How to redo merge after reverting?

What you need to do is rewrite the branch so that git does not consider it as being merged anymore.... and your branch chart does not make clear what the branches look like.... here's one example I am creating out of thin air:

A <- B <- C <- D <- E <- I <- J <- (master) ^ / \ F <- G <- H <-- ^ \ K <- (feature) 

So.... in J, we reverted the merge done in I.... how can we then try to merge feature knowing that a part of it (or even all of it) was already merged/reverted? That will confuse git, right?

We just rewrite the branch so that git does not see the branch as being merged anymore:

 git checkout B git cherry-pick B..K git branch -d feature # set feature over here 

After this is done, we get this:

 / F' <- G' <- H' <- K' <- (feature) v A <- B <- C <- D <- E <- I <- J <- (master) ^ / \ F <- G <- H <-- 

And git will not consider any of the revisions in B..feature to be merged, so this should work:

 git checkout master git merge develop 

Which should give you:

 / F' <- G' <- H' <- K' <-------- (feature) v \ A <- B <- C <- D <- E <- I <- J <- L <- (master) ^ / \ F <- G <- H <--