest args) (if (equal code 0) (message "No differences.") (display-buffer (current-buffer))))