I created a Herald rule to prevent users from pushing a changeset that does not have an approved review. I then created a branch (git), made some changes and put it up for review. After the squawkers stopped squawking, they completed the review and I was allowed to push it up. Before I pushed, I committed more changes to my local branch, then pushed it up. It worked. The push was accepted and a new diff was added to the review, even though it was already approved.
Is there a way to prevent changes from being pushed that were added after the review was approved?