I have a commit, I have stored in a branch, because this should go only to a specific box.

I have merged it to the branch master, but not the branch dev, that I use locally.

Now, by mistake I merged master to dev and that introduced this commit to dev.

I know can git revert sha, to branch dev; but since this is going to introduce a commit that undoes that commit (I am guessing, I haven't exactly tried this), when I merge master, will this commit be undone too?

If so, how do I undo this commit only from the branch dev.

And oh, git reset HEAD^1 --hard is not an option because there are other commits on master, after the un-needed commit.

If reset back again and apply is the only option, then how do I only merge those extra commits from master other than the un-needed commit.

Thanks in advance!