When there are no changes in a git repo, `git diff` used to immediately return with no output. Since git 2.9, such `git diff` commands open a `less`-like window with no text, which I have to manually close by pressing `q`. Is there a way to restore the old `git diff` behavior?

**EDIT**

*Title changed.*

git 2.9 is actually unrelated, this new behavior is due to having recently introduced `LESS="-Ri"` in my environment. How should I change this variable to achieve what I want?