It's possible that when you were doing this things were different, because even in the last year or so it seems like git has become a lot less esoteric in its i

It's possible that when you were doing this things were different, because even in the last year or so it seems like git has become a lot less esoteric in its interface, but the man page for git revert currently explains a fair bit about how to use it to revert a merge commit. Basically you just need to specify which parent (of the merge commit's 2 parents) is the one that should survive the reversion with '--mainline'. This seems intuitive to me, with a maybe deeper than average understanding of git, though the rather more involved process of undoing the reversion is less so.