If you're on a given branch, and you're tracking a specific remote branch, is there any pointer you can use to refer to the upstream branch you're tracking?
For example, if you're currently on branch feature/ABC-123, and you're tracking origin/feature/ABC-123, is there any shortcut that you can use to refer to it, so that you could do something like
git diff UPSTREAM_THINGY
rather than typing in
git diff origin/feature/ABC-123
Related question: compare local git branch with remote branch?