A Better Model for Stacked Pull Requests

I find that the bottom PRs get unwieldy; you can end up merging a multi-thousand line behemoth f1 containing f2, f3, etc. which is hard to verify as correct.

Instead, merge f1 including any changes f1’ you may have force-pushed to that branch. Then do a ‘git rebase f2 —onto master’ where is the old f1 commit that you originally targeted your f2 PR against.

You’ll need to resolve merge conflicts f1..f1’ into your f2. You can now force push that f2 and retarget your f2 PR onto master.

Repeat for f3, f4, ..., though I generally find more than 2-3 stacked PRs to be risky; the further away from master you get, the more likely something is going to change drastically in a PR that you’re branching off.

Anyway, this requires a bit more rebase-fu, but I think it leaves a better paper trail and is easier to work with if you do grok rebase fully.

[1] https://stacked-git.github.io/

  git push origin f1:f1
  git checkout f2
  git merge f1
  git push origin f2:f2
  git checkout f3
  git merge f2
  git push origin f3:f3

> It can't pause when a conflict occurs, so you have to fix the conflict and (somehow) re-run it from the point it stopped at, which is fiddly at best.

There is better way: 1. I use `git rebase -i` from the top of the stack -- it opens a vim with list of changes it's going to do. 2. I have script (https://github.com/mic47/git-tools/blob/master/GitStackTodo.... ) that process this and inserts commands to backup branch and move branch to new location to TODO list. At this point, I can even modify the TODO list to rip out commits I don't want, or squash commits i want. Or you can reorder commits (I usually do code review fix at top of the stack and then reorder commits -- at least if I am reasonably sure there won't be conflicts for this fixes). 3. At this point, you can insert more things, like run tests after each branch, or commit (and pause rebase in case of failure, so you can fix it). 4. When I close this file, rebase starts. In case of conflict, rebase pauses, let you fix it, and when you continue rebase, it will finish the TODO file. 5. After, I have script that removes backup branches. 6. I have script that runs command on each branch, so at the end, I do this to push my changes `git stack-foreach master git push --force-with-lease `

What if you can't resolve conflict and you are in the middle of the rebase? You can run `git rebase --abort` and it will restore top of your commit. Only drawback is that branches that were rebased are not restored, but hence my script also create backup branches so I can fix that manually and move branches back.