Today we're releasing two new branch protections.
Now, before a pull request can be merged, you can require it to be approved by someone other than the last pusher.
Meaning, the most recent user to push their changes will need a pull request approval regardless of the Require approvals branch protection. Or in the case of 1 approval required, someone other than the last user to push their changes will also need to approve. If the approvals come from other folks than the last pusher, those two approvals will be sufficient.
This allows for branches to be locked, prohibiting changes. You can lock a branch allowing you to have a maintenance window and prevent changes, or to protect a fork so it only receives changes from its upstream repository.
To use this feature in a branch protection rule, enable Lock branch.
For more information, read About protected branches in the GitHub documentation.
We appreciate feedback on this and other topics in GitHub's public feedback discussions.