git interactive rebase squash into next commit

Question

In Git I can use an interactive rebase to re-write history, this is great because in my feature branch I made a ton of commits with partially working code as I explored differen

Answer 1

It is indeed possible to squash a commit into the following commit during interactive rebase, and fully preserve the identity of the second of those commits (including author, date etc.).

The method is somewhat involved however, so native support by git rebase -i would still be appreciated nevertheless.

I'll demonstrate with just three commits aaaaaaa A, bbbbbbb B and ccccccc C, where we want to fold A into B and preserve B's identity: (The method easily generalises to more commits)

• git rebase -i aaaaaaa^
• Modify the edit script to stop after commit B and exit the editor:

  pick aaaaaaa A
  edit bbbbbbb B
  pick ccccccc C
  

• When rebase has stopped after B, revert the latest commit twice, then continue:

  git revert HEAD
  git revert HEAD
  git rebase --continue
  

  Because reverting the revert restores the previous state, all following commits will apply cleanly. The sequence of B and Revert "B" together has no effect, but the first of those commits carries the full identity of commit B (in fact, at this stage it still is commit B).
  B and Revert "B" could be squashed together to form a no-op commit carrying the identity of commit B forward with a separate rebase -i --keep-empty aaaaaaa^. However we'll skip that step and just keep the commits together.
  The important commit now is Revert "Revert "B"" which will carry all the changes originally made by B.
• Now rebase -i aaaaaaa^ again to move A past both B and Revert "B", while squashing B into both Revert "B" and A:

  pick   bbbbbbb B
  squash b111111 Revert "B"
  squash a222222 A
  squash b333333 Revert "Revert "B""
  pick   c444444 C
  

  Because the sequence of B and Revert "B" has no effect, you can move any commits past it while creating only trivially resolvable merge conflicts.
• When rebase stops with a merge conflict, use git mergetool with a tool that can automatically resolve trivial conflicts, and let the tools do just that.
• Rebase will stop again to let you edit the commit edit of the squashed commit. Edit to your taste.
• git rebase --continue and you are done.