Despite the misleading/broken github interface there’s actually a way to get what you want. You need to drop one .
Instead of:
- https://github.com/account/repo/compare/ath/branchA…branchB
do
- https://github.com/account/repo/compare/ath/branchA..branchB
This compares branch heads instead of simply using the base branch to find the merge base.
github’s reponse is what clued me in from @edwin-evans’ response:
This is a result of the type of diff we use on GitHub. We use git’s three dot diff, which is the difference between the latest commit on the HEAD branch and the last common ancestor commit with the base branch.