Stories From The Git Frontline (or, how to revert / undo a merge that's already pushed)
So, this happened:
- was working on a different branch
- did a merge back into master too early
- mistook git revert for "take me back to this point" instead of what it actually does (undo one specific commit)
The tree then ended up looking like:
- a revert i don't actually mean to have
- a merge of a bunch of stuff i dont want
- a previous good merge before my merge
- the commit which i mistakenly reverted
- good stuff from before that needs to go out in a release very soon
I tried a lot of things: hard reset, reverting each individual commit of my bad merge, checkout master to a previous point and force push (which, by the way, it looks like Visual Studio Online doesn't really let you do)...
But finally I got it back to exactly where I wanted, before I did the merge, and it turns out to be pretty easy. All I needed to do was:
- revert my revert
- revert my merge
The key points to takeaway is that when you revert a merge, make sure you select the right mainline (normally 1 or 2). My first attempt I didn't really understand or read the documentation for the -m parameter, and just assumed that reverting merges was stupid and broken, where actually I had just selected the wrong branch to consider as the one to keep.
The command is pretty easy, and looks like:
git revert -m 1 commit_hash
So if using a mainline of 1 doesn't give you what you expect, try 2.
While this might not be as easy as "rollback and push-override", this has less of an effect on other people working from the same shared repository, and will leave a nice reminder in the history that I made a mistake, forever :)