Rebase Replay / Rebase 重放

Successful replay

- replay-topic-original names the old topic feature commit.
- replay-topic names a different new commit.
- The old commit has replay-base as its parent.
- The new commit has replay-upstream as its parent.
- Both commits contain topic.txt with topic feature.

No replay

- no-replay and no-replay-before name replay-upstream.
- This invocation has no commit eligible for replay and creates no new commit.

In-progress conflict

git status --short

UU app.txt

Index entries for app.txt during rebase

- stage 1: owner=base, the merge base
- stage 2: owner=upstream, ours after replay starts from upstream
- stage 3: owner=topic, theirs from the commit being replayed

Abort check in test.sh

- git rebase --abort restores branch topic to topic-original.
- The working tree becomes clean and REBASE_HEAD is removed.